| Message ID | 20201021123437.21538-4-nsaenzjulienne@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Default to 32-bit wide ZONE_DMA | expand |
On Wed, 21 Oct 2020 at 14:35, Nicolas Saenz Julienne <nsaenzjulienne@suse.de> wrote: > > Introduce of_dma_get_max_cpu_address(), which provides the highest CPU > physical address addressable by all DMA masters in the system. It's > specially useful for setting memory zones sizes at early boot time. > > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> > > --- > > Changes since v3: > - use u64 with cpu_end > > Changes since v2: > - Use PHYS_ADDR_MAX > - return phys_dma_t > - Rename function > - Correct subject > - Add support to start parsing from an arbitrary device node in order > for the function to work with unit tests > > drivers/of/address.c | 42 ++++++++++++++++++++++++++++++++++++++++++ > include/linux/of.h | 7 +++++++ > 2 files changed, 49 insertions(+) > > diff --git a/drivers/of/address.c b/drivers/of/address.c > index eb9ab4f1e80b..47dfe5881e18 100644 > --- a/drivers/of/address.c > +++ b/drivers/of/address.c > @@ -1024,6 +1024,48 @@ int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map) > } > #endif /* CONFIG_HAS_DMA */ > > +/** > + * of_dma_get_max_cpu_address - Gets highest CPU address suitable for DMA > + * @np: The node to start searching from or NULL to start from the root > + * > + * Gets the highest CPU physical address that is addressable by all DMA masters > + * in the sub-tree pointed by np, or the whole tree if NULL is passed. If no > + * DMA constrained device is found, it returns PHYS_ADDR_MAX. > + */ > +phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np) > +{ > + phys_addr_t max_cpu_addr = PHYS_ADDR_MAX; > + struct of_range_parser parser; > + phys_addr_t subtree_max_addr; > + struct device_node *child; > + struct of_range range; > + const __be32 *ranges; > + u64 cpu_end = 0; > + int len; > + > + if (!np) > + np = of_root; > + > + ranges = of_get_property(np, "dma-ranges", &len); > + if (ranges && len) { > + of_dma_range_parser_init(&parser, np); > + for_each_of_range(&parser, &range) > + if (range.cpu_addr + range.size > cpu_end) > + cpu_end = range.cpu_addr + range.size; Shouldn't this be 'range.cpu_addr + range.size - 1' ? > + > + if (max_cpu_addr > cpu_end) > + max_cpu_addr = cpu_end; > + } > + > + for_each_available_child_of_node(np, child) { > + subtree_max_addr = of_dma_get_max_cpu_address(child); > + if (max_cpu_addr > subtree_max_addr) > + max_cpu_addr = subtree_max_addr; > + } > + > + return max_cpu_addr; > +} > + > /** > * of_dma_is_coherent - Check if device is coherent > * @np: device node > diff --git a/include/linux/of.h b/include/linux/of.h > index 481ec0467285..db8db8f2c967 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -558,6 +558,8 @@ int of_map_id(struct device_node *np, u32 id, > const char *map_name, const char *map_mask_name, > struct device_node **target, u32 *id_out); > > +phys_addr_t of_dma_get_max_cpu_address(struct device_node *np); > + > #else /* CONFIG_OF */ > > static inline void of_core_init(void) > @@ -995,6 +997,11 @@ static inline int of_map_id(struct device_node *np, u32 id, > return -EINVAL; > } > > +static inline phys_addr_t of_dma_get_max_cpu_address(struct device_node *np) > +{ > + return PHYS_ADDR_MAX; > +} > + > #define of_match_ptr(_ptr) NULL > #define of_match_node(_matches, _node) NULL > #endif /* CONFIG_OF */ > -- > 2.28.0 >
On Thu, 2020-10-22 at 14:23 +0200, Ard Biesheuvel wrote: > > +/** > > + * of_dma_get_max_cpu_address - Gets highest CPU address suitable for DMA > > + * @np: The node to start searching from or NULL to start from the root > > + * > > + * Gets the highest CPU physical address that is addressable by all DMA masters > > + * in the sub-tree pointed by np, or the whole tree if NULL is passed. If no > > + * DMA constrained device is found, it returns PHYS_ADDR_MAX. > > + */ > > +phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np) > > +{ > > + phys_addr_t max_cpu_addr = PHYS_ADDR_MAX; > > + struct of_range_parser parser; > > + phys_addr_t subtree_max_addr; > > + struct device_node *child; > > + struct of_range range; > > + const __be32 *ranges; > > + u64 cpu_end = 0; > > + int len; > > + > > + if (!np) > > + np = of_root; > > + > > + ranges = of_get_property(np, "dma-ranges", &len); > > + if (ranges && len) { > > + of_dma_range_parser_init(&parser, np); > > + for_each_of_range(&parser, &range) > > + if (range.cpu_addr + range.size > cpu_end) > > + cpu_end = range.cpu_addr + range.size; > > > Shouldn't this be 'range.cpu_addr + range.size - 1' ? Yes, I agree. In that case arm64's counterpart should be: zone_dma_bits = max(32U, fls64(of_dma_get_max_cpu_address(NULL))); I'll update it. Regards, Nicolas
diff --git a/drivers/of/address.c b/drivers/of/address.c index eb9ab4f1e80b..47dfe5881e18 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -1024,6 +1024,48 @@ int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map) } #endif /* CONFIG_HAS_DMA */ +/** + * of_dma_get_max_cpu_address - Gets highest CPU address suitable for DMA + * @np: The node to start searching from or NULL to start from the root + * + * Gets the highest CPU physical address that is addressable by all DMA masters + * in the sub-tree pointed by np, or the whole tree if NULL is passed. If no + * DMA constrained device is found, it returns PHYS_ADDR_MAX. + */ +phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np) +{ + phys_addr_t max_cpu_addr = PHYS_ADDR_MAX; + struct of_range_parser parser; + phys_addr_t subtree_max_addr; + struct device_node *child; + struct of_range range; + const __be32 *ranges; + u64 cpu_end = 0; + int len; + + if (!np) + np = of_root; + + ranges = of_get_property(np, "dma-ranges", &len); + if (ranges && len) { + of_dma_range_parser_init(&parser, np); + for_each_of_range(&parser, &range) + if (range.cpu_addr + range.size > cpu_end) + cpu_end = range.cpu_addr + range.size; + + if (max_cpu_addr > cpu_end) + max_cpu_addr = cpu_end; + } + + for_each_available_child_of_node(np, child) { + subtree_max_addr = of_dma_get_max_cpu_address(child); + if (max_cpu_addr > subtree_max_addr) + max_cpu_addr = subtree_max_addr; + } + + return max_cpu_addr; +} + /** * of_dma_is_coherent - Check if device is coherent * @np: device node diff --git a/include/linux/of.h b/include/linux/of.h index 481ec0467285..db8db8f2c967 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -558,6 +558,8 @@ int of_map_id(struct device_node *np, u32 id, const char *map_name, const char *map_mask_name, struct device_node **target, u32 *id_out); +phys_addr_t of_dma_get_max_cpu_address(struct device_node *np); + #else /* CONFIG_OF */ static inline void of_core_init(void) @@ -995,6 +997,11 @@ static inline int of_map_id(struct device_node *np, u32 id, return -EINVAL; } +static inline phys_addr_t of_dma_get_max_cpu_address(struct device_node *np) +{ + return PHYS_ADDR_MAX; +} + #define of_match_ptr(_ptr) NULL #define of_match_node(_matches, _node) NULL #endif /* CONFIG_OF */
Introduce of_dma_get_max_cpu_address(), which provides the highest CPU physical address addressable by all DMA masters in the system. It's specially useful for setting memory zones sizes at early boot time. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> --- Changes since v3: - use u64 with cpu_end Changes since v2: - Use PHYS_ADDR_MAX - return phys_dma_t - Rename function - Correct subject - Add support to start parsing from an arbitrary device node in order for the function to work with unit tests drivers/of/address.c | 42 ++++++++++++++++++++++++++++++++++++++++++ include/linux/of.h | 7 +++++++ 2 files changed, 49 insertions(+)