[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v5 09/13] xen/arm,arm64: enable SWIOTLB_XEN
Xen on arm and arm64 needs SWIOTLB_XEN: when running on Xen we need to program the hardware with mfns rather than pfns for dma addresses. Remove SWIOTLB_XEN dependency on X86 and PCI and make XEN select SWIOTLB_XEN on arm and arm64. At the moment always rely on swiotlb-xen, but when Xen starts supporting hardware IOMMUs we'll be able to avoid it conditionally on the presence of an IOMMU on the platform. Implement xen_create_contiguous_region on arm and arm64 by using XENMEM_exchange_and_pin. Initialize the xen-swiotlb from xen_early_init (before the native dma_ops are initialized), set dma_ops to &xen_swiotlb_dma_ops if we are running on Xen. Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> Changes in v4: - remove redefinition of DMA_ERROR_CODE; - update the code to use XENMEM_exchange_and_pin and XENMEM_unpin; - add a note about hardware IOMMU in the commit message. Changes in v3: - code style changes; - warn on XENMEM_put_dma_buf failures. --- arch/arm/Kconfig | 1 + arch/arm/include/asm/xen/page.h | 2 + arch/arm/xen/Makefile | 2 +- arch/arm/xen/enlighten.c | 3 + arch/arm/xen/mm.c | 117 +++++++++++++++++++++++++++++++++++++++ arch/arm64/Kconfig | 1 + arch/arm64/xen/Makefile | 2 +- drivers/xen/Kconfig | 1 - drivers/xen/swiotlb-xen.c | 16 +++++ 9 files changed, 142 insertions(+), 3 deletions(-) create mode 100644 arch/arm/xen/mm.c diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c0bfb33..2c9d112 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1848,6 +1848,7 @@ config XEN depends on CPU_V7 && !CPU_V6 depends on !GENERIC_ATOMIC64 select ARM_PSCI + select SWIOTLB_XEN help Say Y if you want to run Linux in a Virtual Machine on Xen on ARM. diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h index 359a7b5..b0f7150 100644 --- a/arch/arm/include/asm/xen/page.h +++ b/arch/arm/include/asm/xen/page.h @@ -6,12 +6,14 @@ #include <linux/pfn.h> #include <linux/types.h> +#include <linux/dma-mapping.h> #include <xen/interface/grant_table.h> #define pfn_to_mfn(pfn) (pfn) #define phys_to_machine_mapping_valid(pfn) (1) #define mfn_to_pfn(mfn) (mfn) +#define mfn_to_local_pfn(m) (mfn_to_pfn(m)) #define mfn_to_virt(m) (__va(mfn_to_pfn(m) << PAGE_SHIFT)) #define pte_mfn pte_pfn diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile index 4384103..66fc35d 100644 --- a/arch/arm/xen/Makefile +++ b/arch/arm/xen/Makefile @@ -1 +1 @@ -obj-y := enlighten.o hypercall.o grant-table.o +obj-y := enlighten.o hypercall.o grant-table.o mm.o diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 14d17ab..06a6953 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -195,6 +195,7 @@ static void xen_power_off(void) * documentation of the Xen Device Tree format. */ #define GRANT_TABLE_PHYSADDR 0 +extern int xen_mm_init(void); void __init xen_early_init(void) { struct resource res; @@ -230,6 +231,8 @@ void __init xen_early_init(void) xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED; else xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED); + + xen_mm_init(); } static int __init xen_guest_init(void) diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c new file mode 100644 index 0000000..916deb2 --- /dev/null +++ b/arch/arm/xen/mm.c @@ -0,0 +1,117 @@ +#include <linux/bootmem.h> +#include <linux/gfp.h> +#include <linux/export.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/dma-mapping.h> +#include <linux/vmalloc.h> +#include <linux/swiotlb.h> + +#include <xen/xen.h> +#include <xen/interface/memory.h> +#include <xen/swiotlb-xen.h> + +#include <asm/cacheflush.h> +#include <asm/xen/page.h> +#include <asm/xen/hypercall.h> +#include <asm/xen/interface.h> + +static int xen_exchange_memory(xen_ulong_t extents_in, + unsigned int order_in, + xen_pfn_t *pfns_in, + xen_ulong_t extents_out, + unsigned int order_out, + xen_pfn_t *mfns_out, + unsigned int address_bits) +{ + long rc; + int success; + + struct xen_memory_exchange exchange = { + .in = { + .nr_extents = extents_in, + .extent_order = order_in, + .domid = DOMID_SELF + }, + .out = { + .nr_extents = extents_out, + .extent_order = order_out, + .address_bits = address_bits, + .domid = DOMID_SELF + } + }; + set_xen_guest_handle(exchange.in.extent_start, pfns_in); + set_xen_guest_handle(exchange.out.extent_start, mfns_out); + + BUG_ON(extents_in << order_in != extents_out << order_out); + + + rc = HYPERVISOR_memory_op(XENMEM_exchange_and_pin, &exchange); + success = (exchange.nr_exchanged == extents_in); + + BUG_ON(!success && ((exchange.nr_exchanged != 0) || (rc == 0))); + BUG_ON(success && (rc != 0)); + + return success; +} + +int xen_create_contiguous_region(unsigned long vstart, unsigned int order, + unsigned int address_bits, + dma_addr_t *dma_handle) +{ + phys_addr_t pstart = __pa(vstart); + xen_pfn_t in_frame, out_frame; + int success; + + /* Get a new contiguous memory extent. */ + in_frame = out_frame = pstart >> PAGE_SHIFT; + success = xen_exchange_memory(1, order, &in_frame, + 1, order, &out_frame, + address_bits); + + if (!success) + return -ENOMEM; + + *dma_handle = out_frame << PAGE_SHIFT; + + return success ? 0 : -ENOMEM; +} +EXPORT_SYMBOL_GPL(xen_create_contiguous_region); + +void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order) +{ + xen_pfn_t in_frame = __pa(vstart) >> PAGE_SHIFT; + struct xen_unpin unpin = { + .in = { + .nr_extents = 1, + .extent_order = order, + .domid = DOMID_SELF + }, + }; + set_xen_guest_handle(unpin.in.extent_start, &in_frame); + + WARN_ON(HYPERVISOR_memory_op(XENMEM_unpin, &unpin)); +} +EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region); + +static struct dma_map_ops xen_swiotlb_dma_ops = { + .mapping_error = xen_swiotlb_dma_mapping_error, + .alloc = xen_swiotlb_alloc_coherent, + .free = xen_swiotlb_free_coherent, + .sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu, + .sync_single_for_device = xen_swiotlb_sync_single_for_device, + .sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu, + .sync_sg_for_device = xen_swiotlb_sync_sg_for_device, + .map_sg = xen_swiotlb_map_sg_attrs, + .unmap_sg = xen_swiotlb_unmap_sg_attrs, + .map_page = xen_swiotlb_map_page, + .unmap_page = xen_swiotlb_unmap_page, + .dma_supported = xen_swiotlb_dma_supported, +}; + +int __init xen_mm_init(void) +{ + xen_swiotlb_init(1, true); + dma_ops = &xen_swiotlb_dma_ops; + return 0; +} diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 9737e97..aa1f6fb 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -209,6 +209,7 @@ config XEN_DOM0 config XEN bool "Xen guest support on ARM64 (EXPERIMENTAL)" depends on ARM64 && OF + select SWIOTLB_XEN help Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. diff --git a/arch/arm64/xen/Makefile b/arch/arm64/xen/Makefile index be24040..0ef9637 100644 --- a/arch/arm64/xen/Makefile +++ b/arch/arm64/xen/Makefile @@ -1,2 +1,2 @@ -xen-arm-y += $(addprefix ../../arm/xen/, enlighten.o grant-table.o) +xen-arm-y += $(addprefix ../../arm/xen/, enlighten.o grant-table.o mm.o) obj-y := xen-arm.o hypercall.o diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index 9e02d60..7e83688 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -140,7 +140,6 @@ config XEN_GRANT_DEV_ALLOC config SWIOTLB_XEN def_bool y - depends on PCI && X86 select SWIOTLB config XEN_TMEM diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 7bb99ae..b11a11f 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -45,6 +45,8 @@ #include <xen/xen-ops.h> #include <xen/hvc-console.h> #include <xen/features.h> +#include <asm/dma-mapping.h> + /* * Used to do a quick range check in swiotlb_tbl_unmap_single and * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this @@ -58,6 +60,20 @@ static unsigned long xen_io_tlb_nslabs; * Quick lookup value of the bus address of the IOTLB. */ +#ifndef CONFIG_X86 +static unsigned long dma_alloc_coherent_mask(struct device *dev, + gfp_t gfp) +{ + unsigned long dma_mask = 0; + + dma_mask = dev->coherent_dma_mask; + if (!dma_mask) + dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32); + + return dma_mask; +} +#endif + struct xen_dma_info { dma_addr_t dma_addr; phys_addr_t phys_addr; -- 1.7.2.5 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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