1 files changed, 288 insertions, 0 deletions
diff --git a/drivers/pci/controller/cadence/pcie-cadence-host-common.c b/drivers/pci/controller/cadence/pcie-cadence-host-common.c
new file mode 100644
index 000000000000..15415d7f35ee
--- /dev/null
+++ b/drivers/pci/controller/cadence/pcie-cadence-host-common.c
@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cadence PCIe host controller library.
+ *
+ * Copyright (c) 2017 Cadence
+ * 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"
+#include "pcie-cadence-host-common.h"
+
+#define LINK_RETRAIN_TIMEOUT HZ
+
+u64 bar_max_size[] = {
+	[RP_BAR0] = _ULL(128 * SZ_2G),
+	[RP_BAR1] = SZ_2G,
+	[RP_NO_BAR] = _BITULL(63),
+};
+EXPORT_SYMBOL_GPL(bar_max_size);
+
+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;
+}
+EXPORT_SYMBOL_GPL(cdns_pcie_host_training_complete);
+
+int cdns_pcie_host_wait_for_link(struct cdns_pcie *pcie,
+				 cdns_pcie_linkup_func pcie_link_up)
+{
+	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 (pcie_link_up(pcie)) {
+			dev_info(dev, "Link up\n");
+			return 0;
+		}
+		usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX);
+	}
+
+	return -ETIMEDOUT;
+}
+EXPORT_SYMBOL_GPL(cdns_pcie_host_wait_for_link);
+
+int cdns_pcie_retrain(struct cdns_pcie *pcie,
+		      cdns_pcie_linkup_func pcie_link_up)
+{
+	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, pcie_link_up);
+	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdns_pcie_retrain);
+
+int cdns_pcie_host_start_link(struct cdns_pcie_rc *rc,
+			      cdns_pcie_linkup_func pcie_link_up)
+{
+	struct cdns_pcie *pcie = &rc->pcie;
+	int ret;
+
+	ret = cdns_pcie_host_wait_for_link(pcie, pcie_link_up);
+
+	/*
+	 * Retrain link for Gen2 training defect
+	 * if quirk flag is set.
+	 */
+	if (!ret && rc->quirk_retrain_flag)
+		ret = cdns_pcie_retrain(pcie, pcie_link_up);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdns_pcie_host_start_link);
+
+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;
+}
+EXPORT_SYMBOL_GPL(cdns_pcie_host_find_min_bar);
+
+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;
+}
+EXPORT_SYMBOL_GPL(cdns_pcie_host_find_max_bar);
+
+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);
+}
+EXPORT_SYMBOL_GPL(cdns_pcie_host_dma_ranges_cmp);
+
+int cdns_pcie_host_bar_config(struct cdns_pcie_rc *rc,
+			      struct resource_entry *entry,
+			      cdns_pcie_host_bar_ib_cfg pci_host_ib_config)
+{
+	struct cdns_pcie *pcie = &rc->pcie;
+	struct device *dev = pcie->dev;
+	u64 cpu_addr, size, winsize;
+	enum cdns_pcie_rp_bar bar;
+	unsigned long flags;
+	int ret;
+
+	cpu_addr = entry->res->start;
+	flags = entry->res->flags;
+	size = resource_size(entry->res);
+
+	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 = pci_host_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 = pci_host_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;
+}
+
+int cdns_pcie_host_map_dma_ranges(struct cdns_pcie_rc *rc,
+				  cdns_pcie_host_bar_ib_cfg pci_host_ib_config)
+{
+	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 = pci_host_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, pci_host_ib_config);
+		if (err) {
+			dev_err(dev, "Fail to configure IB using dma-ranges\n");
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Cadence PCIe host controller driver");