This patch adds an interface for the swiotlb driver to recognize a new memory pool. Upon successful initialization of the pool, swiotlb returns a handle, which needs to be passed as an argument for any future operations on the pool (map/unmap/alloc/free).
Signed-off-by: Srivatsa Vaddagiri <va...@codeaurora.org> --- include/linux/swiotlb.h | 9 ++++++++ kernel/dma/swiotlb.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+) diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 957697e..97ac82a 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -182,6 +182,9 @@ static inline bool is_swiotlb_buffer(phys_addr_t paddr) return paddr >= swiotlb_start() && paddr < swiotlb_end(); } +extern struct swiotlb_pool *swiotlb_register_pool(char *name, + phys_addr_t start, void *vstart, size_t size); + void __init swiotlb_exit(void); unsigned int swiotlb_max_segment(void); size_t swiotlb_max_mapping_size(struct device *dev); @@ -236,6 +239,12 @@ static inline void swiotlb_free(struct swiotlb_pool *pool, { } +static struct swiotlb_pool *swiotlb_register_pool(char *name, + phys_addr_t start, void *vstart, size_t size) +{ + return NULL; +} + #endif /* CONFIG_SWIOTLB */ extern void swiotlb_print_info(void); diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 7411ce5..9883744 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -36,6 +36,7 @@ #include <linux/scatterlist.h> #include <linux/mem_encrypt.h> #include <linux/set_memory.h> +#include <linux/slab.h> #ifdef CONFIG_DEBUG_FS #include <linux/debugfs.h> #endif @@ -736,6 +737,65 @@ size_t swiotlb_max_mapping_size(struct device *dev) return ((size_t)1 << IO_TLB_SHIFT) * IO_TLB_SEGSIZE; } +struct swiotlb_pool *swiotlb_register_pool(char *name, phys_addr_t start, + void *vstart, size_t size) +{ + struct swiotlb_pool *pool; + unsigned long i, bytes; + unsigned long nslabs; + + nslabs = size >> IO_TLB_SHIFT; + if (!nslabs) + return ERR_PTR(-EINVAL); + + pool = kzalloc(sizeof(*pool), GFP_KERNEL); + if (!pool) + return ERR_PTR(-ENOMEM); + + bytes = nslabs << IO_TLB_SHIFT; + + strncpy(pool->name, name, sizeof(pool->name)); + spin_lock_init(&pool->io_tlb_lock); + pool->late_alloc = 1; + pool->io_tlb_start = start; + pool->io_tlb_end = start + bytes; + pool->io_tlb_vstart = vstart; + pool->io_tlb_nslabs = nslabs; + pool->max_segment = rounddown(bytes, PAGE_SIZE); + + /* + * Allocate and initialize the free list array. This array is used + * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE + * between io_tlb_start and io_tlb_end. + */ + pool->io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL, + get_order(pool->io_tlb_nslabs * sizeof(int))); + if (!pool->io_tlb_list) + goto cleanup; + + pool->io_tlb_orig_addr = (phys_addr_t *) + __get_free_pages(GFP_KERNEL, + get_order(pool->io_tlb_nslabs * + sizeof(phys_addr_t))); + if (!pool->io_tlb_orig_addr) + goto cleanup; + + for (i = 0; i < pool->io_tlb_nslabs; i++) { + pool->io_tlb_list[i] = IO_TLB_SEGSIZE - + OFFSET(i, IO_TLB_SEGSIZE); + pool->io_tlb_orig_addr[i] = INVALID_PHYS_ADDR; + } + + return pool; + +cleanup: + kfree(pool->io_tlb_list); + kfree(pool->io_tlb_orig_addr); + kfree(pool); + + return ERR_PTR(-ENOMEM); +} + bool is_swiotlb_active(void) { /* -- 2.7.4 -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation