RE: [RFC PATCH v2 07/32] PCI/portdrv: use PCIe capabilities access functions to simplify implementation

[Kaneshige, Kenji]

> -----Original Message-----
> From: Jiang Liu [mailto:liu...@gmail.com]
> Sent: Wednesday, July 25, 2012 1:31 AM
> To: Bjorn Helgaas; Don Dutile
> Cc: Jiang Liu; Yinghai Lu; Izumi, Taku/泉 拓; Rafael J . Wysocki; Kaneshige,
> Kenji/金重 憲治; Yijing Wang; linux-kernel@vger.kernel.org;
> linux-...@vger.kernel.org; Jiang Liu
> Subject: [RFC PATCH v2 07/32] PCI/portdrv: use PCIe capabilities access
> functions to simplify implementation
> 
> From: Jiang Liu <jiang....@huawei.com>
> 
> Use PCIe capabilities access functions to simplify PCIe portdrv
> implementation.
> 
> Signed-off-by: Jiang Liu <liu...@gmail.com>
> Signed-off-by: Yijing Wang <wangyij...@huawei.com>
> ---
>  drivers/pci/pcie/portdrv_core.c |   20 ++++++++------------
>  drivers/pci/pcie/portdrv_pci.c  |    7 ++-----
>  2 files changed, 10 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/pci/pcie/portdrv_core.c
> b/drivers/pci/pcie/portdrv_core.c
> index bf320a9..37bff83 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -76,7 +76,6 @@ static int pcie_port_enable_msix(struct pci_dev *dev,
> int *vectors, int mask)
>       struct msix_entry *msix_entries;
>       int idx[PCIE_PORT_DEVICE_MAXSERVICES];
>       int nr_entries, status, pos, i, nvec;
> -     u16 reg16;
>       u32 reg32;
> 
>       nr_entries = pci_msix_table_size(dev);
> @@ -120,9 +119,7 @@ static int pcie_port_enable_msix(struct pci_dev *dev,
> int *vectors, int mask)
>                * the value in this field indicates which MSI-X Table entry
> is
>                * used to generate the interrupt message."
>                */
> -             pos = pci_pcie_cap(dev);
> -             pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &reg16);
> -             entry = (reg16 & PCI_EXP_FLAGS_IRQ) >> 9;
> +             entry = (dev->pcie_flags_reg & PCI_EXP_FLAGS_IRQ) >> 9;
>               if (entry >= nr_entries)
>                       goto Error;

I think we need to use pci_read_config_word() for MSI setup.

"Interrupt Message Number" in the PCIe capability register can vary depending
on whether MSI or MSI-x is enabled. Please see PCIe spec for details.

Could you double-check that?

Regards,
Kenji Kaneshige



> 
> @@ -246,7 +243,7 @@ static void cleanup_service_irqs(struct pci_dev *dev)
>   */
>  static int get_port_device_capability(struct pci_dev *dev)
>  {
> -     int services = 0, pos;
> +     int services = 0;
>       u16 reg16;
>       u32 reg32;
>       int cap_mask = 0;
> @@ -265,11 +262,9 @@ static int get_port_device_capability(struct pci_dev
> *dev)
>                       return 0;
>       }
> 
> -     pos = pci_pcie_cap(dev);
> -     pci_read_config_word(dev, pos + PCI_EXP_FLAGS, &reg16);
>       /* Hot-Plug Capable */
> -     if ((cap_mask & PCIE_PORT_SERVICE_HP) && (reg16 &
> PCI_EXP_FLAGS_SLOT)) {
> -             pci_read_config_dword(dev, pos + PCI_EXP_SLTCAP,
> &reg32);
> +     if ((cap_mask & PCIE_PORT_SERVICE_HP)) {
> +             pci_pcie_capability_read_dword(dev, PCI_EXP_SLTCAP,
> &reg32);
>               if (reg32 & PCI_EXP_SLTCAP_HPC) {
>                       services |= PCIE_PORT_SERVICE_HP;
>                       /*
> @@ -277,10 +272,11 @@ static int get_port_device_capability(struct pci_dev
> *dev)
>                        * enabled by the BIOS and the hot-plug service
> driver
>                        * is not loaded.
>                        */
> -                     pos += PCI_EXP_SLTCTL;
> -                     pci_read_config_word(dev, pos, &reg16);
> +                     pci_pcie_capability_read_word(dev,
> +                                                   PCI_EXP_SLTCTL,
> &reg16);
>                       reg16 &= ~(PCI_EXP_SLTCTL_CCIE |
> PCI_EXP_SLTCTL_HPIE);
> -                     pci_write_config_word(dev, pos, reg16);
> +                     pci_pcie_capability_write_word(dev,
> +                                                    PCI_EXP_SLTCTL,
> reg16);
>               }
>       }
>       /* AER capable */
> diff --git a/drivers/pci/pcie/portdrv_pci.c
> b/drivers/pci/pcie/portdrv_pci.c
> index 24d1463..1b2b378 100644
> --- a/drivers/pci/pcie/portdrv_pci.c
> +++ b/drivers/pci/pcie/portdrv_pci.c
> @@ -64,14 +64,11 @@ __setup("pcie_ports=", pcie_port_setup);
>   */
>  void pcie_clear_root_pme_status(struct pci_dev *dev)
>  {
> -     int rtsta_pos;
>       u32 rtsta;
> 
> -     rtsta_pos = pci_pcie_cap(dev) + PCI_EXP_RTSTA;
> -
> -     pci_read_config_dword(dev, rtsta_pos, &rtsta);
> +     pci_pcie_capability_read_dword(dev, PCI_EXP_RTSTA, &rtsta);
>       rtsta |= PCI_EXP_RTSTA_PME;
> -     pci_write_config_dword(dev, rtsta_pos, rtsta);
> +     pci_pcie_capability_write_dword(dev, PCI_EXP_RTSTA, rtsta);
>  }
> 
>  static int pcie_portdrv_restore_config(struct pci_dev *dev)
> --
> 1.7.9.5

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