[PATCH V6 13/13] pci, pci-thunder-pem: Add ACPI support for ThunderX PEM.

Tomasz Nowicki
2016-04-15T17:06:48Z

This patch uses DECLARE_ACPI_MCFG_FIXUP to overwrite PCI config accessors.
Also, it provides alternative way to find additional configuration region:
thunder_pem_get_acpi_res is looking for host bridge's child (_HID "THRX0001")
which contains mentioned configuration region description.
See example below:

Device (PEM0) {
Name (_HID, EISAID ("PNP0A08"))
Name (_CID, EISAID ("PNP0A03"))

[...]

Device (CFG0)
{
Name (_HID, "THRX0001") // PEM configuration space resources
Name (_CRS, ResourceTemplate () {
QWordMemory(ResourceConsumer, PosDecode, MinFixed, MaxFixed,
NonCacheable, ReadWrite, 0, 0x87e0c5000000, 0x87E0C5FFFFFF,
0, 0x01000000)
})
}
}

Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
---
drivers/pci/host/pci-thunder-pem.c | 137 ++++++++++++++++++++++++++++++++++---
1 file changed, 128 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/host/pci-thunder-pem.c b/drivers/pci/host/pci-thunder-pem.c
index 91cfeb9..685cd79 100644
--- a/drivers/pci/host/pci-thunder-pem.c
+++ b/drivers/pci/host/pci-thunder-pem.c
@@ -18,6 +18,7 @@
#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 "../ecam.h"
@@ -259,6 +260,83 @@ static int thunder_pem_config_write(struct pci_bus *bus, unsigned int devfn,
return pci_generic_config_write(bus, devfn, where, size, val);
}

+#ifdef CONFIG_ACPI
+
+struct pem_acpi_res {
+ struct resource resource;
+ int found;
+};
+
+static acpi_status
+thunder_pem_cfg(struct acpi_resource *resource, void *ctx)
+{
+ struct pem_acpi_res *pem_ctx = ctx;
+ struct resource *res = &pem_ctx->resource;
+
+ if ((resource->type != ACPI_RESOURCE_TYPE_ADDRESS64) ||
+ (resource->data.address32.resource_type != ACPI_MEMORY_RANGE))
+ return AE_OK;
+
+ res->start = resource->data.address64.address.minimum;
+ res->end = resource->data.address64.address.maximum;
+ res->flags = IORESOURCE_MEM;
+
+ pem_ctx->found++;
+ return AE_OK;
+}
+
+static acpi_status
+thunder_pem_find_dev(acpi_handle handle, u32 level, void *ctx, void **ret)
+{
+ struct pem_acpi_res *pem_ctx = ctx;
+ struct acpi_device_info *info;
+ acpi_status status = AE_OK;
+
+ status = acpi_get_object_info(handle, &info);
+ if (ACPI_FAILURE(status))
+ return AE_OK;
+
+ if (strncmp(info->hardware_id.string, "THRX0001", 8) != 0)
+ goto out;
+
+ pem_ctx->found = 0;
+ status = acpi_walk_resources(handle, METHOD_NAME__CRS, thunder_pem_cfg,
+ pem_ctx);
+ if (ACPI_FAILURE(status))
+ goto out;
+
+ if (pem_ctx->found)
+ status = AE_CTRL_TERMINATE;
+out:
+ kfree(info);
+ return status;
+}
+
+static struct resource *thunder_pem_get_acpi_res(struct device *dev)
+{
+ struct acpi_device *adev = ACPI_COMPANION(dev);
+ acpi_handle handle = acpi_device_handle(adev);
+ struct pem_acpi_res *pem_ctx;
+ acpi_status status;
+
+ pem_ctx = devm_kzalloc(dev, sizeof(*pem_ctx), GFP_KERNEL);
+ if (!pem_ctx)
+ return NULL;
+
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
+ thunder_pem_find_dev, NULL, pem_ctx, NULL);
+ if (ACPI_FAILURE(status) || !pem_ctx->found)
+ return NULL;
+
+ return &pem_ctx->resource;
+}
+#else
+static struct resource *thunder_pem_get_acpi_res(struct device *dev)
+{
+ return NULL;
+}
+#endif
+
static int thunder_pem_init(struct device *dev, struct pci_config_window *cfg)
{
resource_size_t bar4_start;
@@ -270,16 +348,20 @@ static int thunder_pem_init(struct device *dev, struct pci_config_window *cfg)
if (!pem_pci)
return -ENOMEM;

- pdev = to_platform_device(dev);
-
- /*
- * The second register range is the PEM bridge to the PCIe
- * bus. It has a different config access method than those
- * devices behind the bridge.
- */
- res_pem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ if (acpi_disabled) {
+ pdev = to_platform_device(dev);
+
+ /*
+ * The second register range is the PEM bridge to the PCIe
+ * bus. It has a different config access method than those
+ * devices behind the bridge.
+ */
+ res_pem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ } else {
+ res_pem = thunder_pem_get_acpi_res(dev);
+ }
if (!res_pem) {
- dev_err(dev, "missing \"reg[1]\"property\n");
+ dev_err(dev, "missing configuration region\n");
return -EINVAL;
}

@@ -332,5 +414,42 @@ static struct platform_driver thunder_pem_driver = {
};
module_platform_driver(thunder_pem_driver);

+#ifdef CONFIG_ACPI
+
+static bool thunder_pem_acpi_init(struct pci_cfg_fixup *fixup,
+ struct acpi_pci_root *root)
+{
+ u32 midr = read_cpuid_id();
+
+ return (MIDR_IMPLEMENTOR(midr) == ARM_CPU_IMP_CAVIUM) &&
+ (MIDR_PARTNUM(midr) == CAVIUM_CPU_PART_THUNDERX);
+}
+
+DECLARE_ACPI_MCFG_FIXUP(NULL, thunder_pem_acpi_init, &pci_thunder_pem_ops,
+ 4, PCI_MCFG_BUS_ANY);
+DECLARE_ACPI_MCFG_FIXUP(NULL, thunder_pem_acpi_init, &pci_thunder_pem_ops,
+ 5, PCI_MCFG_BUS_ANY);
+DECLARE_ACPI_MCFG_FIXUP(NULL, thunder_pem_acpi_init, &pci_thunder_pem_ops,
+ 6, PCI_MCFG_BUS_ANY);
+DECLARE_ACPI_MCFG_FIXUP(NULL, thunder_pem_acpi_init, &pci_thunder_pem_ops,
+ 7, PCI_MCFG_BUS_ANY);
+DECLARE_ACPI_MCFG_FIXUP(NULL, thunder_pem_acpi_init, &pci_thunder_pem_ops,
+ 8, PCI_MCFG_BUS_ANY);
+DECLARE_ACPI_MCFG_FIXUP(NULL, thunder_pem_acpi_init, &pci_thunder_pem_ops,
+ 9, PCI_MCFG_BUS_ANY);
+DECLARE_ACPI_MCFG_FIXUP(NULL, thunder_pem_acpi_init, &pci_thunder_pem_ops,
+ 14, PCI_MCFG_BUS_ANY);
+DECLARE_ACPI_MCFG_FIXUP(NULL, thunder_pem_acpi_init, &pci_thunder_pem_ops,
+ 15, PCI_MCFG_BUS_ANY);
+DECLARE_ACPI_MCFG_FIXUP(NULL, thunder_pem_acpi_init, &pci_thunder_pem_ops,
+ 16, PCI_MCFG_BUS_ANY);
+DECLARE_ACPI_MCFG_FIXUP(NULL, thunder_pem_acpi_init, &pci_thunder_pem_ops,
+ 17, PCI_MCFG_BUS_ANY);
+DECLARE_ACPI_MCFG_FIXUP(NULL, thunder_pem_acpi_init, &pci_thunder_pem_ops,
+ 18, PCI_MCFG_BUS_ANY);
+DECLARE_ACPI_MCFG_FIXUP(NULL, thunder_pem_acpi_init, &pci_thunder_pem_ops,
+ 19, PCI_MCFG_BUS_ANY);
+#endif
+
MODULE_DESCRIPTION("Thunder PEM PCIe host driver");
MODULE_LICENSE("GPL v2");
--
1.9.1