diff options
Diffstat (limited to 'kernel/dma/swiotlb.c')
| -rw-r--r-- | kernel/dma/swiotlb.c | 91 |
1 files changed, 74 insertions, 17 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 1fb6fd68b9c7..53012db1e53c 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -34,6 +34,9 @@ #include <linux/scatterlist.h> #include <linux/mem_encrypt.h> #include <linux/set_memory.h> +#ifdef CONFIG_DEBUG_FS +#include <linux/debugfs.h> +#endif #include <asm/io.h> #include <asm/dma.h> @@ -73,6 +76,11 @@ phys_addr_t io_tlb_start, io_tlb_end; static unsigned long io_tlb_nslabs; /* + * The number of used IO TLB block + */ +static unsigned long io_tlb_used; + +/* * This is a free list describing the number of free entries available from * each index */ @@ -191,6 +199,7 @@ void __init swiotlb_update_mem_attributes(void) int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) { unsigned long i, bytes; + size_t alloc_size; bytes = nslabs << IO_TLB_SHIFT; @@ -203,12 +212,18 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE * between io_tlb_start and io_tlb_end. */ - io_tlb_list = memblock_alloc( - PAGE_ALIGN(io_tlb_nslabs * sizeof(int)), - PAGE_SIZE); - io_tlb_orig_addr = memblock_alloc( - PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)), - PAGE_SIZE); + alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(int)); + io_tlb_list = memblock_alloc(alloc_size, PAGE_SIZE); + if (!io_tlb_list) + panic("%s: Failed to allocate %zu bytes align=0x%lx\n", + __func__, alloc_size, PAGE_SIZE); + + alloc_size = PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)); + io_tlb_orig_addr = memblock_alloc(alloc_size, PAGE_SIZE); + if (!io_tlb_orig_addr) + panic("%s: Failed to allocate %zu bytes align=0x%lx\n", + __func__, alloc_size, PAGE_SIZE); + for (i = 0; i < io_tlb_nslabs; i++) { io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE); io_tlb_orig_addr[i] = INVALID_PHYS_ADDR; @@ -241,7 +256,7 @@ swiotlb_init(int verbose) bytes = io_tlb_nslabs << IO_TLB_SHIFT; /* Get IO TLB memory from the low pages */ - vstart = memblock_alloc_low_nopanic(PAGE_ALIGN(bytes), PAGE_SIZE); + vstart = memblock_alloc_low(PAGE_ALIGN(bytes), PAGE_SIZE); if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose)) return; @@ -385,7 +400,7 @@ void __init swiotlb_exit(void) } /* - * Bounce: copy the swiotlb buffer back to the original dma location + * Bounce: copy the swiotlb buffer from or back to the original dma location */ static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr, size_t size, enum dma_data_direction dir) @@ -475,6 +490,10 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, * request and allocate a buffer from that IO TLB pool. */ spin_lock_irqsave(&io_tlb_lock, flags); + + if (unlikely(nslots > io_tlb_nslabs - io_tlb_used)) + goto not_found; + index = ALIGN(io_tlb_index, stride); if (index >= io_tlb_nslabs) index = 0; @@ -524,6 +543,7 @@ not_found: dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes)\n", size); return DMA_MAPPING_ERROR; found: + io_tlb_used += nslots; spin_unlock_irqrestore(&io_tlb_lock, flags); /* @@ -584,6 +604,8 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, */ for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--) io_tlb_list[i] = ++count; + + io_tlb_used -= nslots; } spin_unlock_irqrestore(&io_tlb_lock, flags); } @@ -651,14 +673,49 @@ bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr, return true; } -/* - * Return whether the given device DMA address mask can be supported - * properly. For example, if your device can only drive the low 24-bits - * during bus mastering, then you would pass 0x00ffffff as the mask to - * this function. - */ -int -swiotlb_dma_supported(struct device *hwdev, u64 mask) +size_t swiotlb_max_mapping_size(struct device *dev) { - return __phys_to_dma(hwdev, io_tlb_end - 1) <= mask; + return ((size_t)1 << IO_TLB_SHIFT) * IO_TLB_SEGSIZE; } + +bool is_swiotlb_active(void) +{ + /* + * When SWIOTLB is initialized, even if io_tlb_start points to physical + * address zero, io_tlb_end surely doesn't. + */ + return io_tlb_end != 0; +} + +#ifdef CONFIG_DEBUG_FS + +static int __init swiotlb_create_debugfs(void) +{ + struct dentry *d_swiotlb_usage; + struct dentry *ent; + + d_swiotlb_usage = debugfs_create_dir("swiotlb", NULL); + + if (!d_swiotlb_usage) + return -ENOMEM; + + ent = debugfs_create_ulong("io_tlb_nslabs", 0400, + d_swiotlb_usage, &io_tlb_nslabs); + if (!ent) + goto fail; + + ent = debugfs_create_ulong("io_tlb_used", 0400, + d_swiotlb_usage, &io_tlb_used); + if (!ent) + goto fail; + + return 0; + +fail: + debugfs_remove_recursive(d_swiotlb_usage); + return -ENOMEM; +} + +late_initcall(swiotlb_create_debugfs); + +#endif |