[PATCH v2 10/25] asm-generic/io.h: Add a non-posted variant of ioremap()
From: Hector Martin <hidden>
Date: 2021-02-15 12:22:25
Also in:
linux-devicetree, lkml
Subsystem:
generic include/asm header files, library code, the rest · Maintainers:
Arnd Bergmann, Andrew Morton, Linus Torvalds
ARM64 currently defaults to posted MMIO (nGnRnE), but some devices require the use of non-posted MMIO (nGnRE). Introduce a new ioremap() variant to handle this case. ioremap_np() is aliased to ioremap() by default on arches that do not implement this variant. This adds the IORESOURCE_MEM_NONPOSTED flag, which maps to this variant and marks a given resource as requiring non-posted mappings. This is implemented in the resource system because it is a SoC-level requirement, so existing drivers do not need special-case code to pick this ioremap variant. Then this is implemented in devres by introducing devm_ioremap_np(), and making devm_ioremap_resource() automatically select this variant when the resource has the IORESOURCE_MEM_NONPOSTED flag set. Signed-off-by: Hector Martin <redacted> --- include/asm-generic/io.h | 8 +++++++- include/linux/io.h | 2 ++ include/linux/ioport.h | 1 + lib/devres.c | 22 ++++++++++++++++++++++ 4 files changed, 32 insertions(+), 1 deletion(-)
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index c6af40ce03be..43e4bb8d633c 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h@@ -942,7 +942,9 @@ static inline void *phys_to_virt(unsigned long address) * * ioremap_wc() and ioremap_wt() can provide more relaxed caching attributes * for specific drivers if the architecture choses to implement them. If they - * are not implemented we fall back to plain ioremap. + * are not implemented we fall back to plain ioremap. Conversely, ioremap_np() + * can provide stricter non-posted write semantics if the architecture + * implements them. */ #ifndef CONFIG_MMU #ifndef ioremap
@@ -980,6 +982,10 @@ static inline void __iomem *ioremap(phys_addr_t addr, size_t size) #define ioremap_wt ioremap #endif +#ifndef ioremap_np +#define ioremap_np ioremap +#endif + /* * ioremap_uc is special in that we do require an explicit architecture * implementation. In general you do not want to use this function in a
diff --git a/include/linux/io.h b/include/linux/io.h
index 8394c56babc2..d718354ed3e1 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h@@ -68,6 +68,8 @@ void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset, resource_size_t size); void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset, resource_size_t size); +void __iomem *devm_ioremap_np(struct device *dev, resource_size_t offset, + resource_size_t size); void devm_iounmap(struct device *dev, void __iomem *addr); int check_signature(const volatile void __iomem *io_addr, const unsigned char *signature, int length);
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index fe48b7840665..5929a67570ae 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h@@ -108,6 +108,7 @@ struct resource { #define IORESOURCE_MEM_32BIT (3<<3) #define IORESOURCE_MEM_SHADOWABLE (1<<5) /* dup: IORESOURCE_SHADOWABLE */ #define IORESOURCE_MEM_EXPANSIONROM (1<<6) +#define IORESOURCE_MEM_NONPOSTED (1<<7) /* PnP I/O specific bits (IORESOURCE_BITS) */ #define IORESOURCE_IO_16BIT_ADDR (1<<0)
diff --git a/lib/devres.c b/lib/devres.c
index 2a4ff5d64288..4679dbb1bf5f 100644
--- a/lib/devres.c
+++ b/lib/devres.c@@ -10,6 +10,7 @@ enum devm_ioremap_type { DEVM_IOREMAP = 0, DEVM_IOREMAP_UC, DEVM_IOREMAP_WC, + DEVM_IOREMAP_NP, }; void devm_ioremap_release(struct device *dev, void *res)
@@ -42,6 +43,9 @@ static void __iomem *__devm_ioremap(struct device *dev, resource_size_t offset, case DEVM_IOREMAP_WC: addr = ioremap_wc(offset, size); break; + case DEVM_IOREMAP_NP: + addr = ioremap_np(offset, size); + break; } if (addr) {
@@ -98,6 +102,21 @@ void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset, } EXPORT_SYMBOL(devm_ioremap_wc); +/** + * devm_ioremap_np - Managed ioremap_np() + * @dev: Generic device to remap IO address for + * @offset: Resource address to map + * @size: Size of map + * + * Managed ioremap_np(). Map is automatically unmapped on driver detach. + */ +void __iomem *devm_ioremap_np(struct device *dev, resource_size_t offset, + resource_size_t size) +{ + return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_NP); +} +EXPORT_SYMBOL(devm_ioremap_np); + /** * devm_iounmap - Managed iounmap() * @dev: Generic device to unmap for
@@ -128,6 +147,9 @@ __devm_ioremap_resource(struct device *dev, const struct resource *res, return IOMEM_ERR_PTR(-EINVAL); } + if (type == DEVM_IOREMAP && res->flags & IORESOURCE_MEM_NONPOSTED) + type = DEVM_IOREMAP_NP; + size = resource_size(res); if (res->name)
--
2.30.0
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel