[PATCH V6 1/5] PCI/ACPI: Extend pci_mcfg_lookup() responsibilities

From: Tomasz Nowicki
Date: Fri Sep 09 2016 - 15:24:57 EST


In preparation for adding MCFG platform specific quirk handling move
CFG resource calculation and ECAM ops assignment to pci_mcfg_lookup().
It becomes the gate for further ops and CFG resource manipulation
in arch-agnostic code (drivers/acpi/pci_mcfg.c).

No functionality changes in this patch.

Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
---
arch/arm64/kernel/pci.c | 17 +++++------------
drivers/acpi/pci_mcfg.c | 28 +++++++++++++++++++++++++---
include/linux/pci-acpi.h | 4 +++-
3 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index acf3872..fb439c7 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -125,24 +125,17 @@ pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
u16 seg = root->segment;
struct pci_config_window *cfg;
struct resource cfgres;
- unsigned int bsz;
+ struct pci_ecam_ops *ecam_ops;
+ int ret;

- /* 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) {
+ ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops);
+ if (ret) {
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);
+ 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));
diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c
index b5b376e..ffcc651 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 {
@@ -35,9 +36,18 @@ struct mcfg_entry {
/* List to save MCFG entries */
static LIST_HEAD(pci_mcfg_list);

-phys_addr_t pci_mcfg_lookup(u16 seg, struct resource *bus_res)
+int pci_mcfg_lookup(struct acpi_pci_root *root, struct resource *cfgres,
+ struct pci_ecam_ops **ecam_ops)
{
+ struct pci_ecam_ops *ops = &pci_generic_ecam_ops;
+ struct resource *bus_res = &root->secondary;
+ u16 seg = root->segment;
struct mcfg_entry *e;
+ struct resource res;
+
+ /* Use address from _CBA if present, otherwise lookup MCFG */
+ if (root->mcfg_addr)
+ goto skip_lookup;

/*
* We expect exact match, unless MCFG entry end bus covers more than
@@ -45,10 +55,22 @@ phys_addr_t pci_mcfg_lookup(u16 seg, struct resource *bus_res)
*/
list_for_each_entry(e, &pci_mcfg_list, list) {
if (e->segment == seg && e->bus_start == bus_res->start &&
- e->bus_end >= bus_res->end)
- return e->addr;
+ e->bus_end >= bus_res->end) {
+ root->mcfg_addr = e->addr;
+ }
+
}

+ if (!root->mcfg_addr)
+ return -ENXIO;
+
+skip_lookup:
+ memset(&res, 0, sizeof(res));
+ res.start = root->mcfg_addr + (bus_res->start << 20);
+ res.end = res.start + (resource_size(bus_res) << 20) - 1;
+ res.flags = IORESOURCE_MEM;
+ *cfgres = res;
+ *ecam_ops = ops;
return 0;
}

diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index 7d63a66..7a4e83a 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -24,7 +24,9 @@ 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);
+struct pci_ecam_ops;
+extern int pci_mcfg_lookup(struct acpi_pci_root *root, struct resource *cfgres,
+ struct pci_ecam_ops **ecam_ops);

static inline acpi_handle acpi_find_root_bridge_handle(struct pci_dev *pdev)
{
--
1.9.1