diff options
Diffstat (limited to 'kernel/arch/arm/xen/mm.c')
| -rw-r--r-- | kernel/arch/arm/xen/mm.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/kernel/arch/arm/xen/mm.c b/kernel/arch/arm/xen/mm.c new file mode 100644 index 000000000..498325074 --- /dev/null +++ b/kernel/arch/arm/xen/mm.c @@ -0,0 +1,201 @@ +#include <linux/cpu.h> +#include <linux/dma-mapping.h> +#include <linux/bootmem.h> +#include <linux/gfp.h> +#include <linux/highmem.h> +#include <linux/export.h> +#include <linux/memblock.h> +#include <linux/of_address.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/grant_table.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> + +unsigned long xen_get_swiotlb_free_pages(unsigned int order) +{ + struct memblock_region *reg; + gfp_t flags = __GFP_NOWARN; + + for_each_memblock(memory, reg) { + if (reg->base < (phys_addr_t)0xffffffff) { + flags |= __GFP_DMA; + break; + } + } + return __get_free_pages(flags, order); +} + +enum dma_cache_op { + DMA_UNMAP, + DMA_MAP, +}; +static bool hypercall_cflush = false; + +/* functions called by SWIOTLB */ + +static void dma_cache_maint(dma_addr_t handle, unsigned long offset, + size_t size, enum dma_data_direction dir, enum dma_cache_op op) +{ + struct gnttab_cache_flush cflush; + unsigned long pfn; + size_t left = size; + + pfn = (handle >> PAGE_SHIFT) + offset / PAGE_SIZE; + offset %= PAGE_SIZE; + + do { + size_t len = left; + + /* buffers in highmem or foreign pages cannot cross page + * boundaries */ + if (len + offset > PAGE_SIZE) + len = PAGE_SIZE - offset; + + cflush.op = 0; + cflush.a.dev_bus_addr = pfn << PAGE_SHIFT; + cflush.offset = offset; + cflush.length = len; + + if (op == DMA_UNMAP && dir != DMA_TO_DEVICE) + cflush.op = GNTTAB_CACHE_INVAL; + if (op == DMA_MAP) { + if (dir == DMA_FROM_DEVICE) + cflush.op = GNTTAB_CACHE_INVAL; + else + cflush.op = GNTTAB_CACHE_CLEAN; + } + if (cflush.op) + HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1); + + offset = 0; + pfn++; + left -= len; + } while (left); +} + +static void __xen_dma_page_dev_to_cpu(struct device *hwdev, dma_addr_t handle, + size_t size, enum dma_data_direction dir) +{ + dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_UNMAP); +} + +static void __xen_dma_page_cpu_to_dev(struct device *hwdev, dma_addr_t handle, + size_t size, enum dma_data_direction dir) +{ + dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_MAP); +} + +void __xen_dma_map_page(struct device *hwdev, struct page *page, + dma_addr_t dev_addr, unsigned long offset, size_t size, + enum dma_data_direction dir, struct dma_attrs *attrs) +{ + if (is_device_dma_coherent(hwdev)) + return; + if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) + return; + + __xen_dma_page_cpu_to_dev(hwdev, dev_addr, size, dir); +} + +void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) + +{ + if (is_device_dma_coherent(hwdev)) + return; + if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) + return; + + __xen_dma_page_dev_to_cpu(hwdev, handle, size, dir); +} + +void __xen_dma_sync_single_for_cpu(struct device *hwdev, + dma_addr_t handle, size_t size, enum dma_data_direction dir) +{ + if (is_device_dma_coherent(hwdev)) + return; + __xen_dma_page_dev_to_cpu(hwdev, handle, size, dir); +} + +void __xen_dma_sync_single_for_device(struct device *hwdev, + dma_addr_t handle, size_t size, enum dma_data_direction dir) +{ + if (is_device_dma_coherent(hwdev)) + return; + __xen_dma_page_cpu_to_dev(hwdev, handle, size, dir); +} + +bool xen_arch_need_swiotlb(struct device *dev, + unsigned long pfn, + unsigned long mfn) +{ + return (!hypercall_cflush && (pfn != mfn) && !is_device_dma_coherent(dev)); +} + +int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, + unsigned int address_bits, + dma_addr_t *dma_handle) +{ + if (!xen_initial_domain()) + return -EINVAL; + + /* we assume that dom0 is mapped 1:1 for now */ + *dma_handle = pstart; + return 0; +} +EXPORT_SYMBOL_GPL(xen_create_contiguous_region); + +void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order) +{ + return; +} +EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region); + +struct dma_map_ops *xen_dma_ops; +EXPORT_SYMBOL(xen_dma_ops); + +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, + .set_dma_mask = xen_swiotlb_set_dma_mask, +}; + +int __init xen_mm_init(void) +{ + struct gnttab_cache_flush cflush; + if (!xen_initial_domain()) + return 0; + xen_swiotlb_init(1, false); + xen_dma_ops = &xen_swiotlb_dma_ops; + + cflush.op = 0; + cflush.a.dev_bus_addr = 0; + cflush.offset = 0; + cflush.length = 0; + if (HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1) != -ENOSYS) + hypercall_cflush = true; + return 0; +} +arch_initcall(xen_mm_init); |