[PATCH] pci, pci-thunder-ecam: Add driver for ThunderX-pass1 on-chip ECAM devices

From: David Daney
Date: Tue Jan 26 2016 - 17:03:16 EST


From: David Daney <david.daney@xxxxxxxxxx>

The cavium,pci-thunder-ecam devices are exactly ECAM based PCI roots.
They are special in that all the BARs are at fixed addresses. To
handle this in a manner compatible with the core PCI code, we have the
config access functions synthesize Enhanced Allocation capability
entries for each BAR.

Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
---

This patch depends on the patch set here:

https://lkml.org/lkml/2016/1/26/921

.../devicetree/bindings/pci/pci-thunder-ecam.txt | 30 ++
drivers/pci/host/Kconfig | 7 +
drivers/pci/host/Makefile | 1 +
drivers/pci/host/pci-thunder-ecam.c | 358 +++++++++++++++++++++
4 files changed, 396 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pci/pci-thunder-ecam.txt
create mode 100644 drivers/pci/host/pci-thunder-ecam.c

diff --git a/Documentation/devicetree/bindings/pci/pci-thunder-ecam.txt b/Documentation/devicetree/bindings/pci/pci-thunder-ecam.txt
new file mode 100644
index 0000000..34658f2
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/pci-thunder-ecam.txt
@@ -0,0 +1,30 @@
+* ThunderX PCI host controller for pass-1.x silicon
+
+Firmware-initialized PCI host controller to on-chip devices found on
+some Cavium ThunderX processors. These devices have ECAM based config
+access, but the BARs are all at fixed addresses. We handle the fixed
+addresses by synthesizing Enhanced Allocation (EA) capabilities for
+these devices.
+
+The properties and their meanings are identical to those described in
+host-generic-pci.txt except as listed below.
+
+Properties of the host controller node that differ from
+host-generic-pci.txt:
+
+- compatible : Must be "cavium,pci-host-thunder-ecam"
+
+Example:
+
+ pci@84b0,00000000 {
+ compatible = "cavium,pci-host-thunder-ecam";
+ device_type = "pci";
+ msi-parent = <&its>;
+ msi-map = <0 &its 0x30000 0x10000>;
+ bus-range = <0 31>;
+ #size-cells = <2>;
+ #address-cells = <3>;
+ #stream-id-cells = <1>;
+ reg = <0x84b0 0x00000000 0 0x02000000>; /* Configuration space */
+ ranges = <0x03000000 0x8180 0x00000000 0x8180 0x00000000 0x80 0x00000000>; /* mem ranges */
+ };
diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index 184df22..f8912c6 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -202,4 +202,11 @@ config PCI_HOST_THUNDER_PEM
help
Say Y here if you want PCIe support for CN88XX Cavium Thunder SoCs.

+config PCI_HOST_THUNDER_ECAM
+ bool "Cavium Thunder ECAMe controller to on-chip devices on pass-1.x silicon"
+ depends on OF && ARM64
+ select PCI_HOST_COMMON
+ help
+ Say Y here if you want ECAM support for CN88XX-Pass-1.x Cavium Thunder SoCs.
+
endmenu
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 8903172..d6af3ba 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -23,4 +23,5 @@ obj-$(CONFIG_PCIE_ALTERA) += pcie-altera.o
obj-$(CONFIG_PCIE_ALTERA_MSI) += pcie-altera-msi.o
obj-$(CONFIG_PCI_HISI) += pcie-hisi.o
obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o
+obj-$(CONFIG_PCI_HOST_THUNDER_ECAM) += pci-thunder-ecam.o
obj-$(CONFIG_PCI_HOST_THUNDER_PEM) += pci-thunder-pem.o
diff --git a/drivers/pci/host/pci-thunder-ecam.c b/drivers/pci/host/pci-thunder-ecam.c
new file mode 100644
index 0000000..0979349
--- /dev/null
+++ b/drivers/pci/host/pci-thunder-ecam.c
@@ -0,0 +1,358 @@
+/*
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2015 Cavium, Inc.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/of_pci.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include "pci-host-common.h"
+
+static void set_val(u32 v, int where, int size, u32 *val)
+{
+ int shift = (where & 3) * 8;
+
+ pr_debug("set_val %04x: %08x\n", (unsigned)(where & ~3), v);
+ v >>= shift;
+ if (size == 1)
+ v &= 0xff;
+ else if (size == 2)
+ v &= 0xffff;
+ *val = v;
+}
+
+static int handle_ea_bar(u32 e0, int bar, struct pci_bus *bus,
+ unsigned int devfn, int where, int size, u32 *val)
+{
+ void __iomem *addr;
+ u32 v;
+ /*
+ * Each entry is 16-byte aligned bits[2,3] select which word
+ * in the entry
+ */
+ int where_a = where & 0xc;
+
+ if (where_a == 0) {
+ set_val(e0, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a == 0x4) {
+ addr = bus->ops->map_bus(bus, devfn, bar); /* BAR 0 */
+ if (!addr) {
+ *val = ~0;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+ v = readl(addr);
+ v &= ~0xf;
+ v |= 2; /* EA entry-1. Base-L */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a == 0x8) {
+ u32 barl_orig;
+ u32 barl_rb;
+
+ addr = bus->ops->map_bus(bus, devfn, bar); /* BAR 0 */
+ if (!addr) {
+ *val = ~0;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+ barl_orig = readl(addr + 0);
+ writel(0xffffffff, addr + 0);
+ barl_rb = readl(addr + 0);
+ writel(barl_orig, addr + 0);
+ /* zeros in unsettable bits. */
+ v = ~barl_rb & ~3;
+ v |= 0xc; /* EA entry-2. Offset-L */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a == 0xc) {
+ addr = bus->ops->map_bus(bus, devfn, bar + 4); /* BAR 1 */
+ if (!addr) {
+ *val = ~0;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+ v = readl(addr); /* EA entry-3. Base-H */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ return PCIBIOS_DEVICE_NOT_FOUND;
+}
+
+static int thunder_ecam_config_write(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 val)
+{
+ /*
+ * All BARs have fixed addresses, ignore BAR writes so they
+ * don't get corrupted.
+ */
+ if ((where >= 0x10 && where < 0x2c) ||
+ (where >= 0x1a4 && where < 0x1bc))
+ /* BAR or SRIOV BAR */
+ return PCIBIOS_SUCCESSFUL;
+
+ return pci_generic_config_write(bus, devfn, where, size, val);
+}
+
+static int thunder_ecam_config_read(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *val)
+{
+ u32 v;
+ u32 vendor_device;
+ void __iomem *addr;
+ int cfg_type;
+ int where_a = where & ~3;
+
+
+ addr = bus->ops->map_bus(bus, devfn, 0xc);
+ if (!addr) {
+ *val = ~0;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+
+ v = readl(addr);
+
+ /* Check for non type-00 header. */
+ cfg_type = (v >> 16) & 0x7f;
+
+ /*
+ * All BARs have fixed addresses specified by the EA
+ * capability, they must return zero on read.
+ */
+ if (cfg_type == 0 &&
+ ((where >= 0x10 && where < 0x2c) ||
+ (where >= 0x1a4 && where < 0x1bc))) {
+ /* BAR or SRIOV BAR */
+ *val = 0;
+ return PCIBIOS_SUCCESSFUL;
+ }
+
+ addr = bus->ops->map_bus(bus, devfn, 0);
+ if (!addr) {
+ *val = ~0;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+
+ vendor_device = readl(addr);
+ if (vendor_device == 0xffffffff)
+ goto no_emulation;
+
+ addr = bus->ops->map_bus(bus, devfn, 8);
+ if (!addr) {
+ *val = ~0;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+
+ v = readl(addr);
+ if (v == 0xffffffff)
+ goto no_emulation;
+
+ pr_debug("%04x:%04x - Fix pass#: %08x, where: %03x, devfn: %03x\n",
+ vendor_device & 0xffff, vendor_device >> 16, v,
+ (unsigned) where, devfn);
+
+ /* Check for non type-00 header. */
+ if (cfg_type == 0) {
+ bool has_msix;
+ bool is_nic = (vendor_device == 0xa01e177d);
+ bool is_tns = (vendor_device == 0xa01f177d);
+
+ addr = bus->ops->map_bus(bus, devfn, 0x70);
+ if (!addr) {
+ *val = ~0;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+ /* E_CAP */
+ v = readl(addr);
+ has_msix = (v & 0xff00) != 0;
+
+ if (!has_msix && where_a == 0x70) {
+ v |= 0xbc00; /* next capability is EA at 0xbc */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a == 0xb0) {
+ addr = bus->ops->map_bus(bus, devfn, where_a);
+ if (!addr) {
+ *val = ~0;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+ v = readl(addr);
+ if (v & 0xff00)
+ pr_err("Bad MSIX cap header: %08x\n", v);
+ v |= 0xbc00; /* next capability is EA at 0xbc */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a == 0xbc) {
+ if (is_nic)
+ v = 0x40014; /* EA last in chain, 4 entries. */
+ else if (is_tns)
+ v = 0x30014; /* EA last in chain, 3 entries. */
+ else if (has_msix)
+ v = 0x20014; /* EA last in chain, 2 entries. */
+ else
+ v = 0x10014; /* EA last in chain, 1 entry. */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a >= 0xc0 && where_a < 0xd0)
+ /* EA entry-0. PP=0, BAR0 Size:3 */
+ return handle_ea_bar(0x80ff0003,
+ 0x10, bus, devfn, where,
+ size, val);
+ if (where_a >= 0xd0 && where_a < 0xe0 && has_msix)
+ /* EA entry-1. PP=0, BAR4 Size:3 */
+ return handle_ea_bar(0x80ff0043,
+ 0x20, bus, devfn, where,
+ size, val);
+ if (where_a >= 0xe0 && where_a < 0xf0 && is_tns)
+ /* EA entry-2. PP=0, BAR2, Size:3 */
+ return handle_ea_bar(0x80ff0023,
+ 0x18, bus, devfn, where,
+ size, val);
+ if (where_a >= 0xe0 && where_a < 0xf0 && is_nic)
+ /* EA entry-2. PP=4, VF_BAR0 (9), Size:3 */
+ return handle_ea_bar(0x80ff0493,
+ 0x1a4, bus, devfn, where,
+ size, val);
+ if (where_a >= 0xf0 && where_a < 0x100 && is_nic)
+ /* EA entry-3. PP=4, VF_BAR4 (d), Size:3 */
+ return handle_ea_bar(0x80ff04d3,
+ 0x1b4, bus, devfn, where,
+ size, val);
+ } else if (cfg_type == 1) {
+ bool is_rsl_bridge = devfn == 0x08;
+ bool is_rad_bridge = devfn == 0xa0;
+ bool is_zip_bridge = devfn == 0xa8;
+ bool is_dfa_bridge = devfn == 0xb0;
+ bool is_nic_bridge = devfn == 0x10;
+
+ if (where_a == 0x70) {
+ addr = bus->ops->map_bus(bus, devfn, where_a);
+ if (!addr) {
+ *val = ~0;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+ v = readl(addr);
+ if (v & 0xff00)
+ pr_err("Bad PCIe cap header: %08x\n", v);
+ v |= 0xbc00; /* next capability is EA at 0xbc */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a == 0xbc) {
+ if (is_nic_bridge)
+ v = 0x10014; /* EA last in chain, 1 entry */
+ else
+ v = 0x00014; /* EA last in chain, no entries */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a == 0xc0) {
+ if (is_rsl_bridge || is_nic_bridge)
+ v = 0x0101; /* subordinate:secondary = 1:1 */
+ else if (is_rad_bridge)
+ v = 0x0202; /* subordinate:secondary = 2:2 */
+ else if (is_zip_bridge)
+ v = 0x0303; /* subordinate:secondary = 3:3 */
+ else if (is_dfa_bridge)
+ v = 0x0404; /* subordinate:secondary = 4:4 */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a == 0xc4 && is_nic_bridge) {
+ /* Enabled, not-Write, SP=ff, PP=05, BEI=6, ES=4 */
+ v = 0x80ff0564;
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a == 0xc8 && is_nic_bridge) {
+ v = 0x00000002; /* Base-L 64-bit */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a == 0xcc && is_nic_bridge) {
+ v = 0xfffffffe; /* MaxOffset-L 64-bit */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a == 0xd0 && is_nic_bridge) {
+ v = 0x00008430; /* NIC Base-H */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ if (where_a == 0xd4 && is_nic_bridge) {
+ v = 0x0000000f; /* MaxOffset-H */
+ set_val(v, where, size, val);
+ return PCIBIOS_SUCCESSFUL;
+ }
+ }
+no_emulation:
+ return pci_generic_config_read(bus, devfn, where, size, val);
+}
+
+/* Mapping is standard ECAM */
+static void __iomem *thunder_ecam_map_bus(struct pci_bus *bus,
+ unsigned int devfn,
+ int where)
+{
+ struct gen_pci *pci = bus->sysdata;
+ resource_size_t idx = bus->number - pci->cfg.bus_range->start;
+
+ return pci->cfg.win[idx] + ((devfn << 12) | where);
+}
+
+static struct gen_pci_cfg_bus_ops thunder_ecam_bus_ops = {
+ .bus_shift = 20,
+ .ops = {
+ .map_bus = thunder_ecam_map_bus,
+ .read = thunder_ecam_config_read,
+ .write = thunder_ecam_config_write,
+ }
+};
+
+static const struct of_device_id thunder_ecam_of_match[] = {
+ { .compatible = "cavium,pci-host-thunder-ecam",
+ .data = &thunder_ecam_bus_ops },
+
+ { },
+};
+MODULE_DEVICE_TABLE(of, thunder_ecam_of_match);
+
+static int thunder_ecam_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ const struct of_device_id *of_id;
+ struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
+
+ if (!pci)
+ return -ENOMEM;
+
+ of_id = of_match_node(thunder_ecam_of_match, dev->of_node);
+ pci->cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
+
+ return pci_host_common_probe(pdev, pci);
+}
+
+static struct platform_driver thunder_ecam_driver = {
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .of_match_table = thunder_ecam_of_match,
+ },
+ .probe = thunder_ecam_probe,
+};
+module_platform_driver(thunder_ecam_driver);
+
+MODULE_DESCRIPTION("Thunder ECAM PCI host driver");
+MODULE_LICENSE("GPL v2");
--
1.8.3.1