Re: [PATCH v5 03/10] pci: drop some duplicate code

From: Fam Zheng
Date: Wed Apr 01 2015 - 23:52:25 EST


On Sun, 03/29 17:04, Michael S. Tsirkin wrote:
> pci_msi_setup_pci_dev and pci_msi_off share a lot of code.
> This used to be justified since pci_msi_setup_pci_dev
> wasn't compiled in when CONFIG_PCI_MSI is off.
> Now that it is, let's reuse code.
>
> Since pci_msi_off is used by early quirks, doing this requires calling
> pci_msi_setup_pci_dev early after device allocation, so move the call to
> pci_setup_device.

The dropping of duplicated code looks good, but doesn't the moving of
pci_msi_setup_pci_dev call belong to a separate patch?

Fam

>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> ---
> drivers/pci/pci.c | 23 ++++-------------------
> drivers/pci/probe.c | 31 +++++++++++++++----------------
> 2 files changed, 19 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 81f06e8..fcee8ea 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -3106,26 +3106,11 @@ EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx);
> */
> void pci_msi_off(struct pci_dev *dev)
> {
> - int pos;
> - u16 control;
> + if (dev->msi_cap)
> + pci_msi_set_enable(dev, 0);
>
> - /*
> - * This looks like it could go in msi.c, but we need it even when
> - * CONFIG_PCI_MSI=n. For the same reason, we can't use
> - * dev->msi_cap or dev->msix_cap here.
> - */
> - pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
> - if (pos) {
> - pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
> - control &= ~PCI_MSI_FLAGS_ENABLE;
> - pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
> - }
> - pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
> - if (pos) {
> - pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
> - control &= ~PCI_MSIX_FLAGS_ENABLE;
> - pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
> - }
> + if (dev->msix_cap)
> + pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
> }
> EXPORT_SYMBOL_GPL(pci_msi_off);
>
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 50dd934..120772c 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1084,6 +1084,18 @@ int pci_cfg_space_size(struct pci_dev *dev)
>
> #define LEGACY_IO_RESOURCE (IORESOURCE_IO | IORESOURCE_PCI_FIXED)
>
> +static void pci_msi_setup_pci_dev(struct pci_dev *dev)
> +{
> + dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI);
> + dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX);
> +
> + /* Disable the msi hardware to avoid screaming interrupts
> + * during boot. This is the power on reset default so
> + * usually this should be a noop.
> + */
> + pci_msi_off(dev);
> +}
> +
> /**
> * pci_setup_device - fill in class and map information of a device
> * @dev: the device structure to fill
> @@ -1139,6 +1151,9 @@ int pci_setup_device(struct pci_dev *dev)
> /* "Unknown power state" */
> dev->current_state = PCI_UNKNOWN;
>
> + /* MSI/MSI-X setup has to be done early since it's used by quirks. */
> + pci_msi_setup_pci_dev(dev);
> +
> /* Early fixups, before probing the BARs */
> pci_fixup_device(pci_fixup_early, dev);
> /* device class may be changed after fixup */
> @@ -1483,26 +1498,10 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
> return dev;
> }
>
> -static void pci_msi_setup_pci_dev(struct pci_dev *dev)
> -{
> - /* Disable the msi hardware to avoid screaming interrupts
> - * during boot. This is the power on reset default so
> - * usually this should be a noop.
> - */
> - dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI);
> - if (dev->msi_cap)
> - pci_msi_set_enable(dev, 0);
> -
> - dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX);
> - if (dev->msix_cap)
> - pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
> -}
> -
> static void pci_init_capabilities(struct pci_dev *dev)
> {
> /* MSI/MSI-X list */
> pci_msi_init_pci_dev(dev);
> - pci_msi_setup_pci_dev(dev);
>
> /* Buffers for saving PCIe and PCI-X capabilities */
> pci_allocate_cap_save_buffers(dev);
> --
> MST
>
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