Create the logic to store coherent reserved memory regions within the coherent DMA code; and provide an iterator (i.e., dma_coherent_get_reserved_region()) to allow consumers of this API retrieving the regions.
Note: since the consumer of this iterator is going to be the specific coherent memory dmabuf heap module, this commit introduces a check for CONFIG_DMABUF_HEAPS_COHERENT, which is defined in the subsequent patch, to maintain a clean split between the kernel code and the heap module code. Signed-off-by: Albert Esteve <[email protected]> --- include/linux/dma-map-ops.h | 7 +++++++ kernel/dma/coherent.c | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 60b63756df821..c87e5e44e5383 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -12,6 +12,7 @@ struct cma; struct iommu_ops; +struct reserved_mem; struct dma_map_ops { void *(*alloc)(struct device *dev, size_t size, @@ -161,6 +162,7 @@ int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size, int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr); int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, size_t size, int *ret); +struct reserved_mem *dma_coherent_get_reserved_region(unsigned int idx); #else static inline int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, dma_addr_t device_addr, size_t size) @@ -172,6 +174,11 @@ static inline int dma_declare_coherent_memory(struct device *dev, #define dma_release_from_dev_coherent(dev, order, vaddr) (0) #define dma_mmap_from_dev_coherent(dev, vma, vaddr, order, ret) (0) static inline void dma_release_coherent_memory(struct device *dev) { } +static inline +struct reserved_mem *dma_coherent_get_reserved_region(unsigned int idx) +{ + return NULL; +} #endif /* CONFIG_DMA_DECLARE_COHERENT */ #ifdef CONFIG_DMA_GLOBAL_POOL diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 1147497bc512c..d0d0979ffb153 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -9,6 +9,7 @@ #include <linux/module.h> #include <linux/dma-direct.h> #include <linux/dma-map-ops.h> +#include <linux/dma-heap.h> struct dma_coherent_mem { void *virt_base; @@ -334,6 +335,31 @@ static phys_addr_t dma_reserved_default_memory_base __initdata; static phys_addr_t dma_reserved_default_memory_size __initdata; #endif +#define MAX_COHERENT_REGIONS 64 + +static struct reserved_mem *rmem_coherent_areas[MAX_COHERENT_REGIONS]; +static unsigned int rmem_coherent_areas_num; + +static int rmem_coherent_insert_area(struct reserved_mem *rmem) +{ + if (rmem_coherent_areas_num >= MAX_COHERENT_REGIONS) { + pr_warn("Deferred heap areas list full, dropping %s\n", + rmem->name ? rmem->name : "unknown"); + return -EINVAL; + } + rmem_coherent_areas[rmem_coherent_areas_num++] = rmem; + return 0; +} + +struct reserved_mem *dma_coherent_get_reserved_region(unsigned int idx) +{ + if (idx >= rmem_coherent_areas_num) + return NULL; + + return rmem_coherent_areas[idx]; +} +EXPORT_SYMBOL_GPL(dma_coherent_get_reserved_region); + static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) { struct dma_coherent_mem *mem = rmem->priv; @@ -393,6 +419,14 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem) rmem->ops = &rmem_dma_ops; pr_info("Reserved memory: created DMA memory pool at %pa, size %ld MiB\n", &rmem->base, (unsigned long)rmem->size / SZ_1M); + + if (IS_ENABLED(CONFIG_DMABUF_HEAPS_COHERENT)) { + int ret = rmem_coherent_insert_area(rmem); + + if (ret) + pr_warn("Reserved memory: failed to store coherent area for %s (%d)\n", + rmem->name ? rmem->name : "unknown", ret); + } return 0; } -- 2.52.0
