[RFC PATCH] PCI/ACPI: xgene: Add ECAM quirk for X-Gene PCIe controller
Duc Dang
dhdang at apm.com
Sat Sep 17 07:24:38 PDT 2016
PCIe controller in X-Gene SoCs is not ECAM compliant: software
needs to configure additional concontroller register to address
device at bus:dev:function.
This patch depends on "ECAM quirks handling for ARM64 platforms"
series (http://www.spinics.net/lists/arm-kernel/msg530692.html)
to address the limitation above for X-Gene PCIe controller.
The quirk will only be applied for X-Gene PCIe MCFG table with
OEM revison 1, 2, 3 or 4 (PCIe controller v1 and v2 on X-Gene SoCs).
Signed-off-by: Duc Dang <dhdang at apm.com>
---
drivers/acpi/pci_mcfg.c | 32 +++++
drivers/pci/host/Makefile | 2 +-
drivers/pci/host/pci-xgene-ecam.c | 280 ++++++++++++++++++++++++++++++++++++++
include/linux/pci-ecam.h | 5 +
4 files changed, 318 insertions(+), 1 deletion(-)
create mode 100644 drivers/pci/host/pci-xgene-ecam.c
diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
index ddf338b..adce35f 100644
--- a/drivers/acpi/pci_mcfg.c
+++ b/drivers/acpi/pci_mcfg.c
@@ -123,6 +123,38 @@ static struct mcfg_fixup mcfg_quirks[] = {
{ "CAVIUM", "THUNDERX", 2, 13, MCFG_BUS_ANY, &pci_thunder_ecam_ops,
MCFG_RES_EMPTY},
#endif
+#ifdef CONFIG_PCI_XGENE
+ {"APM ", "XGENE ", 1, 0, MCFG_BUS_ANY,
+ &xgene_v1_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 1, 1, MCFG_BUS_ANY,
+ &xgene_v1_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 1, 2, MCFG_BUS_ANY,
+ &xgene_v1_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 1, 3, MCFG_BUS_ANY,
+ &xgene_v1_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 1, 4, MCFG_BUS_ANY,
+ &xgene_v1_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 2, 0, MCFG_BUS_ANY,
+ &xgene_v1_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 2, 1, MCFG_BUS_ANY,
+ &xgene_v1_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 2, 2, MCFG_BUS_ANY,
+ &xgene_v1_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 2, 3, MCFG_BUS_ANY,
+ &xgene_v1_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 2, 4, MCFG_BUS_ANY,
+ &xgene_v1_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 3, 0, MCFG_BUS_ANY,
+ &xgene_v2_1_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 3, 1, MCFG_BUS_ANY,
+ &xgene_v2_1_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 4, 0, MCFG_BUS_ANY,
+ &xgene_v2_2_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 4, 1, MCFG_BUS_ANY,
+ &xgene_v2_2_pcie_ecam_ops, MCFG_RES_EMPTY},
+ {"APM ", "XGENE ", 4, 2, MCFG_BUS_ANY,
+ &xgene_v2_2_pcie_ecam_ops, MCFG_RES_EMPTY},
+#endif
};
static char mcfg_oem_id[ACPI_OEM_ID_SIZE];
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 8843410..af4f505 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -15,7 +15,7 @@ obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone-dw.o pci-keystone.o
obj-$(CONFIG_PCIE_XILINX) += pcie-xilinx.o
obj-$(CONFIG_PCIE_XILINX_NWL) += pcie-xilinx-nwl.o
-obj-$(CONFIG_PCI_XGENE) += pci-xgene.o
+obj-$(CONFIG_PCI_XGENE) += pci-xgene.o pci-xgene-ecam.o
obj-$(CONFIG_PCI_XGENE_MSI) += pci-xgene-msi.o
obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o
obj-$(CONFIG_PCI_VERSATILE) += pci-versatile.o
diff --git a/drivers/pci/host/pci-xgene-ecam.c b/drivers/pci/host/pci-xgene-ecam.c
new file mode 100644
index 0000000..b66a04f
--- /dev/null
+++ b/drivers/pci/host/pci-xgene-ecam.c
@@ -0,0 +1,280 @@
+/*
+ * APM X-Gene PCIe ECAM fixup driver
+ *
+ * Copyright (c) 2016, Applied Micro Circuits Corporation
+ * Author:
+ * Duc Dang <dhdang at apm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_pci.h>
+#include <linux/pci-acpi.h>
+#include <linux/platform_device.h>
+#include <linux/pci-ecam.h>
+
+#ifdef CONFIG_ACPI
+#define RTDID 0x160
+#define ROOT_CAP_AND_CTRL 0x5C
+
+/* PCIe IP version */
+#define XGENE_PCIE_IP_VER_UNKN 0
+#define XGENE_PCIE_IP_VER_1 1
+#define XGENE_PCIE_IP_VER_2 2
+
+#define XGENE_CSR_LENGTH 0x10000
+
+struct xgene_pcie_acpi_root {
+ void __iomem *csr_base;
+ u32 version;
+};
+
+static int xgene_v1_pcie_ecam_init(struct pci_config_window *cfg)
+{
+ struct xgene_pcie_acpi_root *xgene_root;
+ struct device *dev = cfg->parent;
+ u32 csr_base;
+
+ xgene_root = devm_kzalloc(dev, sizeof(*xgene_root), GFP_KERNEL);
+ if (!xgene_root)
+ return -ENOMEM;
+
+ switch (cfg->res.start) {
+ case 0xE0D0000000ULL:
+ csr_base = 0x1F2B0000;
+ break;
+ case 0xD0D0000000ULL:
+ csr_base = 0x1F2C0000;
+ break;
+ case 0x90D0000000ULL:
+ csr_base = 0x1F2D0000;
+ break;
+ case 0xA0D0000000ULL:
+ csr_base = 0x1F500000;
+ break;
+ case 0xC0D0000000ULL:
+ csr_base = 0x1F510000;
+ break;
+ default:
+ return -ENODEV;
+ }
+
+ xgene_root->csr_base = ioremap(csr_base, XGENE_CSR_LENGTH);
+ if (!xgene_root->csr_base) {
+ kfree(xgene_root);
+ return -ENODEV;
+ }
+
+ xgene_root->version = XGENE_PCIE_IP_VER_1;
+
+ cfg->priv = xgene_root;
+
+ return 0;
+}
+
+static int xgene_v2_1_pcie_ecam_init(struct pci_config_window *cfg)
+{
+ struct xgene_pcie_acpi_root *xgene_root;
+ struct device *dev = cfg->parent;
+ resource_size_t csr_base;
+
+ xgene_root = devm_kzalloc(dev, sizeof(*xgene_root), GFP_KERNEL);
+ if (!xgene_root)
+ return -ENOMEM;
+
+ switch (cfg->res.start) {
+ case 0xC0D0000000ULL:
+ csr_base = 0x1F2B0000;
+ break;
+ case 0xA0D0000000ULL:
+ csr_base = 0x1F2C0000;
+ break;
+ default:
+ return -ENODEV;
+ }
+
+ xgene_root->csr_base = ioremap(csr_base, XGENE_CSR_LENGTH);
+ if (!xgene_root->csr_base) {
+ kfree(xgene_root);
+ return -ENODEV;
+ }
+
+ xgene_root->version = XGENE_PCIE_IP_VER_2;
+
+ cfg->priv = xgene_root;
+
+ return 0;
+}
+
+static int xgene_v2_2_pcie_ecam_init(struct pci_config_window *cfg)
+{
+ struct xgene_pcie_acpi_root *xgene_root;
+ struct device *dev = cfg->parent;
+ resource_size_t csr_base;
+
+ xgene_root = devm_kzalloc(dev, sizeof(*xgene_root), GFP_KERNEL);
+ if (!xgene_root)
+ return -ENOMEM;
+
+ switch (cfg->res.start) {
+ case 0xE0D0000000ULL:
+ csr_base = 0x1F2B0000;
+ break;
+ case 0xA0D0000000ULL:
+ csr_base = 0x1F500000;
+ break;
+ case 0x90D0000000ULL:
+ csr_base = 0x1F2D0000;
+ break;
+ default:
+ return -ENODEV;
+ }
+
+ xgene_root->csr_base = ioremap(csr_base, XGENE_CSR_LENGTH);
+ if (!xgene_root->csr_base) {
+ kfree(xgene_root);
+ return -ENODEV;
+ }
+
+ xgene_root->version = XGENE_PCIE_IP_VER_2;
+
+ cfg->priv = xgene_root;
+
+ return 0;
+}
+/*
+ * For Configuration request, RTDID register is used as Bus Number,
+ * Device Number and Function number of the header fields.
+ */
+static void xgene_pcie_set_rtdid_reg(struct pci_bus *bus, uint devfn)
+{
+ struct pci_config_window *cfg = bus->sysdata;
+ struct xgene_pcie_acpi_root *port = cfg->priv;
+ unsigned int b, d, f;
+ u32 rtdid_val = 0;
+
+ b = bus->number;
+ d = PCI_SLOT(devfn);
+ f = PCI_FUNC(devfn);
+
+ if (!pci_is_root_bus(bus))
+ rtdid_val = (b << 8) | (d << 3) | f;
+
+ writel(rtdid_val, port->csr_base + RTDID);
+ /* read the register back to ensure flush */
+ readl(port->csr_base + RTDID);
+}
+
+/*
+ * X-Gene PCIe port uses BAR0-BAR1 of RC's configuration space as
+ * the translation from PCI bus to native BUS. Entire DDR region
+ * is mapped into PCIe space using these registers, so it can be
+ * reached by DMA from EP devices. The BAR0/1 of bridge should be
+ * hidden during enumeration to avoid the sizing and resource allocation
+ * by PCIe core.
+ */
+static bool xgene_pcie_hide_rc_bars(struct pci_bus *bus, int offset)
+{
+ if (pci_is_root_bus(bus) && ((offset == PCI_BASE_ADDRESS_0) ||
+ (offset == PCI_BASE_ADDRESS_1)))
+ return true;
+
+ return false;
+}
+
+void __iomem *xgene_pcie_ecam_map_bus(struct pci_bus *bus,
+ unsigned int devfn, int where)
+{
+ struct pci_config_window *cfg = bus->sysdata;
+ unsigned int busn = bus->number;
+ void __iomem *base;
+
+ if (busn < cfg->busr.start || busn > cfg->busr.end)
+ return NULL;
+
+ if ((pci_is_root_bus(bus) && devfn != 0) ||
+ xgene_pcie_hide_rc_bars(bus, where))
+ return NULL;
+
+ xgene_pcie_set_rtdid_reg(bus, devfn);
+
+ if (busn > cfg->busr.start)
+ base = cfg->win + (1 << cfg->ops->bus_shift);
+ else
+ base = cfg->win;
+
+ return base + where;
+}
+
+static int xgene_pcie_config_read32(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *val)
+{
+ struct pci_config_window *cfg = bus->sysdata;
+ struct xgene_pcie_acpi_root *port = cfg->priv;
+
+ if (pci_generic_config_read32(bus, devfn, where & ~0x3, 4, val) !=
+ PCIBIOS_SUCCESSFUL)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ /*
+ * The v1 controller has a bug in its Configuration Request
+ * Retry Status (CRS) logic: when CRS is enabled and we read the
+ * Vendor and Device ID of a non-existent device, the controller
+ * fabricates return data of 0xFFFF0001 ("device exists but is not
+ * ready") instead of 0xFFFFFFFF ("device does not exist"). This
+ * causes the PCI core to retry the read until it times out.
+ * Avoid this by not claiming to support CRS.
+ */
+ if (pci_is_root_bus(bus) && (port->version == XGENE_PCIE_IP_VER_1) &&
+ ((where & ~0x3) == ROOT_CAP_AND_CTRL))
+ *val &= ~(PCI_EXP_RTCAP_CRSVIS << 16);
+
+ if (size <= 2)
+ *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1);
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+struct pci_ecam_ops xgene_v1_pcie_ecam_ops = {
+ .bus_shift = 16,
+ .init = xgene_v1_pcie_ecam_init,
+ .pci_ops = {
+ .map_bus = xgene_pcie_ecam_map_bus,
+ .read = xgene_pcie_config_read32,
+ .write = pci_generic_config_write,
+ }
+};
+
+struct pci_ecam_ops xgene_v2_1_pcie_ecam_ops = {
+ .bus_shift = 16,
+ .init = xgene_v2_1_pcie_ecam_init,
+ .pci_ops = {
+ .map_bus = xgene_pcie_ecam_map_bus,
+ .read = xgene_pcie_config_read32,
+ .write = pci_generic_config_write,
+ }
+};
+
+struct pci_ecam_ops xgene_v2_2_pcie_ecam_ops = {
+ .bus_shift = 16,
+ .init = xgene_v2_2_pcie_ecam_init,
+ .pci_ops = {
+ .map_bus = xgene_pcie_ecam_map_bus,
+ .read = xgene_pcie_config_read32,
+ .write = pci_generic_config_write,
+ }
+};
+#endif
diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h
index 35f0e81..40da3e7 100644
--- a/include/linux/pci-ecam.h
+++ b/include/linux/pci-ecam.h
@@ -65,6 +65,11 @@ extern struct pci_ecam_ops pci_thunder_pem_ops;
#ifdef CONFIG_PCI_HOST_THUNDER_ECAM
extern struct pci_ecam_ops pci_thunder_ecam_ops;
#endif
+#ifdef CONFIG_PCI_XGENE
+extern struct pci_ecam_ops xgene_v1_pcie_ecam_ops;
+extern struct pci_ecam_ops xgene_v2_1_pcie_ecam_ops;
+extern struct pci_ecam_ops xgene_v2_2_pcie_ecam_ops;
+#endif
#ifdef CONFIG_PCI_HOST_GENERIC
/* for DT-based PCI controllers that support ECAM */
--
1.9.1
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