lib: provide a simple generic ioremap implementation
A lot of architectures reuse the same simple ioremap implementation, so
start lifting the most simple variant to lib/ioremap.c. It provides
ioremap_prot and iounmap, plus a default ioremap that uses prot_noncached,
although that can be overridden by asm/io.h.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Palmer Dabbelt <palmer@dabbelt.com>
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index bd676f2..325fc98 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -923,9 +923,10 @@ static inline void *phys_to_virt(unsigned long address)
* DOC: ioremap() and ioremap_*() variants
*
* Architectures with an MMU are expected to provide ioremap() and iounmap()
- * themselves. For NOMMU architectures we provide a default nop-op
- * implementation that expect that the physical address used for MMIO are
- * already marked as uncached, and can be used as kernel virtual addresses.
+ * themselves or rely on GENERIC_IOREMAP. For NOMMU architectures we provide
+ * a default nop-op implementation that expect that the physical address used
+ * for MMIO are already marked as uncached, and can be used as kernel virtual
+ * addresses.
*
* ioremap_wc() and ioremap_wt() can provide more relaxed caching attributes
* for specific drivers if the architecture choses to implement them. If they
@@ -946,7 +947,18 @@ static inline void iounmap(void __iomem *addr)
{
}
#endif
-#endif /* CONFIG_MMU */
+#elif defined(CONFIG_GENERIC_IOREMAP)
+#include <asm/pgtable.h>
+
+void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot);
+void iounmap(volatile void __iomem *addr);
+
+static inline void __iomem *ioremap(phys_addr_t addr, size_t size)
+{
+ /* _PAGE_IOREMAP needs to be supplied by the architecture */
+ return ioremap_prot(addr, size, _PAGE_IOREMAP);
+}
+#endif /* !CONFIG_MMU || CONFIG_GENERIC_IOREMAP */
#ifndef ioremap_nocache
#define ioremap_nocache ioremap