diff options
Diffstat (limited to 'drivers/xen/swiotlb-xen.c')
| -rw-r--r-- | drivers/xen/swiotlb-xen.c | 62 |
1 files changed, 49 insertions, 13 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index fd60dff..89588e7 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -35,9 +35,11 @@ #include <linux/bootmem.h> #include <linux/dma-mapping.h> +#include <linux/export.h> #include <xen/swiotlb-xen.h> #include <xen/page.h> #include <xen/xen-ops.h> +#include <xen/hvc-console.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 @@ -146,8 +148,10 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs) void __init xen_swiotlb_init(int verbose) { unsigned long bytes; - int rc; + int rc = -ENOMEM; unsigned long nr_tbl; + char *m = NULL; + unsigned int repeat = 3; nr_tbl = swioltb_nr_tbl(); if (nr_tbl) @@ -156,16 +160,17 @@ void __init xen_swiotlb_init(int verbose) xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT); xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE); } - +retry: bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT; /* * Get IO TLB memory from any location. */ xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes)); - if (!xen_io_tlb_start) - panic("Cannot allocate SWIOTLB buffer"); - + if (!xen_io_tlb_start) { + m = "Cannot allocate Xen-SWIOTLB buffer!\n"; + goto error; + } xen_io_tlb_end = xen_io_tlb_start + bytes; /* * And replace that memory with pages under 4GB. @@ -173,17 +178,28 @@ void __init xen_swiotlb_init(int verbose) rc = xen_swiotlb_fixup(xen_io_tlb_start, bytes, xen_io_tlb_nslabs); - if (rc) + if (rc) { + free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes)); + m = "Failed to get contiguous memory for DMA from Xen!\n"\ + "You either: don't have the permissions, do not have"\ + " enough free memory under 4GB, or the hypervisor memory"\ + "is too fragmented!"; goto error; - + } start_dma_addr = xen_virt_to_bus(xen_io_tlb_start); swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, verbose); return; error: - panic("DMA(%d): Failed to exchange pages allocated for DMA with Xen! "\ - "We either don't have the permission or you do not have enough"\ - "free memory under 4GB!\n", rc); + if (repeat--) { + xen_io_tlb_nslabs = max(1024UL, /* Min is 2MB */ + (xen_io_tlb_nslabs >> 1)); + printk(KERN_INFO "Xen-SWIOTLB: Lowering to %luMB\n", + (xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20); + goto retry; + } + xen_raw_printk("%s (rc:%d)", m, rc); + panic("%s (rc:%d)", m, rc); } void * @@ -194,6 +210,8 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, int order = get_order(size); u64 dma_mask = DMA_BIT_MASK(32); unsigned long vstart; + phys_addr_t phys; + dma_addr_t dev_addr; /* * Ignore region specifiers - the kernel's ideas of @@ -209,18 +227,26 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, vstart = __get_free_pages(flags, order); ret = (void *)vstart; + if (!ret) + return ret; + if (hwdev && hwdev->coherent_dma_mask) dma_mask = dma_alloc_coherent_mask(hwdev, flags); - if (ret) { + phys = virt_to_phys(ret); + dev_addr = xen_phys_to_bus(phys); + if (((dev_addr + size - 1 <= dma_mask)) && + !range_straddles_page_boundary(phys, size)) + *dma_handle = dev_addr; + else { if (xen_create_contiguous_region(vstart, order, fls64(dma_mask)) != 0) { free_pages(vstart, order); return NULL; } - memset(ret, 0, size); *dma_handle = virt_to_machine(ret).maddr; } + memset(ret, 0, size); return ret; } EXPORT_SYMBOL_GPL(xen_swiotlb_alloc_coherent); @@ -230,11 +256,21 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dev_addr) { int order = get_order(size); + phys_addr_t phys; + u64 dma_mask = DMA_BIT_MASK(32); if (dma_release_from_coherent(hwdev, order, vaddr)) return; - xen_destroy_contiguous_region((unsigned long)vaddr, order); + if (hwdev && hwdev->coherent_dma_mask) + dma_mask = hwdev->coherent_dma_mask; + + phys = virt_to_phys(vaddr); + + if (((dev_addr + size - 1 > dma_mask)) || + range_straddles_page_boundary(phys, size)) + xen_destroy_contiguous_region((unsigned long)vaddr, order); + free_pages((unsigned long)vaddr, order); } EXPORT_SYMBOL_GPL(xen_swiotlb_free_coherent); |