From: Tomasz Nowicki <tn@xxxxxxxxxxxx>
Some platforms may not be fully compliant with the generic PCI config
operations. For these cases we implement a way to use custom map and
accessor functions. The algorithm traverses the available quirk list,
matches against <oem_id, oem_table_id, oem_revision, domain, bus number>
tuples and returns corresponding PCI config ops. oem_id, oem_table_id, and
oem_revision come from the MCFG table standard header. All quirks can be
defined using the DECLARE_ACPI_MCFG_FIXUP() macro and are kept self
contained. Example:
/* Custom PCI config ops */
static struct pci_generic_ecam_ops foo_pci_ops = {
.bus_shift = 24,
.pci_ops = {
.map_bus = pci_ecam_map_bus,
.read = foo_ecam_config_read,
.write = foo_ecam_config_write,
}
};
DECLARE_ACPI_MCFG_FIXUP(&foo_pci_ops, "OEM", "TABLE-ID", <revision>,
<domain_nr>, <bus_nr>);
Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
Signed-off-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
Signed-off-by: Christopher Covington <cov@xxxxxxxxxxxxxx>
---
Changes from v2 to v3:
* Match against all three of oem_id, oem_table_id, and oem_revision.
* Perform substring match, so padding oem_id and oem_table_id isn't
required. (Using min_t() thanks to Duc Dang's suggestion.)
* Print when quirk matched.
* Use __UNIQUE_ID() macro to generate a valid, unique symbol name even
when OEM and table IDs contain characters such as dash "-".
* Move extern declaration to header and fix spelling and formatting to
satisfy checkpatch/coding style.
---
drivers/acpi/pci_mcfg.c | 49 ++++++++++++++++++++++++++++++++++++---
include/asm-generic/vmlinux.lds.h | 7 ++++++
include/linux/pci-acpi.h | 24 +++++++++++++++++++
3 files changed, 77 insertions(+), 3 deletions(-)
diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
index b5b376e..2a5d3dd 100644
--- a/drivers/acpi/pci_mcfg.c
+++ b/drivers/acpi/pci_mcfg.c
@@ -22,6 +22,10 @@
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci-acpi.h>
+#include <linux/pci-ecam.h>
+
+/* Root pointer to the mapped MCFG table */
+static struct acpi_table_mcfg *mcfg_table;
/* Structure to hold entries from the MCFG table */
struct mcfg_entry {
@@ -35,6 +39,46 @@ struct mcfg_entry {
/* List to save MCFG entries */
static LIST_HEAD(pci_mcfg_list);
+static bool pci_mcfg_fixup_match(struct pci_cfg_fixup *f,
+ struct acpi_table_header *h)
+{
+ int olen = min_t(u8, strlen(f->oem_id), ACPI_OEM_ID_SIZE);
+ int tlen = min_t(u8, strlen(f->oem_table_id), ACPI_OEM_TABLE_ID_SIZE);
+
+ return (!strncmp(f->oem_id, h->oem_id, olen) &&
+ !strncmp(f->oem_table_id, h->oem_table_id, tlen) &&
+ f->oem_revision == h->oem_revision);
+}
+
+struct pci_ecam_ops *pci_mcfg_get_ops(struct acpi_pci_root *root)
+{
+ int bus_num = root->secondary.start;
+ int domain = root->segment;
+ struct pci_cfg_fixup *f;
+
+ if (!mcfg_table)
+ return &pci_generic_ecam_ops;
+
+ /*
+ * Match against platform specific quirks and return corresponding CAM
+ * ops.
+ *
+ * First match against PCI topology <domain:bus> then use OEM ID, OEM
+ * table ID, and OEM revision from MCFG table standard header.
+ */
+ for (f = __start_acpi_mcfg_fixups; f < __end_acpi_mcfg_fixups; f++) {
+ if ((f->domain == domain || f->domain == PCI_MCFG_DOMAIN_ANY) &&
+ (f->bus_num == bus_num || f->bus_num == PCI_MCFG_BUS_ANY) &&
+ pci_mcfg_fixup_match(f, &mcfg_table->header)) {
+ pr_info("Handling %s %s r%d PCI MCFG quirks\n",
+ f->oem_id, f->oem_table_id, f->oem_revision);
+ return f->ops;
+ }
+ }
+ /* No quirks, use ECAM */
+ return &pci_generic_ecam_ops;
+}
+
phys_addr_t pci_mcfg_lookup(u16 seg, struct resource *bus_res)
{
struct mcfg_entry *e;
@@ -54,7 +98,6 @@ phys_addr_t pci_mcfg_lookup(u16 seg, struct resource *bus_res)
static __init int pci_mcfg_parse(struct acpi_table_header *header)
{
- struct acpi_table_mcfg *mcfg;
struct acpi_mcfg_allocation *mptr;
struct mcfg_entry *e, *arr;
int i, n;
@@ -64,8 +107,8 @@ static __init int pci_mcfg_parse(struct acpi_table_header *header)
n = (header->length - sizeof(struct acpi_table_mcfg)) /
sizeof(struct acpi_mcfg_allocation);
- mcfg = (struct acpi_table_mcfg *)header;
- mptr = (struct acpi_mcfg_allocation *) &mcfg[1];
+ mcfg_table = (struct acpi_table_mcfg *)header;
+ mptr = (struct acpi_mcfg_allocation *) &mcfg_table[1];
arr = kcalloc(n, sizeof(*arr), GFP_KERNEL);
if (!arr)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 6a67ab9..43604fc 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -300,6 +300,13 @@
VMLINUX_SYMBOL(__end_pci_fixups_suspend_late) = .; \
} \
\
+ /* ACPI MCFG quirks */ \
+ .acpi_fixup : AT(ADDR(.acpi_fixup) - LOAD_OFFSET) { \
+ VMLINUX_SYMBOL(__start_acpi_mcfg_fixups) = .; \
+ *(.acpi_fixup_mcfg) \
+ VMLINUX_SYMBOL(__end_acpi_mcfg_fixups) = .; \
+ } \
+ \
/* Built-in firmware blobs */ \
.builtin_fw : AT(ADDR(.builtin_fw) - LOAD_OFFSET) { \
VMLINUX_SYMBOL(__start_builtin_fw) = .; \
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index 7d63a66..dac851b 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -25,6 +25,7 @@ static inline acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
extern phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle);
extern phys_addr_t pci_mcfg_lookup(u16 domain, struct resource *bus_res);
+extern struct pci_ecam_ops *pci_mcfg_get_ops(struct acpi_pci_root *root);
static inline acpi_handle acpi_find_root_bridge_handle(struct pci_dev *pdev)
{
@@ -72,6 +73,29 @@ struct acpi_pci_root_ops {
int (*prepare_resources)(struct acpi_pci_root_info *info);
};
+struct pci_cfg_fixup {
+ struct pci_ecam_ops *ops;
+ char *oem_id;
+ char *oem_table_id;
+ u32 oem_revision;
+ int domain;
+ int bus_num;
+};
+
+extern struct pci_cfg_fixup __start_acpi_mcfg_fixups[];
+extern struct pci_cfg_fixup __end_acpi_mcfg_fixups[];
+
+#define PCI_MCFG_DOMAIN_ANY -1
+#define PCI_MCFG_BUS_ANY -1
+
+/* Designate a routine to fix up buggy MCFG */
+#define DECLARE_ACPI_MCFG_FIXUP(ops, oem, table, rev, dom, bus) \
+ static const struct pci_cfg_fixup \
+ __UNIQUE_ID(mcfg_fixup_) \
+ __used __attribute__((__section__(".acpi_fixup_mcfg"), \
+ aligned((sizeof(void *))))) = \
+ { ops, oem, table, rev, dom, bus }
+
extern int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info);
extern struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
struct acpi_pci_root_ops *ops,
--
Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
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