From 8febcaa2aac184d7e729acb75e9c4b80b04ad1b9 Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Thu, 24 Apr 2014 11:30:01 -0400 Subject: [PATCH 1/7] device: introduce per device dma_pfn_offset On few architectures, there are few restrictions on DMAble area of system RAM. That also means that devices needs to know about this restrictions so that the dma_masks can be updated accordingly and dma address translation helpers can add/subtract the dma offset. In most of cases DMA addresses can be performed using offset value of Bus address space relatively to physical address space as following: PFN->DMA: __pfn_to_phys(pfn + [-]dma_pfn_offset) DMA->PFN: __phys_to_pfn(dma_addr) + [-]dma_pfn_offset So we introduce per device dma_pfn_offset which can be popullated by architecture init code while creating the devices. Cc: Greg Kroah-Hartman Cc: Russell King Cc: Arnd Bergmann Cc: Olof Johansson Cc: Grant Likely Cc: Catalin Marinas Cc: Linus Walleij Reviewed-by: Rob Herring Signed-off-by: Grygorii Strashko Signed-off-by: Santosh Shilimkar --- include/linux/device.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/device.h b/include/linux/device.h index 233bbbeb768d..85a52d698f78 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -691,6 +691,7 @@ struct acpi_dev_node { * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all * hardware supports 64-bit addresses for consistent allocations * such descriptors. + * @dma_pfn_offset: offset of DMA memory range relatively of RAM * @dma_parms: A low level driver may set these to teach IOMMU code about * segment limitations. * @dma_pools: Dma pools (if dma'ble device). @@ -756,6 +757,7 @@ struct device { not all hardware supports 64 bit addresses for consistent allocations such descriptors. */ + unsigned long dma_pfn_offset; struct device_dma_parameters *dma_parms; From 18308c94723e162ed121942335bc186e66820a7a Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Thu, 24 Apr 2014 11:30:02 -0400 Subject: [PATCH 2/7] of: introduce of_dma_get_range() helper The of_dma_get_range() allows to find "dma-range" property for the specified device and parse it. dma-ranges format: DMA addr (dma_addr) : naddr cells CPU addr (phys_addr_t) : pna cells size : nsize cells Cc: Greg Kroah-Hartman Cc: Russell King Cc: Arnd Bergmann Cc: Olof Johansson Cc: Grant Likely Cc: Catalin Marinas Cc: Linus Walleij Reviewed-by: Rob Herring Signed-off-by: Grygorii Strashko Signed-off-by: Santosh Shilimkar --- drivers/of/address.c | 87 ++++++++++++++++++++++++++++++++++++++ include/linux/of_address.h | 8 ++++ 2 files changed, 95 insertions(+) diff --git a/drivers/of/address.c b/drivers/of/address.c index cb4242a69cd5..c54baee87d93 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -721,3 +721,90 @@ void __iomem *of_iomap(struct device_node *np, int index) return ioremap(res.start, resource_size(&res)); } EXPORT_SYMBOL(of_iomap); + +/** + * of_dma_get_range - Get DMA range info + * @np: device node to get DMA range info + * @dma_addr: pointer to store initial DMA address of DMA range + * @paddr: pointer to store initial CPU address of DMA range + * @size: pointer to store size of DMA range + * + * Look in bottom up direction for the first "dma-ranges" property + * and parse it. + * dma-ranges format: + * DMA addr (dma_addr) : naddr cells + * CPU addr (phys_addr_t) : pna cells + * size : nsize cells + * + * It returns -ENODEV if "dma-ranges" property was not found + * for this device in DT. + */ +int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size) +{ + struct device_node *node = of_node_get(np); + const __be32 *ranges = NULL; + int len, naddr, nsize, pna; + int ret = 0; + u64 dmaaddr; + + if (!node) + return -EINVAL; + + while (1) { + naddr = of_n_addr_cells(node); + nsize = of_n_size_cells(node); + node = of_get_next_parent(node); + if (!node) + break; + + ranges = of_get_property(node, "dma-ranges", &len); + + /* Ignore empty ranges, they imply no translation required */ + if (ranges && len > 0) + break; + + /* + * At least empty ranges has to be defined for parent node if + * DMA is supported + */ + if (!ranges) + break; + } + + if (!ranges) { + pr_debug("%s: no dma-ranges found for node(%s)\n", + __func__, np->full_name); + ret = -ENODEV; + goto out; + } + + len /= sizeof(u32); + + pna = of_n_addr_cells(node); + + /* dma-ranges format: + * DMA addr : naddr cells + * CPU addr : pna cells + * size : nsize cells + */ + dmaaddr = of_read_number(ranges, naddr); + *paddr = of_translate_dma_address(np, ranges); + if (*paddr == OF_BAD_ADDR) { + pr_err("%s: translation of DMA address(%pad) to CPU address failed node(%s)\n", + __func__, dma_addr, np->full_name); + ret = -EINVAL; + goto out; + } + *dma_addr = dmaaddr; + + *size = of_read_number(ranges + naddr + pna, nsize); + + pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n", + *dma_addr, *paddr, *size); + +out: + of_node_put(node); + + return ret; +} +EXPORT_SYMBOL_GPL(of_dma_get_range); diff --git a/include/linux/of_address.h b/include/linux/of_address.h index 5f6ed6b182b8..4d7b325af2ca 100644 --- a/include/linux/of_address.h +++ b/include/linux/of_address.h @@ -63,6 +63,8 @@ extern int of_pci_range_parser_init(struct of_pci_range_parser *parser, extern struct of_pci_range *of_pci_range_parser_one( struct of_pci_range_parser *parser, struct of_pci_range *range); +extern int of_dma_get_range(struct device_node *np, u64 *dma_addr, + u64 *paddr, u64 *size); #else /* CONFIG_OF_ADDRESS */ static inline struct device_node *of_find_matching_node_by_address( struct device_node *from, @@ -90,6 +92,12 @@ static inline struct of_pci_range *of_pci_range_parser_one( { return NULL; } + +static inline int of_dma_get_range(struct device_node *np, u64 *dma_addr, + u64 *paddr, u64 *size) +{ + return -ENODEV; +} #endif /* CONFIG_OF_ADDRESS */ #ifdef CONFIG_OF From 92ea637edea36e58236e3124f199161da6f5c5de Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Thu, 24 Apr 2014 11:30:03 -0400 Subject: [PATCH 3/7] of: introduce of_dma_is_coherent() helper The of_dma_is_coherent() helper parses the given DT device node to see if the "dma-coherent" property is supported and returns true or false accordingly. If the arch is always coherent or always noncoherent, then the default DMA ops has to be specified accordingly. Cc: Greg Kroah-Hartman Cc: Russell King Cc: Arnd Bergmann Cc: Olof Johansson Cc: Grant Likely Cc: Catalin Marinas Cc: Linus Walleij Reviewed-by: Rob Herring Signed-off-by: Santosh Shilimkar Signed-off-by: Grygorii Strashko --- drivers/of/address.c | 23 +++++++++++++++++++++++ include/linux/of_address.h | 6 ++++++ 2 files changed, 29 insertions(+) diff --git a/drivers/of/address.c b/drivers/of/address.c index c54baee87d93..d244b2859aac 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -808,3 +808,26 @@ out: return ret; } EXPORT_SYMBOL_GPL(of_dma_get_range); + +/** + * of_dma_is_coherent - Check if device is coherent + * @np: device node + * + * It returns true if "dma-coherent" property was found + * for this device in DT. + */ +bool of_dma_is_coherent(struct device_node *np) +{ + struct device_node *node = of_node_get(np); + + while (node) { + if (of_property_read_bool(node, "dma-coherent")) { + of_node_put(node); + return true; + } + node = of_get_next_parent(node); + } + of_node_put(node); + return false; +} +EXPORT_SYMBOL_GPL(of_dma_is_coherent); \ No newline at end of file diff --git a/include/linux/of_address.h b/include/linux/of_address.h index 4d7b325af2ca..839a3521b28e 100644 --- a/include/linux/of_address.h +++ b/include/linux/of_address.h @@ -65,6 +65,7 @@ extern struct of_pci_range *of_pci_range_parser_one( struct of_pci_range *range); extern int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size); +extern bool of_dma_is_coherent(struct device_node *np); #else /* CONFIG_OF_ADDRESS */ static inline struct device_node *of_find_matching_node_by_address( struct device_node *from, @@ -98,6 +99,11 @@ static inline int of_dma_get_range(struct device_node *np, u64 *dma_addr, { return -ENODEV; } + +static inline bool of_dma_is_coherent(struct device_node *np) +{ + return false; +} #endif /* CONFIG_OF_ADDRESS */ #ifdef CONFIG_OF From 591c1ee465ce5372385dbc41e7d3e36cbb477bd8 Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Thu, 24 Apr 2014 11:30:04 -0400 Subject: [PATCH 4/7] of: configure the platform device dma parameters Retrieve DMA configuration from DT and setup platform device's DMA parameters. The DMA configuration in DT has to be specified using "dma-ranges" and "dma-coherent" properties if supported. We setup dma_pfn_offset using "dma-ranges" and dma_coherent_ops using "dma-coherent" device tree properties. The set_arch_dma_coherent_ops macro has to be defined by arch if it supports coherent dma_ops. Otherwise, set_arch_dma_coherent_ops() is declared as nop. Cc: Greg Kroah-Hartman Cc: Russell King Cc: Arnd Bergmann Cc: Olof Johansson Cc: Grant Likely Cc: Catalin Marinas Cc: Linus Walleij Reviewed-by: Rob Herring Signed-off-by: Grygorii Strashko Signed-off-by: Santosh Shilimkar --- drivers/of/platform.c | 65 +++++++++++++++++++++++++++++++++---- include/linux/dma-mapping.h | 7 ++++ 2 files changed, 66 insertions(+), 6 deletions(-) diff --git a/drivers/of/platform.c b/drivers/of/platform.c index 404d1daebefa..91fa9838b56f 100644 --- a/drivers/of/platform.c +++ b/drivers/of/platform.c @@ -186,6 +186,64 @@ struct platform_device *of_device_alloc(struct device_node *np, } EXPORT_SYMBOL(of_device_alloc); +/** + * of_dma_configure - Setup DMA configuration + * @dev: Device to apply DMA configuration + * + * Try to get devices's DMA configuration from DT and update it + * accordingly. + * + * In case if platform code need to use own special DMA configuration,it + * can use Platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE event + * to fix up DMA configuration. + */ +static void of_dma_configure(struct platform_device *pdev) +{ + u64 dma_addr, paddr, size; + int ret; + struct device *dev = &pdev->dev; + +#if defined(CONFIG_MICROBLAZE) + pdev->archdata.dma_mask = 0xffffffffUL; +#endif + + /* + * Set default dma-mask to 32 bit. Drivers are expected to setup + * the correct supported dma_mask. + */ + dev->coherent_dma_mask = DMA_BIT_MASK(32); + + /* + * Set it to coherent_dma_mask by default if the architecture + * code has not set it. + */ + if (!dev->dma_mask) + dev->dma_mask = &dev->coherent_dma_mask; + + /* + * if dma-coherent property exist, call arch hook to setup + * dma coherent operations. + */ + if (of_dma_is_coherent(dev->of_node)) { + set_arch_dma_coherent_ops(dev); + dev_dbg(dev, "device is dma coherent\n"); + } + + /* + * if dma-ranges property doesn't exist - just return else + * setup the dma offset + */ + ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size); + if (ret < 0) { + dev_dbg(dev, "no dma range information to setup\n"); + return; + } + + /* DMA ranges found. Calculate and set dma_pfn_offset */ + dev->dma_pfn_offset = PFN_DOWN(paddr - dma_addr); + dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", dev->dma_pfn_offset); +} + /** * of_platform_device_create_pdata - Alloc, initialize and register an of_device * @np: pointer to node to create device for @@ -211,12 +269,7 @@ static struct platform_device *of_platform_device_create_pdata( if (!dev) return NULL; -#if defined(CONFIG_MICROBLAZE) - dev->archdata.dma_mask = 0xffffffffUL; -#endif - dev->dev.coherent_dma_mask = DMA_BIT_MASK(32); - if (!dev->dev.dma_mask) - dev->dev.dma_mask = &dev->dev.coherent_dma_mask; + of_dma_configure(dev); dev->dev.bus = &platform_bus_type; dev->dev.platform_data = platform_data; diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index fd4aee29ad10..c7d9b1b14ce7 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -123,6 +123,13 @@ static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask) extern u64 dma_get_required_mask(struct device *dev); +#ifndef set_arch_dma_coherent_ops +static inline int set_arch_dma_coherent_ops(struct device *dev) +{ + return 0; +} +#endif + static inline unsigned int dma_get_max_seg_size(struct device *dev) { return dev->dma_parms ? dev->dma_parms->max_segment_size : 65536; From 6ce0d20016925d031f1e24d64302e4c976d7cec6 Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Thu, 24 Apr 2014 11:30:05 -0400 Subject: [PATCH 5/7] ARM: dma: Use dma_pfn_offset for dma address translation In most of cases DMA addresses can be performed using offset value of Bus address space relatively to physical address space as following: PFN->DMA: __pfn_to_phys(pfn + [-]dma_pfn_offset) DMA->PFN: __phys_to_pfn(dma_addr) + [-]dma_pfn_offset Thanks to Russell King for suggesting the optimised macro's for conversion. Cc: Greg Kroah-Hartman Cc: Russell King Cc: Arnd Bergmann Cc: Olof Johansson Cc: Grant Likely Cc: Catalin Marinas Cc: Linus Walleij Reviewed-by: Rob Herring Signed-off-by: Grygorii Strashko Signed-off-by: Santosh Shilimkar --- arch/arm/include/asm/dma-mapping.h | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index e701a4d9aa59..b0c79fdd9375 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -58,21 +58,37 @@ static inline int dma_set_mask(struct device *dev, u64 mask) #ifndef __arch_pfn_to_dma static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn) { + if (dev) + pfn -= dev->dma_pfn_offset; return (dma_addr_t)__pfn_to_bus(pfn); } static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr) { - return __bus_to_pfn(addr); + unsigned long pfn = __bus_to_pfn(addr); + + if (dev) + pfn += dev->dma_pfn_offset; + + return pfn; } static inline void *dma_to_virt(struct device *dev, dma_addr_t addr) { + if (dev) { + unsigned long pfn = dma_to_pfn(dev, addr); + + return phys_to_virt(__pfn_to_phys(pfn)); + } + return (void *)__bus_to_virt((unsigned long)addr); } static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) { + if (dev) + return pfn_to_dma(dev, virt_to_pfn(addr)); + return (dma_addr_t)__virt_to_bus((unsigned long)(addr)); } From 812b99e4b024d6f83e9281ec1a0bd4bf63dad90f Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Thu, 24 Apr 2014 11:30:06 -0400 Subject: [PATCH 6/7] ARM: dma: implement set_arch_dma_coherent_ops() Implement the set_arch_dma_coherent_ops() for ARM architecture. Cc: Greg Kroah-Hartman Cc: Russell King Cc: Arnd Bergmann Cc: Olof Johansson Cc: Grant Likely Cc: Catalin Marinas Cc: Linus Walleij Reviewed-by: Rob Herring Signed-off-by: Grygorii Strashko Signed-off-by: Santosh Shilimkar --- arch/arm/include/asm/dma-mapping.h | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index b0c79fdd9375..c45b61a4b4a5 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -121,6 +121,13 @@ static inline unsigned long dma_max_pfn(struct device *dev) } #define dma_max_pfn(dev) dma_max_pfn(dev) +static inline int set_arch_dma_coherent_ops(struct device *dev) +{ + set_dma_ops(dev, &arm_coherent_dma_ops); + return 0; +} +#define set_arch_dma_coherent_ops(dev) set_arch_dma_coherent_ops(dev) + static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) { unsigned int offset = paddr & ~PAGE_MASK; From 2161c2485d03520060f6094359b22f33913eefa2 Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Thu, 24 Apr 2014 11:30:07 -0400 Subject: [PATCH 7/7] ARM: dma: use phys_addr_t in __dma_page_[cpu_to_dev/dev_to_cpu] On a 32 bit ARM architecture with LPAE extension physical addresses cannot fit into unsigned long variable. So fix it by using phys_addr_t instead of unsigned long. Cc: Nicolas Pitre Cc: Russell King - ARM Linux Cc: Catalin Marinas Acked-by: Will Deacon Signed-off-by: Santosh Shilimkar --- arch/arm/mm/dma-mapping.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index f62aa0677e5c..5260f43c3d03 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -885,7 +885,7 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset, static void __dma_page_cpu_to_dev(struct page *page, unsigned long off, size_t size, enum dma_data_direction dir) { - unsigned long paddr; + phys_addr_t paddr; dma_cache_maint_page(page, off, size, dir, dmac_map_area); @@ -901,7 +901,7 @@ static void __dma_page_cpu_to_dev(struct page *page, unsigned long off, static void __dma_page_dev_to_cpu(struct page *page, unsigned long off, size_t size, enum dma_data_direction dir) { - unsigned long paddr = page_to_phys(page) + off; + phys_addr_t paddr = page_to_phys(page) + off; /* FIXME: non-speculating: not required */ /* don't bother invalidating if DMA to device */