Re: [PATCH v2 2/2] AMD IOMMU: use ioremap()

[Suravee Suthikulanit <suravee.suthikulpanit@amd.com>]

On 7/11/2013 3:22 AM, Jan Beulich wrote:
> There's no point in using the fixmap here, and it gets
> map_iommu_mmio_region() in line with unmap_iommu_mmio_region(), which
> was already using iounmap() (thus crashing if actually used).
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Acked-by: Keir Fraser <keir@xen.org>
Acked-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>

> ---
> v2: Fix polarity of error check (thanks for noticing, Suravee).
>
> --- a/xen/drivers/passthrough/amd/iommu_init.c
> +++ b/xen/drivers/passthrough/amd/iommu_init.c
> @@ -48,19 +48,10 @@ static int iommu_has_ht_flag(struct amd_
>   
>   static int __init map_iommu_mmio_region(struct amd_iommu *iommu)
>   {
> -    unsigned long mfn;
> -
> -    if ( nr_amd_iommus > MAX_AMD_IOMMUS )
> -    {
> -        AMD_IOMMU_DEBUG("nr_amd_iommus %d > MAX_IOMMUS\n", nr_amd_iommus);
> +    iommu->mmio_base = ioremap(iommu->mmio_base_phys,
> +                               IOMMU_MMIO_REGION_LENGTH);
> +    if ( !iommu->mmio_base )
>           return -ENOMEM;
> -    }
> -
> -    iommu->mmio_base = (void *)fix_to_virt(
> -        FIX_IOMMU_MMIO_BASE_0 + nr_amd_iommus * MMIO_PAGES_PER_IOMMU);
> -    mfn = (unsigned long)(iommu->mmio_base_phys >> PAGE_SHIFT);
> -    map_pages_to_xen((unsigned long)iommu->mmio_base, mfn,
> -                     MMIO_PAGES_PER_IOMMU, PAGE_HYPERVISOR_NOCACHE);
>   
>       memset(iommu->mmio_base, 0, IOMMU_MMIO_REGION_LENGTH);
>   
> --- a/xen/include/asm-x86/fixmap.h
> +++ b/xen/include/asm-x86/fixmap.h
> @@ -60,8 +60,6 @@ enum fixed_addresses {
>       FIX_KEXEC_BASE_0,
>       FIX_KEXEC_BASE_END = FIX_KEXEC_BASE_0 \
>         + ((KEXEC_XEN_NO_PAGES >> 1) * KEXEC_IMAGE_NR) - 1,
> -    FIX_IOMMU_MMIO_BASE_0,
> -    FIX_IOMMU_MMIO_END = FIX_IOMMU_MMIO_BASE_0 + IOMMU_PAGES -1,
>       FIX_TBOOT_SHARED_BASE,
>       FIX_MSIX_IO_RESERV_BASE,
>       FIX_MSIX_IO_RESERV_END = FIX_MSIX_IO_RESERV_BASE + FIX_MSIX_MAX_PAGES -1,
> --- a/xen/include/asm-x86/hvm/svm/amd-iommu-defs.h
> +++ b/xen/include/asm-x86/hvm/svm/amd-iommu-defs.h
> @@ -464,10 +464,7 @@
>   #define IOMMU_CONTROL_DISABLED	0
>   #define IOMMU_CONTROL_ENABLED	1
>   
> -#define MMIO_PAGES_PER_IOMMU        (IOMMU_MMIO_REGION_LENGTH / PAGE_SIZE_4K)
> -#define IOMMU_PAGES                 (MMIO_PAGES_PER_IOMMU * MAX_AMD_IOMMUS)
>   #define DEFAULT_DOMAIN_ADDRESS_WIDTH    48
> -#define MAX_AMD_IOMMUS                  32
>   
>   /* interrupt remapping table */
>   #define INT_REMAP_INDEX_DM_MASK         0x1C00
>
>
>