PCI/ACPI: Extend pci_mcfg_lookup() to return ECAM config accessors

pci_mcfg_lookup() is the external interface to the generic MCFG code.
Previously it merely looked up the ECAM base address for a given domain and
bus range.  We want a way to add MCFG quirks, some of which may require
special config accessors and adjustments to the ECAM address range.

Extend pci_mcfg_lookup() so it can return a pointer to a pci_ecam_ops
structure and a struct resource for the ECAM address space.  For now, it
always returns &pci_generic_ecam_ops (the standard accessor) and the
resource described by the MCFG.

No functional changes intended.

[bhelgaas: changelog]
Signed-off-by: Tomasz Nowicki <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
This commit is contained in:
Tomasz Nowicki 2016-09-09 21:24:03 +02:00 • committed by Bjorn Helgaas
commit 13983eb89d
3 changed files with 33 additions and 16 deletions

View file

@ -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;
}