From 8febcaa2aac184d7e729acb75e9c4b80b04ad1b9 Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Thu, 24 Apr 2014 11:30:01 -0400 Subject: 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(+) (limited to 'include') 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; -- cgit v1.2.3 From 18308c94723e162ed121942335bc186e66820a7a Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Thu, 24 Apr 2014 11:30:02 -0400 Subject: 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 --- include/linux/of_address.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include') 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 -- cgit v1.2.3 From 92ea637edea36e58236e3124f199161da6f5c5de Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Thu, 24 Apr 2014 11:30:03 -0400 Subject: 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 --- include/linux/of_address.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include') 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 -- cgit v1.2.3 From 591c1ee465ce5372385dbc41e7d3e36cbb477bd8 Mon Sep 17 00:00:00 2001 From: Santosh Shilimkar Date: Thu, 24 Apr 2014 11:30:04 -0400 Subject: 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 --- include/linux/dma-mapping.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include') 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; -- cgit v1.2.3