[PATCH 0/7] Add definition for the number of standard PCI BARs

Code that iterates over all standard PCI BARs typically uses
PCI_STD_RESOURCE_END, but this is error-prone because it requires
"i <= PCI_STD_RESOURCE_END" rather than something like
"i < PCI_STD_NUM_BARS". We could add such a definition and use it the same
way PCI_SRIOV_NUM_BARS is used. There is already the definition
PCI_BAR_COUNT for s390 only. Thus, this patchset introduces it globally.

The patch is splitted into 7 parts for different drivers/subsystems for
easy readability.

Denis Efremov (7):
  PCI: Add define for the number of standard PCI BARs
  s390/pci: Replace PCI_BAR_COUNT with PCI_STD_NUM_BARS
  x86/PCI: Use PCI_STD_NUM_BARS in loops instead of PCI_STD_RESOURCE_END
  PCI/net: Use PCI_STD_NUM_BARS in loops instead of PCI_STD_RESOURCE_END
  rapidio/tsi721: use PCI_STD_NUM_BARS in loops instead of
    PCI_STD_RESOURCE_END
  efifb: Use PCI_STD_NUM_BARS in loops instead of PCI_STD_RESOURCE_END
  vfio_pci: Use PCI_STD_NUM_BARS in loops instead of
    PCI_STD_RESOURCE_END

 arch/s390/include/asm/pci.h                      |  5 +----
 arch/s390/include/asm/pci_clp.h                  |  6 +++---
 arch/s390/pci/pci.c                              | 16 ++++++++--------
 arch/s390/pci/pci_clp.c                          |  6 +++---
 arch/x86/pci/common.c                            |  2 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c |  4 ++--
 drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c   |  2 +-
 drivers/pci/quirks.c                             |  2 +-
 drivers/rapidio/devices/tsi721.c                 |  2 +-
 drivers/vfio/pci/vfio_pci.c                      |  4 ++--
 drivers/vfio/pci/vfio_pci_config.c               |  2 +-
 drivers/vfio/pci/vfio_pci_private.h              |  4 ++--
 drivers/video/fbdev/efifb.c                      |  2 +-
 include/linux/pci.h                              |  2 +-
 include/uapi/linux/pci_regs.h                    |  1 +
 15 files changed, 29 insertions(+), 31 deletions(-)

-- 
2.21.0

Code that iterates over all standard PCI BARs typically uses
PCI_STD_RESOURCE_END. However, it requires the "unusual" loop condition
"i <= PCI_STD_RESOURCE_END" rather than something more standard like
"i < PCI_STD_NUM_BARS".

This patch adds the definition PCI_STD_NUM_BARS which is equivalent to
"PCI_STD_RESOURCE_END + 1" and updates loop conditions to use it.

Signed-off-by: Denis Efremov <efremov@linux.com>
---
 drivers/pci/quirks.c          | 2 +-
 include/linux/pci.h           | 2 +-
 include/uapi/linux/pci_regs.h | 1 +
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 208aacf39329..02bdf3a0231e 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c

@@ -475,7 +475,7 @@ static void quirk_extend_bar_to_page(struct pci_dev *dev)
 {
 	int i;
 
-	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
+	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 		struct resource *r = &dev->resource[i];
 
 		if (r->flags & IORESOURCE_MEM && resource_size(r) < PAGE_SIZE) {

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 9e700d9f9f28..7b9590d5dc2d 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h

@@ -76,7 +76,7 @@ enum pci_mmap_state {
 enum {
 	/* #0-5: standard PCI resources */
 	PCI_STD_RESOURCES,
-	PCI_STD_RESOURCE_END = 5,
+	PCI_STD_RESOURCE_END = PCI_STD_RESOURCES + PCI_STD_NUM_BARS - 1,
 
 	/* #6: expansion ROM resource */
 	PCI_ROM_RESOURCE,

diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index f28e562d7ca8..68b571d491eb 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h

@@ -34,6 +34,7 @@
  * of which the first 64 bytes are standardized as follows:
  */
 #define PCI_STD_HEADER_SIZEOF	64
+#define PCI_STD_NUM_BARS	6	/* Number of standard BARs */
 #define PCI_VENDOR_ID		0x00	/* 16 bits */
 #define PCI_DEVICE_ID		0x02	/* 16 bits */
 #define PCI_COMMAND		0x04	/* 16 bits */

-- 
2.21.0

This patch refactors the loop condition scheme from
'i <= PCI_STD_RESOURCE_END' to 'i < PCI_STD_NUM_BARS'.

Signed-off-by: Denis Efremov <efremov@linux.com>
---
 drivers/video/fbdev/efifb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
index 04a22663b4fb..6c72b825e92a 100644
--- a/drivers/video/fbdev/efifb.c
+++ b/drivers/video/fbdev/efifb.c

@@ -668,7 +668,7 @@ static void efifb_fixup_resources(struct pci_dev *dev)
 	if (!base)
 		return;
 
-	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
+	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 		struct resource *res = &dev->resource[i];
 
 		if (!(res->flags & IORESOURCE_MEM))

-- 
2.21.0

On Sun, Aug 11, 2019 at 06:07:55PM +0300, Denis Efremov wrote:

Code that iterates over all standard PCI BARs typically uses
PCI_STD_RESOURCE_END, but this is error-prone because it requires
"i <= PCI_STD_RESOURCE_END" rather than something like
"i < PCI_STD_NUM_BARS". We could add such a definition and use it the same
way PCI_SRIOV_NUM_BARS is used. There is already the definition
PCI_BAR_COUNT for s390 only. Thus, this patchset introduces it globally.

The patch is splitted into 7 parts for different drivers/subsystems for
easy readability.

Denis Efremov (7):
  PCI: Add define for the number of standard PCI BARs
  s390/pci: Replace PCI_BAR_COUNT with PCI_STD_NUM_BARS
  x86/PCI: Use PCI_STD_NUM_BARS in loops instead of PCI_STD_RESOURCE_END
  PCI/net: Use PCI_STD_NUM_BARS in loops instead of PCI_STD_RESOURCE_END
  rapidio/tsi721: use PCI_STD_NUM_BARS in loops instead of
    PCI_STD_RESOURCE_END
  efifb: Use PCI_STD_NUM_BARS in loops instead of PCI_STD_RESOURCE_END
  vfio_pci: Use PCI_STD_NUM_BARS in loops instead of
    PCI_STD_RESOURCE_END

 arch/s390/include/asm/pci.h                      |  5 +----
 arch/s390/include/asm/pci_clp.h                  |  6 +++---
 arch/s390/pci/pci.c                              | 16 ++++++++--------
 arch/s390/pci/pci_clp.c                          |  6 +++---
 arch/x86/pci/common.c                            |  2 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c |  4 ++--
 drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c   |  2 +-
 drivers/pci/quirks.c                             |  2 +-
 drivers/rapidio/devices/tsi721.c                 |  2 +-
 drivers/vfio/pci/vfio_pci.c                      |  4 ++--
 drivers/vfio/pci/vfio_pci_config.c               |  2 +-
 drivers/vfio/pci/vfio_pci_private.h              |  4 ++--
 drivers/video/fbdev/efifb.c                      |  2 +-
 include/linux/pci.h                              |  2 +-
 include/uapi/linux/pci_regs.h                    |  1 +

Hi Denis,

You could also fix up a few cases where the number of BARs is hard coded in
loops, e.g.

drivers/pci/controller/pci-hyperv.c - look for uses of probed_bar in loops
drivers/pci/pci.c - pci_release_selected_regions and __pci_request_selected_regions
drivers/pci/quirks.c - quirk_alder_ioapic

Thanks,

Andrew Murray

 15 files changed, 29 insertions(+), 31 deletions(-)

-- 
2.21.0

On Sun, Aug 11, 2019 at 06:07:55PM +0300, Denis Efremov wrote:

Code that iterates over all standard PCI BARs typically uses
PCI_STD_RESOURCE_END, but this is error-prone because it requires
"i <= PCI_STD_RESOURCE_END" rather than something like
"i < PCI_STD_NUM_BARS". We could add such a definition and use it the same
way PCI_SRIOV_NUM_BARS is used. There is already the definition
PCI_BAR_COUNT for s390 only. Thus, this patchset introduces it globally.

The patch is splitted into 7 parts for different drivers/subsystems for
easy readability.

This looks good.  I can take all these together, since they all depend
on the first patch.  I have a few comments on the individual patches.

Denis Efremov (7):
  PCI: Add define for the number of standard PCI BARs
  s390/pci: Replace PCI_BAR_COUNT with PCI_STD_NUM_BARS
  x86/PCI: Use PCI_STD_NUM_BARS in loops instead of PCI_STD_RESOURCE_END
  PCI/net: Use PCI_STD_NUM_BARS in loops instead of PCI_STD_RESOURCE_END
  rapidio/tsi721: use PCI_STD_NUM_BARS in loops instead of
    PCI_STD_RESOURCE_END
  efifb: Use PCI_STD_NUM_BARS in loops instead of PCI_STD_RESOURCE_END
  vfio_pci: Use PCI_STD_NUM_BARS in loops instead of
    PCI_STD_RESOURCE_END

 arch/s390/include/asm/pci.h                      |  5 +----
 arch/s390/include/asm/pci_clp.h                  |  6 +++---
 arch/s390/pci/pci.c                              | 16 ++++++++--------
 arch/s390/pci/pci_clp.c                          |  6 +++---
 arch/x86/pci/common.c                            |  2 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c |  4 ++--
 drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c   |  2 +-
 drivers/pci/quirks.c                             |  2 +-
 drivers/rapidio/devices/tsi721.c                 |  2 +-
 drivers/vfio/pci/vfio_pci.c                      |  4 ++--
 drivers/vfio/pci/vfio_pci_config.c               |  2 +-
 drivers/vfio/pci/vfio_pci_private.h              |  4 ++--
 drivers/video/fbdev/efifb.c                      |  2 +-
 include/linux/pci.h                              |  2 +-
 include/uapi/linux/pci_regs.h                    |  1 +
 15 files changed, 29 insertions(+), 31 deletions(-)

-- 
2.21.0

On Mon, 12 Aug 2019, Bjorn Helgaas wrote:

On Sun, Aug 11, 2019 at 06:07:55PM +0300, Denis Efremov wrote:

quoted

Code that iterates over all standard PCI BARs typically uses
PCI_STD_RESOURCE_END, but this is error-prone because it requires
"i <= PCI_STD_RESOURCE_END" rather than something like
"i < PCI_STD_NUM_BARS". We could add such a definition and use it the same
way PCI_SRIOV_NUM_BARS is used. There is already the definition
PCI_BAR_COUNT for s390 only. Thus, this patchset introduces it globally.

The patch is splitted into 7 parts for different drivers/subsystems for
easy readability.

This looks good.  I can take all these together, since they all depend
on the first patch.  I have a few comments on the individual patches.

quoted

Denis Efremov (7):
  PCI: Add define for the number of standard PCI BARs
  s390/pci: Replace PCI_BAR_COUNT with PCI_STD_NUM_BARS
  x86/PCI: Use PCI_STD_NUM_BARS in loops instead of PCI_STD_RESOURCE_END

Fine with me for the x86 part. That's your turf anyway :)

Thanks,

	tglx

On 12.08.2019 12:06, Andrew Murray wrote:

Hi Denis,

Hi!

You could also fix up a few cases where the number of BARs is hard coded in
loops, e.g.

drivers/pci/controller/pci-hyperv.c - look for uses of probed_bar in loops
drivers/pci/pci.c - pci_release_selected_regions and __pci_request_selected_regions
drivers/pci/quirks.c - quirk_alder_ioapic

Thanks for pointing me on that. I will take this into account in v2.

Denis

On 8/11/19 5:08 PM, Denis Efremov wrote:

This patch refactors the loop condition scheme from
'i <= PCI_STD_RESOURCE_END' to 'i < PCI_STD_NUM_BARS'.

Signed-off-by: Denis Efremov <efremov@linux.com>

Acked-by: Bartlomiej Zolnierkiewicz <redacted>

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics