| Message ID | 1412244417-12251-2-git-send-email-stefano.stabellini@eu.citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 02/10/14 11:06, Stefano Stabellini wrote: > Introduce support for new hypercall XENMEM_cache_flush. > Use it to perform cache flashing on pages used for dma when necessary. [...] > --- a/arch/arm/xen/mm32.c > +++ b/arch/arm/xen/mm32.c [...] > @@ -24,7 +27,21 @@ static void dma_cache_maint(dma_addr_t handle, unsigned long offset, > > if (!pfn_valid(pfn)) > { > - /* TODO: cache flush */ > + struct xen_cache_flush cflush; > + > + cflush.op = 0; > + cflush.addr = handle + offset; > + cflush.size = size; > + > + if (op == dmac_unmap_area && dir != DMA_TO_DEVICE) > + cflush.op = XENMEM_CACHE_INVAL; > + if (op == dmac_map_area) { > + cflush.op = XENMEM_CACHE_CLEAN; > + if (dir == DMA_FROM_DEVICE) > + cflush.op |= XENMEM_CACHE_INVAL; > + } > + if (cflush.op) > + HYPERVISOR_memory_op(XENMEM_cache_flush, &cflush); > } else { > struct page *page = pfn_to_page(pfn); > [...] > --- a/include/xen/interface/memory.h > +++ b/include/xen/interface/memory.h > @@ -263,4 +263,20 @@ struct xen_remove_from_physmap { > }; > DEFINE_GUEST_HANDLE_STRUCT(xen_remove_from_physmap); > > +/* > + * Issue one or more cache maintenance operations on a memory range > + * owned by the calling domain or granted to the calling domain by a > + * foreign domain. > + */ > +#define XENMEM_cache_flush 27 > +struct xen_cache_flush { > +/* addr is the machine address at the start of the memory range */ You say machine address here but call it with a bus address. With no IOMMU these are equivalent but what's correct if an IOMMU is used? David > +uint64_t addr; > +uint64_t size; > +#define XENMEM_CACHE_CLEAN (1<<0) > +#define XENMEM_CACHE_INVAL (1<<1) > +uint32_t op; > +}; > +DEFINE_GUEST_HANDLE_STRUCT(xen_cache_flush); > + > #endif /* __XEN_PUBLIC_MEMORY_H__ */ >
On Thu, 2 Oct 2014, David Vrabel wrote: > On 02/10/14 11:06, Stefano Stabellini wrote: > > Introduce support for new hypercall XENMEM_cache_flush. > > Use it to perform cache flashing on pages used for dma when necessary. > [...] > > --- a/arch/arm/xen/mm32.c > > +++ b/arch/arm/xen/mm32.c > [...] > > @@ -24,7 +27,21 @@ static void dma_cache_maint(dma_addr_t handle, unsigned long offset, > > > > if (!pfn_valid(pfn)) > > { > > - /* TODO: cache flush */ > > + struct xen_cache_flush cflush; > > + > > + cflush.op = 0; > > + cflush.addr = handle + offset; > > + cflush.size = size; > > + > > + if (op == dmac_unmap_area && dir != DMA_TO_DEVICE) > > + cflush.op = XENMEM_CACHE_INVAL; > > + if (op == dmac_map_area) { > > + cflush.op = XENMEM_CACHE_CLEAN; > > + if (dir == DMA_FROM_DEVICE) > > + cflush.op |= XENMEM_CACHE_INVAL; > > + } > > + if (cflush.op) > > + HYPERVISOR_memory_op(XENMEM_cache_flush, &cflush); > > } else { > > struct page *page = pfn_to_page(pfn); > > > [...] > > --- a/include/xen/interface/memory.h > > +++ b/include/xen/interface/memory.h > > @@ -263,4 +263,20 @@ struct xen_remove_from_physmap { > > }; > > DEFINE_GUEST_HANDLE_STRUCT(xen_remove_from_physmap); > > > > +/* > > + * Issue one or more cache maintenance operations on a memory range > > + * owned by the calling domain or granted to the calling domain by a > > + * foreign domain. > > + */ > > +#define XENMEM_cache_flush 27 > > +struct xen_cache_flush { > > +/* addr is the machine address at the start of the memory range */ > > You say machine address here but call it with a bus address. With no > IOMMU these are equivalent but what's correct if an IOMMU is used? I mean mfns, real machine addresses. With an IOMMU the hypercall should not be used. > > +uint64_t addr; > > +uint64_t size; > > +#define XENMEM_CACHE_CLEAN (1<<0) > > +#define XENMEM_CACHE_INVAL (1<<1) > > +uint32_t op; > > +}; > > +DEFINE_GUEST_HANDLE_STRUCT(xen_cache_flush); > > + > > #endif /* __XEN_PUBLIC_MEMORY_H__ */ > > >
diff --git a/arch/arm/xen/mm32.c b/arch/arm/xen/mm32.c index a5a93fc..aa45332 100644 --- a/arch/arm/xen/mm32.c +++ b/arch/arm/xen/mm32.c @@ -4,6 +4,9 @@ #include <linux/highmem.h> #include <xen/features.h> +#include <xen/interface/memory.h> + +#include <asm/xen/hypercall.h> /* functions called by SWIOTLB */ @@ -24,7 +27,21 @@ static void dma_cache_maint(dma_addr_t handle, unsigned long offset, if (!pfn_valid(pfn)) { - /* TODO: cache flush */ + struct xen_cache_flush cflush; + + cflush.op = 0; + cflush.addr = handle + offset; + cflush.size = size; + + if (op == dmac_unmap_area && dir != DMA_TO_DEVICE) + cflush.op = XENMEM_CACHE_INVAL; + if (op == dmac_map_area) { + cflush.op = XENMEM_CACHE_CLEAN; + if (dir == DMA_FROM_DEVICE) + cflush.op |= XENMEM_CACHE_INVAL; + } + if (cflush.op) + HYPERVISOR_memory_op(XENMEM_cache_flush, &cflush); } else { struct page *page = pfn_to_page(pfn); diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h index 2ecfe4f..7d7e039 100644 --- a/include/xen/interface/memory.h +++ b/include/xen/interface/memory.h @@ -263,4 +263,20 @@ struct xen_remove_from_physmap { }; DEFINE_GUEST_HANDLE_STRUCT(xen_remove_from_physmap); +/* + * Issue one or more cache maintenance operations on a memory range + * owned by the calling domain or granted to the calling domain by a + * foreign domain. + */ +#define XENMEM_cache_flush 27 +struct xen_cache_flush { +/* addr is the machine address at the start of the memory range */ +uint64_t addr; +uint64_t size; +#define XENMEM_CACHE_CLEAN (1<<0) +#define XENMEM_CACHE_INVAL (1<<1) +uint32_t op; +}; +DEFINE_GUEST_HANDLE_STRUCT(xen_cache_flush); + #endif /* __XEN_PUBLIC_MEMORY_H__ */
Introduce support for new hypercall XENMEM_cache_flush. Use it to perform cache flashing on pages used for dma when necessary. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> --- arch/arm/xen/mm32.c | 19 ++++++++++++++++++- include/xen/interface/memory.h | 16 ++++++++++++++++ 2 files changed, 34 insertions(+), 1 deletion(-)