[PATCH V1 1/2] PCI: thunder: Enable ACPI PCI controller for ThunderX pass2.x silicon version

From: Tomasz Nowicki
Date: Tue Nov 15 2016 - 04:17:57 EST


ThunderX PCIe controller to off-chip devices (so-called PEM) is not fully
compliant with ECAM standard. It uses non-standard configuration space
accessors (see pci_thunder_pem_ops) and custom configuration space granulation
(see bus_shift = 24). In order to access configuration space and
probe PEM as ACPI based PCI host controller we need to add MCFG quirk
infrastructure. This involves:
1. thunder_pem_init() ACPI extension so that we can probe PEM-specific
register ranges analogously to DT
2. Export PEM pci_thunder_pem_ops structure so it is visible to MCFG quirk
code.
3. New quirk entries for each PEM segment. Each contains platform IDs,
mentioned pci_thunder_pem_ops and CFG resources.

Quirk is considered for ThunderX silicon pass2.x only which is identified
via MCFG revision 1.

Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
---
drivers/acpi/pci_mcfg.c | 20 +++++++
drivers/pci/host/pci-thunder-pem.c | 107 ++++++++++++++++++++++++++++++++-----
include/linux/pci-ecam.h | 4 ++
3 files changed, 117 insertions(+), 14 deletions(-)

diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
index ac21db3..e4e2b9b 100644
--- a/drivers/acpi/pci_mcfg.c
+++ b/drivers/acpi/pci_mcfg.c
@@ -57,6 +57,26 @@ static struct mcfg_fixup mcfg_quirks[] = {
{ "QCOM ", "QDF2432 ", 1, 5, MCFG_BUS_ANY, &pci_32b_ops },
{ "QCOM ", "QDF2432 ", 1, 6, MCFG_BUS_ANY, &pci_32b_ops },
{ "QCOM ", "QDF2432 ", 1, 7, MCFG_BUS_ANY, &pci_32b_ops },
+#ifdef CONFIG_PCI_HOST_THUNDER_PEM
+#define THUNDER_MCFG_RES(addr, node) \
+ DEFINE_RES_MEM(addr + (node << 44), 0x39 * SZ_16M)
+#define THUNDER_MCFG_QUIRK(rev, node) \
+ { "CAVIUM", "THUNDERX", rev, 4 + (10 * node), MCFG_BUS_ANY, \
+ &pci_thunder_pem_ops, THUNDER_MCFG_RES(0x88001f000000UL, node) }, \
+ { "CAVIUM", "THUNDERX", rev, 5 + (10 * node), MCFG_BUS_ANY, \
+ &pci_thunder_pem_ops, THUNDER_MCFG_RES(0x884057000000UL, node) }, \
+ { "CAVIUM", "THUNDERX", rev, 6 + (10 * node), MCFG_BUS_ANY, \
+ &pci_thunder_pem_ops, THUNDER_MCFG_RES(0x88808f000000UL, node) }, \
+ { "CAVIUM", "THUNDERX", rev, 7 + (10 * node), MCFG_BUS_ANY, \
+ &pci_thunder_pem_ops, THUNDER_MCFG_RES(0x89001f000000UL, node) }, \
+ { "CAVIUM", "THUNDERX", rev, 8 + (10 * node), MCFG_BUS_ANY, \
+ &pci_thunder_pem_ops, THUNDER_MCFG_RES(0x894057000000UL, node) }, \
+ { "CAVIUM", "THUNDERX", rev, 9 + (10 * node), MCFG_BUS_ANY, \
+ &pci_thunder_pem_ops, THUNDER_MCFG_RES(0x89808f000000UL, node) }
+ /* SoC pass2.x */
+ THUNDER_MCFG_QUIRK(1, 0UL),
+ THUNDER_MCFG_QUIRK(1, 1UL),
+#endif
};

static char mcfg_oem_id[ACPI_OEM_ID_SIZE];
diff --git a/drivers/pci/host/pci-thunder-pem.c b/drivers/pci/host/pci-thunder-pem.c
index 6abaf80..7bdc4cd 100644
--- a/drivers/pci/host/pci-thunder-pem.c
+++ b/drivers/pci/host/pci-thunder-pem.c
@@ -18,6 +18,7 @@
#include <linux/init.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
+#include <linux/pci-acpi.h>
#include <linux/pci-ecam.h>
#include <linux/platform_device.h>

@@ -284,6 +285,84 @@ 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
+
+/*
+ * Retrieve PEM bridge register base and size from PNP0C02 sub-device under
+ * the RC.
+ *
+ * Device (RES0)
+ * {
+ * Name (_HID, "THRX0002")
+ * Name (_CID, "PNP0C02")
+ * Name (_CRS, ResourceTemplate () {
+ * // Device specific registers range
+ * QWordMemory(ResourceConsumer, PosDecode, MinFixed,
+ * MaxFixed, Cacheable, ReadWrite, 0,
+ * 0x87e0c2000000, 0x87E0C2FFFFFF, 0, 0x1000000)
+ * })
+ * }
+ */
+
+static const struct acpi_device_id thunder_pem_reg_ids[] = {
+ {"THRX0002", 0},
+ {"", 0},
+};
+
+static struct resource *thunder_pem_acpi_res(struct pci_config_window *cfg)
+{
+ struct device *dev = cfg->parent;
+ struct acpi_device *adev = to_acpi_device(dev);
+ struct acpi_device *child_adev;
+ struct resource *res_pem;
+
+ res_pem = devm_kzalloc(dev, sizeof(*res_pem), GFP_KERNEL);
+ if (!res_pem) {
+ dev_err(dev, "failed to allocate PEM resource\n");
+ return NULL;
+ }
+
+ list_for_each_entry(child_adev, &adev->children, node) {
+ struct resource_entry *entry;
+ struct list_head list;
+ unsigned long flags;
+ int ret;
+
+ ret = acpi_match_device_ids(child_adev, thunder_pem_reg_ids);
+ if (ret)
+ continue;
+
+ INIT_LIST_HEAD(&list);
+ flags = IORESOURCE_MEM;
+ ret = acpi_dev_get_resources(child_adev, &list,
+ acpi_dev_filter_resource_type_cb,
+ (void *)flags);
+ if (ret < 0) {
+ dev_err(&child_adev->dev,
+ "failed to parse _CRS method, error code %d\n",
+ ret);
+ return NULL;
+ } else if (ret == 0) {
+ dev_err(&child_adev->dev,
+ "no memory resources present in _CRS\n");
+ return NULL;
+ }
+
+ entry = list_first_entry(&list, struct resource_entry, node);
+ *res_pem = *entry->res;
+ acpi_dev_free_resource_list(&list);
+ return res_pem;
+ }
+
+ return NULL;
+}
+#else
+static struct resource *thunder_pem_acpi_res(struct pci_config_window *cfg)
+{
+ return NULL;
+}
+#endif
+
static int thunder_pem_init(struct pci_config_window *cfg)
{
struct device *dev = cfg->parent;
@@ -292,24 +371,24 @@ static int thunder_pem_init(struct pci_config_window *cfg)
struct thunder_pem_pci *pem_pci;
struct platform_device *pdev;

- /* Only OF support for now */
- if (!dev->of_node)
- return -EINVAL;
-
pem_pci = devm_kzalloc(dev, sizeof(*pem_pci), GFP_KERNEL);
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_acpi_res(cfg);
+ }
if (!res_pem) {
- dev_err(dev, "missing \"reg[1]\"property\n");
+ dev_err(dev, "missing configuration region\n");
return -EINVAL;
}

@@ -332,7 +411,7 @@ static int thunder_pem_init(struct pci_config_window *cfg)
return 0;
}

-static struct pci_ecam_ops pci_thunder_pem_ops = {
+struct pci_ecam_ops pci_thunder_pem_ops = {
.bus_shift = 24,
.init = thunder_pem_init,
.pci_ops = {
diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h
index f5740b7..3f2a98f 100644
--- a/include/linux/pci-ecam.h
+++ b/include/linux/pci-ecam.h
@@ -58,6 +58,10 @@ void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
int where);
/* default ECAM ops */
extern struct pci_ecam_ops pci_generic_ecam_ops;
+/* ECAM ops for known quirks */
+#ifdef CONFIG_PCI_HOST_THUNDER_PEM
+extern struct pci_ecam_ops pci_thunder_pem_ops;
+#endif

/* ops for buggy ECAM that supports only 32-bit accesses */
extern struct pci_ecam_ops pci_32b_ops;
--
2.7.4