On Thu, Sep 19, 2013 at 12:59:17PM +0530, Bharat Bhushan wrote:
> This patch adds interface to get following information
> - Number of MSI regions (which is number of MSI banks for powerpc).
> - Get the region address range: Physical page which have the
> address/addresses used for generating MSI interrupt
> and size of the page.
>
> These are required to create IOMMU (Freescale PAMU) mapping for
> devices which are directly assigned using VFIO.
>
> Signed-off-by: Bharat Bhushan <bharat.bhus...@freescale.com>
> ---
> arch/powerpc/include/asm/machdep.h | 8 +++++++
> arch/powerpc/include/asm/pci.h | 2 +
> arch/powerpc/kernel/msi.c | 18 ++++++++++++++++
> arch/powerpc/sysdev/fsl_msi.c | 39 +++++++++++++++++++++++++++++++++--
> arch/powerpc/sysdev/fsl_msi.h | 11 ++++++++-
> drivers/pci/msi.c | 26 ++++++++++++++++++++++++
> include/linux/msi.h | 8 +++++++
> include/linux/pci.h | 13 ++++++++++++
> 8 files changed, 120 insertions(+), 5 deletions(-)
>
> ...
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index aca7578..6d85c15 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -30,6 +30,20 @@ static int pci_msi_enable = 1;
>
> /* Arch hooks */
>
> +#ifndef arch_msi_get_region_count
> +int arch_msi_get_region_count(void)
> +{
> + return 0;
> +}
> +#endif
> +
> +#ifndef arch_msi_get_region
> +int arch_msi_get_region(int region_num, struct msi_region *region)
> +{
> + return 0;
> +}
> +#endif
This #define strategy is gone; see 4287d824 ("PCI: use weak functions for
MSI arch-specific functions"). Please use the weak function strategy
for your new MSI region functions.
> +
> #ifndef arch_msi_check_device
> int arch_msi_check_device(struct pci_dev *dev, int nvec, int type)
> {
> @@ -903,6 +917,18 @@ void pci_disable_msi(struct pci_dev *dev)
> }
> EXPORT_SYMBOL(pci_disable_msi);
>
> +int msi_get_region_count(void)
> +{
> + return arch_msi_get_region_count();
> +}
> +EXPORT_SYMBOL(msi_get_region_count);
> +
> +int msi_get_region(int region_num, struct msi_region *region)
> +{
> + return arch_msi_get_region(region_num, region);
> +}
> +EXPORT_SYMBOL(msi_get_region);
Please split these interface additions, i.e., the drivers/pci/msi.c,
include/linux/msi.h, and include/linux/pci.h changes, into a separate
patch.
I don't know enough about VFIO to understand why these new interfaces
are needed. Is this the first VFIO IOMMU driver? I see
vfio_iommu_spapr_tce.c and vfio_iommu_type1.c but I don't know if
they're comparable to the Freescale PAMU. Do other VFIO IOMMU
implementations support MSI? If so, do they handle the problem of
mapping the MSI regions in a different way?
> /**
> * pci_msix_table_size - return the number of device's MSI-X table entries
> * @dev: pointer to the pci_dev data structure of MSI-X device function
> diff --git a/include/linux/msi.h b/include/linux/msi.h
> index ee66f3a..ae32601 100644
> --- a/include/linux/msi.h
> +++ b/include/linux/msi.h
> @@ -50,6 +50,12 @@ struct msi_desc {
> struct kobject kobj;
> };
>
> +struct msi_region {
> + int region_num;
> + dma_addr_t addr;
> + size_t size;
> +};
This needs some sort of explanatory comment.
> /*
> * The arch hook for setup up msi irqs
> */
> @@ -58,5 +64,7 @@ void arch_teardown_msi_irq(unsigned int irq);
> int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
> void arch_teardown_msi_irqs(struct pci_dev *dev);
> int arch_msi_check_device(struct pci_dev* dev, int nvec, int type);
> +int arch_msi_get_region_count(void);
> +int arch_msi_get_region(int region_num, struct msi_region *region);
>
> #endif /* LINUX_MSI_H */
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 186540d..2b26a59 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1126,6 +1126,7 @@ struct msix_entry {
> u16 entry; /* driver uses to specify entry, OS writes */
> };
>
> +struct msi_region;
>
> #ifndef CONFIG_PCI_MSI
> static inline int pci_enable_msi_block(struct pci_dev *dev, unsigned int
> nvec)
> @@ -1168,6 +1169,16 @@ static inline int pci_msi_enabled(void)
> {
> return 0;
> }
> +
> +static inline int msi_get_region_count(void)
> +{
> + return 0;
> +}
> +
> +static inline int msi_get_region(int region_num, struct msi_region *region)
> +{
> + return 0;
> +}
> #else
> int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec);
> int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec);
> @@ -1180,6 +1191,8 @@ void pci_disable_msix(struct pci_dev *dev);
> void msi_remove_pci_irq_vectors(struct pci_dev *dev);
> void pci_restore_msi_state(struct pci_dev *dev);
> int pci_msi_enabled(void);
> +int msi_get_region_count(void);
> +int msi_get_region(int region_num, struct msi_region *region);
> #endif
>
> #ifdef CONFIG_PCIEPORTBUS
> --
> 1.7.0.4
>
>
> --
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