[RFC PATCH v4 2/5] PCI/ACPI: Move ACPI ECAM mapping to generic MCFG driver

From: Tomasz Nowicki
Date: Tue Jun 28 2016 - 03:56:30 EST


pci_acpi_setup_ecam_mapping() is not really ARM64 specific so move it out
of arch/arm64/ directory. In preparation for adding MCFG quirk handling
extend pci_acpi_setup_ecam_mapping() functionality to accept custom
PCI config accessors (function's argument).

For ARM64 ACPI based PCI host controller we still use pci_generic_ecam_ops.

Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
---
arch/arm64/kernel/pci.c | 41 ++---------------------------------------
drivers/acpi/pci_mcfg.c | 40 ++++++++++++++++++++++++++++++++++++++++
include/linux/pci-acpi.h | 3 +++
3 files changed, 45 insertions(+), 39 deletions(-)

diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index cb4dee7..addf00c 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -127,44 +127,6 @@ int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
return 0;
}

-/*
- * Lookup the bus range for the domain in MCFG, and set up config space
- * mapping.
- */
-static struct pci_config_window *
-pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
-{
- struct resource *bus_res = &root->secondary;
- u16 seg = root->segment;
- struct pci_config_window *cfg;
- struct resource cfgres;
- unsigned int bsz;
-
- /* Use address from _CBA if present, otherwise lookup MCFG */
- if (!root->mcfg_addr)
- root->mcfg_addr = pci_mcfg_lookup(seg, bus_res);
-
- if (!root->mcfg_addr) {
- dev_err(&root->device->dev, "%04x:%pR ECAM region not found\n",
- seg, bus_res);
- return NULL;
- }
-
- bsz = 1 << pci_generic_ecam_ops.bus_shift;
- cfgres.start = root->mcfg_addr + bus_res->start * bsz;
- cfgres.end = cfgres.start + resource_size(bus_res) * bsz - 1;
- cfgres.flags = IORESOURCE_MEM;
- cfg = pci_ecam_create(&root->device->dev, &cfgres, bus_res,
- &pci_generic_ecam_ops);
- if (IS_ERR(cfg)) {
- dev_err(&root->device->dev, "%04x:%pR error %ld mapping ECAM\n",
- seg, bus_res, PTR_ERR(cfg));
- return NULL;
- }
-
- return cfg;
-}
-
/* release_info: free resources allocated by init_info */
static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
{
@@ -190,7 +152,8 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
if (!ri)
return NULL;

- ri->cfg = pci_acpi_setup_ecam_mapping(root);
+ ri->cfg = pci_acpi_setup_ecam_mapping(root,
+ &pci_generic_ecam_ops.pci_ops);
if (!ri->cfg) {
kfree(ri);
return NULL;
diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
index b5b376e..331b560 100644
--- a/drivers/acpi/pci_mcfg.c
+++ b/drivers/acpi/pci_mcfg.c
@@ -22,6 +22,7 @@
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci-acpi.h>
+#include <linux/pci-ecam.h>

/* Structure to hold entries from the MCFG table */
struct mcfg_entry {
@@ -52,6 +53,45 @@ phys_addr_t pci_mcfg_lookup(u16 seg, struct resource *bus_res)
return 0;
}

+/*
+ * Lookup the bus range for the domain in MCFG, and set up config space
+ * mapping.
+ */
+struct pci_config_window *
+pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root, struct pci_ops *ops)
+{
+ struct resource *bus_res = &root->secondary;
+ u16 seg = root->segment;
+ struct pci_config_window *cfg;
+ struct resource cfgres;
+ struct pci_ecam_ops ecam_ops = {
+ .bus_shift = 20,
+ .pci_ops = *ops,
+ };
+
+ /* Use address from _CBA if present, otherwise lookup MCFG */
+ if (!root->mcfg_addr)
+ root->mcfg_addr = pci_mcfg_lookup(seg, bus_res);
+
+ if (!root->mcfg_addr) {
+ dev_err(&root->device->dev, "%04x:%pR ECAM region not found\n",
+ seg, bus_res);
+ return NULL;
+ }
+
+ cfgres.start = root->mcfg_addr + (bus_res->start << 20);
+ cfgres.end = cfgres.start + (resource_size(bus_res) << 20) - 1;
+ cfgres.flags = IORESOURCE_MEM;
+ cfg = pci_ecam_create(&root->device->dev, &cfgres, bus_res, &ecam_ops);
+ if (IS_ERR(cfg)) {
+ dev_err(&root->device->dev, "%04x:%pR error %ld mapping ECAM\n",
+ seg, bus_res, PTR_ERR(cfg));
+ return NULL;
+ }
+
+ return cfg;
+}
+
static __init int pci_mcfg_parse(struct acpi_table_header *header)
{
struct acpi_table_mcfg *mcfg;
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index 7d63a66..e9bfe00 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -26,6 +26,9 @@ 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_config_window *
+pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root, struct pci_ops *ops);
+
static inline acpi_handle acpi_find_root_bridge_handle(struct pci_dev *pdev)
{
struct pci_bus *pbus = pdev->bus;
--
1.9.1