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Subject[PATCH v3 16/25] PCI/ERR: Use RESPONSE_IS_PCI_ERROR() to check read from hardware
Date
An MMIO read from a PCI device that doesn't exist or doesn't respond
causes a PCI error. There's no real data to return to satisfy the
CPU read, so most hardware fabricates ~0 data.

Use RESPONSE_IS_PCI_ERROR() to check the response we get when we read
data from hardware.

This unifies PCI error response checking and make error checks
consistent and easier to find.

Signed-off-by: Naveen Naidu <naveennaidu479@gmail.com>
---
drivers/pci/pci.c | 10 +++++-----
drivers/pci/probe.c | 10 +++++-----
2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ce2ab62b64cf..4eaf29f004bd 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1077,7 +1077,7 @@ static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
return -EIO;

pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
- if (pmcsr == (u16) ~0) {
+ if (RESPONSE_IS_PCI_ERROR(pmcsr)) {
pci_err(dev, "can't change power state from %s to %s (config space inaccessible)\n",
pci_power_name(dev->current_state),
pci_power_name(state));
@@ -1239,16 +1239,16 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
* After reset, the device should not silently discard config
* requests, but it may still indicate that it needs more time by
* responding to them with CRS completions. The Root Port will
- * generally synthesize ~0 data to complete the read (except when
- * CRS SV is enabled and the read was for the Vendor ID; in that
- * case it synthesizes 0x0001 data).
+ * generally synthesize ~0 (PCI_ERROR_RESPONSE) data to complete
+ * the read (except when CRS SV is enabled and the read was for the
+ * Vendor ID; in that case it synthesizes 0x0001 data).
*
* Wait for the device to return a non-CRS completion. Read the
* Command register instead of Vendor ID so we don't have to
* contend with the CRS SV value.
*/
pci_read_config_dword(dev, PCI_COMMAND, &id);
- while (id == ~0) {
+ while (RESPONSE_IS_PCI_ERROR(id)) {
if (delay > timeout) {
pci_warn(dev, "not ready %dms after %s; giving up\n",
delay - 1, reset_type);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index d9fc02a71baa..8bf4034ddbd4 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -206,14 +206,14 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
* memory BAR or a ROM, bit 0 must be clear; if it's an io BAR, bit
* 1 must be clear.
*/
- if (sz == 0xffffffff)
+ if (RESPONSE_IS_PCI_ERROR(sz))
sz = 0;

/*
* I don't know how l can have all bits set. Copied from old code.
* Maybe it fixes a bug on some ancient platform.
*/
- if (l == 0xffffffff)
+ if (RESPONSE_IS_PCI_ERROR(l))
l = 0;

if (type == pci_bar_unknown) {
@@ -1660,7 +1660,7 @@ static int pci_cfg_space_size_ext(struct pci_dev *dev)

if (pci_read_config_dword(dev, pos, &status) != PCIBIOS_SUCCESSFUL)
return PCI_CFG_SPACE_SIZE;
- if (status == 0xffffffff || pci_ext_cfg_is_aliased(dev))
+ if (RESPONSE_IS_PCI_ERROR(status) || pci_ext_cfg_is_aliased(dev))
return PCI_CFG_SPACE_SIZE;

return PCI_CFG_SPACE_EXP_SIZE;
@@ -2336,8 +2336,8 @@ bool pci_bus_generic_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l,
if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l))
return false;

- /* Some broken boards return 0 or ~0 if a slot is empty: */
- if (*l == 0xffffffff || *l == 0x00000000 ||
+ /* Some broken boards return 0 or ~0 (PCI_ERROR_RESPONSE) if a slot is empty: */
+ if (RESPONSE_IS_PCI_ERROR(*l) || *l == 0x00000000 ||
*l == 0x0000ffff || *l == 0xffff0000)
return false;

--
2.25.1
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