From fffe3cc8c2194f60c4af4fac7f27d25e8828f001 Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Thu, 29 Jul 2021 14:15:19 -0600 Subject: dma-mapping: allow map_sg() ops to return negative error codes Allow dma_map_sgtable() to pass errors from the map_sg() ops. This will be required for returning appropriate error codes when mapping P2PDMA memory. Introduce __dma_map_sg_attrs() which will return the raw error code from the map_sg operation (whether it be negative or zero). Then add a dma_map_sg_attrs() wrapper to convert any negative errors to zero to satisfy the existing calling convention. dma_map_sgtable() defines three error codes that .map_sg implementations are allowed to return: -EINVAL, -ENOMEM and -EIO. The latter of which is a generic return for cases that are passing DMA_MAPPING_ERROR through. dma_map_sgtable() will convert a zero error return for old map_sg() ops into a -EIO return and return any negative errors as reported. This allows map_sg implementations to start returning multiple negative error codes. Legacy map_sg implementations can continue to return zero until they are all converted. Signed-off-by: Logan Gunthorpe Signed-off-by: Christoph Hellwig --- include/linux/dma-map-ops.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'include/linux/dma-map-ops.h') diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 0d53a96a3d64..2f842498c448 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -41,8 +41,9 @@ struct dma_map_ops { size_t size, enum dma_data_direction dir, unsigned long attrs); /* - * map_sg returns 0 on error and a value > 0 on success. - * It should never return a value < 0. + * map_sg should return a negative error code on error. See + * dma_map_sgtable() for a list of appropriate error codes + * and their meanings. */ int (*map_sg)(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir, unsigned long attrs); -- cgit v1.2.3 From 39a2d3506b2d53c569a6db13d65b2f3728c4feec Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 23 Jun 2021 16:05:05 +0200 Subject: dma-mapping: add a dma_init_global_coherent helper Add a new helper to initialize the global coherent pool. This both cleans up the existing initialization which indirects through the reserved_mem_ops that are normally only used for struct device, and also allows using the global pool for non-devicetree architectures. Signed-off-by: Christoph Hellwig Tested-by: Dillon Min --- include/linux/dma-map-ops.h | 2 +- kernel/dma/coherent.c | 32 ++++++++++++++------------------ 2 files changed, 15 insertions(+), 19 deletions(-) (limited to 'include/linux/dma-map-ops.h') diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 2f842498c448..068f1b11a6a4 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -177,7 +177,7 @@ void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, int dma_release_from_global_coherent(int order, void *vaddr); int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *cpu_addr, size_t size, int *ret); - +int dma_init_global_coherent(phys_addr_t phys_addr, size_t size); #else static inline int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, dma_addr_t device_addr, size_t size) diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index ab397ebfd5ad..160d4e246ecb 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -300,6 +300,18 @@ int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr, vaddr, size, ret); } +int dma_init_global_coherent(phys_addr_t phys_addr, size_t size) +{ + struct dma_coherent_mem *mem; + + mem = dma_init_coherent_memory(phys_addr, phys_addr, size, true); + if (IS_ERR(mem)) + return PTR_ERR(mem); + dma_coherent_default_memory = mem; + pr_info("DMA: default coherent area is set\n"); + return 0; +} + /* * Support for reserved memory regions defined in device tree */ @@ -367,26 +379,10 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem) static int __init dma_init_reserved_memory(void) { - const struct reserved_mem_ops *ops; - int ret; - if (!dma_reserved_default_memory) return -ENOMEM; - - ops = dma_reserved_default_memory->ops; - - /* - * We rely on rmem_dma_device_init() does not propagate error of - * dma_assign_coherent_memory() for "NULL" device. - */ - ret = ops->device_init(dma_reserved_default_memory, NULL); - - if (!ret) { - dma_coherent_default_memory = dma_reserved_default_memory->priv; - pr_info("DMA: default coherent area is set\n"); - } - - return ret; + return dma_init_global_coherent(dma_reserved_default_memory->base, + dma_reserved_default_memory->size); } core_initcall(dma_init_reserved_memory); -- cgit v1.2.3 From 22f9feb49950885cdb6e37513f134d154175e743 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 24 Jun 2021 19:37:00 +0200 Subject: dma-mapping: make the global coherent pool conditional Only build the code to support the global coherent pool if support for it is enabled. Signed-off-by: Christoph Hellwig Tested-by: Dillon Min --- include/linux/dma-map-ops.h | 18 +++++++++-------- kernel/dma/coherent.c | 49 +++++++++++++++++++++++++-------------------- 2 files changed, 37 insertions(+), 30 deletions(-) (limited to 'include/linux/dma-map-ops.h') diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 068f1b11a6a4..0d5b06b3a4a6 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -171,13 +171,6 @@ 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); - -void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, - dma_addr_t *dma_handle); -int dma_release_from_global_coherent(int order, void *vaddr); -int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *cpu_addr, - size_t size, int *ret); -int dma_init_global_coherent(phys_addr_t phys_addr, size_t size); #else static inline int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, dma_addr_t device_addr, size_t size) @@ -187,7 +180,16 @@ static inline int dma_declare_coherent_memory(struct device *dev, #define dma_alloc_from_dev_coherent(dev, size, handle, ret) (0) #define dma_release_from_dev_coherent(dev, order, vaddr) (0) #define dma_mmap_from_dev_coherent(dev, vma, vaddr, order, ret) (0) +#endif /* CONFIG_DMA_DECLARE_COHERENT */ +#ifdef CONFIG_DMA_GLOBAL_POOL +void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, + dma_addr_t *dma_handle); +int dma_release_from_global_coherent(int order, void *vaddr); +int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *cpu_addr, + size_t size, int *ret); +int dma_init_global_coherent(phys_addr_t phys_addr, size_t size); +#else static inline void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, dma_addr_t *dma_handle) { @@ -202,7 +204,7 @@ static inline int dma_mmap_from_global_coherent(struct vm_area_struct *vma, { return 0; } -#endif /* CONFIG_DMA_DECLARE_COHERENT */ +#endif /* CONFIG_DMA_GLOBAL_POOL */ /* * This is the actual return value from the ->alloc_noncontiguous method. diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 160d4e246ecb..25fc85a7aebe 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -20,8 +20,6 @@ struct dma_coherent_mem { bool use_dev_dma_pfn_offset; }; -static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init; - static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *dev) { if (dev && dev->dma_mem) @@ -191,16 +189,6 @@ int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size, return 1; } -void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, - dma_addr_t *dma_handle) -{ - if (!dma_coherent_default_memory) - return NULL; - - return __dma_alloc_from_coherent(dev, dma_coherent_default_memory, size, - dma_handle); -} - static int __dma_release_from_coherent(struct dma_coherent_mem *mem, int order, void *vaddr) { @@ -236,15 +224,6 @@ int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr) return __dma_release_from_coherent(mem, order, vaddr); } -int dma_release_from_global_coherent(int order, void *vaddr) -{ - if (!dma_coherent_default_memory) - return 0; - - return __dma_release_from_coherent(dma_coherent_default_memory, order, - vaddr); -} - static int __dma_mmap_from_coherent(struct dma_coherent_mem *mem, struct vm_area_struct *vma, void *vaddr, size_t size, int *ret) { @@ -290,6 +269,28 @@ int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma, return __dma_mmap_from_coherent(mem, vma, vaddr, size, ret); } +#ifdef CONFIG_DMA_GLOBAL_POOL +static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init; + +void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, + dma_addr_t *dma_handle) +{ + if (!dma_coherent_default_memory) + return NULL; + + return __dma_alloc_from_coherent(dev, dma_coherent_default_memory, size, + dma_handle); +} + +int dma_release_from_global_coherent(int order, void *vaddr) +{ + if (!dma_coherent_default_memory) + return 0; + + return __dma_release_from_coherent(dma_coherent_default_memory, order, + vaddr); +} + int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr, size_t size, int *ret) { @@ -311,6 +312,7 @@ int dma_init_global_coherent(phys_addr_t phys_addr, size_t size) pr_info("DMA: default coherent area is set\n"); return 0; } +#endif /* CONFIG_DMA_GLOBAL_POOL */ /* * Support for reserved memory regions defined in device tree @@ -320,7 +322,9 @@ int dma_init_global_coherent(phys_addr_t phys_addr, size_t size) #include #include +#ifdef CONFIG_DMA_GLOBAL_POOL static struct reserved_mem *dma_reserved_default_memory __initdata; +#endif static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) { @@ -377,6 +381,7 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem) return 0; } +#ifdef CONFIG_DMA_GLOBAL_POOL static int __init dma_init_reserved_memory(void) { if (!dma_reserved_default_memory) @@ -384,8 +389,8 @@ static int __init dma_init_reserved_memory(void) return dma_init_global_coherent(dma_reserved_default_memory->base, dma_reserved_default_memory->size); } - core_initcall(dma_init_reserved_memory); +#endif /* CONFIG_DMA_GLOBAL_POOL */ RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup); #endif -- cgit v1.2.3