[RFC PATCH v2 3/6] pci: Remove priv_flags and use dev->error_state for "disconnected" status

From: Benjamin Herrenschmidt
Date: Fri Aug 17 2018 - 01:14:11 EST


This already represents whether a device is accessible or not,
creating a new flag isn't particularly helpful.

dev->error_state being an int, assigning it doesn't require
an atomic operation per-se. The existing atomic bitop only
protects the field, not anything else anyway.

Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
---

v2. Initialize the io channel state before we try to read the header

drivers/pci/access.c | 12 ++++++------
drivers/pci/msi.c | 4 ++--
drivers/pci/pci.c | 2 +-
drivers/pci/pci.h | 11 ++---------
drivers/pci/probe.c | 4 +++-
include/linux/pci.h | 2 --
6 files changed, 14 insertions(+), 21 deletions(-)

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index a3ad2fe185b9..ad97a3544636 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -535,7 +535,7 @@ EXPORT_SYMBOL(pcie_capability_clear_and_set_dword);

int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val)
{
- if (pci_dev_is_disconnected(dev)) {
+ if (pci_channel_offline(dev)) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
@@ -545,7 +545,7 @@ EXPORT_SYMBOL(pci_read_config_byte);

int pci_read_config_word(const struct pci_dev *dev, int where, u16 *val)
{
- if (pci_dev_is_disconnected(dev)) {
+ if (pci_channel_offline(dev)) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
@@ -556,7 +556,7 @@ EXPORT_SYMBOL(pci_read_config_word);
int pci_read_config_dword(const struct pci_dev *dev, int where,
u32 *val)
{
- if (pci_dev_is_disconnected(dev)) {
+ if (pci_channel_offline(dev)) {
*val = ~0;
return PCIBIOS_DEVICE_NOT_FOUND;
}
@@ -566,7 +566,7 @@ EXPORT_SYMBOL(pci_read_config_dword);

int pci_write_config_byte(const struct pci_dev *dev, int where, u8 val)
{
- if (pci_dev_is_disconnected(dev))
+ if (pci_channel_offline(dev))
return PCIBIOS_DEVICE_NOT_FOUND;
return pci_bus_write_config_byte(dev->bus, dev->devfn, where, val);
}
@@ -574,7 +574,7 @@ EXPORT_SYMBOL(pci_write_config_byte);

int pci_write_config_word(const struct pci_dev *dev, int where, u16 val)
{
- if (pci_dev_is_disconnected(dev))
+ if (pci_channel_offline(dev))
return PCIBIOS_DEVICE_NOT_FOUND;
return pci_bus_write_config_word(dev->bus, dev->devfn, where, val);
}
@@ -583,7 +583,7 @@ EXPORT_SYMBOL(pci_write_config_word);
int pci_write_config_dword(const struct pci_dev *dev, int where,
u32 val)
{
- if (pci_dev_is_disconnected(dev))
+ if (pci_channel_offline(dev))
return PCIBIOS_DEVICE_NOT_FOUND;
return pci_bus_write_config_dword(dev->bus, dev->devfn, where, val);
}
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index f2ef896464b3..2f872db40042 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -298,7 +298,7 @@ void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
{
struct pci_dev *dev = msi_desc_to_pci_dev(entry);

- if (dev->current_state != PCI_D0 || pci_dev_is_disconnected(dev)) {
+ if (dev->current_state != PCI_D0 || pci_channel_offline(dev)) {
/* Don't touch the hardware now */
} else if (entry->msi_attrib.is_msix) {
void __iomem *base = pci_msix_desc_addr(entry);
@@ -975,7 +975,7 @@ static void pci_msix_shutdown(struct pci_dev *dev)
if (!pci_msi_enable || !dev || !dev->msix_enabled)
return;

- if (pci_dev_is_disconnected(dev)) {
+ if (pci_channel_offline(dev)) {
dev->msix_enabled = 0;
return;
}
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 29ff9619b5fa..62591c153999 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5713,7 +5713,7 @@ bool pci_device_is_present(struct pci_dev *pdev)
{
u32 v;

- if (pci_dev_is_disconnected(pdev))
+ if (pci_channel_offline(pdev))
return false;
return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0);
}
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 473aa10a5dbf..f7704333e6a1 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -293,18 +293,11 @@ struct pci_sriov {
bool drivers_autoprobe; /* Auto probing of VFs by driver */
};

-/* pci_dev priv_flags */
-#define PCI_DEV_DISCONNECTED 0
-
static inline int pci_dev_set_disconnected(struct pci_dev *dev, void *unused)
{
- set_bit(PCI_DEV_DISCONNECTED, &dev->priv_flags);
- return 0;
-}
+ dev->error_state = pci_channel_io_perm_failure;

-static inline bool pci_dev_is_disconnected(const struct pci_dev *dev)
-{
- return test_bit(PCI_DEV_DISCONNECTED, &dev->priv_flags);
+ return 0;
}

#ifdef CONFIG_PCIEAER
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 440445ac7dfa..5cf982b3031b 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1581,6 +1581,9 @@ int pci_setup_device(struct pci_dev *dev)
struct pci_bus_region region;
struct resource *res;

+ /* This must be set before any config space access */
+ dev->error_state = pci_channel_io_normal;
+
hdr_type = pci_hdr_type(dev);

dev->sysdata = dev->bus->sysdata;
@@ -1588,7 +1591,6 @@ int pci_setup_device(struct pci_dev *dev)
dev->dev.bus = &pci_bus_type;
dev->hdr_type = hdr_type & 0x7f;
dev->multifunction = !!(hdr_type & 0x80);
- dev->error_state = pci_channel_io_normal;
set_pcie_port_type(dev);

pci_dev_assign_slot(dev);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 9799109c5e25..f58bda204f09 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -443,8 +443,6 @@ struct pci_dev {
phys_addr_t rom; /* Physical address if not from BAR */
size_t romlen; /* Length if not from BAR */
char *driver_override; /* Driver name to force a match */
-
- unsigned long priv_flags; /* Private flags for the PCI driver */
};

static inline struct pci_dev *pci_physfn(struct pci_dev *dev)