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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/atm/horizon.c
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/atm/horizon.c')
-rw-r--r--drivers/atm/horizon.c2953
1 files changed, 2953 insertions, 0 deletions
diff --git a/drivers/atm/horizon.c b/drivers/atm/horizon.c
new file mode 100644
index 000000000000..924a2c8988bd
--- /dev/null
+++ b/drivers/atm/horizon.c
@@ -0,0 +1,2953 @@
+/*
+ Madge Horizon ATM Adapter driver.
+ Copyright (C) 1995-1999 Madge Networks Ltd.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+ The GNU GPL is contained in /usr/doc/copyright/GPL on a Debian
+ system and in the file COPYING in the Linux kernel source.
+*/
+
+/*
+ IMPORTANT NOTE: Madge Networks no longer makes the adapters
+ supported by this driver and makes no commitment to maintain it.
+*/
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/pci.h>
+#include <linux/errno.h>
+#include <linux/atm.h>
+#include <linux/atmdev.h>
+#include <linux/sonet.h>
+#include <linux/skbuff.h>
+#include <linux/time.h>
+#include <linux/delay.h>
+#include <linux/uio.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/wait.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/atomic.h>
+#include <asm/uaccess.h>
+#include <asm/string.h>
+#include <asm/byteorder.h>
+
+#include "horizon.h"
+
+#define maintainer_string "Giuliano Procida at Madge Networks <gprocida@madge.com>"
+#define description_string "Madge ATM Horizon [Ultra] driver"
+#define version_string "1.2.1"
+
+static inline void __init show_version (void) {
+ printk ("%s version %s\n", description_string, version_string);
+}
+
+/*
+
+ CREDITS
+
+ Driver and documentation by:
+
+ Chris Aston Madge Networks
+ Giuliano Procida Madge Networks
+ Simon Benham Madge Networks
+ Simon Johnson Madge Networks
+ Various Others Madge Networks
+
+ Some inspiration taken from other drivers by:
+
+ Alexandru Cucos UTBv
+ Kari Mettinen University of Helsinki
+ Werner Almesberger EPFL LRC
+
+ Theory of Operation
+
+ I Hardware, detection, initialisation and shutdown.
+
+ 1. Supported Hardware
+
+ This driver should handle all variants of the PCI Madge ATM adapters
+ with the Horizon chipset. These are all PCI cards supporting PIO, BM
+ DMA and a form of MMIO (registers only, not internal RAM).
+
+ The driver is only known to work with SONET and UTP Horizon Ultra
+ cards at 155Mb/s. However, code is in place to deal with both the
+ original Horizon and 25Mb/s operation.
+
+ There are two revisions of the Horizon ASIC: the original and the
+ Ultra. Details of hardware bugs are in section III.
+
+ The ASIC version can be distinguished by chip markings but is NOT
+ indicated by the PCI revision (all adapters seem to have PCI rev 1).
+
+ I believe that:
+
+ Horizon => Collage 25 PCI Adapter (UTP and STP)
+ Horizon Ultra => Collage 155 PCI Client (UTP or SONET)
+ Ambassador x => Collage 155 PCI Server (completely different)
+
+ Horizon (25Mb/s) is fitted with UTP and STP connectors. It seems to
+ have a Madge B154 plus glue logic serializer. I have also found a
+ really ancient version of this with slightly different glue. It
+ comes with the revision 0 (140-025-01) ASIC.
+
+ Horizon Ultra (155Mb/s) is fitted with either a Pulse Medialink
+ output (UTP) or an HP HFBR 5205 output (SONET). It has either
+ Madge's SAMBA framer or a SUNI-lite device (early versions). It
+ comes with the revision 1 (140-027-01) ASIC.
+
+ 2. Detection
+
+ All Horizon-based cards present with the same PCI Vendor and Device
+ IDs. The standard Linux 2.2 PCI API is used to locate any cards and
+ to enable bus-mastering (with appropriate latency).
+
+ ATM_LAYER_STATUS in the control register distinguishes between the
+ two possible physical layers (25 and 155). It is not clear whether
+ the 155 cards can also operate at 25Mbps. We rely on the fact that a
+ card operates at 155 if and only if it has the newer Horizon Ultra
+ ASIC.
+
+ For 155 cards the two possible framers are probed for and then set
+ up for loop-timing.
+
+ 3. Initialisation
+
+ The card is reset and then put into a known state. The physical
+ layer is configured for normal operation at the appropriate speed;
+ in the case of the 155 cards, the framer is initialised with
+ line-based timing; the internal RAM is zeroed and the allocation of
+ buffers for RX and TX is made; the Burnt In Address is read and
+ copied to the ATM ESI; various policy settings for RX (VPI bits,
+ unknown VCs, oam cells) are made. Ideally all policy items should be
+ configurable at module load (if not actually on-demand), however,
+ only the vpi vs vci bit allocation can be specified at insmod.
+
+ 4. Shutdown
+
+ This is in response to module_cleaup. No VCs are in use and the card
+ should be idle; it is reset.
+
+ II Driver software (as it should be)
+
+ 0. Traffic Parameters
+
+ The traffic classes (not an enumeration) are currently: ATM_NONE (no
+ traffic), ATM_UBR, ATM_CBR, ATM_VBR and ATM_ABR, ATM_ANYCLASS
+ (compatible with everything). Together with (perhaps only some of)
+ the following items they make up the traffic specification.
+
+ struct atm_trafprm {
+ unsigned char traffic_class; traffic class (ATM_UBR, ...)
+ int max_pcr; maximum PCR in cells per second
+ int pcr; desired PCR in cells per second
+ int min_pcr; minimum PCR in cells per second
+ int max_cdv; maximum CDV in microseconds
+ int max_sdu; maximum SDU in bytes
+ };
+
+ Note that these denote bandwidth available not bandwidth used; the
+ possibilities according to ATMF are:
+
+ Real Time (cdv and max CDT given)
+
+ CBR(pcr) pcr bandwidth always available
+ rtVBR(pcr,scr,mbs) scr bandwidth always available, upto pcr at mbs too
+
+ Non Real Time
+
+ nrtVBR(pcr,scr,mbs) scr bandwidth always available, upto pcr at mbs too
+ UBR()
+ ABR(mcr,pcr) mcr bandwidth always available, upto pcr (depending) too
+
+ mbs is max burst size (bucket)
+ pcr and scr have associated cdvt values
+ mcr is like scr but has no cdtv
+ cdtv may differ at each hop
+
+ Some of the above items are qos items (as opposed to traffic
+ parameters). We have nothing to do with qos. All except ABR can have
+ their traffic parameters converted to GCRA parameters. The GCRA may
+ be implemented as a (real-number) leaky bucket. The GCRA can be used
+ in complicated ways by switches and in simpler ways by end-stations.
+ It can be used both to filter incoming cells and shape out-going
+ cells.
+
+ ATM Linux actually supports:
+
+ ATM_NONE() (no traffic in this direction)
+ ATM_UBR(max_frame_size)
+ ATM_CBR(max/min_pcr, max_cdv, max_frame_size)
+
+ 0 or ATM_MAX_PCR are used to indicate maximum available PCR
+
+ A traffic specification consists of the AAL type and separate
+ traffic specifications for either direction. In ATM Linux it is:
+
+ struct atm_qos {
+ struct atm_trafprm txtp;
+ struct atm_trafprm rxtp;
+ unsigned char aal;
+ };
+
+ AAL types are:
+
+ ATM_NO_AAL AAL not specified
+ ATM_AAL0 "raw" ATM cells
+ ATM_AAL1 AAL1 (CBR)
+ ATM_AAL2 AAL2 (VBR)
+ ATM_AAL34 AAL3/4 (data)
+ ATM_AAL5 AAL5 (data)
+ ATM_SAAL signaling AAL
+
+ The Horizon has support for AAL frame types: 0, 3/4 and 5. However,
+ it does not implement AAL 3/4 SAR and it has a different notion of
+ "raw cell" to ATM Linux's (48 bytes vs. 52 bytes) so neither are
+ supported by this driver.
+
+ The Horizon has limited support for ABR (including UBR), VBR and
+ CBR. Each TX channel has a bucket (containing up to 31 cell units)
+ and two timers (PCR and SCR) associated with it that can be used to
+ govern cell emissions and host notification (in the case of ABR this
+ is presumably so that RM cells may be emitted at appropriate times).
+ The timers may either be disabled or may be set to any of 240 values
+ (determined by the clock crystal, a fixed (?) per-device divider, a
+ configurable divider and a configurable timer preload value).
+
+ At the moment only UBR and CBR are supported by the driver. VBR will
+ be supported as soon as ATM for Linux supports it. ABR support is
+ very unlikely as RM cell handling is completely up to the driver.
+
+ 1. TX (TX channel setup and TX transfer)
+
+ The TX half of the driver owns the TX Horizon registers. The TX
+ component in the IRQ handler is the BM completion handler. This can
+ only be entered when tx_busy is true (enforced by hardware). The
+ other TX component can only be entered when tx_busy is false
+ (enforced by driver). So TX is single-threaded.
+
+ Apart from a minor optimisation to not re-select the last channel,
+ the TX send component works as follows:
+
+ Atomic test and set tx_busy until we succeed; we should implement
+ some sort of timeout so that tx_busy will never be stuck at true.
+
+ If no TX channel is set up for this VC we wait for an idle one (if
+ necessary) and set it up.
+
+ At this point we have a TX channel ready for use. We wait for enough
+ buffers to become available then start a TX transmit (set the TX
+ descriptor, schedule transfer, exit).
+
+ The IRQ component handles TX completion (stats, free buffer, tx_busy
+ unset, exit). We also re-schedule further transfers for the same
+ frame if needed.
+
+ TX setup in more detail:
+
+ TX open is a nop, the relevant information is held in the hrz_vcc
+ (vcc->dev_data) structure and is "cached" on the card.
+
+ TX close gets the TX lock and clears the channel from the "cache".
+
+ 2. RX (Data Available and RX transfer)
+
+ The RX half of the driver owns the RX registers. There are two RX
+ components in the IRQ handler: the data available handler deals with
+ fresh data that has arrived on the card, the BM completion handler
+ is very similar to the TX completion handler. The data available
+ handler grabs the rx_lock and it is only released once the data has
+ been discarded or completely transferred to the host. The BM
+ completion handler only runs when the lock is held; the data
+ available handler is locked out over the same period.
+
+ Data available on the card triggers an interrupt. If the data is not
+ suitable for our existing RX channels or we cannot allocate a buffer
+ it is flushed. Otherwise an RX receive is scheduled. Multiple RX
+ transfers may be scheduled for the same frame.
+
+ RX setup in more detail:
+
+ RX open...
+ RX close...
+
+ III Hardware Bugs
+
+ 0. Byte vs Word addressing of adapter RAM.
+
+ A design feature; see the .h file (especially the memory map).
+
+ 1. Bus Master Data Transfers (original Horizon only, fixed in Ultra)
+
+ The host must not start a transmit direction transfer at a
+ non-four-byte boundary in host memory. Instead the host should
+ perform a byte, or a two byte, or one byte followed by two byte
+ transfer in order to start the rest of the transfer on a four byte
+ boundary. RX is OK.
+
+ Simultaneous transmit and receive direction bus master transfers are
+ not allowed.
+
+ The simplest solution to these two is to always do PIO (never DMA)
+ in the TX direction on the original Horizon. More complicated
+ solutions are likely to hurt my brain.
+
+ 2. Loss of buffer on close VC
+
+ When a VC is being closed, the buffer associated with it is not
+ returned to the pool. The host must store the reference to this
+ buffer and when opening a new VC then give it to that new VC.
+
+ The host intervention currently consists of stacking such a buffer
+ pointer at VC close and checking the stack at VC open.
+
+ 3. Failure to close a VC
+
+ If a VC is currently receiving a frame then closing the VC may fail
+ and the frame continues to be received.
+
+ The solution is to make sure any received frames are flushed when
+ ready. This is currently done just before the solution to 2.
+
+ 4. PCI bus (original Horizon only, fixed in Ultra)
+
+ Reading from the data port prior to initialisation will hang the PCI
+ bus. Just don't do that then! We don't.
+
+ IV To Do List
+
+ . Timer code may be broken.
+
+ . Allow users to specify buffer allocation split for TX and RX.
+
+ . Deal once and for all with buggy VC close.
+
+ . Handle interrupted and/or non-blocking operations.
+
+ . Change some macros to functions and move from .h to .c.
+
+ . Try to limit the number of TX frames each VC may have queued, in
+ order to reduce the chances of TX buffer exhaustion.
+
+ . Implement VBR (bucket and timers not understood) and ABR (need to
+ do RM cells manually); also no Linux support for either.
+
+ . Implement QoS changes on open VCs (involves extracting parts of VC open
+ and close into separate functions and using them to make changes).
+
+*/
+
+/********** globals **********/
+
+static void do_housekeeping (unsigned long arg);
+
+static unsigned short debug = 0;
+static unsigned short vpi_bits = 0;
+static int max_tx_size = 9000;
+static int max_rx_size = 9000;
+static unsigned char pci_lat = 0;
+
+/********** access functions **********/
+
+/* Read / Write Horizon registers */
+static inline void wr_regl (const hrz_dev * dev, unsigned char reg, u32 data) {
+ outl (cpu_to_le32 (data), dev->iobase + reg);
+}
+
+static inline u32 rd_regl (const hrz_dev * dev, unsigned char reg) {
+ return le32_to_cpu (inl (dev->iobase + reg));
+}
+
+static inline void wr_regw (const hrz_dev * dev, unsigned char reg, u16 data) {
+ outw (cpu_to_le16 (data), dev->iobase + reg);
+}
+
+static inline u16 rd_regw (const hrz_dev * dev, unsigned char reg) {
+ return le16_to_cpu (inw (dev->iobase + reg));
+}
+
+static inline void wrs_regb (const hrz_dev * dev, unsigned char reg, void * addr, u32 len) {
+ outsb (dev->iobase + reg, addr, len);
+}
+
+static inline void rds_regb (const hrz_dev * dev, unsigned char reg, void * addr, u32 len) {
+ insb (dev->iobase + reg, addr, len);
+}
+
+/* Read / Write to a given address in Horizon buffer memory.
+ Interrupts must be disabled between the address register and data
+ port accesses as these must form an atomic operation. */
+static inline void wr_mem (const hrz_dev * dev, HDW * addr, u32 data) {
+ // wr_regl (dev, MEM_WR_ADDR_REG_OFF, (u32) addr);
+ wr_regl (dev, MEM_WR_ADDR_REG_OFF, (addr - (HDW *) 0) * sizeof(HDW));
+ wr_regl (dev, MEMORY_PORT_OFF, data);
+}
+
+static inline u32 rd_mem (const hrz_dev * dev, HDW * addr) {
+ // wr_regl (dev, MEM_RD_ADDR_REG_OFF, (u32) addr);
+ wr_regl (dev, MEM_RD_ADDR_REG_OFF, (addr - (HDW *) 0) * sizeof(HDW));
+ return rd_regl (dev, MEMORY_PORT_OFF);
+}
+
+static inline void wr_framer (const hrz_dev * dev, u32 addr, u32 data) {
+ wr_regl (dev, MEM_WR_ADDR_REG_OFF, (u32) addr | 0x80000000);
+ wr_regl (dev, MEMORY_PORT_OFF, data);
+}
+
+static inline u32 rd_framer (const hrz_dev * dev, u32 addr) {
+ wr_regl (dev, MEM_RD_ADDR_REG_OFF, (u32) addr | 0x80000000);
+ return rd_regl (dev, MEMORY_PORT_OFF);
+}
+
+/********** specialised access functions **********/
+
+/* RX */
+
+static inline void FLUSH_RX_CHANNEL (hrz_dev * dev, u16 channel) {
+ wr_regw (dev, RX_CHANNEL_PORT_OFF, FLUSH_CHANNEL | channel);
+ return;
+}
+
+static inline void WAIT_FLUSH_RX_COMPLETE (hrz_dev * dev) {
+ while (rd_regw (dev, RX_CHANNEL_PORT_OFF) & FLUSH_CHANNEL)
+ ;
+ return;
+}
+
+static inline void SELECT_RX_CHANNEL (hrz_dev * dev, u16 channel) {
+ wr_regw (dev, RX_CHANNEL_PORT_OFF, channel);
+ return;
+}
+
+static inline void WAIT_UPDATE_COMPLETE (hrz_dev * dev) {
+ while (rd_regw (dev, RX_CHANNEL_PORT_OFF) & RX_CHANNEL_UPDATE_IN_PROGRESS)
+ ;
+ return;
+}
+
+/* TX */
+
+static inline void SELECT_TX_CHANNEL (hrz_dev * dev, u16 tx_channel) {
+ wr_regl (dev, TX_CHANNEL_PORT_OFF, tx_channel);
+ return;
+}
+
+/* Update or query one configuration parameter of a particular channel. */
+
+static inline void update_tx_channel_config (hrz_dev * dev, short chan, u8 mode, u16 value) {
+ wr_regw (dev, TX_CHANNEL_CONFIG_COMMAND_OFF,
+ chan * TX_CHANNEL_CONFIG_MULT | mode);
+ wr_regw (dev, TX_CHANNEL_CONFIG_DATA_OFF, value);
+ return;
+}
+
+static inline u16 query_tx_channel_config (hrz_dev * dev, short chan, u8 mode) {
+ wr_regw (dev, TX_CHANNEL_CONFIG_COMMAND_OFF,
+ chan * TX_CHANNEL_CONFIG_MULT | mode);
+ return rd_regw (dev, TX_CHANNEL_CONFIG_DATA_OFF);
+}
+
+/********** dump functions **********/
+
+static inline void dump_skb (char * prefix, unsigned int vc, struct sk_buff * skb) {
+#ifdef DEBUG_HORIZON
+ unsigned int i;
+ unsigned char * data = skb->data;
+ PRINTDB (DBG_DATA, "%s(%u) ", prefix, vc);
+ for (i=0; i<skb->len && i < 256;i++)
+ PRINTDM (DBG_DATA, "%02x ", data[i]);
+ PRINTDE (DBG_DATA,"");
+#else
+ (void) prefix;
+ (void) vc;
+ (void) skb;
+#endif
+ return;
+}
+
+static inline void dump_regs (hrz_dev * dev) {
+#ifdef DEBUG_HORIZON
+ PRINTD (DBG_REGS, "CONTROL 0: %#x", rd_regl (dev, CONTROL_0_REG));
+ PRINTD (DBG_REGS, "RX CONFIG: %#x", rd_regw (dev, RX_CONFIG_OFF));
+ PRINTD (DBG_REGS, "TX CONFIG: %#x", rd_regw (dev, TX_CONFIG_OFF));
+ PRINTD (DBG_REGS, "TX STATUS: %#x", rd_regw (dev, TX_STATUS_OFF));
+ PRINTD (DBG_REGS, "IRQ ENBLE: %#x", rd_regl (dev, INT_ENABLE_REG_OFF));
+ PRINTD (DBG_REGS, "IRQ SORCE: %#x", rd_regl (dev, INT_SOURCE_REG_OFF));
+#else
+ (void) dev;
+#endif
+ return;
+}
+
+static inline void dump_framer (hrz_dev * dev) {
+#ifdef DEBUG_HORIZON
+ unsigned int i;
+ PRINTDB (DBG_REGS, "framer registers:");
+ for (i = 0; i < 0x10; ++i)
+ PRINTDM (DBG_REGS, " %02x", rd_framer (dev, i));
+ PRINTDE (DBG_REGS,"");
+#else
+ (void) dev;
+#endif
+ return;
+}
+
+/********** VPI/VCI <-> (RX) channel conversions **********/
+
+/* RX channels are 10 bit integers, these fns are quite paranoid */
+
+static inline int channel_to_vpivci (const u16 channel, short * vpi, int * vci) {
+ unsigned short vci_bits = 10 - vpi_bits;
+ if ((channel & RX_CHANNEL_MASK) == channel) {
+ *vci = channel & ((~0)<<vci_bits);
+ *vpi = channel >> vci_bits;
+ return channel ? 0 : -EINVAL;
+ }
+ return -EINVAL;
+}
+
+static inline int vpivci_to_channel (u16 * channel, const short vpi, const int vci) {
+ unsigned short vci_bits = 10 - vpi_bits;
+ if (0 <= vpi && vpi < 1<<vpi_bits && 0 <= vci && vci < 1<<vci_bits) {
+ *channel = vpi<<vci_bits | vci;
+ return *channel ? 0 : -EINVAL;
+ }
+ return -EINVAL;
+}
+
+/********** decode RX queue entries **********/
+
+static inline u16 rx_q_entry_to_length (u32 x) {
+ return x & RX_Q_ENTRY_LENGTH_MASK;
+}
+
+static inline u16 rx_q_entry_to_rx_channel (u32 x) {
+ return (x>>RX_Q_ENTRY_CHANNEL_SHIFT) & RX_CHANNEL_MASK;
+}
+
+/* Cell Transmit Rate Values
+ *
+ * the cell transmit rate (cells per sec) can be set to a variety of
+ * different values by specifying two parameters: a timer preload from
+ * 1 to 16 (stored as 0 to 15) and a clock divider (2 to the power of
+ * an exponent from 0 to 14; the special value 15 disables the timer).
+ *
+ * cellrate = baserate / (preload * 2^divider)
+ *
+ * The maximum cell rate that can be specified is therefore just the
+ * base rate. Halving the preload is equivalent to adding 1 to the
+ * divider and so values 1 to 8 of the preload are redundant except
+ * in the case of a maximal divider (14).
+ *
+ * Given a desired cell rate, an algorithm to determine the preload
+ * and divider is:
+ *
+ * a) x = baserate / cellrate, want p * 2^d = x (as far as possible)
+ * b) if x > 16 * 2^14 then set p = 16, d = 14 (min rate), done
+ * if x <= 16 then set p = x, d = 0 (high rates), done
+ * c) now have 16 < x <= 2^18, or 1 < x/16 <= 2^14 and we want to
+ * know n such that 2^(n-1) < x/16 <= 2^n, so slide a bit until
+ * we find the range (n will be between 1 and 14), set d = n
+ * d) Also have 8 < x/2^n <= 16, so set p nearest x/2^n
+ *
+ * The algorithm used below is a minor variant of the above.
+ *
+ * The base rate is derived from the oscillator frequency (Hz) using a
+ * fixed divider:
+ *
+ * baserate = freq / 32 in the case of some Unknown Card
+ * baserate = freq / 8 in the case of the Horizon 25
+ * baserate = freq / 8 in the case of the Horizon Ultra 155
+ *
+ * The Horizon cards have oscillators and base rates as follows:
+ *
+ * Card Oscillator Base Rate
+ * Unknown Card 33 MHz 1.03125 MHz (33 MHz = PCI freq)
+ * Horizon 25 32 MHz 4 MHz
+ * Horizon Ultra 155 40 MHz 5 MHz
+ *
+ * The following defines give the base rates in Hz. These were
+ * previously a factor of 100 larger, no doubt someone was using
+ * cps*100.
+ */
+
+#define BR_UKN 1031250l
+#define BR_HRZ 4000000l
+#define BR_ULT 5000000l
+
+// d is an exponent
+#define CR_MIND 0
+#define CR_MAXD 14
+
+// p ranges from 1 to a power of 2
+#define CR_MAXPEXP 4
+
+static int make_rate (const hrz_dev * dev, u32 c, rounding r,
+ u16 * bits, unsigned int * actual)
+{
+ // note: rounding the rate down means rounding 'p' up
+ const unsigned long br = test_bit(ultra, &dev->flags) ? BR_ULT : BR_HRZ;
+
+ u32 div = CR_MIND;
+ u32 pre;
+
+ // br_exp and br_man are used to avoid overflowing (c*maxp*2^d) in
+ // the tests below. We could think harder about exact possibilities
+ // of failure...
+
+ unsigned long br_man = br;
+ unsigned int br_exp = 0;
+
+ PRINTD (DBG_QOS|DBG_FLOW, "make_rate b=%lu, c=%u, %s", br, c,
+ r == round_up ? "up" : r == round_down ? "down" : "nearest");
+
+ // avoid div by zero
+ if (!c) {
+ PRINTD (DBG_QOS|DBG_ERR, "zero rate is not allowed!");
+ return -EINVAL;
+ }
+
+ while (br_exp < CR_MAXPEXP + CR_MIND && (br_man % 2 == 0)) {
+ br_man = br_man >> 1;
+ ++br_exp;
+ }
+ // (br >>br_exp) <<br_exp == br and
+ // br_exp <= CR_MAXPEXP+CR_MIND
+
+ if (br_man <= (c << (CR_MAXPEXP+CR_MIND-br_exp))) {
+ // Equivalent to: B <= (c << (MAXPEXP+MIND))
+ // take care of rounding
+ switch (r) {
+ case round_down:
+ pre = (br+(c<<div)-1)/(c<<div);
+ // but p must be non-zero
+ if (!pre)
+ pre = 1;
+ break;
+ case round_nearest:
+ pre = (br+(c<<div)/2)/(c<<div);
+ // but p must be non-zero
+ if (!pre)
+ pre = 1;
+ break;
+ default: /* round_up */
+ pre = br/(c<<div);
+ // but p must be non-zero
+ if (!pre)
+ return -EINVAL;
+ }
+ PRINTD (DBG_QOS, "A: p=%u, d=%u", pre, div);
+ goto got_it;
+ }
+
+ // at this point we have
+ // d == MIND and (c << (MAXPEXP+MIND)) < B
+ while (div < CR_MAXD) {
+ div++;
+ if (br_man <= (c << (CR_MAXPEXP+div-br_exp))) {
+ // Equivalent to: B <= (c << (MAXPEXP+d))
+ // c << (MAXPEXP+d-1) < B <= c << (MAXPEXP+d)
+ // 1 << (MAXPEXP-1) < B/2^d/c <= 1 << MAXPEXP
+ // MAXP/2 < B/c2^d <= MAXP
+ // take care of rounding
+ switch (r) {
+ case round_down:
+ pre = (br+(c<<div)-1)/(c<<div);
+ break;
+ case round_nearest:
+ pre = (br+(c<<div)/2)/(c<<div);
+ break;
+ default: /* round_up */
+ pre = br/(c<<div);
+ }
+ PRINTD (DBG_QOS, "B: p=%u, d=%u", pre, div);
+ goto got_it;
+ }
+ }
+ // at this point we have
+ // d == MAXD and (c << (MAXPEXP+MAXD)) < B
+ // but we cannot go any higher
+ // take care of rounding
+ if (r == round_down)
+ return -EINVAL;
+ pre = 1 << CR_MAXPEXP;
+ PRINTD (DBG_QOS, "C: p=%u, d=%u", pre, div);
+got_it:
+ // paranoia
+ if (div > CR_MAXD || (!pre) || pre > 1<<CR_MAXPEXP) {
+ PRINTD (DBG_QOS, "set_cr internal failure: d=%u p=%u",
+ div, pre);
+ return -EINVAL;
+ } else {
+ if (bits)
+ *bits = (div<<CLOCK_SELECT_SHIFT) | (pre-1);
+ if (actual) {
+ *actual = (br + (pre<<div) - 1) / (pre<<div);
+ PRINTD (DBG_QOS, "actual rate: %u", *actual);
+ }
+ return 0;
+ }
+}
+
+static int make_rate_with_tolerance (const hrz_dev * dev, u32 c, rounding r, unsigned int tol,
+ u16 * bit_pattern, unsigned int * actual) {
+ unsigned int my_actual;
+
+ PRINTD (DBG_QOS|DBG_FLOW, "make_rate_with_tolerance c=%u, %s, tol=%u",
+ c, (r == round_up) ? "up" : (r == round_down) ? "down" : "nearest", tol);
+
+ if (!actual)
+ // actual rate is not returned
+ actual = &my_actual;
+
+ if (make_rate (dev, c, round_nearest, bit_pattern, actual))
+ // should never happen as round_nearest always succeeds
+ return -1;
+
+ if (c - tol <= *actual && *actual <= c + tol)
+ // within tolerance
+ return 0;
+ else
+ // intolerant, try rounding instead
+ return make_rate (dev, c, r, bit_pattern, actual);
+}
+
+/********** Listen on a VC **********/
+
+static int hrz_open_rx (hrz_dev * dev, u16 channel) {
+ // is there any guarantee that we don't get two simulataneous
+ // identical calls of this function from different processes? yes
+ // rate_lock
+ unsigned long flags;
+ u32 channel_type; // u16?
+
+ u16 buf_ptr = RX_CHANNEL_IDLE;
+
+ rx_ch_desc * rx_desc = &memmap->rx_descs[channel];
+
+ PRINTD (DBG_FLOW, "hrz_open_rx %x", channel);
+
+ spin_lock_irqsave (&dev->mem_lock, flags);
+ channel_type = rd_mem (dev, &rx_desc->wr_buf_type) & BUFFER_PTR_MASK;
+ spin_unlock_irqrestore (&dev->mem_lock, flags);
+
+ // very serious error, should never occur
+ if (channel_type != RX_CHANNEL_DISABLED) {
+ PRINTD (DBG_ERR|DBG_VCC, "RX channel for VC already open");
+ return -EBUSY; // clean up?
+ }
+
+ // Give back spare buffer
+ if (dev->noof_spare_buffers) {
+ buf_ptr = dev->spare_buffers[--dev->noof_spare_buffers];
+ PRINTD (DBG_VCC, "using a spare buffer: %u", buf_ptr);
+ // should never occur
+ if (buf_ptr == RX_CHANNEL_DISABLED || buf_ptr == RX_CHANNEL_IDLE) {
+ // but easy to recover from
+ PRINTD (DBG_ERR|DBG_VCC, "bad spare buffer pointer, using IDLE");
+ buf_ptr = RX_CHANNEL_IDLE;
+ }
+ } else {
+ PRINTD (DBG_VCC, "using IDLE buffer pointer");
+ }
+
+ // Channel is currently disabled so change its status to idle
+
+ // do we really need to save the flags again?
+ spin_lock_irqsave (&dev->mem_lock, flags);
+
+ wr_mem (dev, &rx_desc->wr_buf_type,
+ buf_ptr | CHANNEL_TYPE_AAL5 | FIRST_CELL_OF_AAL5_FRAME);
+ if (buf_ptr != RX_CHANNEL_IDLE)
+ wr_mem (dev, &rx_desc->rd_buf_type, buf_ptr);
+
+ spin_unlock_irqrestore (&dev->mem_lock, flags);
+
+ // rxer->rate = make_rate (qos->peak_cells);
+
+ PRINTD (DBG_FLOW, "hrz_open_rx ok");
+
+ return 0;
+}
+
+#if 0
+/********** change vc rate for a given vc **********/
+
+static void hrz_change_vc_qos (ATM_RXER * rxer, MAAL_QOS * qos) {
+ rxer->rate = make_rate (qos->peak_cells);
+}
+#endif
+
+/********** free an skb (as per ATM device driver documentation) **********/
+
+static inline void hrz_kfree_skb (struct sk_buff * skb) {
+ if (ATM_SKB(skb)->vcc->pop) {
+ ATM_SKB(skb)->vcc->pop (ATM_SKB(skb)->vcc, skb);
+ } else {
+ dev_kfree_skb_any (skb);
+ }
+}
+
+/********** cancel listen on a VC **********/
+
+static void hrz_close_rx (hrz_dev * dev, u16 vc) {
+ unsigned long flags;
+
+ u32 value;
+
+ u32 r1, r2;
+
+ rx_ch_desc * rx_desc = &memmap->rx_descs[vc];
+
+ int was_idle = 0;
+
+ spin_lock_irqsave (&dev->mem_lock, flags);
+ value = rd_mem (dev, &rx_desc->wr_buf_type) & BUFFER_PTR_MASK;
+ spin_unlock_irqrestore (&dev->mem_lock, flags);
+
+ if (value == RX_CHANNEL_DISABLED) {
+ // I suppose this could happen once we deal with _NONE traffic properly
+ PRINTD (DBG_VCC, "closing VC: RX channel %u already disabled", vc);
+ return;
+ }
+ if (value == RX_CHANNEL_IDLE)
+ was_idle = 1;
+
+ spin_lock_irqsave (&dev->mem_lock, flags);
+
+ for (;;) {
+ wr_mem (dev, &rx_desc->wr_buf_type, RX_CHANNEL_DISABLED);
+
+ if ((rd_mem (dev, &rx_desc->wr_buf_type) & BUFFER_PTR_MASK) == RX_CHANNEL_DISABLED)
+ break;
+
+ was_idle = 0;
+ }
+
+ if (was_idle) {
+ spin_unlock_irqrestore (&dev->mem_lock, flags);
+ return;
+ }
+
+ WAIT_FLUSH_RX_COMPLETE(dev);
+
+ // XXX Is this all really necessary? We can rely on the rx_data_av
+ // handler to discard frames that remain queued for delivery. If the
+ // worry is that immediately reopening the channel (perhaps by a
+ // different process) may cause some data to be mis-delivered then
+ // there may still be a simpler solution (such as busy-waiting on
+ // rx_busy once the channel is disabled or before a new one is
+ // opened - does this leave any holes?). Arguably setting up and
+ // tearing down the TX and RX halves of each virtual circuit could
+ // most safely be done within ?x_busy protected regions.
+
+ // OK, current changes are that Simon's marker is disabled and we DO
+ // look for NULL rxer elsewhere. The code here seems flush frames
+ // and then remember the last dead cell belonging to the channel
+ // just disabled - the cell gets relinked at the next vc_open.
+ // However, when all VCs are closed or only a few opened there are a
+ // handful of buffers that are unusable.
+
+ // Does anyone feel like documenting spare_buffers properly?
+ // Does anyone feel like fixing this in a nicer way?
+
+ // Flush any data which is left in the channel
+ for (;;) {
+ // Change the rx channel port to something different to the RX
+ // channel we are trying to close to force Horizon to flush the rx
+ // channel read and write pointers.
+
+ u16 other = vc^(RX_CHANS/2);
+
+ SELECT_RX_CHANNEL (dev, other);
+ WAIT_UPDATE_COMPLETE (dev);
+
+ r1 = rd_mem (dev, &rx_desc->rd_buf_type);
+
+ // Select this RX channel. Flush doesn't seem to work unless we
+ // select an RX channel before hand
+
+ SELECT_RX_CHANNEL (dev, vc);
+ WAIT_UPDATE_COMPLETE (dev);
+
+ // Attempt to flush a frame on this RX channel
+
+ FLUSH_RX_CHANNEL (dev, vc);
+ WAIT_FLUSH_RX_COMPLETE (dev);
+
+ // Force Horizon to flush rx channel read and write pointers as before
+
+ SELECT_RX_CHANNEL (dev, other);
+ WAIT_UPDATE_COMPLETE (dev);
+
+ r2 = rd_mem (dev, &rx_desc->rd_buf_type);
+
+ PRINTD (DBG_VCC|DBG_RX, "r1 = %u, r2 = %u", r1, r2);
+
+ if (r1 == r2) {
+ dev->spare_buffers[dev->noof_spare_buffers++] = (u16)r1;
+ break;
+ }
+ }
+
+#if 0
+ {
+ rx_q_entry * wr_ptr = &memmap->rx_q_entries[rd_regw (dev, RX_QUEUE_WR_PTR_OFF)];
+ rx_q_entry * rd_ptr = dev->rx_q_entry;
+
+ PRINTD (DBG_VCC|DBG_RX, "rd_ptr = %u, wr_ptr = %u", rd_ptr, wr_ptr);
+
+ while (rd_ptr != wr_ptr) {
+ u32 x = rd_mem (dev, (HDW *) rd_ptr);
+
+ if (vc == rx_q_entry_to_rx_channel (x)) {
+ x |= SIMONS_DODGEY_MARKER;
+
+ PRINTD (DBG_RX|DBG_VCC|DBG_WARN, "marking a frame as dodgey");
+
+ wr_mem (dev, (HDW *) rd_ptr, x);
+ }
+
+ if (rd_ptr == dev->rx_q_wrap)
+ rd_ptr = dev->rx_q_reset;
+ else
+ rd_ptr++;
+ }
+ }
+#endif
+
+ spin_unlock_irqrestore (&dev->mem_lock, flags);
+
+ return;
+}
+
+/********** schedule RX transfers **********/
+
+// Note on tail recursion: a GCC developer said that it is not likely
+// to be fixed soon, so do not define TAILRECUSRIONWORKS unless you
+// are sure it does as you may otherwise overflow the kernel stack.
+
+// giving this fn a return value would help GCC, alledgedly
+
+static void rx_schedule (hrz_dev * dev, int irq) {
+ unsigned int rx_bytes;
+
+ int pio_instead = 0;
+#ifndef TAILRECURSIONWORKS
+ pio_instead = 1;
+ while (pio_instead) {
+#endif
+ // bytes waiting for RX transfer
+ rx_bytes = dev->rx_bytes;
+
+#if 0
+ spin_count = 0;
+ while (rd_regl (dev, MASTER_RX_COUNT_REG_OFF)) {
+ PRINTD (DBG_RX|DBG_WARN, "RX error: other PCI Bus Master RX still in progress!");
+ if (++spin_count > 10) {
+ PRINTD (DBG_RX|DBG_ERR, "spun out waiting PCI Bus Master RX completion");
+ wr_regl (dev, MASTER_RX_COUNT_REG_OFF, 0);
+ clear_bit (rx_busy, &dev->flags);
+ hrz_kfree_skb (dev->rx_skb);
+ return;
+ }
+ }
+#endif
+
+ // this code follows the TX code but (at the moment) there is only
+ // one region - the skb itself. I don't know if this will change,
+ // but it doesn't hurt to have the code here, disabled.
+
+ if (rx_bytes) {
+ // start next transfer within same region
+ if (rx_bytes <= MAX_PIO_COUNT) {
+ PRINTD (DBG_RX|DBG_BUS, "(pio)");
+ pio_instead = 1;
+ }
+ if (rx_bytes <= MAX_TRANSFER_COUNT) {
+ PRINTD (DBG_RX|DBG_BUS, "(simple or last multi)");
+ dev->rx_bytes = 0;
+ } else {
+ PRINTD (DBG_RX|DBG_BUS, "(continuing multi)");
+ dev->rx_bytes = rx_bytes - MAX_TRANSFER_COUNT;
+ rx_bytes = MAX_TRANSFER_COUNT;
+ }
+ } else {
+ // rx_bytes == 0 -- we're between regions
+ // regions remaining to transfer
+#if 0
+ unsigned int rx_regions = dev->rx_regions;
+#else
+ unsigned int rx_regions = 0;
+#endif
+
+ if (rx_regions) {
+#if 0
+ // start a new region
+ dev->rx_addr = dev->rx_iovec->iov_base;
+ rx_bytes = dev->rx_iovec->iov_len;
+ ++dev->rx_iovec;
+ dev->rx_regions = rx_regions - 1;
+
+ if (rx_bytes <= MAX_PIO_COUNT) {
+ PRINTD (DBG_RX|DBG_BUS, "(pio)");
+ pio_instead = 1;
+ }
+ if (rx_bytes <= MAX_TRANSFER_COUNT) {
+ PRINTD (DBG_RX|DBG_BUS, "(full region)");
+ dev->rx_bytes = 0;
+ } else {
+ PRINTD (DBG_RX|DBG_BUS, "(start multi region)");
+ dev->rx_bytes = rx_bytes - MAX_TRANSFER_COUNT;
+ rx_bytes = MAX_TRANSFER_COUNT;
+ }
+#endif
+ } else {
+ // rx_regions == 0
+ // that's all folks - end of frame
+ struct sk_buff * skb = dev->rx_skb;
+ // dev->rx_iovec = 0;
+
+ FLUSH_RX_CHANNEL (dev, dev->rx_channel);
+
+ dump_skb ("<<<", dev->rx_channel, skb);
+
+ PRINTD (DBG_RX|DBG_SKB, "push %p %u", skb->data, skb->len);
+
+ {
+ struct atm_vcc * vcc = ATM_SKB(skb)->vcc;
+ // VC layer stats
+ atomic_inc(&vcc->stats->rx);
+ do_gettimeofday(&skb->stamp);
+ // end of our responsability
+ vcc->push (vcc, skb);
+ }
+ }
+ }
+
+ // note: writing RX_COUNT clears any interrupt condition
+ if (rx_bytes) {
+ if (pio_instead) {
+ if (irq)
+ wr_regl (dev, MASTER_RX_COUNT_REG_OFF, 0);
+ rds_regb (dev, DATA_PORT_OFF, dev->rx_addr, rx_bytes);
+ } else {
+ wr_regl (dev, MASTER_RX_ADDR_REG_OFF, virt_to_bus (dev->rx_addr));
+ wr_regl (dev, MASTER_RX_COUNT_REG_OFF, rx_bytes);
+ }
+ dev->rx_addr += rx_bytes;
+ } else {
+ if (irq)
+ wr_regl (dev, MASTER_RX_COUNT_REG_OFF, 0);
+ // allow another RX thread to start
+ YELLOW_LED_ON(dev);
+ clear_bit (rx_busy, &dev->flags);
+ PRINTD (DBG_RX, "cleared rx_busy for dev %p", dev);
+ }
+
+#ifdef TAILRECURSIONWORKS
+ // and we all bless optimised tail calls
+ if (pio_instead)
+ return rx_schedule (dev, 0);
+ return;
+#else
+ // grrrrrrr!
+ irq = 0;
+ }
+ return;
+#endif
+}
+
+/********** handle RX bus master complete events **********/
+
+static inline void rx_bus_master_complete_handler (hrz_dev * dev) {
+ if (test_bit (rx_busy, &dev->flags)) {
+ rx_schedule (dev, 1);
+ } else {
+ PRINTD (DBG_RX|DBG_ERR, "unexpected RX bus master completion");
+ // clear interrupt condition on adapter
+ wr_regl (dev, MASTER_RX_COUNT_REG_OFF, 0);
+ }
+ return;
+}
+
+/********** (queue to) become the next TX thread **********/
+
+static inline int tx_hold (hrz_dev * dev) {
+ PRINTD (DBG_TX, "sleeping at tx lock %p %lu", dev, dev->flags);
+ wait_event_interruptible(dev->tx_queue, (!test_and_set_bit(tx_busy, &dev->flags)));
+ PRINTD (DBG_TX, "woken at tx lock %p %lu", dev, dev->flags);
+ if (signal_pending (current))
+ return -1;
+ PRINTD (DBG_TX, "set tx_busy for dev %p", dev);
+ return 0;
+}
+
+/********** allow another TX thread to start **********/
+
+static inline void tx_release (hrz_dev * dev) {
+ clear_bit (tx_busy, &dev->flags);
+ PRINTD (DBG_TX, "cleared tx_busy for dev %p", dev);
+ wake_up_interruptible (&dev->tx_queue);
+}
+
+/********** schedule TX transfers **********/
+
+static void tx_schedule (hrz_dev * const dev, int irq) {
+ unsigned int tx_bytes;
+
+ int append_desc = 0;
+
+ int pio_instead = 0;
+#ifndef TAILRECURSIONWORKS
+ pio_instead = 1;
+ while (pio_instead) {
+#endif
+ // bytes in current region waiting for TX transfer
+ tx_bytes = dev->tx_bytes;
+
+#if 0
+ spin_count = 0;
+ while (rd_regl (dev, MASTER_TX_COUNT_REG_OFF)) {
+ PRINTD (DBG_TX|DBG_WARN, "TX error: other PCI Bus Master TX still in progress!");
+ if (++spin_count > 10) {
+ PRINTD (DBG_TX|DBG_ERR, "spun out waiting PCI Bus Master TX completion");
+ wr_regl (dev, MASTER_TX_COUNT_REG_OFF, 0);
+ tx_release (dev);
+ hrz_kfree_skb (dev->tx_skb);
+ return;
+ }
+ }
+#endif
+
+ if (tx_bytes) {
+ // start next transfer within same region
+ if (!test_bit (ultra, &dev->flags) || tx_bytes <= MAX_PIO_COUNT) {
+ PRINTD (DBG_TX|DBG_BUS, "(pio)");
+ pio_instead = 1;
+ }
+ if (tx_bytes <= MAX_TRANSFER_COUNT) {
+ PRINTD (DBG_TX|DBG_BUS, "(simple or last multi)");
+ if (!dev->tx_iovec) {
+ // end of last region
+ append_desc = 1;
+ }
+ dev->tx_bytes = 0;
+ } else {
+ PRINTD (DBG_TX|DBG_BUS, "(continuing multi)");
+ dev->tx_bytes = tx_bytes - MAX_TRANSFER_COUNT;
+ tx_bytes = MAX_TRANSFER_COUNT;
+ }
+ } else {
+ // tx_bytes == 0 -- we're between regions
+ // regions remaining to transfer
+ unsigned int tx_regions = dev->tx_regions;
+
+ if (tx_regions) {
+ // start a new region
+ dev->tx_addr = dev->tx_iovec->iov_base;
+ tx_bytes = dev->tx_iovec->iov_len;
+ ++dev->tx_iovec;
+ dev->tx_regions = tx_regions - 1;
+
+ if (!test_bit (ultra, &dev->flags) || tx_bytes <= MAX_PIO_COUNT) {
+ PRINTD (DBG_TX|DBG_BUS, "(pio)");
+ pio_instead = 1;
+ }
+ if (tx_bytes <= MAX_TRANSFER_COUNT) {
+ PRINTD (DBG_TX|DBG_BUS, "(full region)");
+ dev->tx_bytes = 0;
+ } else {
+ PRINTD (DBG_TX|DBG_BUS, "(start multi region)");
+ dev->tx_bytes = tx_bytes - MAX_TRANSFER_COUNT;
+ tx_bytes = MAX_TRANSFER_COUNT;
+ }
+ } else {
+ // tx_regions == 0
+ // that's all folks - end of frame
+ struct sk_buff * skb = dev->tx_skb;
+ dev->tx_iovec = NULL;
+
+ // VC layer stats
+ atomic_inc(&ATM_SKB(skb)->vcc->stats->tx);
+
+ // free the skb
+ hrz_kfree_skb (skb);
+ }
+ }
+
+ // note: writing TX_COUNT clears any interrupt condition
+ if (tx_bytes) {
+ if (pio_instead) {
+ if (irq)
+ wr_regl (dev, MASTER_TX_COUNT_REG_OFF, 0);
+ wrs_regb (dev, DATA_PORT_OFF, dev->tx_addr, tx_bytes);
+ if (append_desc)
+ wr_regl (dev, TX_DESCRIPTOR_PORT_OFF, cpu_to_be32 (dev->tx_skb->len));
+ } else {
+ wr_regl (dev, MASTER_TX_ADDR_REG_OFF, virt_to_bus (dev->tx_addr));
+ if (append_desc)
+ wr_regl (dev, TX_DESCRIPTOR_REG_OFF, cpu_to_be32 (dev->tx_skb->len));
+ wr_regl (dev, MASTER_TX_COUNT_REG_OFF,
+ append_desc
+ ? tx_bytes | MASTER_TX_AUTO_APPEND_DESC
+ : tx_bytes);
+ }
+ dev->tx_addr += tx_bytes;
+ } else {
+ if (irq)
+ wr_regl (dev, MASTER_TX_COUNT_REG_OFF, 0);
+ YELLOW_LED_ON(dev);
+ tx_release (dev);
+ }
+
+#ifdef TAILRECURSIONWORKS
+ // and we all bless optimised tail calls
+ if (pio_instead)
+ return tx_schedule (dev, 0);
+ return;
+#else
+ // grrrrrrr!
+ irq = 0;
+ }
+ return;
+#endif
+}
+
+/********** handle TX bus master complete events **********/
+
+static inline void tx_bus_master_complete_handler (hrz_dev * dev) {
+ if (test_bit (tx_busy, &dev->flags)) {
+ tx_schedule (dev, 1);
+ } else {
+ PRINTD (DBG_TX|DBG_ERR, "unexpected TX bus master completion");
+ // clear interrupt condition on adapter
+ wr_regl (dev, MASTER_TX_COUNT_REG_OFF, 0);
+ }
+ return;
+}
+
+/********** move RX Q pointer to next item in circular buffer **********/
+
+// called only from IRQ sub-handler
+static inline u32 rx_queue_entry_next (hrz_dev * dev) {
+ u32 rx_queue_entry;
+ spin_lock (&dev->mem_lock);
+ rx_queue_entry = rd_mem (dev, &dev->rx_q_entry->entry);
+ if (dev->rx_q_entry == dev->rx_q_wrap)
+ dev->rx_q_entry = dev->rx_q_reset;
+ else
+ dev->rx_q_entry++;
+ wr_regw (dev, RX_QUEUE_RD_PTR_OFF, dev->rx_q_entry - dev->rx_q_reset);
+ spin_unlock (&dev->mem_lock);
+ return rx_queue_entry;
+}
+
+/********** handle RX disabled by device **********/
+
+static inline void rx_disabled_handler (hrz_dev * dev) {
+ wr_regw (dev, RX_CONFIG_OFF, rd_regw (dev, RX_CONFIG_OFF) | RX_ENABLE);
+ // count me please
+ PRINTK (KERN_WARNING, "RX was disabled!");
+}
+
+/********** handle RX data received by device **********/
+
+// called from IRQ handler
+static inline void rx_data_av_handler (hrz_dev * dev) {
+ u32 rx_queue_entry;
+ u32 rx_queue_entry_flags;
+ u16 rx_len;
+ u16 rx_channel;
+
+ PRINTD (DBG_FLOW, "hrz_data_av_handler");
+
+ // try to grab rx lock (not possible during RX bus mastering)
+ if (test_and_set_bit (rx_busy, &dev->flags)) {
+ PRINTD (DBG_RX, "locked out of rx lock");
+ return;
+ }
+ PRINTD (DBG_RX, "set rx_busy for dev %p", dev);
+ // lock is cleared if we fail now, o/w after bus master completion
+
+ YELLOW_LED_OFF(dev);
+
+ rx_queue_entry = rx_queue_entry_next (dev);
+
+ rx_len = rx_q_entry_to_length (rx_queue_entry);
+ rx_channel = rx_q_entry_to_rx_channel (rx_queue_entry);
+
+ WAIT_FLUSH_RX_COMPLETE (dev);
+
+ SELECT_RX_CHANNEL (dev, rx_channel);
+
+ PRINTD (DBG_RX, "rx_queue_entry is: %#x", rx_queue_entry);
+ rx_queue_entry_flags = rx_queue_entry & (RX_CRC_32_OK|RX_COMPLETE_FRAME|SIMONS_DODGEY_MARKER);
+
+ if (!rx_len) {
+ // (at least) bus-mastering breaks if we try to handle a
+ // zero-length frame, besides AAL5 does not support them
+ PRINTK (KERN_ERR, "zero-length frame!");
+ rx_queue_entry_flags &= ~RX_COMPLETE_FRAME;
+ }
+
+ if (rx_queue_entry_flags & SIMONS_DODGEY_MARKER) {
+ PRINTD (DBG_RX|DBG_ERR, "Simon's marker detected!");
+ }
+ if (rx_queue_entry_flags == (RX_CRC_32_OK | RX_COMPLETE_FRAME)) {
+ struct atm_vcc * atm_vcc;
+
+ PRINTD (DBG_RX, "got a frame on rx_channel %x len %u", rx_channel, rx_len);
+
+ atm_vcc = dev->rxer[rx_channel];
+ // if no vcc is assigned to this channel, we should drop the frame
+ // (is this what SIMONS etc. was trying to achieve?)
+
+ if (atm_vcc) {
+
+ if (atm_vcc->qos.rxtp.traffic_class != ATM_NONE) {
+
+ if (rx_len <= atm_vcc->qos.rxtp.max_sdu) {
+
+ struct sk_buff * skb = atm_alloc_charge (atm_vcc, rx_len, GFP_ATOMIC);
+ if (skb) {
+ // remember this so we can push it later
+ dev->rx_skb = skb;
+ // remember this so we can flush it later
+ dev->rx_channel = rx_channel;
+
+ // prepare socket buffer
+ skb_put (skb, rx_len);
+ ATM_SKB(skb)->vcc = atm_vcc;
+
+ // simple transfer
+ // dev->rx_regions = 0;
+ // dev->rx_iovec = 0;
+ dev->rx_bytes = rx_len;
+ dev->rx_addr = skb->data;
+ PRINTD (DBG_RX, "RX start simple transfer (addr %p, len %d)",
+ skb->data, rx_len);
+
+ // do the business
+ rx_schedule (dev, 0);
+ return;
+
+ } else {
+ PRINTD (DBG_SKB|DBG_WARN, "failed to get skb");
+ }
+
+ } else {
+ PRINTK (KERN_INFO, "frame received on TX-only VC %x", rx_channel);
+ // do we count this?
+ }
+
+ } else {
+ PRINTK (KERN_WARNING, "dropped over-size frame");
+ // do we count this?
+ }
+
+ } else {
+ PRINTD (DBG_WARN|DBG_VCC|DBG_RX, "no VCC for this frame (VC closed)");
+ // do we count this?
+ }
+
+ } else {
+ // Wait update complete ? SPONG
+ }
+
+ // RX was aborted
+ YELLOW_LED_ON(dev);
+
+ FLUSH_RX_CHANNEL (dev,rx_channel);
+ clear_bit (rx_busy, &dev->flags);
+
+ return;
+}
+
+/********** interrupt handler **********/
+
+static irqreturn_t interrupt_handler(int irq, void *dev_id,
+ struct pt_regs *pt_regs) {
+ hrz_dev * dev = (hrz_dev *) dev_id;
+ u32 int_source;
+ unsigned int irq_ok;
+ (void) pt_regs;
+
+ PRINTD (DBG_FLOW, "interrupt_handler: %p", dev_id);
+
+ if (!dev_id) {
+ PRINTD (DBG_IRQ|DBG_ERR, "irq with NULL dev_id: %d", irq);
+ return IRQ_NONE;
+ }
+ if (irq != dev->irq) {
+ PRINTD (DBG_IRQ|DBG_ERR, "irq mismatch: %d", irq);
+ return IRQ_NONE;
+ }
+
+ // definitely for us
+ irq_ok = 0;
+ while ((int_source = rd_regl (dev, INT_SOURCE_REG_OFF)
+ & INTERESTING_INTERRUPTS)) {
+ // In the interests of fairness, the (inline) handlers below are
+ // called in sequence and without immediate return to the head of
+ // the while loop. This is only of issue for slow hosts (or when
+ // debugging messages are on). Really slow hosts may find a fast
+ // sender keeps them permanently in the IRQ handler. :(
+
+ // (only an issue for slow hosts) RX completion goes before
+ // rx_data_av as the former implies rx_busy and so the latter
+ // would just abort. If it reschedules another transfer
+ // (continuing the same frame) then it will not clear rx_busy.
+
+ // (only an issue for slow hosts) TX completion goes before RX
+ // data available as it is a much shorter routine - there is the
+ // chance that any further transfers it schedules will be complete
+ // by the time of the return to the head of the while loop
+
+ if (int_source & RX_BUS_MASTER_COMPLETE) {
+ ++irq_ok;
+ PRINTD (DBG_IRQ|DBG_BUS|DBG_RX, "rx_bus_master_complete asserted");
+ rx_bus_master_complete_handler (dev);
+ }
+ if (int_source & TX_BUS_MASTER_COMPLETE) {
+ ++irq_ok;
+ PRINTD (DBG_IRQ|DBG_BUS|DBG_TX, "tx_bus_master_complete asserted");
+ tx_bus_master_complete_handler (dev);
+ }
+ if (int_source & RX_DATA_AV) {
+ ++irq_ok;
+ PRINTD (DBG_IRQ|DBG_RX, "rx_data_av asserted");
+ rx_data_av_handler (dev);
+ }
+ }
+ if (irq_ok) {
+ PRINTD (DBG_IRQ, "work done: %u", irq_ok);
+ } else {
+ PRINTD (DBG_IRQ|DBG_WARN, "spurious interrupt source: %#x", int_source);
+ }
+
+ PRINTD (DBG_IRQ|DBG_FLOW, "interrupt_handler done: %p", dev_id);
+ if (irq_ok)
+ return IRQ_HANDLED;
+ return IRQ_NONE;
+}
+
+/********** housekeeping **********/
+
+static void do_housekeeping (unsigned long arg) {
+ // just stats at the moment
+ hrz_dev * dev = (hrz_dev *) arg;
+
+ // collect device-specific (not driver/atm-linux) stats here
+ dev->tx_cell_count += rd_regw (dev, TX_CELL_COUNT_OFF);
+ dev->rx_cell_count += rd_regw (dev, RX_CELL_COUNT_OFF);
+ dev->hec_error_count += rd_regw (dev, HEC_ERROR_COUNT_OFF);
+ dev->unassigned_cell_count += rd_regw (dev, UNASSIGNED_CELL_COUNT_OFF);
+
+ mod_timer (&dev->housekeeping, jiffies + HZ/10);
+
+ return;
+}
+
+/********** find an idle channel for TX and set it up **********/
+
+// called with tx_busy set
+static inline short setup_idle_tx_channel (hrz_dev * dev, hrz_vcc * vcc) {
+ unsigned short idle_channels;
+ short tx_channel = -1;
+ unsigned int spin_count;
+ PRINTD (DBG_FLOW|DBG_TX, "setup_idle_tx_channel %p", dev);
+
+ // better would be to fail immediately, the caller can then decide whether
+ // to wait or drop (depending on whether this is UBR etc.)
+ spin_count = 0;
+ while (!(idle_channels = rd_regw (dev, TX_STATUS_OFF) & IDLE_CHANNELS_MASK)) {
+ PRINTD (DBG_TX|DBG_WARN, "waiting for idle TX channel");
+ // delay a bit here
+ if (++spin_count > 100) {
+ PRINTD (DBG_TX|DBG_ERR, "spun out waiting for idle TX channel");
+ return -EBUSY;
+ }
+ }
+
+ // got an idle channel
+ {
+ // tx_idle ensures we look for idle channels in RR order
+ int chan = dev->tx_idle;
+
+ int keep_going = 1;
+ while (keep_going) {
+ if (idle_channels & (1<<chan)) {
+ tx_channel = chan;
+ keep_going = 0;
+ }
+ ++chan;
+ if (chan == TX_CHANS)
+ chan = 0;
+ }
+
+ dev->tx_idle = chan;
+ }
+
+ // set up the channel we found
+ {
+ // Initialise the cell header in the transmit channel descriptor
+ // a.k.a. prepare the channel and remember that we have done so.
+
+ tx_ch_desc * tx_desc = &memmap->tx_descs[tx_channel];
+ u16 rd_ptr;
+ u16 wr_ptr;
+ u16 channel = vcc->channel;
+
+ unsigned long flags;
+ spin_lock_irqsave (&dev->mem_lock, flags);
+
+ // Update the transmit channel record.
+ dev->tx_channel_record[tx_channel] = channel;
+
+ // xBR channel
+ update_tx_channel_config (dev, tx_channel, RATE_TYPE_ACCESS,
+ vcc->tx_xbr_bits);
+
+ // Update the PCR counter preload value etc.
+ update_tx_channel_config (dev, tx_channel, PCR_TIMER_ACCESS,
+ vcc->tx_pcr_bits);
+
+#if 0
+ if (vcc->tx_xbr_bits == VBR_RATE_TYPE) {
+ // SCR timer
+ update_tx_channel_config (dev, tx_channel, SCR_TIMER_ACCESS,
+ vcc->tx_scr_bits);
+
+ // Bucket size...
+ update_tx_channel_config (dev, tx_channel, BUCKET_CAPACITY_ACCESS,
+ vcc->tx_bucket_bits);
+
+ // ... and fullness
+ update_tx_channel_config (dev, tx_channel, BUCKET_FULLNESS_ACCESS,
+ vcc->tx_bucket_bits);
+ }
+#endif
+
+ // Initialise the read and write buffer pointers
+ rd_ptr = rd_mem (dev, &tx_desc->rd_buf_type) & BUFFER_PTR_MASK;
+ wr_ptr = rd_mem (dev, &tx_desc->wr_buf_type) & BUFFER_PTR_MASK;
+
+ // idle TX channels should have identical pointers
+ if (rd_ptr != wr_ptr) {
+ PRINTD (DBG_TX|DBG_ERR, "TX buffer pointers are broken!");
+ // spin_unlock... return -E...
+ // I wonder if gcc would get rid of one of the pointer aliases
+ }
+ PRINTD (DBG_TX, "TX buffer pointers are: rd %x, wr %x.",
+ rd_ptr, wr_ptr);
+
+ switch (vcc->aal) {
+ case aal0:
+ PRINTD (DBG_QOS|DBG_TX, "tx_channel: aal0");
+ rd_ptr |= CHANNEL_TYPE_RAW_CELLS;
+ wr_ptr |= CHANNEL_TYPE_RAW_CELLS;
+ break;
+ case aal34:
+ PRINTD (DBG_QOS|DBG_TX, "tx_channel: aal34");
+ rd_ptr |= CHANNEL_TYPE_AAL3_4;
+ wr_ptr |= CHANNEL_TYPE_AAL3_4;
+ break;
+ case aal5:
+ rd_ptr |= CHANNEL_TYPE_AAL5;
+ wr_ptr |= CHANNEL_TYPE_AAL5;
+ // Initialise the CRC
+ wr_mem (dev, &tx_desc->partial_crc, INITIAL_CRC);
+ break;
+ }
+
+ wr_mem (dev, &tx_desc->rd_buf_type, rd_ptr);
+ wr_mem (dev, &tx_desc->wr_buf_type, wr_ptr);
+
+ // Write the Cell Header
+ // Payload Type, CLP and GFC would go here if non-zero
+ wr_mem (dev, &tx_desc->cell_header, channel);
+
+ spin_unlock_irqrestore (&dev->mem_lock, flags);
+ }
+
+ return tx_channel;
+}
+
+/********** send a frame **********/
+
+static int hrz_send (struct atm_vcc * atm_vcc, struct sk_buff * skb) {
+ unsigned int spin_count;
+ int free_buffers;
+ hrz_dev * dev = HRZ_DEV(atm_vcc->dev);
+ hrz_vcc * vcc = HRZ_VCC(atm_vcc);
+ u16 channel = vcc->channel;
+
+ u32 buffers_required;
+
+ /* signed for error return */
+ short tx_channel;
+
+ PRINTD (DBG_FLOW|DBG_TX, "hrz_send vc %x data %p len %u",
+ channel, skb->data, skb->len);
+
+ dump_skb (">>>", channel, skb);
+
+ if (atm_vcc->qos.txtp.traffic_class == ATM_NONE) {
+ PRINTK (KERN_ERR, "attempt to send on RX-only VC %x", channel);
+ hrz_kfree_skb (skb);
+ return -EIO;
+ }
+
+ // don't understand this
+ ATM_SKB(skb)->vcc = atm_vcc;
+
+ if (skb->len > atm_vcc->qos.txtp.max_sdu) {
+ PRINTK (KERN_ERR, "sk_buff length greater than agreed max_sdu, dropping...");
+ hrz_kfree_skb (skb);
+ return -EIO;
+ }
+
+ if (!channel) {
+ PRINTD (DBG_ERR|DBG_TX, "attempt to transmit on zero (rx_)channel");
+ hrz_kfree_skb (skb);
+ return -EIO;
+ }
+
+#if 0
+ {
+ // where would be a better place for this? housekeeping?
+ u16 status;
+ pci_read_config_word (dev->pci_dev, PCI_STATUS, &status);
+ if (status & PCI_STATUS_REC_MASTER_ABORT) {
+ PRINTD (DBG_BUS|DBG_ERR, "Clearing PCI Master Abort (and cleaning up)");
+ status &= ~PCI_STATUS_REC_MASTER_ABORT;
+ pci_write_config_word (dev->pci_dev, PCI_STATUS, status);
+ if (test_bit (tx_busy, &dev->flags)) {
+ hrz_kfree_skb (dev->tx_skb);
+ tx_release (dev);
+ }
+ }
+ }
+#endif
+
+#ifdef DEBUG_HORIZON
+ /* wey-hey! */
+ if (channel == 1023) {
+ unsigned int i;
+ unsigned short d = 0;
+ char * s = skb->data;
+ if (*s++ == 'D') {
+ for (i = 0; i < 4; ++i) {
+ d = (d<<4) | ((*s <= '9') ? (*s - '0') : (*s - 'a' + 10));
+ ++s;
+ }
+ PRINTK (KERN_INFO, "debug bitmap is now %hx", debug = d);
+ }
+ }
+#endif
+
+ // wait until TX is free and grab lock
+ if (tx_hold (dev)) {
+ hrz_kfree_skb (skb);
+ return -ERESTARTSYS;
+ }
+
+ // Wait for enough space to be available in transmit buffer memory.
+
+ // should be number of cells needed + 2 (according to hardware docs)
+ // = ((framelen+8)+47) / 48 + 2
+ // = (framelen+7) / 48 + 3, hmm... faster to put addition inside XXX
+ buffers_required = (skb->len+(ATM_AAL5_TRAILER-1)) / ATM_CELL_PAYLOAD + 3;
+
+ // replace with timer and sleep, add dev->tx_buffers_queue (max 1 entry)
+ spin_count = 0;
+ while ((free_buffers = rd_regw (dev, TX_FREE_BUFFER_COUNT_OFF)) < buffers_required) {
+ PRINTD (DBG_TX, "waiting for free TX buffers, got %d of %d",
+ free_buffers, buffers_required);
+ // what is the appropriate delay? implement a timeout? (depending on line speed?)
+ // mdelay (1);
+ // what happens if we kill (current_pid, SIGKILL) ?
+ schedule();
+ if (++spin_count > 1000) {
+ PRINTD (DBG_TX|DBG_ERR, "spun out waiting for tx buffers, got %d of %d",
+ free_buffers, buffers_required);
+ tx_release (dev);
+ hrz_kfree_skb (skb);
+ return -ERESTARTSYS;
+ }
+ }
+
+ // Select a channel to transmit the frame on.
+ if (channel == dev->last_vc) {
+ PRINTD (DBG_TX, "last vc hack: hit");
+ tx_channel = dev->tx_last;
+ } else {
+ PRINTD (DBG_TX, "last vc hack: miss");
+ // Are we currently transmitting this VC on one of the channels?
+ for (tx_channel = 0; tx_channel < TX_CHANS; ++tx_channel)
+ if (dev->tx_channel_record[tx_channel] == channel) {
+ PRINTD (DBG_TX, "vc already on channel: hit");
+ break;
+ }
+ if (tx_channel == TX_CHANS) {
+ PRINTD (DBG_TX, "vc already on channel: miss");
+ // Find and set up an idle channel.
+ tx_channel = setup_idle_tx_channel (dev, vcc);
+ if (tx_channel < 0) {
+ PRINTD (DBG_TX|DBG_ERR, "failed to get channel");
+ tx_release (dev);
+ return tx_channel;
+ }
+ }
+
+ PRINTD (DBG_TX, "got channel");
+ SELECT_TX_CHANNEL(dev, tx_channel);
+
+ dev->last_vc = channel;
+ dev->tx_last = tx_channel;
+ }
+
+ PRINTD (DBG_TX, "using channel %u", tx_channel);
+
+ YELLOW_LED_OFF(dev);
+
+ // TX start transfer
+
+ {
+ unsigned int tx_len = skb->len;
+ unsigned int tx_iovcnt = skb_shinfo(skb)->nr_frags;
+ // remember this so we can free it later
+ dev->tx_skb = skb;
+
+ if (tx_iovcnt) {
+ // scatter gather transfer
+ dev->tx_regions = tx_iovcnt;
+ dev->tx_iovec = NULL; /* @@@ needs rewritten */
+ dev->tx_bytes = 0;
+ PRINTD (DBG_TX|DBG_BUS, "TX start scatter-gather transfer (iovec %p, len %d)",
+ skb->data, tx_len);
+ tx_release (dev);
+ hrz_kfree_skb (skb);
+ return -EIO;
+ } else {
+ // simple transfer
+ dev->tx_regions = 0;
+ dev->tx_iovec = NULL;
+ dev->tx_bytes = tx_len;
+ dev->tx_addr = skb->data;
+ PRINTD (DBG_TX|DBG_BUS, "TX start simple transfer (addr %p, len %d)",
+ skb->data, tx_len);
+ }
+
+ // and do the business
+ tx_schedule (dev, 0);
+
+ }
+
+ return 0;
+}
+
+/********** reset a card **********/
+
+static void hrz_reset (const hrz_dev * dev) {
+ u32 control_0_reg = rd_regl (dev, CONTROL_0_REG);
+
+ // why not set RESET_HORIZON to one and wait for the card to
+ // reassert that bit as zero? Like so:
+ control_0_reg = control_0_reg & RESET_HORIZON;
+ wr_regl (dev, CONTROL_0_REG, control_0_reg);
+ while (control_0_reg & RESET_HORIZON)
+ control_0_reg = rd_regl (dev, CONTROL_0_REG);
+
+ // old reset code retained:
+ wr_regl (dev, CONTROL_0_REG, control_0_reg |
+ RESET_ATM | RESET_RX | RESET_TX | RESET_HOST);
+ // just guessing here
+ udelay (1000);
+
+ wr_regl (dev, CONTROL_0_REG, control_0_reg);
+}
+
+/********** read the burnt in address **********/
+
+static inline void WRITE_IT_WAIT (const hrz_dev *dev, u32 ctrl)
+{
+ wr_regl (dev, CONTROL_0_REG, ctrl);
+ udelay (5);
+}
+
+static inline void CLOCK_IT (const hrz_dev *dev, u32 ctrl)
+{
+ // DI must be valid around rising SK edge
+ WRITE_IT_WAIT(dev, ctrl & ~SEEPROM_SK);
+ WRITE_IT_WAIT(dev, ctrl | SEEPROM_SK);
+}
+
+static u16 __init read_bia (const hrz_dev * dev, u16 addr)
+{
+ u32 ctrl = rd_regl (dev, CONTROL_0_REG);
+
+ const unsigned int addr_bits = 6;
+ const unsigned int data_bits = 16;
+
+ unsigned int i;
+
+ u16 res;
+
+ ctrl &= ~(SEEPROM_CS | SEEPROM_SK | SEEPROM_DI);
+ WRITE_IT_WAIT(dev, ctrl);
+
+ // wake Serial EEPROM and send 110 (READ) command
+ ctrl |= (SEEPROM_CS | SEEPROM_DI);
+ CLOCK_IT(dev, ctrl);
+
+ ctrl |= SEEPROM_DI;
+ CLOCK_IT(dev, ctrl);
+
+ ctrl &= ~SEEPROM_DI;
+ CLOCK_IT(dev, ctrl);
+
+ for (i=0; i<addr_bits; i++) {
+ if (addr & (1 << (addr_bits-1)))
+ ctrl |= SEEPROM_DI;
+ else
+ ctrl &= ~SEEPROM_DI;
+
+ CLOCK_IT(dev, ctrl);
+
+ addr = addr << 1;
+ }
+
+ // we could check that we have DO = 0 here
+ ctrl &= ~SEEPROM_DI;
+
+ res = 0;
+ for (i=0;i<data_bits;i++) {
+ res = res >> 1;
+
+ CLOCK_IT(dev, ctrl);
+
+ if (rd_regl (dev, CONTROL_0_REG) & SEEPROM_DO)
+ res |= (1 << (data_bits-1));
+ }
+
+ ctrl &= ~(SEEPROM_SK | SEEPROM_CS);
+ WRITE_IT_WAIT(dev, ctrl);
+
+ return res;
+}
+
+/********** initialise a card **********/
+
+static int __init hrz_init (hrz_dev * dev) {
+ int onefivefive;
+
+ u16 chan;
+
+ int buff_count;
+
+ HDW * mem;
+
+ cell_buf * tx_desc;
+ cell_buf * rx_desc;
+
+ u32 ctrl;
+
+ ctrl = rd_regl (dev, CONTROL_0_REG);
+ PRINTD (DBG_INFO, "ctrl0reg is %#x", ctrl);
+ onefivefive = ctrl & ATM_LAYER_STATUS;
+
+ if (onefivefive)
+ printk (DEV_LABEL ": Horizon Ultra (at 155.52 MBps)");
+ else
+ printk (DEV_LABEL ": Horizon (at 25 MBps)");
+
+ printk (":");
+ // Reset the card to get everything in a known state
+
+ printk (" reset");
+ hrz_reset (dev);
+
+ // Clear all the buffer memory
+
+ printk (" clearing memory");
+
+ for (mem = (HDW *) memmap; mem < (HDW *) (memmap + 1); ++mem)
+ wr_mem (dev, mem, 0);
+
+ printk (" tx channels");
+
+ // All transmit eight channels are set up as AAL5 ABR channels with
+ // a 16us cell spacing. Why?
+
+ // Channel 0 gets the free buffer at 100h, channel 1 gets the free
+ // buffer at 110h etc.
+
+ for (chan = 0; chan < TX_CHANS; ++chan) {
+ tx_ch_desc * tx_desc = &memmap->tx_descs[chan];
+ cell_buf * buf = &memmap->inittxbufs[chan];
+
+ // initialise the read and write buffer pointers
+ wr_mem (dev, &tx_desc->rd_buf_type, BUF_PTR(buf));
+ wr_mem (dev, &tx_desc->wr_buf_type, BUF_PTR(buf));
+
+ // set the status of the initial buffers to empty
+ wr_mem (dev, &buf->next, BUFF_STATUS_EMPTY);
+ }
+
+ // Use space bufn3 at the moment for tx buffers
+
+ printk (" tx buffers");
+
+ tx_desc = memmap->bufn3;
+
+ wr_mem (dev, &memmap->txfreebufstart.next, BUF_PTR(tx_desc) | BUFF_STATUS_EMPTY);
+
+ for (buff_count = 0; buff_count < BUFN3_SIZE-1; buff_count++) {
+ wr_mem (dev, &tx_desc->next, BUF_PTR(tx_desc+1) | BUFF_STATUS_EMPTY);
+ tx_desc++;
+ }
+
+ wr_mem (dev, &tx_desc->next, BUF_PTR(&memmap->txfreebufend) | BUFF_STATUS_EMPTY);
+
+ // Initialise the transmit free buffer count
+ wr_regw (dev, TX_FREE_BUFFER_COUNT_OFF, BUFN3_SIZE);
+
+ printk (" rx channels");
+
+ // Initialise all of the receive channels to be AAL5 disabled with
+ // an interrupt threshold of 0
+
+ for (chan = 0; chan < RX_CHANS; ++chan) {
+ rx_ch_desc * rx_desc = &memmap->rx_descs[chan];
+
+ wr_mem (dev, &rx_desc->wr_buf_type, CHANNEL_TYPE_AAL5 | RX_CHANNEL_DISABLED);
+ }
+
+ printk (" rx buffers");
+
+ // Use space bufn4 at the moment for rx buffers
+
+ rx_desc = memmap->bufn4;
+
+ wr_mem (dev, &memmap->rxfreebufstart.next, BUF_PTR(rx_desc) | BUFF_STATUS_EMPTY);
+
+ for (buff_count = 0; buff_count < BUFN4_SIZE-1; buff_count++) {
+ wr_mem (dev, &rx_desc->next, BUF_PTR(rx_desc+1) | BUFF_STATUS_EMPTY);
+
+ rx_desc++;
+ }
+
+ wr_mem (dev, &rx_desc->next, BUF_PTR(&memmap->rxfreebufend) | BUFF_STATUS_EMPTY);
+
+ // Initialise the receive free buffer count
+ wr_regw (dev, RX_FREE_BUFFER_COUNT_OFF, BUFN4_SIZE);
+
+ // Initialize Horizons registers
+
+ // TX config
+ wr_regw (dev, TX_CONFIG_OFF,
+ ABR_ROUND_ROBIN | TX_NORMAL_OPERATION | DRVR_DRVRBAR_ENABLE);
+
+ // RX config. Use 10-x VC bits, x VP bits, non user cells in channel 0.
+ wr_regw (dev, RX_CONFIG_OFF,
+ DISCARD_UNUSED_VPI_VCI_BITS_SET | NON_USER_CELLS_IN_ONE_CHANNEL | vpi_bits);
+
+ // RX line config
+ wr_regw (dev, RX_LINE_CONFIG_OFF,
+ LOCK_DETECT_ENABLE | FREQUENCY_DETECT_ENABLE | GXTALOUT_SELECT_DIV4);
+
+ // Set the max AAL5 cell count to be just enough to contain the
+ // largest AAL5 frame that the user wants to receive
+ wr_regw (dev, MAX_AAL5_CELL_COUNT_OFF,
+ (max_rx_size + ATM_AAL5_TRAILER + ATM_CELL_PAYLOAD - 1) / ATM_CELL_PAYLOAD);
+
+ // Enable receive
+ wr_regw (dev, RX_CONFIG_OFF, rd_regw (dev, RX_CONFIG_OFF) | RX_ENABLE);
+
+ printk (" control");
+
+ // Drive the OE of the LEDs then turn the green LED on
+ ctrl |= GREEN_LED_OE | YELLOW_LED_OE | GREEN_LED | YELLOW_LED;
+ wr_regl (dev, CONTROL_0_REG, ctrl);
+
+ // Test for a 155-capable card
+
+ if (onefivefive) {
+ // Select 155 mode... make this a choice (or: how do we detect
+ // external line speed and switch?)
+ ctrl |= ATM_LAYER_SELECT;
+ wr_regl (dev, CONTROL_0_REG, ctrl);
+
+ // test SUNI-lite vs SAMBA
+
+ // Register 0x00 in the SUNI will have some of bits 3-7 set, and
+ // they will always be zero for the SAMBA. Ha! Bloody hardware
+ // engineers. It'll never work.
+
+ if (rd_framer (dev, 0) & 0x00f0) {
+ // SUNI
+ printk (" SUNI");
+
+ // Reset, just in case
+ wr_framer (dev, 0x00, 0x0080);
+ wr_framer (dev, 0x00, 0x0000);
+
+ // Configure transmit FIFO
+ wr_framer (dev, 0x63, rd_framer (dev, 0x63) | 0x0002);
+
+ // Set line timed mode
+ wr_framer (dev, 0x05, rd_framer (dev, 0x05) | 0x0001);
+ } else {
+ // SAMBA
+ printk (" SAMBA");
+
+ // Reset, just in case
+ wr_framer (dev, 0, rd_framer (dev, 0) | 0x0001);
+ wr_framer (dev, 0, rd_framer (dev, 0) &~ 0x0001);
+
+ // Turn off diagnostic loopback and enable line-timed mode
+ wr_framer (dev, 0, 0x0002);
+
+ // Turn on transmit outputs
+ wr_framer (dev, 2, 0x0B80);
+ }
+ } else {
+ // Select 25 mode
+ ctrl &= ~ATM_LAYER_SELECT;
+
+ // Madge B154 setup
+ // none required?
+ }
+
+ printk (" LEDs");
+
+ GREEN_LED_ON(dev);
+ YELLOW_LED_ON(dev);
+
+ printk (" ESI=");
+
+ {
+ u16 b = 0;
+ int i;
+ u8 * esi = dev->atm_dev->esi;
+
+ // in the card I have, EEPROM
+ // addresses 0, 1, 2 contain 0
+ // addresess 5, 6 etc. contain ffff
+ // NB: Madge prefix is 00 00 f6 (which is 00 00 6f in Ethernet bit order)
+ // the read_bia routine gets the BIA in Ethernet bit order
+
+ for (i=0; i < ESI_LEN; ++i) {
+ if (i % 2 == 0)
+ b = read_bia (dev, i/2 + 2);
+ else
+ b = b >> 8;
+ esi[i] = b & 0xFF;
+ printk ("%02x", esi[i]);
+ }
+ }
+
+ // Enable RX_Q and ?X_COMPLETE interrupts only
+ wr_regl (dev, INT_ENABLE_REG_OFF, INTERESTING_INTERRUPTS);
+ printk (" IRQ on");
+
+ printk (".\n");
+
+ return onefivefive;
+}
+
+/********** check max_sdu **********/
+
+static int check_max_sdu (hrz_aal aal, struct atm_trafprm * tp, unsigned int max_frame_size) {
+ PRINTD (DBG_FLOW|DBG_QOS, "check_max_sdu");
+
+ switch (aal) {
+ case aal0:
+ if (!(tp->max_sdu)) {
+ PRINTD (DBG_QOS, "defaulting max_sdu");
+ tp->max_sdu = ATM_AAL0_SDU;
+ } else if (tp->max_sdu != ATM_AAL0_SDU) {
+ PRINTD (DBG_QOS|DBG_ERR, "rejecting max_sdu");
+ return -EINVAL;
+ }
+ break;
+ case aal34:
+ if (tp->max_sdu == 0 || tp->max_sdu > ATM_MAX_AAL34_PDU) {
+ PRINTD (DBG_QOS, "%sing max_sdu", tp->max_sdu ? "capp" : "default");
+ tp->max_sdu = ATM_MAX_AAL34_PDU;
+ }
+ break;
+ case aal5:
+ if (tp->max_sdu == 0 || tp->max_sdu > max_frame_size) {
+ PRINTD (DBG_QOS, "%sing max_sdu", tp->max_sdu ? "capp" : "default");
+ tp->max_sdu = max_frame_size;
+ }
+ break;
+ }
+ return 0;
+}
+
+/********** check pcr **********/
+
+// something like this should be part of ATM Linux
+static int atm_pcr_check (struct atm_trafprm * tp, unsigned int pcr) {
+ // we are assuming non-UBR, and non-special values of pcr
+ if (tp->min_pcr == ATM_MAX_PCR)
+ PRINTD (DBG_QOS, "luser gave min_pcr = ATM_MAX_PCR");
+ else if (tp->min_pcr < 0)
+ PRINTD (DBG_QOS, "luser gave negative min_pcr");
+ else if (tp->min_pcr && tp->min_pcr > pcr)
+ PRINTD (DBG_QOS, "pcr less than min_pcr");
+ else
+ // !! max_pcr = UNSPEC (0) is equivalent to max_pcr = MAX (-1)
+ // easier to #define ATM_MAX_PCR 0 and have all rates unsigned?
+ // [this would get rid of next two conditionals]
+ if ((0) && tp->max_pcr == ATM_MAX_PCR)
+ PRINTD (DBG_QOS, "luser gave max_pcr = ATM_MAX_PCR");
+ else if ((tp->max_pcr != ATM_MAX_PCR) && tp->max_pcr < 0)
+ PRINTD (DBG_QOS, "luser gave negative max_pcr");
+ else if (tp->max_pcr && tp->max_pcr != ATM_MAX_PCR && tp->max_pcr < pcr)
+ PRINTD (DBG_QOS, "pcr greater than max_pcr");
+ else {
+ // each limit unspecified or not violated
+ PRINTD (DBG_QOS, "xBR(pcr) OK");
+ return 0;
+ }
+ PRINTD (DBG_QOS, "pcr=%u, tp: min_pcr=%d, pcr=%d, max_pcr=%d",
+ pcr, tp->min_pcr, tp->pcr, tp->max_pcr);
+ return -EINVAL;
+}
+
+/********** open VC **********/
+
+static int hrz_open (struct atm_vcc *atm_vcc)
+{
+ int error;
+ u16 channel;
+
+ struct atm_qos * qos;
+ struct atm_trafprm * txtp;
+ struct atm_trafprm * rxtp;
+
+ hrz_dev * dev = HRZ_DEV(atm_vcc->dev);
+ hrz_vcc vcc;
+ hrz_vcc * vccp; // allocated late
+ short vpi = atm_vcc->vpi;
+ int vci = atm_vcc->vci;
+ PRINTD (DBG_FLOW|DBG_VCC, "hrz_open %x %x", vpi, vci);
+
+#ifdef ATM_VPI_UNSPEC
+ // UNSPEC is deprecated, remove this code eventually
+ if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC) {
+ PRINTK (KERN_WARNING, "rejecting open with unspecified VPI/VCI (deprecated)");
+ return -EINVAL;
+ }
+#endif
+
+ error = vpivci_to_channel (&channel, vpi, vci);
+ if (error) {
+ PRINTD (DBG_WARN|DBG_VCC, "VPI/VCI out of range: %hd/%d", vpi, vci);
+ return error;
+ }
+
+ vcc.channel = channel;
+ // max speed for the moment
+ vcc.tx_rate = 0x0;
+
+ qos = &atm_vcc->qos;
+
+ // check AAL and remember it
+ switch (qos->aal) {
+ case ATM_AAL0:
+ // we would if it were 48 bytes and not 52!
+ PRINTD (DBG_QOS|DBG_VCC, "AAL0");
+ vcc.aal = aal0;
+ break;
+ case ATM_AAL34:
+ // we would if I knew how do the SAR!
+ PRINTD (DBG_QOS|DBG_VCC, "AAL3/4");
+ vcc.aal = aal34;
+ break;
+ case ATM_AAL5:
+ PRINTD (DBG_QOS|DBG_VCC, "AAL5");
+ vcc.aal = aal5;
+ break;
+ default:
+ PRINTD (DBG_QOS|DBG_VCC, "Bad AAL!");
+ return -EINVAL;
+ break;
+ }
+
+ // TX traffic parameters
+
+ // there are two, interrelated problems here: 1. the reservation of
+ // PCR is not a binary choice, we are given bounds and/or a
+ // desirable value; 2. the device is only capable of certain values,
+ // most of which are not integers. It is almost certainly acceptable
+ // to be off by a maximum of 1 to 10 cps.
+
+ // Pragmatic choice: always store an integral PCR as that which has
+ // been allocated, even if we allocate a little (or a lot) less,
+ // after rounding. The actual allocation depends on what we can
+ // manage with our rate selection algorithm. The rate selection
+ // algorithm is given an integral PCR and a tolerance and told
+ // whether it should round the value up or down if the tolerance is
+ // exceeded; it returns: a) the actual rate selected (rounded up to
+ // the nearest integer), b) a bit pattern to feed to the timer
+ // register, and c) a failure value if no applicable rate exists.
+
+ // Part of the job is done by atm_pcr_goal which gives us a PCR
+ // specification which says: EITHER grab the maximum available PCR
+ // (and perhaps a lower bound which we musn't pass), OR grab this
+ // amount, rounding down if you have to (and perhaps a lower bound
+ // which we musn't pass) OR grab this amount, rounding up if you
+ // have to (and perhaps an upper bound which we musn't pass). If any
+ // bounds ARE passed we fail. Note that rounding is only rounding to
+ // match device limitations, we do not round down to satisfy
+ // bandwidth availability even if this would not violate any given
+ // lower bound.
+
+ // Note: telephony = 64kb/s = 48 byte cell payload @ 500/3 cells/s
+ // (say) so this is not even a binary fixpoint cell rate (but this
+ // device can do it). To avoid this sort of hassle we use a
+ // tolerance parameter (currently fixed at 10 cps).
+
+ PRINTD (DBG_QOS, "TX:");
+
+ txtp = &qos->txtp;
+
+ // set up defaults for no traffic
+ vcc.tx_rate = 0;
+ // who knows what would actually happen if you try and send on this?
+ vcc.tx_xbr_bits = IDLE_RATE_TYPE;
+ vcc.tx_pcr_bits = CLOCK_DISABLE;
+#if 0
+ vcc.tx_scr_bits = CLOCK_DISABLE;
+ vcc.tx_bucket_bits = 0;
+#endif
+
+ if (txtp->traffic_class != ATM_NONE) {
+ error = check_max_sdu (vcc.aal, txtp, max_tx_size);
+ if (error) {
+ PRINTD (DBG_QOS, "TX max_sdu check failed");
+ return error;
+ }
+
+ switch (txtp->traffic_class) {
+ case ATM_UBR: {
+ // we take "the PCR" as a rate-cap
+ // not reserved
+ vcc.tx_rate = 0;
+ make_rate (dev, 1<<30, round_nearest, &vcc.tx_pcr_bits, NULL);
+ vcc.tx_xbr_bits = ABR_RATE_TYPE;
+ break;
+ }
+#if 0
+ case ATM_ABR: {
+ // reserve min, allow up to max
+ vcc.tx_rate = 0; // ?
+ make_rate (dev, 1<<30, round_nearest, &vcc.tx_pcr_bits, 0);
+ vcc.tx_xbr_bits = ABR_RATE_TYPE;
+ break;
+ }
+#endif
+ case ATM_CBR: {
+ int pcr = atm_pcr_goal (txtp);
+ rounding r;
+ if (!pcr) {
+ // down vs. up, remaining bandwidth vs. unlimited bandwidth!!
+ // should really have: once someone gets unlimited bandwidth
+ // that no more non-UBR channels can be opened until the
+ // unlimited one closes?? For the moment, round_down means
+ // greedy people actually get something and not nothing
+ r = round_down;
+ // slight race (no locking) here so we may get -EAGAIN
+ // later; the greedy bastards would deserve it :)
+ PRINTD (DBG_QOS, "snatching all remaining TX bandwidth");
+ pcr = dev->tx_avail;
+ } else if (pcr < 0) {
+ r = round_down;
+ pcr = -pcr;
+ } else {
+ r = round_up;
+ }
+ error = make_rate_with_tolerance (dev, pcr, r, 10,
+ &vcc.tx_pcr_bits, &vcc.tx_rate);
+ if (error) {
+ PRINTD (DBG_QOS, "could not make rate from TX PCR");
+ return error;
+ }
+ // not really clear what further checking is needed
+ error = atm_pcr_check (txtp, vcc.tx_rate);
+ if (error) {
+ PRINTD (DBG_QOS, "TX PCR failed consistency check");
+ return error;
+ }
+ vcc.tx_xbr_bits = CBR_RATE_TYPE;
+ break;
+ }
+#if 0
+ case ATM_VBR: {
+ int pcr = atm_pcr_goal (txtp);
+ // int scr = atm_scr_goal (txtp);
+ int scr = pcr/2; // just for fun
+ unsigned int mbs = 60; // just for fun
+ rounding pr;
+ rounding sr;
+ unsigned int bucket;
+ if (!pcr) {
+ pr = round_nearest;
+ pcr = 1<<30;
+ } else if (pcr < 0) {
+ pr = round_down;
+ pcr = -pcr;
+ } else {
+ pr = round_up;
+ }
+ error = make_rate_with_tolerance (dev, pcr, pr, 10,
+ &vcc.tx_pcr_bits, 0);
+ if (!scr) {
+ // see comments for PCR with CBR above
+ sr = round_down;
+ // slight race (no locking) here so we may get -EAGAIN
+ // later; the greedy bastards would deserve it :)
+ PRINTD (DBG_QOS, "snatching all remaining TX bandwidth");
+ scr = dev->tx_avail;
+ } else if (scr < 0) {
+ sr = round_down;
+ scr = -scr;
+ } else {
+ sr = round_up;
+ }
+ error = make_rate_with_tolerance (dev, scr, sr, 10,
+ &vcc.tx_scr_bits, &vcc.tx_rate);
+ if (error) {
+ PRINTD (DBG_QOS, "could not make rate from TX SCR");
+ return error;
+ }
+ // not really clear what further checking is needed
+ // error = atm_scr_check (txtp, vcc.tx_rate);
+ if (error) {
+ PRINTD (DBG_QOS, "TX SCR failed consistency check");
+ return error;
+ }
+ // bucket calculations (from a piece of paper...) cell bucket
+ // capacity must be largest integer smaller than m(p-s)/p + 1
+ // where m = max burst size, p = pcr, s = scr
+ bucket = mbs*(pcr-scr)/pcr;
+ if (bucket*pcr != mbs*(pcr-scr))
+ bucket += 1;
+ if (bucket > BUCKET_MAX_SIZE) {
+ PRINTD (DBG_QOS, "shrinking bucket from %u to %u",
+ bucket, BUCKET_MAX_SIZE);
+ bucket = BUCKET_MAX_SIZE;
+ }
+ vcc.tx_xbr_bits = VBR_RATE_TYPE;
+ vcc.tx_bucket_bits = bucket;
+ break;
+ }
+#endif
+ default: {
+ PRINTD (DBG_QOS, "unsupported TX traffic class");
+ return -EINVAL;
+ break;
+ }
+ }
+ }
+
+ // RX traffic parameters
+
+ PRINTD (DBG_QOS, "RX:");
+
+ rxtp = &qos->rxtp;
+
+ // set up defaults for no traffic
+ vcc.rx_rate = 0;
+
+ if (rxtp->traffic_class != ATM_NONE) {
+ error = check_max_sdu (vcc.aal, rxtp, max_rx_size);
+ if (error) {
+ PRINTD (DBG_QOS, "RX max_sdu check failed");
+ return error;
+ }
+ switch (rxtp->traffic_class) {
+ case ATM_UBR: {
+ // not reserved
+ break;
+ }
+#if 0
+ case ATM_ABR: {
+ // reserve min
+ vcc.rx_rate = 0; // ?
+ break;
+ }
+#endif
+ case ATM_CBR: {
+ int pcr = atm_pcr_goal (rxtp);
+ if (!pcr) {
+ // slight race (no locking) here so we may get -EAGAIN
+ // later; the greedy bastards would deserve it :)
+ PRINTD (DBG_QOS, "snatching all remaining RX bandwidth");
+ pcr = dev->rx_avail;
+ } else if (pcr < 0) {
+ pcr = -pcr;
+ }
+ vcc.rx_rate = pcr;
+ // not really clear what further checking is needed
+ error = atm_pcr_check (rxtp, vcc.rx_rate);
+ if (error) {
+ PRINTD (DBG_QOS, "RX PCR failed consistency check");
+ return error;
+ }
+ break;
+ }
+#if 0
+ case ATM_VBR: {
+ // int scr = atm_scr_goal (rxtp);
+ int scr = 1<<16; // just for fun
+ if (!scr) {
+ // slight race (no locking) here so we may get -EAGAIN
+ // later; the greedy bastards would deserve it :)
+ PRINTD (DBG_QOS, "snatching all remaining RX bandwidth");
+ scr = dev->rx_avail;
+ } else if (scr < 0) {
+ scr = -scr;
+ }
+ vcc.rx_rate = scr;
+ // not really clear what further checking is needed
+ // error = atm_scr_check (rxtp, vcc.rx_rate);
+ if (error) {
+ PRINTD (DBG_QOS, "RX SCR failed consistency check");
+ return error;
+ }
+ break;
+ }
+#endif
+ default: {
+ PRINTD (DBG_QOS, "unsupported RX traffic class");
+ return -EINVAL;
+ break;
+ }
+ }
+ }
+
+
+ // late abort useful for diagnostics
+ if (vcc.aal != aal5) {
+ PRINTD (DBG_QOS, "AAL not supported");
+ return -EINVAL;
+ }
+
+ // get space for our vcc stuff and copy parameters into it
+ vccp = kmalloc (sizeof(hrz_vcc), GFP_KERNEL);
+ if (!vccp) {
+ PRINTK (KERN_ERR, "out of memory!");
+ return -ENOMEM;
+ }
+ *vccp = vcc;
+
+ // clear error and grab cell rate resource lock
+ error = 0;
+ spin_lock (&dev->rate_lock);
+
+ if (vcc.tx_rate > dev->tx_avail) {
+ PRINTD (DBG_QOS, "not enough TX PCR left");
+ error = -EAGAIN;
+ }
+
+ if (vcc.rx_rate > dev->rx_avail) {
+ PRINTD (DBG_QOS, "not enough RX PCR left");
+ error = -EAGAIN;
+ }
+
+ if (!error) {
+ // really consume cell rates
+ dev->tx_avail -= vcc.tx_rate;
+ dev->rx_avail -= vcc.rx_rate;
+ PRINTD (DBG_QOS|DBG_VCC, "reserving %u TX PCR and %u RX PCR",
+ vcc.tx_rate, vcc.rx_rate);
+ }
+
+ // release lock and exit on error
+ spin_unlock (&dev->rate_lock);
+ if (error) {
+ PRINTD (DBG_QOS|DBG_VCC, "insufficient cell rate resources");
+ kfree (vccp);
+ return error;
+ }
+
+ // this is "immediately before allocating the connection identifier
+ // in hardware" - so long as the next call does not fail :)
+ set_bit(ATM_VF_ADDR,&atm_vcc->flags);
+
+ // any errors here are very serious and should never occur
+
+ if (rxtp->traffic_class != ATM_NONE) {
+ if (dev->rxer[channel]) {
+ PRINTD (DBG_ERR|DBG_VCC, "VC already open for RX");
+ error = -EBUSY;
+ }
+ if (!error)
+ error = hrz_open_rx (dev, channel);
+ if (error) {
+ kfree (vccp);
+ return error;
+ }
+ // this link allows RX frames through
+ dev->rxer[channel] = atm_vcc;
+ }
+
+ // success, set elements of atm_vcc
+ atm_vcc->dev_data = (void *) vccp;
+
+ // indicate readiness
+ set_bit(ATM_VF_READY,&atm_vcc->flags);
+
+ return 0;
+}
+
+/********** close VC **********/
+
+static void hrz_close (struct atm_vcc * atm_vcc) {
+ hrz_dev * dev = HRZ_DEV(atm_vcc->dev);
+ hrz_vcc * vcc = HRZ_VCC(atm_vcc);
+ u16 channel = vcc->channel;
+ PRINTD (DBG_VCC|DBG_FLOW, "hrz_close");
+
+ // indicate unreadiness
+ clear_bit(ATM_VF_READY,&atm_vcc->flags);
+
+ if (atm_vcc->qos.txtp.traffic_class != ATM_NONE) {
+ unsigned int i;
+
+ // let any TX on this channel that has started complete
+ // no restart, just keep trying
+ while (tx_hold (dev))
+ ;
+ // remove record of any tx_channel having been setup for this channel
+ for (i = 0; i < TX_CHANS; ++i)
+ if (dev->tx_channel_record[i] == channel) {
+ dev->tx_channel_record[i] = -1;
+ break;
+ }
+ if (dev->last_vc == channel)
+ dev->tx_last = -1;
+ tx_release (dev);
+ }
+
+ if (atm_vcc->qos.rxtp.traffic_class != ATM_NONE) {
+ // disable RXing - it tries quite hard
+ hrz_close_rx (dev, channel);
+ // forget the vcc - no more skbs will be pushed
+ if (atm_vcc != dev->rxer[channel])
+ PRINTK (KERN_ERR, "%s atm_vcc=%p rxer[channel]=%p",
+ "arghhh! we're going to die!",
+ atm_vcc, dev->rxer[channel]);
+ dev->rxer[channel] = NULL;
+ }
+
+ // atomically release our rate reservation
+ spin_lock (&dev->rate_lock);
+ PRINTD (DBG_QOS|DBG_VCC, "releasing %u TX PCR and %u RX PCR",
+ vcc->tx_rate, vcc->rx_rate);
+ dev->tx_avail += vcc->tx_rate;
+ dev->rx_avail += vcc->rx_rate;
+ spin_unlock (&dev->rate_lock);
+
+ // free our structure
+ kfree (vcc);
+ // say the VPI/VCI is free again
+ clear_bit(ATM_VF_ADDR,&atm_vcc->flags);
+}
+
+#if 0
+static int hrz_getsockopt (struct atm_vcc * atm_vcc, int level, int optname,
+ void *optval, int optlen) {
+ hrz_dev * dev = HRZ_DEV(atm_vcc->dev);
+ PRINTD (DBG_FLOW|DBG_VCC, "hrz_getsockopt");
+ switch (level) {
+ case SOL_SOCKET:
+ switch (optname) {
+// case SO_BCTXOPT:
+// break;
+// case SO_BCRXOPT:
+// break;
+ default:
+ return -ENOPROTOOPT;
+ break;
+ };
+ break;
+ }
+ return -EINVAL;
+}
+
+static int hrz_setsockopt (struct atm_vcc * atm_vcc, int level, int optname,
+ void *optval, int optlen) {
+ hrz_dev * dev = HRZ_DEV(atm_vcc->dev);
+ PRINTD (DBG_FLOW|DBG_VCC, "hrz_setsockopt");
+ switch (level) {
+ case SOL_SOCKET:
+ switch (optname) {
+// case SO_BCTXOPT:
+// break;
+// case SO_BCRXOPT:
+// break;
+ default:
+ return -ENOPROTOOPT;
+ break;
+ };
+ break;
+ }
+ return -EINVAL;
+}
+#endif
+
+#if 0
+static int hrz_ioctl (struct atm_dev * atm_dev, unsigned int cmd, void *arg) {
+ hrz_dev * dev = HRZ_DEV(atm_dev);
+ PRINTD (DBG_FLOW, "hrz_ioctl");
+ return -1;
+}
+
+unsigned char hrz_phy_get (struct atm_dev * atm_dev, unsigned long addr) {
+ hrz_dev * dev = HRZ_DEV(atm_dev);
+ PRINTD (DBG_FLOW, "hrz_phy_get");
+ return 0;
+}
+
+static void hrz_phy_put (struct atm_dev * atm_dev, unsigned char value,
+ unsigned long addr) {
+ hrz_dev * dev = HRZ_DEV(atm_dev);
+ PRINTD (DBG_FLOW, "hrz_phy_put");
+}
+
+static int hrz_change_qos (struct atm_vcc * atm_vcc, struct atm_qos *qos, int flgs) {
+ hrz_dev * dev = HRZ_DEV(vcc->dev);
+ PRINTD (DBG_FLOW, "hrz_change_qos");
+ return -1;
+}
+#endif
+
+/********** proc file contents **********/
+
+static int hrz_proc_read (struct atm_dev * atm_dev, loff_t * pos, char * page) {
+ hrz_dev * dev = HRZ_DEV(atm_dev);
+ int left = *pos;
+ PRINTD (DBG_FLOW, "hrz_proc_read");
+
+ /* more diagnostics here? */
+
+#if 0
+ if (!left--) {
+ unsigned int count = sprintf (page, "vbr buckets:");
+ unsigned int i;
+ for (i = 0; i < TX_CHANS; ++i)
+ count += sprintf (page, " %u/%u",
+ query_tx_channel_config (dev, i, BUCKET_FULLNESS_ACCESS),
+ query_tx_channel_config (dev, i, BUCKET_CAPACITY_ACCESS));
+ count += sprintf (page+count, ".\n");
+ return count;
+ }
+#endif
+
+ if (!left--)
+ return sprintf (page,
+ "cells: TX %lu, RX %lu, HEC errors %lu, unassigned %lu.\n",
+ dev->tx_cell_count, dev->rx_cell_count,
+ dev->hec_error_count, dev->unassigned_cell_count);
+
+ if (!left--)
+ return sprintf (page,
+ "free cell buffers: TX %hu, RX %hu+%hu.\n",
+ rd_regw (dev, TX_FREE_BUFFER_COUNT_OFF),
+ rd_regw (dev, RX_FREE_BUFFER_COUNT_OFF),
+ dev->noof_spare_buffers);
+
+ if (!left--)
+ return sprintf (page,
+ "cps remaining: TX %u, RX %u\n",
+ dev->tx_avail, dev->rx_avail);
+
+ return 0;
+}
+
+static const struct atmdev_ops hrz_ops = {
+ .open = hrz_open,
+ .close = hrz_close,
+ .send = hrz_send,
+ .proc_read = hrz_proc_read,
+ .owner = THIS_MODULE,
+};
+
+static int __devinit hrz_probe(struct pci_dev *pci_dev, const struct pci_device_id *pci_ent)
+{
+ hrz_dev * dev;
+ int err = 0;
+
+ // adapter slot free, read resources from PCI configuration space
+ u32 iobase = pci_resource_start (pci_dev, 0);
+ u32 * membase = bus_to_virt (pci_resource_start (pci_dev, 1));
+ unsigned int irq;
+ unsigned char lat;
+
+ PRINTD (DBG_FLOW, "hrz_probe");
+
+ if (pci_enable_device(pci_dev))
+ return -EINVAL;
+
+ /* XXX DEV_LABEL is a guess */
+ if (!request_region(iobase, HRZ_IO_EXTENT, DEV_LABEL)) {
+ return -EINVAL;
+ goto out_disable;
+ }
+
+ dev = kmalloc(sizeof(hrz_dev), GFP_KERNEL);
+ if (!dev) {
+ // perhaps we should be nice: deregister all adapters and abort?
+ PRINTD(DBG_ERR, "out of memory");
+ err = -ENOMEM;
+ goto out_release;
+ }
+
+ memset(dev, 0, sizeof(hrz_dev));
+
+ pci_set_drvdata(pci_dev, dev);
+
+ // grab IRQ and install handler - move this someplace more sensible
+ irq = pci_dev->irq;
+ if (request_irq(irq,
+ interrupt_handler,
+ SA_SHIRQ, /* irqflags guess */
+ DEV_LABEL, /* name guess */
+ dev)) {
+ PRINTD(DBG_WARN, "request IRQ failed!");
+ err = -EINVAL;
+ goto out_free;
+ }
+
+ PRINTD(DBG_INFO, "found Madge ATM adapter (hrz) at: IO %x, IRQ %u, MEM %p",
+ iobase, irq, membase);
+
+ dev->atm_dev = atm_dev_register(DEV_LABEL, &hrz_ops, -1, NULL);
+ if (!(dev->atm_dev)) {
+ PRINTD(DBG_ERR, "failed to register Madge ATM adapter");
+ err = -EINVAL;
+ goto out_free_irq;
+ }
+
+ PRINTD(DBG_INFO, "registered Madge ATM adapter (no. %d) (%p) at %p",
+ dev->atm_dev->number, dev, dev->atm_dev);
+ dev->atm_dev->dev_data = (void *) dev;
+ dev->pci_dev = pci_dev;
+
+ // enable bus master accesses
+ pci_set_master(pci_dev);
+
+ // frobnicate latency (upwards, usually)
+ pci_read_config_byte(pci_dev, PCI_LATENCY_TIMER, &lat);
+ if (pci_lat) {
+ PRINTD(DBG_INFO, "%s PCI latency timer from %hu to %hu",
+ "changing", lat, pci_lat);
+ pci_write_config_byte(pci_dev, PCI_LATENCY_TIMER, pci_lat);
+ } else if (lat < MIN_PCI_LATENCY) {
+ PRINTK(KERN_INFO, "%s PCI latency timer from %hu to %hu",
+ "increasing", lat, MIN_PCI_LATENCY);
+ pci_write_config_byte(pci_dev, PCI_LATENCY_TIMER, MIN_PCI_LATENCY);
+ }
+
+ dev->iobase = iobase;
+ dev->irq = irq;
+ dev->membase = membase;
+
+ dev->rx_q_entry = dev->rx_q_reset = &memmap->rx_q_entries[0];
+ dev->rx_q_wrap = &memmap->rx_q_entries[RX_CHANS-1];
+
+ // these next three are performance hacks
+ dev->last_vc = -1;
+ dev->tx_last = -1;
+ dev->tx_idle = 0;
+
+ dev->tx_regions = 0;
+ dev->tx_bytes = 0;
+ dev->tx_skb = NULL;
+ dev->tx_iovec = NULL;
+
+ dev->tx_cell_count = 0;
+ dev->rx_cell_count = 0;
+ dev->hec_error_count = 0;
+ dev->unassigned_cell_count = 0;
+
+ dev->noof_spare_buffers = 0;
+
+ {
+ unsigned int i;
+ for (i = 0; i < TX_CHANS; ++i)
+ dev->tx_channel_record[i] = -1;
+ }
+
+ dev->flags = 0;
+
+ // Allocate cell rates and remember ASIC version
+ // Fibre: ATM_OC3_PCR = 1555200000/8/270*260/53 - 29/53
+ // Copper: (WRONG) we want 6 into the above, close to 25Mb/s
+ // Copper: (plagarise!) 25600000/8/270*260/53 - n/53
+
+ if (hrz_init(dev)) {
+ // to be really pedantic, this should be ATM_OC3c_PCR
+ dev->tx_avail = ATM_OC3_PCR;
+ dev->rx_avail = ATM_OC3_PCR;
+ set_bit(ultra, &dev->flags); // NOT "|= ultra" !
+ } else {
+ dev->tx_avail = ((25600000/8)*26)/(27*53);
+ dev->rx_avail = ((25600000/8)*26)/(27*53);
+ PRINTD(DBG_WARN, "Buggy ASIC: no TX bus-mastering.");
+ }
+
+ // rate changes spinlock
+ spin_lock_init(&dev->rate_lock);
+
+ // on-board memory access spinlock; we want atomic reads and
+ // writes to adapter memory (handles IRQ and SMP)
+ spin_lock_init(&dev->mem_lock);
+
+ init_waitqueue_head(&dev->tx_queue);
+
+ // vpi in 0..4, vci in 6..10
+ dev->atm_dev->ci_range.vpi_bits = vpi_bits;
+ dev->atm_dev->ci_range.vci_bits = 10-vpi_bits;
+
+ init_timer(&dev->housekeeping);
+ dev->housekeeping.function = do_housekeeping;
+ dev->housekeeping.data = (unsigned long) dev;
+ mod_timer(&dev->housekeeping, jiffies);
+
+out:
+ return err;
+
+out_free_irq:
+ free_irq(dev->irq, dev);
+out_free:
+ kfree(dev);
+out_release:
+ release_region(iobase, HRZ_IO_EXTENT);
+out_disable:
+ pci_disable_device(pci_dev);
+ goto out;
+}
+
+static void __devexit hrz_remove_one(struct pci_dev *pci_dev)
+{
+ hrz_dev *dev;
+
+ dev = pci_get_drvdata(pci_dev);
+
+ PRINTD(DBG_INFO, "closing %p (atm_dev = %p)", dev, dev->atm_dev);
+ del_timer_sync(&dev->housekeeping);
+ hrz_reset(dev);
+ atm_dev_deregister(dev->atm_dev);
+ free_irq(dev->irq, dev);
+ release_region(dev->iobase, HRZ_IO_EXTENT);
+ kfree(dev);
+
+ pci_disable_device(pci_dev);
+}
+
+static void __init hrz_check_args (void) {
+#ifdef DEBUG_HORIZON
+ PRINTK (KERN_NOTICE, "debug bitmap is %hx", debug &= DBG_MASK);
+#else
+ if (debug)
+ PRINTK (KERN_NOTICE, "no debug support in this image");
+#endif
+
+ if (vpi_bits > HRZ_MAX_VPI)
+ PRINTK (KERN_ERR, "vpi_bits has been limited to %hu",
+ vpi_bits = HRZ_MAX_VPI);
+
+ if (max_tx_size < 0 || max_tx_size > TX_AAL5_LIMIT)
+ PRINTK (KERN_NOTICE, "max_tx_size has been limited to %hu",
+ max_tx_size = TX_AAL5_LIMIT);
+
+ if (max_rx_size < 0 || max_rx_size > RX_AAL5_LIMIT)
+ PRINTK (KERN_NOTICE, "max_rx_size has been limited to %hu",
+ max_rx_size = RX_AAL5_LIMIT);
+
+ return;
+}
+
+MODULE_AUTHOR(maintainer_string);
+MODULE_DESCRIPTION(description_string);
+MODULE_LICENSE("GPL");
+module_param(debug, ushort, 0644);
+module_param(vpi_bits, ushort, 0);
+module_param(max_tx_size, int, 0);
+module_param(max_rx_size, int, 0);
+module_param(pci_lat, byte, 0);
+MODULE_PARM_DESC(debug, "debug bitmap, see .h file");
+MODULE_PARM_DESC(vpi_bits, "number of bits (0..4) to allocate to VPIs");
+MODULE_PARM_DESC(max_tx_size, "maximum size of TX AAL5 frames");
+MODULE_PARM_DESC(max_rx_size, "maximum size of RX AAL5 frames");
+MODULE_PARM_DESC(pci_lat, "PCI latency in bus cycles");
+
+static struct pci_device_id hrz_pci_tbl[] = {
+ { PCI_VENDOR_ID_MADGE, PCI_DEVICE_ID_MADGE_HORIZON, PCI_ANY_ID, PCI_ANY_ID,
+ 0, 0, 0 },
+ { 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, hrz_pci_tbl);
+
+static struct pci_driver hrz_driver = {
+ .name = "horizon",
+ .probe = hrz_probe,
+ .remove = __devexit_p(hrz_remove_one),
+ .id_table = hrz_pci_tbl,
+};
+
+/********** module entry **********/
+
+static int __init hrz_module_init (void) {
+ // sanity check - cast is needed since printk does not support %Zu
+ if (sizeof(struct MEMMAP) != 128*1024/4) {
+ PRINTK (KERN_ERR, "Fix struct MEMMAP (is %lu fakewords).",
+ (unsigned long) sizeof(struct MEMMAP));
+ return -ENOMEM;
+ }
+
+ show_version();
+
+ // check arguments
+ hrz_check_args();
+
+ // get the juice
+ return pci_register_driver(&hrz_driver);
+}
+
+/********** module exit **********/
+
+static void __exit hrz_module_exit (void) {
+ PRINTD (DBG_FLOW, "cleanup_module");
+
+ return pci_unregister_driver(&hrz_driver);
+}
+
+module_init(hrz_module_init);
+module_exit(hrz_module_exit);