Re: [PATCH 3/9] xen: add hooks for mapping phys<->bus addresses inswiotlb

From: Joerg Roedel
Date: Mon May 11 2009 - 10:11:23 EST


On Thu, May 07, 2009 at 05:17:16PM -0700, Jeremy Fitzhardinge wrote:
> From: Ian Campbell <ian.campbell@xxxxxxxxxx>
>
> Impact: Xen support for DMA
>
> Add hooks to allow Xen to do translation between pfn and mfns for the swiotlb
> layer, so that dma actually ends up going to the proper machine pages.
>
> Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
> Reviewed-by: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Cc: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>

Acked-by: Joerg Roedel <joerg.roedel@xxxxxxx>

> ---
> arch/x86/kernel/pci-swiotlb.c | 10 ----------
> arch/x86/xen/pci-swiotlb.c | 18 ++++++++++++++++++
> drivers/pci/xen-iommu.c | 11 +++++++++++
> include/xen/swiotlb.h | 2 ++
> 4 files changed, 31 insertions(+), 10 deletions(-)
>
> diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
> index bc09da7..3216674 100644
> --- a/arch/x86/kernel/pci-swiotlb.c
> +++ b/arch/x86/kernel/pci-swiotlb.c
> @@ -13,16 +13,6 @@
>
> int swiotlb __read_mostly;
>
> -dma_addr_t swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
> -{
> - return paddr;
> -}
> -
> -phys_addr_t swiotlb_bus_to_phys(dma_addr_t baddr)
> -{
> - return baddr;
> -}
> -
> int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
> {
> return 0;
> diff --git a/arch/x86/xen/pci-swiotlb.c b/arch/x86/xen/pci-swiotlb.c
> index 25f0365..1d43fde 100644
> --- a/arch/x86/xen/pci-swiotlb.c
> +++ b/arch/x86/xen/pci-swiotlb.c
> @@ -1,5 +1,7 @@
> #include <linux/bootmem.h>
> #include <linux/gfp.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/swiotlb.h>
>
> #include <xen/swiotlb.h>
> #include <asm/xen/hypervisor.h>
> @@ -25,3 +27,19 @@ void *swiotlb_alloc(unsigned order, unsigned long nslabs)
> WARN_ON(1);
> return NULL;
> }
> +
> +dma_addr_t swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
> +{
> + if (xen_pv_domain())
> + return xen_phys_to_bus(paddr);
> +
> + return paddr;
> +}
> +
> +phys_addr_t swiotlb_bus_to_phys(dma_addr_t baddr)
> +{
> + if (xen_pv_domain())
> + return xen_bus_to_phys(baddr);
> +
> + return baddr;
> +}
> diff --git a/drivers/pci/xen-iommu.c b/drivers/pci/xen-iommu.c
> index b9b4620..e3d6ddb 100644
> --- a/drivers/pci/xen-iommu.c
> +++ b/drivers/pci/xen-iommu.c
> @@ -59,6 +59,17 @@ void xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
> panic(KERN_ERR "xen_create_contiguous_region failed\n");
> }
> }
> +
> +dma_addr_t xen_phys_to_bus(phys_addr_t paddr)
> +{
> + return phys_to_machine(XPADDR(paddr)).maddr;
> +}
> +
> +phys_addr_t xen_bus_to_phys(dma_addr_t daddr)
> +{
> + return machine_to_phys(XMADDR(daddr)).paddr;
> +}
> +
> static inline int address_needs_mapping(struct device *hwdev,
> dma_addr_t addr)
> {
> diff --git a/include/xen/swiotlb.h b/include/xen/swiotlb.h
> index 67b7b42..4229f27 100644
> --- a/include/xen/swiotlb.h
> +++ b/include/xen/swiotlb.h
> @@ -2,5 +2,7 @@
> #define _XEN_SWIOTLB_H
>
> extern void xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs);
> +extern phys_addr_t xen_bus_to_phys(dma_addr_t daddr);
> +extern dma_addr_t xen_phys_to_bus(phys_addr_t paddr);
>
> #endif /* _XEN_SWIOTLB_H */
> --
> 1.6.0.6
>
> --
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