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

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

[Denis Efremov]

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

[PATCH 1/7] PCI: Add define for the number of standard PCI BARs

[Denis Efremov]

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

[PATCH 4/7] PCI/net: Use PCI_STD_NUM_BARS in loops instead of PCI_STD_RESOURCE_END

[Denis Efremov]

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/net/ethernet/stmicro/stmmac/stmmac_pci.c | 4 ++--
 drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c   | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
index 86f9c07a38cf..cfe496cdd78b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
@@ -258,7 +258,7 @@ static int stmmac_pci_probe(struct pci_dev *pdev,
 	}
 
 	/* Get the base address of device */
-	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
+	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 		if (pci_resource_len(pdev, i) == 0)
 			continue;
 		ret = pcim_iomap_regions(pdev, BIT(i), pci_name(pdev));
@@ -296,7 +296,7 @@ static void stmmac_pci_remove(struct pci_dev *pdev)
 
 	stmmac_dvr_remove(&pdev->dev);
 
-	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
+	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 		if (pci_resource_len(pdev, i) == 0)
 			continue;
 		pcim_iounmap_regions(pdev, BIT(i));
diff --git a/drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c b/drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c
index 386bafe74c3f..fa8604d7b797 100644
--- a/drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c
+++ b/drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c
@@ -34,7 +34,7 @@ static int xlgmac_probe(struct pci_dev *pcidev, const struct pci_device_id *id)
 		return ret;
 	}
 
-	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
+	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 		if (pci_resource_len(pcidev, i) == 0)
 			continue;
 		ret = pcim_iomap_regions(pcidev, BIT(i), XLGMAC_DRV_NAME);
-- 
2.21.0

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

[Andrew Murray]

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
> 

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

[Bjorn Helgaas]

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
> 

Re: [PATCH 4/7] PCI/net: Use PCI_STD_NUM_BARS in loops instead of PCI_STD_RESOURCE_END

[Bjorn Helgaas]

The subject can be simply:

  <prefix>: Loop using PCI_STD_NUM_BARS

to keep them a little shorter so "git log --online" doesn't wrap.

On Sun, Aug 11, 2019 at 06:08:00PM +0300, Denis Efremov wrote:
> This patch refactors the loop condition scheme from
> 'i <= PCI_STD_RESOURCE_END' to 'i < PCI_STD_NUM_BARS'.

  Refactor loops to use 'i < PCI_STD_NUM_BARS' instead of 'i <=
  PCI_STD_RESOURCE_END'.

See https://chris.beams.io/posts/git-commit/

> Signed-off-by: Denis Efremov <efremov@linux.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c | 4 ++--
>  drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c   | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)

This patch touches two unrelated drivers and should be split up.
When you do that, pay attention to the convention for commit log
prefixes, e.g.,

  $ git log --oneline drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
  37e9c087c814 stmmac: pci: Fix typo in IOT2000 comment
  d4a62ea411f9 stmmac: pci: Use pci_dev_id() helper
  e0c1d14a1a32 stmmac: pci: Adjust IOT2000 matching

  $ git log --oneline drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c
  ea8c1c642ea5 net: dwc-xlgmac: declaration of dual license in headers
  65e0ace2c5cd net: dwc-xlgmac: Initial driver for DesignWare Enterprise Ethernet

> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
> index 86f9c07a38cf..cfe496cdd78b 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
> @@ -258,7 +258,7 @@ static int stmmac_pci_probe(struct pci_dev *pdev,
>  	}
>  
>  	/* Get the base address of device */
> -	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
> +	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
>  		if (pci_resource_len(pdev, i) == 0)
>  			continue;
>  		ret = pcim_iomap_regions(pdev, BIT(i), pci_name(pdev));
> @@ -296,7 +296,7 @@ static void stmmac_pci_remove(struct pci_dev *pdev)
>  
>  	stmmac_dvr_remove(&pdev->dev);
>  
> -	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
> +	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
>  		if (pci_resource_len(pdev, i) == 0)
>  			continue;
>  		pcim_iounmap_regions(pdev, BIT(i));
> diff --git a/drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c b/drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c
> index 386bafe74c3f..fa8604d7b797 100644
> --- a/drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c
> +++ b/drivers/net/ethernet/synopsys/dwc-xlgmac-pci.c
> @@ -34,7 +34,7 @@ static int xlgmac_probe(struct pci_dev *pcidev, const struct pci_device_id *id)
>  		return ret;
>  	}
>  
> -	for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
> +	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
>  		if (pci_resource_len(pcidev, i) == 0)
>  			continue;
>  		ret = pcim_iomap_regions(pcidev, BIT(i), XLGMAC_DRV_NAME);
> -- 
> 2.21.0
> 

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

[Thomas Gleixner]

On Mon, 12 Aug 2019, Bjorn Helgaas wrote:

> 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

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

Thanks,

	tglx

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

[Denis Efremov]

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