The indirection from the global 'io_tlb_default_mem' pointer to the static '_io_tlb_default_mem' structure is ugly and unnecessary.
Convert all users to reference the static structure directly, using the 'nslabs' field to determine whether swiotlb has been initialised. Cc: Claire Chang <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Robin Murphy <[email protected]> Cc: Konrad Rzeszutek Wilk <[email protected]> Tested-by: Nathan Chancellor <[email protected]> Signed-off-by: Will Deacon <[email protected]> --- drivers/base/core.c | 2 +- drivers/xen/swiotlb-xen.c | 4 ++-- include/linux/swiotlb.h | 2 +- kernel/dma/swiotlb.c | 38 ++++++++++++++++++-------------------- 4 files changed, 22 insertions(+), 24 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index ea5b85354526..b49824001cfa 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2848,7 +2848,7 @@ void device_initialize(struct device *dev) dev->dma_coherent = dma_default_coherent; #endif #ifdef CONFIG_SWIOTLB - dev->dma_io_tlb_mem = io_tlb_default_mem; + dev->dma_io_tlb_mem = &io_tlb_default_mem; #endif } EXPORT_SYMBOL_GPL(device_initialize); diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 785ec7e8be01..f06d9b4f1e0f 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -164,7 +164,7 @@ int __ref xen_swiotlb_init(void) int rc = -ENOMEM; char *start; - if (io_tlb_default_mem != NULL) { + if (io_tlb_default_mem.nslabs) { pr_warn("swiotlb buffer already initialized\n"); return -EEXIST; } @@ -547,7 +547,7 @@ xen_swiotlb_sync_sg_for_device(struct device *dev, struct scatterlist *sgl, static int xen_swiotlb_dma_supported(struct device *hwdev, u64 mask) { - return xen_phys_to_dma(hwdev, io_tlb_default_mem->end - 1) <= mask; + return xen_phys_to_dma(hwdev, io_tlb_default_mem.end - 1) <= mask; } const struct dma_map_ops xen_swiotlb_dma_ops = { diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index d3b617c19045..b0cb2a9973f4 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -105,7 +105,7 @@ struct io_tlb_mem { unsigned int list; } *slots; }; -extern struct io_tlb_mem *io_tlb_default_mem; +extern struct io_tlb_mem io_tlb_default_mem; static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr) { diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 992d73cdc944..7948f274f9bb 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -70,8 +70,7 @@ enum swiotlb_force swiotlb_force; -struct io_tlb_mem *io_tlb_default_mem; -static struct io_tlb_mem _io_tlb_default_mem; +struct io_tlb_mem io_tlb_default_mem; /* * Max segment that we can provide which (if pages are contingous) will @@ -102,7 +101,7 @@ early_param("swiotlb", setup_io_tlb_npages); unsigned int swiotlb_max_segment(void) { - return io_tlb_default_mem ? max_segment : 0; + return io_tlb_default_mem.nslabs ? max_segment : 0; } EXPORT_SYMBOL_GPL(swiotlb_max_segment); @@ -135,9 +134,9 @@ void __init swiotlb_adjust_size(unsigned long size) void swiotlb_print_info(void) { - struct io_tlb_mem *mem = io_tlb_default_mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; - if (!mem) { + if (!mem->nslabs) { pr_warn("No low mem\n"); return; } @@ -164,11 +163,11 @@ static inline unsigned long nr_slots(u64 val) */ void __init swiotlb_update_mem_attributes(void) { - struct io_tlb_mem *mem = io_tlb_default_mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; void *vaddr; unsigned long bytes; - if (!mem || mem->late_alloc) + if (!mem->nslabs || mem->late_alloc) return; vaddr = phys_to_virt(mem->start); bytes = PAGE_ALIGN(mem->nslabs << IO_TLB_SHIFT); @@ -202,14 +201,14 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) { - struct io_tlb_mem *mem = &_io_tlb_default_mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; size_t alloc_size; if (swiotlb_force == SWIOTLB_NO_FORCE) return 0; /* protect against double initialization */ - if (WARN_ON_ONCE(io_tlb_default_mem)) + if (WARN_ON_ONCE(mem->nslabs)) return -ENOMEM; alloc_size = PAGE_ALIGN(array_size(sizeof(*mem->slots), nslabs)); @@ -220,7 +219,6 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) swiotlb_init_io_tlb_mem(mem, __pa(tlb), nslabs, false); - io_tlb_default_mem = mem; if (verbose) swiotlb_print_info(); swiotlb_set_max_segment(mem->nslabs << IO_TLB_SHIFT); @@ -305,14 +303,14 @@ swiotlb_late_init_with_default_size(size_t default_size) int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) { - struct io_tlb_mem *mem = &_io_tlb_default_mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; unsigned long bytes = nslabs << IO_TLB_SHIFT; if (swiotlb_force == SWIOTLB_NO_FORCE) return 0; /* protect against double initialization */ - if (WARN_ON_ONCE(io_tlb_default_mem)) + if (WARN_ON_ONCE(mem->nslabs)) return -ENOMEM; mem->slots = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, @@ -323,7 +321,6 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT); swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true); - io_tlb_default_mem = mem; swiotlb_print_info(); swiotlb_set_max_segment(mem->nslabs << IO_TLB_SHIFT); return 0; @@ -331,10 +328,10 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) void __init swiotlb_exit(void) { - struct io_tlb_mem *mem = io_tlb_default_mem; size_t size; + struct io_tlb_mem *mem = &io_tlb_default_mem; - if (!mem) + if (!mem->nslabs) return; size = array_size(sizeof(*mem->slots), mem->nslabs); @@ -342,7 +339,6 @@ void __init swiotlb_exit(void) free_pages((unsigned long)mem->slots, get_order(size)); else memblock_free_late(__pa(mem->slots), PAGE_ALIGN(size)); - io_tlb_default_mem = NULL; memset(mem, 0, sizeof(*mem)); } @@ -697,7 +693,9 @@ size_t swiotlb_max_mapping_size(struct device *dev) bool is_swiotlb_active(struct device *dev) { - return dev->dma_io_tlb_mem != NULL; + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; + + return mem && mem->nslabs; } EXPORT_SYMBOL_GPL(is_swiotlb_active); @@ -712,10 +710,10 @@ static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem) static int __init swiotlb_create_default_debugfs(void) { - struct io_tlb_mem *mem = io_tlb_default_mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; debugfs_dir = debugfs_create_dir("swiotlb", NULL); - if (mem) { + if (mem->nslabs) { mem->debugfs = debugfs_dir; swiotlb_create_debugfs_files(mem); } @@ -814,7 +812,7 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem, static void rmem_swiotlb_device_release(struct reserved_mem *rmem, struct device *dev) { - dev->dma_io_tlb_mem = io_tlb_default_mem; + dev->dma_io_tlb_mem = &io_tlb_default_mem; } static const struct reserved_mem_ops rmem_swiotlb_ops = { -- 2.32.0.402.g57bb445576-goog _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
