Re: [PATCH v2 00/10] Add definition for the number of standard PCI BARs

Andrew Murray
2019-08-16T10:51:38Z

On Fri, Aug 16, 2019 at 12:24:27PM +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.
>
> Changes in v2:
> - Reverse checks in pci_iomap_range,pci_iomap_wc_range.
> - Refactor loops in vfio_pci to keep PCI_STD_RESOURCES.
> - Add 2 new patches to replace the magic constant with new define.
> - Split net patch in v1 to separate stmmac and dwc-xlgmac patches.
>
> Denis Efremov (10):
> PCI: Add define for the number of standard PCI BARs
> s390/pci: Loop using PCI_STD_NUM_BARS
> x86/PCI: Loop using PCI_STD_NUM_BARS
> stmmac: pci: Loop using PCI_STD_NUM_BARS
> net: dwc-xlgmac: Loop using PCI_STD_NUM_BARS
> rapidio/tsi721: Loop using PCI_STD_NUM_BARS
> efifb: Loop using PCI_STD_NUM_BARS
> vfio_pci: Loop using PCI_STD_NUM_BARS
> PCI: hv: Use PCI_STD_NUM_BARS
> PCI: Use PCI_STD_NUM_BARS
>
> 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/controller/pci-hyperv.c | 10 +++++-----
> drivers/pci/pci.c | 11 ++++++-----
> drivers/pci/quirks.c | 4 ++--
> drivers/rapidio/devices/tsi721.c | 2 +-
> drivers/vfio/pci/vfio_pci.c | 11 +++++++----
> drivers/vfio/pci/vfio_pci_config.c | 10 ++++++----
> 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 +
> 17 files changed, 51 insertions(+), 47 deletions(-)

I've come across a few more places where this change can be made. There
may be multiple instances in the same file, but only the first is shown
below:

drivers/misc/pci_endpoint_test.c: for (bar = BAR_0; bar <= BAR_5; bar++) {
drivers/net/ethernet/intel/e1000/e1000_main.c: for (i = BAR_1; i <= BAR_5; i++) {
drivers/net/ethernet/intel/ixgb/ixgb_main.c: for (i = BAR_1; i <= BAR_5; i++) {
drivers/pci/controller/dwc/pci-dra7xx.c: for (bar = BAR_0; bar <= BAR_5; bar++)
drivers/pci/controller/dwc/pci-layerscape-ep.c: for (bar = BAR_0; bar <= BAR_5; bar++)
drivers/pci/controller/dwc/pcie-artpec6.c: for (bar = BAR_0; bar <= BAR_5; bar++)
drivers/pci/controller/dwc/pcie-designware-plat.c: for (bar = BAR_0; bar <= BAR_5; bar++)
drivers/pci/endpoint/functions/pci-epf-test.c: for (bar = BAR_0; bar <= BAR_5; bar++) {
include/linux/pci-epc.h: u64 bar_fixed_size[BAR_5 + 1];
drivers/scsi/pm8001/pm8001_hwi.c: for (bar = 0; bar < 6; bar++) {
drivers/scsi/pm8001/pm8001_init.c: for (bar = 0; bar < 6; bar++) {
drivers/ata/sata_nv.c: for (bar = 0; bar < 6; bar++)
drivers/video/fbdev/core/fbmem.c: for (idx = 0, bar = 0; bar < PCI_ROM_RESOURCE; bar++) {
drivers/staging/gasket/gasket_core.c: for (i = 0; i < GASKET_NUM_BARS; i++) {
drivers/tty/serial/8250/8250_pci.c: for (i = 0; i < PCI_NUM_BAR_RESOURCES; i++) { <-----------

It looks like BARs are often iterated with PCI_NUM_BAR_RESOURCES, there
are a load of these too found with:

git grep PCI_ROM_RESOURCE | grep "< "

I'm happy to share patches if preferred.

Thanks,

Andrew Murray

>
> --
> 2.21.0
>