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path: root/drivers/pci/controller/cadence/pcie-cadence-host.c
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-rw-r--r--drivers/pci/controller/cadence/pcie-cadence-host.c571
1 files changed, 571 insertions, 0 deletions
diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c
new file mode 100644
index 000000000..5b14f7ee3
--- /dev/null
+++ b/drivers/pci/controller/cadence/pcie-cadence-host.c
@@ -0,0 +1,571 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2017 Cadence
+// Cadence PCIe host controller driver.
+// Author: Cyrille Pitchen <cyrille.pitchen@free-electrons.com>
+
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/list_sort.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/platform_device.h>
+
+#include "pcie-cadence.h"
+
+#define LINK_RETRAIN_TIMEOUT HZ
+
+static u64 bar_max_size[] = {
+ [RP_BAR0] = _ULL(128 * SZ_2G),
+ [RP_BAR1] = SZ_2G,
+ [RP_NO_BAR] = _BITULL(63),
+};
+
+static u8 bar_aperture_mask[] = {
+ [RP_BAR0] = 0x1F,
+ [RP_BAR1] = 0xF,
+};
+
+void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
+ int where)
+{
+ struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
+ struct cdns_pcie_rc *rc = pci_host_bridge_priv(bridge);
+ struct cdns_pcie *pcie = &rc->pcie;
+ unsigned int busn = bus->number;
+ u32 addr0, desc0;
+
+ if (pci_is_root_bus(bus)) {
+ /*
+ * Only the root port (devfn == 0) is connected to this bus.
+ * All other PCI devices are behind some bridge hence on another
+ * bus.
+ */
+ if (devfn)
+ return NULL;
+
+ return pcie->reg_base + (where & 0xfff);
+ }
+ /* Check that the link is up */
+ if (!(cdns_pcie_readl(pcie, CDNS_PCIE_LM_BASE) & 0x1))
+ return NULL;
+ /* Clear AXI link-down status */
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_LINKDOWN, 0x0);
+
+ /* Update Output registers for AXI region 0. */
+ addr0 = CDNS_PCIE_AT_OB_REGION_PCI_ADDR0_NBITS(12) |
+ CDNS_PCIE_AT_OB_REGION_PCI_ADDR0_DEVFN(devfn) |
+ CDNS_PCIE_AT_OB_REGION_PCI_ADDR0_BUS(busn);
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR0(0), addr0);
+
+ /* Configuration Type 0 or Type 1 access. */
+ desc0 = CDNS_PCIE_AT_OB_REGION_DESC0_HARDCODED_RID |
+ CDNS_PCIE_AT_OB_REGION_DESC0_DEVFN(0);
+ /*
+ * The bus number was already set once for all in desc1 by
+ * cdns_pcie_host_init_address_translation().
+ */
+ if (busn == bridge->busnr + 1)
+ desc0 |= CDNS_PCIE_AT_OB_REGION_DESC0_TYPE_CONF_TYPE0;
+ else
+ desc0 |= CDNS_PCIE_AT_OB_REGION_DESC0_TYPE_CONF_TYPE1;
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC0(0), desc0);
+
+ return rc->cfg_base + (where & 0xfff);
+}
+
+static struct pci_ops cdns_pcie_host_ops = {
+ .map_bus = cdns_pci_map_bus,
+ .read = pci_generic_config_read,
+ .write = pci_generic_config_write,
+};
+
+static int cdns_pcie_host_training_complete(struct cdns_pcie *pcie)
+{
+ u32 pcie_cap_off = CDNS_PCIE_RP_CAP_OFFSET;
+ unsigned long end_jiffies;
+ u16 lnk_stat;
+
+ /* Wait for link training to complete. Exit after timeout. */
+ end_jiffies = jiffies + LINK_RETRAIN_TIMEOUT;
+ do {
+ lnk_stat = cdns_pcie_rp_readw(pcie, pcie_cap_off + PCI_EXP_LNKSTA);
+ if (!(lnk_stat & PCI_EXP_LNKSTA_LT))
+ break;
+ usleep_range(0, 1000);
+ } while (time_before(jiffies, end_jiffies));
+
+ if (!(lnk_stat & PCI_EXP_LNKSTA_LT))
+ return 0;
+
+ return -ETIMEDOUT;
+}
+
+static int cdns_pcie_host_wait_for_link(struct cdns_pcie *pcie)
+{
+ struct device *dev = pcie->dev;
+ int retries;
+
+ /* Check if the link is up or not */
+ for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
+ if (cdns_pcie_link_up(pcie)) {
+ dev_info(dev, "Link up\n");
+ return 0;
+ }
+ usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX);
+ }
+
+ return -ETIMEDOUT;
+}
+
+static int cdns_pcie_retrain(struct cdns_pcie *pcie)
+{
+ u32 lnk_cap_sls, pcie_cap_off = CDNS_PCIE_RP_CAP_OFFSET;
+ u16 lnk_stat, lnk_ctl;
+ int ret = 0;
+
+ /*
+ * Set retrain bit if current speed is 2.5 GB/s,
+ * but the PCIe root port support is > 2.5 GB/s.
+ */
+
+ lnk_cap_sls = cdns_pcie_readl(pcie, (CDNS_PCIE_RP_BASE + pcie_cap_off +
+ PCI_EXP_LNKCAP));
+ if ((lnk_cap_sls & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
+ return ret;
+
+ lnk_stat = cdns_pcie_rp_readw(pcie, pcie_cap_off + PCI_EXP_LNKSTA);
+ if ((lnk_stat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB) {
+ lnk_ctl = cdns_pcie_rp_readw(pcie,
+ pcie_cap_off + PCI_EXP_LNKCTL);
+ lnk_ctl |= PCI_EXP_LNKCTL_RL;
+ cdns_pcie_rp_writew(pcie, pcie_cap_off + PCI_EXP_LNKCTL,
+ lnk_ctl);
+
+ ret = cdns_pcie_host_training_complete(pcie);
+ if (ret)
+ return ret;
+
+ ret = cdns_pcie_host_wait_for_link(pcie);
+ }
+ return ret;
+}
+
+static void cdns_pcie_host_enable_ptm_response(struct cdns_pcie *pcie)
+{
+ u32 val;
+
+ val = cdns_pcie_readl(pcie, CDNS_PCIE_LM_PTM_CTRL);
+ cdns_pcie_writel(pcie, CDNS_PCIE_LM_PTM_CTRL, val | CDNS_PCIE_LM_TPM_CTRL_PTMRSEN);
+}
+
+static int cdns_pcie_host_start_link(struct cdns_pcie_rc *rc)
+{
+ struct cdns_pcie *pcie = &rc->pcie;
+ int ret;
+
+ ret = cdns_pcie_host_wait_for_link(pcie);
+
+ /*
+ * Retrain link for Gen2 training defect
+ * if quirk flag is set.
+ */
+ if (!ret && rc->quirk_retrain_flag)
+ ret = cdns_pcie_retrain(pcie);
+
+ return ret;
+}
+
+static int cdns_pcie_host_init_root_port(struct cdns_pcie_rc *rc)
+{
+ struct cdns_pcie *pcie = &rc->pcie;
+ u32 value, ctrl;
+ u32 id;
+
+ /*
+ * Set the root complex BAR configuration register:
+ * - disable both BAR0 and BAR1.
+ * - enable Prefetchable Memory Base and Limit registers in type 1
+ * config space (64 bits).
+ * - enable IO Base and Limit registers in type 1 config
+ * space (32 bits).
+ */
+ ctrl = CDNS_PCIE_LM_BAR_CFG_CTRL_DISABLED;
+ value = CDNS_PCIE_LM_RC_BAR_CFG_BAR0_CTRL(ctrl) |
+ CDNS_PCIE_LM_RC_BAR_CFG_BAR1_CTRL(ctrl) |
+ CDNS_PCIE_LM_RC_BAR_CFG_PREFETCH_MEM_ENABLE |
+ CDNS_PCIE_LM_RC_BAR_CFG_PREFETCH_MEM_64BITS |
+ CDNS_PCIE_LM_RC_BAR_CFG_IO_ENABLE |
+ CDNS_PCIE_LM_RC_BAR_CFG_IO_32BITS;
+ cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
+
+ /* Set root port configuration space */
+ if (rc->vendor_id != 0xffff) {
+ id = CDNS_PCIE_LM_ID_VENDOR(rc->vendor_id) |
+ CDNS_PCIE_LM_ID_SUBSYS(rc->vendor_id);
+ cdns_pcie_writel(pcie, CDNS_PCIE_LM_ID, id);
+ }
+
+ if (rc->device_id != 0xffff)
+ cdns_pcie_rp_writew(pcie, PCI_DEVICE_ID, rc->device_id);
+
+ cdns_pcie_rp_writeb(pcie, PCI_CLASS_REVISION, 0);
+ cdns_pcie_rp_writeb(pcie, PCI_CLASS_PROG, 0);
+ cdns_pcie_rp_writew(pcie, PCI_CLASS_DEVICE, PCI_CLASS_BRIDGE_PCI);
+
+ return 0;
+}
+
+static int cdns_pcie_host_bar_ib_config(struct cdns_pcie_rc *rc,
+ enum cdns_pcie_rp_bar bar,
+ u64 cpu_addr, u64 size,
+ unsigned long flags)
+{
+ struct cdns_pcie *pcie = &rc->pcie;
+ u32 addr0, addr1, aperture, value;
+
+ if (!rc->avail_ib_bar[bar])
+ return -EBUSY;
+
+ rc->avail_ib_bar[bar] = false;
+
+ aperture = ilog2(size);
+ addr0 = CDNS_PCIE_AT_IB_RP_BAR_ADDR0_NBITS(aperture) |
+ (lower_32_bits(cpu_addr) & GENMASK(31, 8));
+ addr1 = upper_32_bits(cpu_addr);
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR0(bar), addr0);
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_IB_RP_BAR_ADDR1(bar), addr1);
+
+ if (bar == RP_NO_BAR)
+ return 0;
+
+ value = cdns_pcie_readl(pcie, CDNS_PCIE_LM_RC_BAR_CFG);
+ value &= ~(LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar) |
+ LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar) |
+ LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar) |
+ LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar) |
+ LM_RC_BAR_CFG_APERTURE(bar, bar_aperture_mask[bar] + 2));
+ if (size + cpu_addr >= SZ_4G) {
+ if (!(flags & IORESOURCE_PREFETCH))
+ value |= LM_RC_BAR_CFG_CTRL_MEM_64BITS(bar);
+ value |= LM_RC_BAR_CFG_CTRL_PREF_MEM_64BITS(bar);
+ } else {
+ if (!(flags & IORESOURCE_PREFETCH))
+ value |= LM_RC_BAR_CFG_CTRL_MEM_32BITS(bar);
+ value |= LM_RC_BAR_CFG_CTRL_PREF_MEM_32BITS(bar);
+ }
+
+ value |= LM_RC_BAR_CFG_APERTURE(bar, aperture);
+ cdns_pcie_writel(pcie, CDNS_PCIE_LM_RC_BAR_CFG, value);
+
+ return 0;
+}
+
+static enum cdns_pcie_rp_bar
+cdns_pcie_host_find_min_bar(struct cdns_pcie_rc *rc, u64 size)
+{
+ enum cdns_pcie_rp_bar bar, sel_bar;
+
+ sel_bar = RP_BAR_UNDEFINED;
+ for (bar = RP_BAR0; bar <= RP_NO_BAR; bar++) {
+ if (!rc->avail_ib_bar[bar])
+ continue;
+
+ if (size <= bar_max_size[bar]) {
+ if (sel_bar == RP_BAR_UNDEFINED) {
+ sel_bar = bar;
+ continue;
+ }
+
+ if (bar_max_size[bar] < bar_max_size[sel_bar])
+ sel_bar = bar;
+ }
+ }
+
+ return sel_bar;
+}
+
+static enum cdns_pcie_rp_bar
+cdns_pcie_host_find_max_bar(struct cdns_pcie_rc *rc, u64 size)
+{
+ enum cdns_pcie_rp_bar bar, sel_bar;
+
+ sel_bar = RP_BAR_UNDEFINED;
+ for (bar = RP_BAR0; bar <= RP_NO_BAR; bar++) {
+ if (!rc->avail_ib_bar[bar])
+ continue;
+
+ if (size >= bar_max_size[bar]) {
+ if (sel_bar == RP_BAR_UNDEFINED) {
+ sel_bar = bar;
+ continue;
+ }
+
+ if (bar_max_size[bar] > bar_max_size[sel_bar])
+ sel_bar = bar;
+ }
+ }
+
+ return sel_bar;
+}
+
+static int cdns_pcie_host_bar_config(struct cdns_pcie_rc *rc,
+ struct resource_entry *entry)
+{
+ u64 cpu_addr, pci_addr, size, winsize;
+ struct cdns_pcie *pcie = &rc->pcie;
+ struct device *dev = pcie->dev;
+ enum cdns_pcie_rp_bar bar;
+ unsigned long flags;
+ int ret;
+
+ cpu_addr = entry->res->start;
+ pci_addr = entry->res->start - entry->offset;
+ flags = entry->res->flags;
+ size = resource_size(entry->res);
+
+ if (entry->offset) {
+ dev_err(dev, "PCI addr: %llx must be equal to CPU addr: %llx\n",
+ pci_addr, cpu_addr);
+ return -EINVAL;
+ }
+
+ while (size > 0) {
+ /*
+ * Try to find a minimum BAR whose size is greater than
+ * or equal to the remaining resource_entry size. This will
+ * fail if the size of each of the available BARs is less than
+ * the remaining resource_entry size.
+ * If a minimum BAR is found, IB ATU will be configured and
+ * exited.
+ */
+ bar = cdns_pcie_host_find_min_bar(rc, size);
+ if (bar != RP_BAR_UNDEFINED) {
+ ret = cdns_pcie_host_bar_ib_config(rc, bar, cpu_addr,
+ size, flags);
+ if (ret)
+ dev_err(dev, "IB BAR: %d config failed\n", bar);
+ return ret;
+ }
+
+ /*
+ * If the control reaches here, it would mean the remaining
+ * resource_entry size cannot be fitted in a single BAR. So we
+ * find a maximum BAR whose size is less than or equal to the
+ * remaining resource_entry size and split the resource entry
+ * so that part of resource entry is fitted inside the maximum
+ * BAR. The remaining size would be fitted during the next
+ * iteration of the loop.
+ * If a maximum BAR is not found, there is no way we can fit
+ * this resource_entry, so we error out.
+ */
+ bar = cdns_pcie_host_find_max_bar(rc, size);
+ if (bar == RP_BAR_UNDEFINED) {
+ dev_err(dev, "No free BAR to map cpu_addr %llx\n",
+ cpu_addr);
+ return -EINVAL;
+ }
+
+ winsize = bar_max_size[bar];
+ ret = cdns_pcie_host_bar_ib_config(rc, bar, cpu_addr, winsize,
+ flags);
+ if (ret) {
+ dev_err(dev, "IB BAR: %d config failed\n", bar);
+ return ret;
+ }
+
+ size -= winsize;
+ cpu_addr += winsize;
+ }
+
+ return 0;
+}
+
+static int cdns_pcie_host_dma_ranges_cmp(void *priv, const struct list_head *a,
+ const struct list_head *b)
+{
+ struct resource_entry *entry1, *entry2;
+
+ entry1 = container_of(a, struct resource_entry, node);
+ entry2 = container_of(b, struct resource_entry, node);
+
+ return resource_size(entry2->res) - resource_size(entry1->res);
+}
+
+static int cdns_pcie_host_map_dma_ranges(struct cdns_pcie_rc *rc)
+{
+ struct cdns_pcie *pcie = &rc->pcie;
+ struct device *dev = pcie->dev;
+ struct device_node *np = dev->of_node;
+ struct pci_host_bridge *bridge;
+ struct resource_entry *entry;
+ u32 no_bar_nbits = 32;
+ int err;
+
+ bridge = pci_host_bridge_from_priv(rc);
+ if (!bridge)
+ return -ENOMEM;
+
+ if (list_empty(&bridge->dma_ranges)) {
+ of_property_read_u32(np, "cdns,no-bar-match-nbits",
+ &no_bar_nbits);
+ err = cdns_pcie_host_bar_ib_config(rc, RP_NO_BAR, 0x0,
+ (u64)1 << no_bar_nbits, 0);
+ if (err)
+ dev_err(dev, "IB BAR: %d config failed\n", RP_NO_BAR);
+ return err;
+ }
+
+ list_sort(NULL, &bridge->dma_ranges, cdns_pcie_host_dma_ranges_cmp);
+
+ resource_list_for_each_entry(entry, &bridge->dma_ranges) {
+ err = cdns_pcie_host_bar_config(rc, entry);
+ if (err) {
+ dev_err(dev, "Fail to configure IB using dma-ranges\n");
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+static int cdns_pcie_host_init_address_translation(struct cdns_pcie_rc *rc)
+{
+ struct cdns_pcie *pcie = &rc->pcie;
+ struct pci_host_bridge *bridge = pci_host_bridge_from_priv(rc);
+ struct resource *cfg_res = rc->cfg_res;
+ struct resource_entry *entry;
+ u64 cpu_addr = cfg_res->start;
+ u32 addr0, addr1, desc1;
+ int r, busnr = 0;
+
+ entry = resource_list_first_type(&bridge->windows, IORESOURCE_BUS);
+ if (entry)
+ busnr = entry->res->start;
+
+ /*
+ * Reserve region 0 for PCI configure space accesses:
+ * OB_REGION_PCI_ADDR0 and OB_REGION_DESC0 are updated dynamically by
+ * cdns_pci_map_bus(), other region registers are set here once for all.
+ */
+ addr1 = 0; /* Should be programmed to zero. */
+ desc1 = CDNS_PCIE_AT_OB_REGION_DESC1_BUS(busnr);
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_PCI_ADDR1(0), addr1);
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_DESC1(0), desc1);
+
+ if (pcie->ops->cpu_addr_fixup)
+ cpu_addr = pcie->ops->cpu_addr_fixup(pcie, cpu_addr);
+
+ addr0 = CDNS_PCIE_AT_OB_REGION_CPU_ADDR0_NBITS(12) |
+ (lower_32_bits(cpu_addr) & GENMASK(31, 8));
+ addr1 = upper_32_bits(cpu_addr);
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR0(0), addr0);
+ cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR1(0), addr1);
+
+ r = 1;
+ resource_list_for_each_entry(entry, &bridge->windows) {
+ struct resource *res = entry->res;
+ u64 pci_addr = res->start - entry->offset;
+
+ if (resource_type(res) == IORESOURCE_IO)
+ cdns_pcie_set_outbound_region(pcie, busnr, 0, r,
+ true,
+ pci_pio_to_address(res->start),
+ pci_addr,
+ resource_size(res));
+ else
+ cdns_pcie_set_outbound_region(pcie, busnr, 0, r,
+ false,
+ res->start,
+ pci_addr,
+ resource_size(res));
+
+ r++;
+ }
+
+ return cdns_pcie_host_map_dma_ranges(rc);
+}
+
+static int cdns_pcie_host_init(struct device *dev,
+ struct cdns_pcie_rc *rc)
+{
+ int err;
+
+ err = cdns_pcie_host_init_root_port(rc);
+ if (err)
+ return err;
+
+ return cdns_pcie_host_init_address_translation(rc);
+}
+
+int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
+{
+ struct device *dev = rc->pcie.dev;
+ struct platform_device *pdev = to_platform_device(dev);
+ struct device_node *np = dev->of_node;
+ struct pci_host_bridge *bridge;
+ enum cdns_pcie_rp_bar bar;
+ struct cdns_pcie *pcie;
+ struct resource *res;
+ int ret;
+
+ bridge = pci_host_bridge_from_priv(rc);
+ if (!bridge)
+ return -ENOMEM;
+
+ pcie = &rc->pcie;
+ pcie->is_rc = true;
+
+ rc->vendor_id = 0xffff;
+ of_property_read_u32(np, "vendor-id", &rc->vendor_id);
+
+ rc->device_id = 0xffff;
+ of_property_read_u32(np, "device-id", &rc->device_id);
+
+ pcie->reg_base = devm_platform_ioremap_resource_byname(pdev, "reg");
+ 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, "cfg");
+ rc->cfg_base = devm_pci_remap_cfg_resource(dev, res);
+ if (IS_ERR(rc->cfg_base))
+ return PTR_ERR(rc->cfg_base);
+ rc->cfg_res = res;
+
+ if (rc->quirk_detect_quiet_flag)
+ cdns_pcie_detect_quiet_min_delay_set(&rc->pcie);
+
+ cdns_pcie_host_enable_ptm_response(pcie);
+
+ ret = cdns_pcie_start_link(pcie);
+ if (ret) {
+ dev_err(dev, "Failed to start link\n");
+ return ret;
+ }
+
+ ret = cdns_pcie_host_start_link(rc);
+ if (ret)
+ dev_dbg(dev, "PCIe link never came up\n");
+
+ for (bar = RP_BAR0; bar <= RP_NO_BAR; bar++)
+ rc->avail_ib_bar[bar] = true;
+
+ ret = cdns_pcie_host_init(dev, rc);
+ if (ret)
+ return ret;
+
+ if (!bridge->ops)
+ bridge->ops = &cdns_pcie_host_ops;
+
+ ret = pci_host_probe(bridge);
+ if (ret < 0)
+ goto err_init;
+
+ return 0;
+
+ err_init:
+ pm_runtime_put_sync(dev);
+
+ return ret;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 01:42:22 +0000