1 files changed, 561 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..4d8d15ac5
--- /dev/null
+++ b/drivers/pci/controller/cadence/pcie-cadence-host.c
@@ -0,0 +1,561 @@
+// 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 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);
+
+	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;
+}