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path: root/drivers/pci/cadence/pcie-cadence-ep.c
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Diffstat (limited to 'drivers/pci/cadence/pcie-cadence-ep.c')
-rw-r--r--drivers/pci/cadence/pcie-cadence-ep.c542
1 files changed, 542 insertions, 0 deletions
diff --git a/drivers/pci/cadence/pcie-cadence-ep.c b/drivers/pci/cadence/pcie-cadence-ep.c
new file mode 100644
index 000000000000..3c3a97743453
--- /dev/null
+++ b/drivers/pci/cadence/pcie-cadence-ep.c
@@ -0,0 +1,542 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2017 Cadence
+// Cadence PCIe endpoint controller driver.
+// Author: Cyrille Pitchen <cyrille.pitchen@free-electrons.com>
+
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/pci-epc.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/sizes.h>
+
+#include "pcie-cadence.h"
+
+#define CDNS_PCIE_EP_MIN_APERTURE 128 /* 128 bytes */
+#define CDNS_PCIE_EP_IRQ_PCI_ADDR_NONE 0x1
+#define CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY 0x3
+
+/**
+ * struct cdns_pcie_ep - private data for this PCIe endpoint controller driver
+ * @pcie: Cadence PCIe controller
+ * @max_regions: maximum number of regions supported by hardware
+ * @ob_region_map: bitmask of mapped outbound regions
+ * @ob_addr: base addresses in the AXI bus where the outbound regions start
+ * @irq_phys_addr: base address on the AXI bus where the MSI/legacy IRQ
+ * dedicated outbound regions is mapped.
+ * @irq_cpu_addr: base address in the CPU space where a write access triggers
+ * the sending of a memory write (MSI) / normal message (legacy
+ * IRQ) TLP through the PCIe bus.
+ * @irq_pci_addr: used to save the current mapping of the MSI/legacy IRQ
+ * dedicated outbound region.
+ * @irq_pci_fn: the latest PCI function that has updated the mapping of
+ * the MSI/legacy IRQ dedicated outbound region.
+ * @irq_pending: bitmask of asserted legacy IRQs.
+ */
+struct cdns_pcie_ep {
+ struct cdns_pcie pcie;
+ u32 max_regions;
+ unsigned long ob_region_map;
+ phys_addr_t *ob_addr;
+ phys_addr_t irq_phys_addr;
+ void __iomem *irq_cpu_addr;
+ u64 irq_pci_addr;
+ u8 irq_pci_fn;
+ u8 irq_pending;
+};
+
+static int cdns_pcie_ep_write_header(struct pci_epc *epc, u8 fn,
+ struct pci_epf_header *hdr)
+{
+ struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
+ struct cdns_pcie *pcie = &ep->pcie;
+
+ cdns_pcie_ep_fn_writew(pcie, fn, PCI_DEVICE_ID, hdr->deviceid);
+ cdns_pcie_ep_fn_writeb(pcie, fn, PCI_REVISION_ID, hdr->revid);
+ cdns_pcie_ep_fn_writeb(pcie, fn, PCI_CLASS_PROG, hdr->progif_code);
+ cdns_pcie_ep_fn_writew(pcie, fn, PCI_CLASS_DEVICE,
+ hdr->subclass_code | hdr->baseclass_code << 8);
+ cdns_pcie_ep_fn_writeb(pcie, fn, PCI_CACHE_LINE_SIZE,
+ hdr->cache_line_size);
+ cdns_pcie_ep_fn_writew(pcie, fn, PCI_SUBSYSTEM_ID, hdr->subsys_id);
+ cdns_pcie_ep_fn_writeb(pcie, fn, PCI_INTERRUPT_PIN, hdr->interrupt_pin);
+
+ /*
+ * Vendor ID can only be modified from function 0, all other functions
+ * use the same vendor ID as function 0.
+ */
+ if (fn == 0) {
+ /* Update the vendor IDs. */
+ u32 id = CDNS_PCIE_LM_ID_VENDOR(hdr->vendorid) |
+ CDNS_PCIE_LM_ID_SUBSYS(hdr->subsys_vendor_id);
+
+ cdns_pcie_writel(pcie, CDNS_PCIE_LM_ID, id);
+ }
+
+ return 0;
+}
+
+static int cdns_pcie_ep_set_bar(struct pci_epc *epc, u8 fn, enum pci_barno bar,
+ dma_addr_t bar_phys, size_t size, int flags)
+{
+ struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
+ struct cdns_pcie *pcie = &ep->pcie;
+ u32 addr0, addr1, reg, cfg, b, aperture, ctrl;
+ u64 sz;
+
+ /* BAR size is 2^(aperture + 7) */
+ sz = max_t(size_t, size, CDNS_PCIE_EP_MIN_APERTURE);
+ /*
+ * roundup_pow_of_two() returns an unsigned long, which is not suited
+ * for 64bit values.
+ */
+ sz = 1ULL << fls64(sz - 1);
+ aperture = ilog2(sz) - 7; /* 128B -> 0, 256B -> 1, 512B -> 2, ... */
+
+ if ((flags & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
+ ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_IO_32BITS;
+ } else {
+ bool is_prefetch = !!(flags & PCI_BASE_ADDRESS_MEM_PREFETCH);
+ bool is_64bits = sz > SZ_2G;
+
+ if (is_64bits && (bar & 1))
+ return -EINVAL;
+
+ if (is_64bits && is_prefetch)
+ ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_64BITS;
+ else if (is_prefetch)
+ ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_PREFETCH_MEM_32BITS;
+ else if (is_64bits)
+ ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_64BITS;
+ else
+ ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_MEM_32BITS;
+ }
+
+ addr0 = lower_32_bits(bar_phys);
+ addr1 = upper_32_bits(bar_phys);
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar),
+ addr0);
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar),
+ addr1);
+
+ if (bar < BAR_4) {
+ reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG0(fn);
+ b = bar;
+ } else {
+ reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG1(fn);
+ b = bar - BAR_4;
+ }
+
+ cfg = cdns_pcie_readl(pcie, reg);
+ cfg &= ~(CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) |
+ CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b));
+ cfg |= (CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE(b, aperture) |
+ CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl));
+ cdns_pcie_writel(pcie, reg, cfg);
+
+ return 0;
+}
+
+static void cdns_pcie_ep_clear_bar(struct pci_epc *epc, u8 fn,
+ enum pci_barno bar)
+{
+ struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
+ struct cdns_pcie *pcie = &ep->pcie;
+ u32 reg, cfg, b, ctrl;
+
+ if (bar < BAR_4) {
+ reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG0(fn);
+ b = bar;
+ } else {
+ reg = CDNS_PCIE_LM_EP_FUNC_BAR_CFG1(fn);
+ b = bar - BAR_4;
+ }
+
+ ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED;
+ cfg = cdns_pcie_readl(pcie, reg);
+ cfg &= ~(CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_APERTURE_MASK(b) |
+ CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL_MASK(b));
+ cfg |= CDNS_PCIE_LM_EP_FUNC_BAR_CFG_BAR_CTRL(b, ctrl);
+ cdns_pcie_writel(pcie, reg, cfg);
+
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR0(fn, bar), 0);
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_EP_FUNC_BAR_ADDR1(fn, bar), 0);
+}
+
+static int cdns_pcie_ep_map_addr(struct pci_epc *epc, u8 fn, phys_addr_t addr,
+ u64 pci_addr, size_t size)
+{
+ struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
+ struct cdns_pcie *pcie = &ep->pcie;
+ u32 r;
+
+ r = find_first_zero_bit(&ep->ob_region_map,
+ sizeof(ep->ob_region_map) * BITS_PER_LONG);
+ if (r >= ep->max_regions - 1) {
+ dev_err(&epc->dev, "no free outbound region\n");
+ return -EINVAL;
+ }
+
+ cdns_pcie_set_outbound_region(pcie, fn, r, false, addr, pci_addr, size);
+
+ set_bit(r, &ep->ob_region_map);
+ ep->ob_addr[r] = addr;
+
+ return 0;
+}
+
+static void cdns_pcie_ep_unmap_addr(struct pci_epc *epc, u8 fn,
+ phys_addr_t addr)
+{
+ struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
+ struct cdns_pcie *pcie = &ep->pcie;
+ u32 r;
+
+ for (r = 0; r < ep->max_regions - 1; r++)
+ if (ep->ob_addr[r] == addr)
+ break;
+
+ if (r == ep->max_regions - 1)
+ return;
+
+ cdns_pcie_reset_outbound_region(pcie, r);
+
+ ep->ob_addr[r] = 0;
+ clear_bit(r, &ep->ob_region_map);
+}
+
+static int cdns_pcie_ep_set_msi(struct pci_epc *epc, u8 fn, u8 mmc)
+{
+ struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
+ struct cdns_pcie *pcie = &ep->pcie;
+ u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;
+ u16 flags;
+
+ /*
+ * Set the Multiple Message Capable bitfield into the Message Control
+ * register.
+ */
+ flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS);
+ flags = (flags & ~PCI_MSI_FLAGS_QMASK) | (mmc << 1);
+ flags |= PCI_MSI_FLAGS_64BIT;
+ flags &= ~PCI_MSI_FLAGS_MASKBIT;
+ cdns_pcie_ep_fn_writew(pcie, fn, cap + PCI_MSI_FLAGS, flags);
+
+ return 0;
+}
+
+static int cdns_pcie_ep_get_msi(struct pci_epc *epc, u8 fn)
+{
+ struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
+ struct cdns_pcie *pcie = &ep->pcie;
+ u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;
+ u16 flags, mmc, mme;
+
+ /* Validate that the MSI feature is actually enabled. */
+ flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS);
+ if (!(flags & PCI_MSI_FLAGS_ENABLE))
+ return -EINVAL;
+
+ /*
+ * Get the Multiple Message Enable bitfield from the Message Control
+ * register.
+ */
+ mmc = (flags & PCI_MSI_FLAGS_QMASK) >> 1;
+ mme = (flags & PCI_MSI_FLAGS_QSIZE) >> 4;
+
+ return mme;
+}
+
+static void cdns_pcie_ep_assert_intx(struct cdns_pcie_ep *ep, u8 fn,
+ u8 intx, bool is_asserted)
+{
+ struct cdns_pcie *pcie = &ep->pcie;
+ u32 r = ep->max_regions - 1;
+ u32 offset;
+ u16 status;
+ u8 msg_code;
+
+ intx &= 3;
+
+ /* Set the outbound region if needed. */
+ if (unlikely(ep->irq_pci_addr != CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY ||
+ ep->irq_pci_fn != fn)) {
+ /* Last region was reserved for IRQ writes. */
+ cdns_pcie_set_outbound_region_for_normal_msg(pcie, fn, r,
+ ep->irq_phys_addr);
+ ep->irq_pci_addr = CDNS_PCIE_EP_IRQ_PCI_ADDR_LEGACY;
+ ep->irq_pci_fn = fn;
+ }
+
+ if (is_asserted) {
+ ep->irq_pending |= BIT(intx);
+ msg_code = MSG_CODE_ASSERT_INTA + intx;
+ } else {
+ ep->irq_pending &= ~BIT(intx);
+ msg_code = MSG_CODE_DEASSERT_INTA + intx;
+ }
+
+ status = cdns_pcie_ep_fn_readw(pcie, fn, PCI_STATUS);
+ if (((status & PCI_STATUS_INTERRUPT) != 0) ^ (ep->irq_pending != 0)) {
+ status ^= PCI_STATUS_INTERRUPT;
+ cdns_pcie_ep_fn_writew(pcie, fn, PCI_STATUS, status);
+ }
+
+ offset = CDNS_PCIE_NORMAL_MSG_ROUTING(MSG_ROUTING_LOCAL) |
+ CDNS_PCIE_NORMAL_MSG_CODE(msg_code) |
+ CDNS_PCIE_MSG_NO_DATA;
+ writel(0, ep->irq_cpu_addr + offset);
+}
+
+static int cdns_pcie_ep_send_legacy_irq(struct cdns_pcie_ep *ep, u8 fn, u8 intx)
+{
+ u16 cmd;
+
+ cmd = cdns_pcie_ep_fn_readw(&ep->pcie, fn, PCI_COMMAND);
+ if (cmd & PCI_COMMAND_INTX_DISABLE)
+ return -EINVAL;
+
+ cdns_pcie_ep_assert_intx(ep, fn, intx, true);
+ /*
+ * The mdelay() value was taken from dra7xx_pcie_raise_legacy_irq()
+ * from drivers/pci/dwc/pci-dra7xx.c
+ */
+ mdelay(1);
+ cdns_pcie_ep_assert_intx(ep, fn, intx, false);
+ return 0;
+}
+
+static int cdns_pcie_ep_send_msi_irq(struct cdns_pcie_ep *ep, u8 fn,
+ u8 interrupt_num)
+{
+ struct cdns_pcie *pcie = &ep->pcie;
+ u32 cap = CDNS_PCIE_EP_FUNC_MSI_CAP_OFFSET;
+ u16 flags, mme, data, data_mask;
+ u8 msi_count;
+ u64 pci_addr, pci_addr_mask = 0xff;
+
+ /* Check whether the MSI feature has been enabled by the PCI host. */
+ flags = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_FLAGS);
+ if (!(flags & PCI_MSI_FLAGS_ENABLE))
+ return -EINVAL;
+
+ /* Get the number of enabled MSIs */
+ mme = (flags & PCI_MSI_FLAGS_QSIZE) >> 4;
+ msi_count = 1 << mme;
+ if (!interrupt_num || interrupt_num > msi_count)
+ return -EINVAL;
+
+ /* Compute the data value to be written. */
+ data_mask = msi_count - 1;
+ data = cdns_pcie_ep_fn_readw(pcie, fn, cap + PCI_MSI_DATA_64);
+ data = (data & ~data_mask) | ((interrupt_num - 1) & data_mask);
+
+ /* Get the PCI address where to write the data into. */
+ pci_addr = cdns_pcie_ep_fn_readl(pcie, fn, cap + PCI_MSI_ADDRESS_HI);
+ pci_addr <<= 32;
+ pci_addr |= cdns_pcie_ep_fn_readl(pcie, fn, cap + PCI_MSI_ADDRESS_LO);
+ pci_addr &= GENMASK_ULL(63, 2);
+
+ /* Set the outbound region if needed. */
+ if (unlikely(ep->irq_pci_addr != (pci_addr & ~pci_addr_mask) ||
+ ep->irq_pci_fn != fn)) {
+ /* Last region was reserved for IRQ writes. */
+ cdns_pcie_set_outbound_region(pcie, fn, ep->max_regions - 1,
+ false,
+ ep->irq_phys_addr,
+ pci_addr & ~pci_addr_mask,
+ pci_addr_mask + 1);
+ ep->irq_pci_addr = (pci_addr & ~pci_addr_mask);
+ ep->irq_pci_fn = fn;
+ }
+ writew(data, ep->irq_cpu_addr + (pci_addr & pci_addr_mask));
+
+ return 0;
+}
+
+static int cdns_pcie_ep_raise_irq(struct pci_epc *epc, u8 fn,
+ enum pci_epc_irq_type type, u8 interrupt_num)
+{
+ struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
+
+ switch (type) {
+ case PCI_EPC_IRQ_LEGACY:
+ return cdns_pcie_ep_send_legacy_irq(ep, fn, 0);
+
+ case PCI_EPC_IRQ_MSI:
+ return cdns_pcie_ep_send_msi_irq(ep, fn, interrupt_num);
+
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+
+static int cdns_pcie_ep_start(struct pci_epc *epc)
+{
+ struct cdns_pcie_ep *ep = epc_get_drvdata(epc);
+ struct cdns_pcie *pcie = &ep->pcie;
+ struct pci_epf *epf;
+ u32 cfg;
+
+ /*
+ * BIT(0) is hardwired to 1, hence function 0 is always enabled
+ * and can't be disabled anyway.
+ */
+ cfg = BIT(0);
+ list_for_each_entry(epf, &epc->pci_epf, list)
+ cfg |= BIT(epf->func_no);
+ cdns_pcie_writel(pcie, CDNS_PCIE_LM_EP_FUNC_CFG, cfg);
+
+ /*
+ * The PCIe links are automatically established by the controller
+ * once for all at powerup: the software can neither start nor stop
+ * those links later at runtime.
+ *
+ * Then we only have to notify the EP core that our links are already
+ * established. However we don't call directly pci_epc_linkup() because
+ * we've already locked the epc->lock.
+ */
+ list_for_each_entry(epf, &epc->pci_epf, list)
+ pci_epf_linkup(epf);
+
+ return 0;
+}
+
+static const struct pci_epc_ops cdns_pcie_epc_ops = {
+ .write_header = cdns_pcie_ep_write_header,
+ .set_bar = cdns_pcie_ep_set_bar,
+ .clear_bar = cdns_pcie_ep_clear_bar,
+ .map_addr = cdns_pcie_ep_map_addr,
+ .unmap_addr = cdns_pcie_ep_unmap_addr,
+ .set_msi = cdns_pcie_ep_set_msi,
+ .get_msi = cdns_pcie_ep_get_msi,
+ .raise_irq = cdns_pcie_ep_raise_irq,
+ .start = cdns_pcie_ep_start,
+};
+
+static const struct of_device_id cdns_pcie_ep_of_match[] = {
+ { .compatible = "cdns,cdns-pcie-ep" },
+
+ { },
+};
+
+static int cdns_pcie_ep_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct cdns_pcie_ep *ep;
+ struct cdns_pcie *pcie;
+ struct pci_epc *epc;
+ struct resource *res;
+ int ret;
+
+ ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
+ if (!ep)
+ return -ENOMEM;
+
+ pcie = &ep->pcie;
+ pcie->is_rc = false;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg");
+ pcie->reg_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(pcie->reg_base)) {
+ dev_err(dev, "missing \"reg\"\n");
+ return PTR_ERR(pcie->reg_base);
+ }
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem");
+ if (!res) {
+ dev_err(dev, "missing \"mem\"\n");
+ return -EINVAL;
+ }
+ pcie->mem_res = res;
+
+ ret = of_property_read_u32(np, "cdns,max-outbound-regions",
+ &ep->max_regions);
+ if (ret < 0) {
+ dev_err(dev, "missing \"cdns,max-outbound-regions\"\n");
+ return ret;
+ }
+ ep->ob_addr = devm_kzalloc(dev, ep->max_regions * sizeof(*ep->ob_addr),
+ GFP_KERNEL);
+ if (!ep->ob_addr)
+ return -ENOMEM;
+
+ pm_runtime_enable(dev);
+ ret = pm_runtime_get_sync(dev);
+ if (ret < 0) {
+ dev_err(dev, "pm_runtime_get_sync() failed\n");
+ goto err_get_sync;
+ }
+
+ /* Disable all but function 0 (anyway BIT(0) is hardwired to 1). */
+ cdns_pcie_writel(pcie, CDNS_PCIE_LM_EP_FUNC_CFG, BIT(0));
+
+ epc = devm_pci_epc_create(dev, &cdns_pcie_epc_ops);
+ if (IS_ERR(epc)) {
+ dev_err(dev, "failed to create epc device\n");
+ ret = PTR_ERR(epc);
+ goto err_init;
+ }
+
+ epc_set_drvdata(epc, ep);
+
+ if (of_property_read_u8(np, "max-functions", &epc->max_functions) < 0)
+ epc->max_functions = 1;
+
+ ret = pci_epc_mem_init(epc, pcie->mem_res->start,
+ resource_size(pcie->mem_res));
+ if (ret < 0) {
+ dev_err(dev, "failed to initialize the memory space\n");
+ goto err_init;
+ }
+
+ ep->irq_cpu_addr = pci_epc_mem_alloc_addr(epc, &ep->irq_phys_addr,
+ SZ_128K);
+ if (!ep->irq_cpu_addr) {
+ dev_err(dev, "failed to reserve memory space for MSI\n");
+ ret = -ENOMEM;
+ goto free_epc_mem;
+ }
+ ep->irq_pci_addr = CDNS_PCIE_EP_IRQ_PCI_ADDR_NONE;
+
+ return 0;
+
+ free_epc_mem:
+ pci_epc_mem_exit(epc);
+
+ err_init:
+ pm_runtime_put_sync(dev);
+
+ err_get_sync:
+ pm_runtime_disable(dev);
+
+ return ret;
+}
+
+static void cdns_pcie_ep_shutdown(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ ret = pm_runtime_put_sync(dev);
+ if (ret < 0)
+ dev_dbg(dev, "pm_runtime_put_sync failed\n");
+
+ pm_runtime_disable(dev);
+
+ /* The PCIe controller can't be disabled. */
+}
+
+static struct platform_driver cdns_pcie_ep_driver = {
+ .driver = {
+ .name = "cdns-pcie-ep",
+ .of_match_table = cdns_pcie_ep_of_match,
+ },
+ .probe = cdns_pcie_ep_probe,
+ .shutdown = cdns_pcie_ep_shutdown,
+};
+builtin_platform_driver(cdns_pcie_ep_driver);