From 1ce849c755342b236fc6236dfe39dbbf536b64b6 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Tue, 20 Jul 2021 05:27:54 +0200 Subject: x86/PCI: Add support for the ALi M1487 (IBC) PIRQ router The ALi M1487 ISA Bus Controller (IBC), a part of the ALi FinALi 486 chipset, implements PCI interrupt steering with a PIRQ router[1] in the form of four 4-bit mappings, spread across two PCI INTx Routing Table Mapping Registers, available in the port I/O space accessible indirectly via the index/data register pair at 0x22/0x23, located at indices 0x42 and 0x43 for the INT1/INT2 and INT3/INT4 lines respectively. Additionally there is a separate PCI INTx Sensitivity Register at index 0x44 in the same port I/O space, whose bits 3:0 select the trigger mode for INT[4:1] lines respectively[2]. Manufacturer's documentation says that this register has to be set consistently with the relevant ELCR register[3]. Add a router-specific hook then and use it to handle this register. Accesses to the port I/O space concerned here need to be unlocked by writing the value of 0xc5 to the Lock Register at index 0x03 beforehand[4]. Do so then and then lock access after use for safety. The IBC is implemented as a peer bridge on the host bus rather than a southbridge on PCI and therefore it does not itself appear in the PCI configuration space. It is complemented by the M1489 Cache-Memory PCI Controller (CMP) host-to-PCI bridge, so use that device's identification for determining the presence of the IBC. References: [1] "M1489/M1487: 486 PCI Chip Set", Version 1.2, Acer Laboratories Inc., July 1997, Section 4: "Configuration Registers", pp. 76-77 [2] same, p. 77 [3] same, Section 5: "M1489/M1487 Software Programming Guide", pp. 99-100 [4] same, Section 4: "Configuration Registers", p. 37 Signed-off-by: Maciej W. Rozycki Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/alpine.DEB.2.21.2107191702020.9461@angie.orcam.me.uk --- arch/x86/pci/irq.c | 154 +++++++++++++++++++++++++++++++++++++++++++++++- include/linux/pci_ids.h | 1 + 2 files changed, 153 insertions(+), 2 deletions(-) diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c index d3a73f9335e1..1bccbc419630 100644 --- a/arch/x86/pci/irq.c +++ b/arch/x86/pci/irq.c @@ -13,9 +13,12 @@ #include #include #include +#include #include #include #include + +#include #include #define PIRQ_SIGNATURE (('$' << 0) + ('P' << 8) + ('I' << 16) + ('R' << 24)) @@ -47,6 +50,8 @@ struct irq_router { int (*get)(struct pci_dev *router, struct pci_dev *dev, int pirq); int (*set)(struct pci_dev *router, struct pci_dev *dev, int pirq, int new); + int (*lvl)(struct pci_dev *router, struct pci_dev *dev, int pirq, + int irq); }; struct irq_router_handler { @@ -169,6 +174,139 @@ void elcr_set_level_irq(unsigned int irq) } } +/* + * PIRQ routing for the M1487 ISA Bus Controller (IBC) ASIC used + * with the ALi FinALi 486 chipset. The IBC is not decoded in the + * PCI configuration space, so we identify it by the accompanying + * M1489 Cache-Memory PCI Controller (CMP) ASIC. + * + * There are four 4-bit mappings provided, spread across two PCI + * INTx Routing Table Mapping Registers, available in the port I/O + * space accessible indirectly via the index/data register pair at + * 0x22/0x23, located at indices 0x42 and 0x43 for the INT1/INT2 + * and INT3/INT4 lines respectively. The INT1/INT3 and INT2/INT4 + * lines are mapped in the low and the high 4-bit nibble of the + * corresponding register as follows: + * + * 0000 : Disabled + * 0001 : IRQ9 + * 0010 : IRQ3 + * 0011 : IRQ10 + * 0100 : IRQ4 + * 0101 : IRQ5 + * 0110 : IRQ7 + * 0111 : IRQ6 + * 1000 : Reserved + * 1001 : IRQ11 + * 1010 : Reserved + * 1011 : IRQ12 + * 1100 : Reserved + * 1101 : IRQ14 + * 1110 : Reserved + * 1111 : IRQ15 + * + * In addition to the usual ELCR register pair there is a separate + * PCI INTx Sensitivity Register at index 0x44 in the same port I/O + * space, whose bits 3:0 select the trigger mode for INT[4:1] lines + * respectively. Any bit set to 1 causes interrupts coming on the + * corresponding line to be passed to ISA as edge-triggered and + * otherwise they are passed as level-triggered. Manufacturer's + * documentation says this register has to be set consistently with + * the relevant ELCR register. + * + * Accesses to the port I/O space concerned here need to be unlocked + * by writing the value of 0xc5 to the Lock Register at index 0x03 + * beforehand. Any other value written to said register prevents + * further accesses from reaching the register file, except for the + * Lock Register being written with 0xc5 again. + * + * References: + * + * "M1489/M1487: 486 PCI Chip Set", Version 1.2, Acer Laboratories + * Inc., July 1997 + */ + +#define PC_CONF_FINALI_LOCK 0x03u +#define PC_CONF_FINALI_PCI_INTX_RT1 0x42u +#define PC_CONF_FINALI_PCI_INTX_RT2 0x43u +#define PC_CONF_FINALI_PCI_INTX_SENS 0x44u + +#define PC_CONF_FINALI_LOCK_KEY 0xc5u + +static u8 read_pc_conf_nybble(u8 base, u8 index) +{ + u8 reg = base + (index >> 1); + u8 x; + + x = pc_conf_get(reg); + return index & 1 ? x >> 4 : x & 0xf; +} + +static void write_pc_conf_nybble(u8 base, u8 index, u8 val) +{ + u8 reg = base + (index >> 1); + u8 x; + + x = pc_conf_get(reg); + x = index & 1 ? (x & 0x0f) | (val << 4) : (x & 0xf0) | val; + pc_conf_set(reg, x); +} + +static int pirq_finali_get(struct pci_dev *router, struct pci_dev *dev, + int pirq) +{ + static const u8 irqmap[16] = { + 0, 9, 3, 10, 4, 5, 7, 6, 0, 11, 0, 12, 0, 14, 0, 15 + }; + unsigned long flags; + u8 x; + + raw_spin_lock_irqsave(&pc_conf_lock, flags); + pc_conf_set(PC_CONF_FINALI_LOCK, PC_CONF_FINALI_LOCK_KEY); + x = irqmap[read_pc_conf_nybble(PC_CONF_FINALI_PCI_INTX_RT1, pirq - 1)]; + pc_conf_set(PC_CONF_FINALI_LOCK, 0); + raw_spin_unlock_irqrestore(&pc_conf_lock, flags); + return x; +} + +static int pirq_finali_set(struct pci_dev *router, struct pci_dev *dev, + int pirq, int irq) +{ + static const u8 irqmap[16] = { + 0, 0, 0, 2, 4, 5, 7, 6, 0, 1, 3, 9, 11, 0, 13, 15 + }; + u8 val = irqmap[irq]; + unsigned long flags; + + if (!val) + return 0; + + raw_spin_lock_irqsave(&pc_conf_lock, flags); + pc_conf_set(PC_CONF_FINALI_LOCK, PC_CONF_FINALI_LOCK_KEY); + write_pc_conf_nybble(PC_CONF_FINALI_PCI_INTX_RT1, pirq - 1, val); + pc_conf_set(PC_CONF_FINALI_LOCK, 0); + raw_spin_unlock_irqrestore(&pc_conf_lock, flags); + return 1; +} + +static int pirq_finali_lvl(struct pci_dev *router, struct pci_dev *dev, + int pirq, int irq) +{ + u8 mask = ~(1u << (pirq - 1)); + unsigned long flags; + u8 trig; + + elcr_set_level_irq(irq); + raw_spin_lock_irqsave(&pc_conf_lock, flags); + pc_conf_set(PC_CONF_FINALI_LOCK, PC_CONF_FINALI_LOCK_KEY); + trig = pc_conf_get(PC_CONF_FINALI_PCI_INTX_SENS); + trig &= mask; + pc_conf_set(PC_CONF_FINALI_PCI_INTX_SENS, trig); + pc_conf_set(PC_CONF_FINALI_LOCK, 0); + raw_spin_unlock_irqrestore(&pc_conf_lock, flags); + return 1; +} + /* * Common IRQ routing practice: nibbles in config space, * offset by some magic constant. @@ -745,6 +883,12 @@ static __init int ite_router_probe(struct irq_router *r, struct pci_dev *router, static __init int ali_router_probe(struct irq_router *r, struct pci_dev *router, u16 device) { switch (device) { + case PCI_DEVICE_ID_AL_M1489: + r->name = "FinALi"; + r->get = pirq_finali_get; + r->set = pirq_finali_set; + r->lvl = pirq_finali_lvl; + return 1; case PCI_DEVICE_ID_AL_M1533: case PCI_DEVICE_ID_AL_M1563: r->name = "ALI"; @@ -968,11 +1112,17 @@ static int pcibios_lookup_irq(struct pci_dev *dev, int assign) } else if (r->get && (irq = r->get(pirq_router_dev, dev, pirq)) && \ ((!(pci_probe & PCI_USE_PIRQ_MASK)) || ((1 << irq) & mask))) { msg = "found"; - elcr_set_level_irq(irq); + if (r->lvl) + r->lvl(pirq_router_dev, dev, pirq, irq); + else + elcr_set_level_irq(irq); } else if (newirq && r->set && (dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) { if (r->set(pirq_router_dev, dev, pirq, newirq)) { - elcr_set_level_irq(newirq); + if (r->lvl) + r->lvl(pirq_router_dev, dev, pirq, newirq); + else + elcr_set_level_irq(newirq); msg = "assigned"; irq = newirq; } diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h index 4bac1831de80..256fa4d7e86c 100644 --- a/include/linux/pci_ids.h +++ b/include/linux/pci_ids.h @@ -1121,6 +1121,7 @@ #define PCI_DEVICE_ID_3COM_3CR990SVR 0x990a #define PCI_VENDOR_ID_AL 0x10b9 +#define PCI_DEVICE_ID_AL_M1489 0x1489 #define PCI_DEVICE_ID_AL_M1533 0x1533 #define PCI_DEVICE_ID_AL_M1535 0x1535 #define PCI_DEVICE_ID_AL_M1541 0x1541 -- cgit