pciexp: Refactor extended capability handling

Add some inline functions for the bit-wise operations, change the loop
body to an if-bail-out style and remove stateful variables.

Change-Id: Ia8db915f375737064e3486d313383d9b6c3eb2b8
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66458
Reviewed-by: Bill XIE <persmule@hardenedlinux.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Nico Huber 2022-08-05 14:47:35 +02:00 committed by Felix Held
parent b511804169
commit 077dc2eca2
1 changed files with 21 additions and 11 deletions

View File

@ -9,22 +9,32 @@
#include <device/pci_ops.h>
#include <device/pciexp.h>
static unsigned int pciexp_get_ext_cap_offset(const struct device *dev, unsigned int cap,
unsigned int offset)
static unsigned int ext_cap_id(unsigned int cap)
{
return cap & 0xffff;
}
static unsigned int ext_cap_next_offset(unsigned int cap)
{
return cap >> 20;
}
static unsigned int find_ext_cap_offset(const struct device *dev, unsigned int cap_id,
unsigned int offset)
{
unsigned int this_cap_offset = offset;
unsigned int next_cap_offset, this_cap;
while (this_cap_offset != 0) {
this_cap = pci_read_config32(dev, this_cap_offset);
const unsigned int this_cap = pci_read_config32(dev, this_cap_offset);
/* Bail out when this request is unsupported */
if (this_cap == 0xffffffff)
break;
if ((this_cap & 0xffff) == cap) {
if (ext_cap_id(this_cap) == cap_id)
return this_cap_offset;
} else {
next_cap_offset = this_cap >> 20;
this_cap_offset = next_cap_offset;
}
this_cap_offset = ext_cap_next_offset(this_cap);
}
return 0;
@ -46,11 +56,11 @@ unsigned int pciexp_find_extended_cap(const struct device *dev, unsigned int cap
unsigned int next_cap_offset;
if (offset)
next_cap_offset = pci_read_config32(dev, offset) >> 20;
next_cap_offset = ext_cap_next_offset(pci_read_config32(dev, offset));
else
next_cap_offset = PCIE_EXT_CAP_OFFSET;
return pciexp_get_ext_cap_offset(dev, cap, next_cap_offset);
return find_ext_cap_offset(dev, cap, next_cap_offset);
}
/*