From: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
I recently copied this into lib/ for use by the RISC-V port.
[I haven't even build tested this. The lib/ patch is on riscv/for-next,
which I'm targeting for 5.9, so this won't work alone. See the cover
letter for more details.]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/io.h | 2 --
arch/arm64/mm/mmap.c | 21 ---------------------
3 files changed, 1 insertion(+), 23 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 66dc41fd49f2..0770ed21a8c4 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -110,6 +110,7 @@ config ARM64
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
select GENERIC_IRQ_SHOW_LEVEL
+ select GENERIC_LIB_DEVMEM_IS_ALLOWED
select GENERIC_PCI_IOMAP
select GENERIC_PTDUMP
select GENERIC_SCHED_CLOCK
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index ff50dd731852..c53eba1a7fd2 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -200,6 +200,4 @@ extern void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size);
extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
-extern int devmem_is_allowed(unsigned long pfn);
-
#endif /* __ASM_IO_H */
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
index 3028bacbc4e9..07937b49cb88 100644
--- a/arch/arm64/mm/mmap.c
+++ b/arch/arm64/mm/mmap.c
@@ -47,24 +47,3 @@ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
{
return !(((pfn << PAGE_SHIFT) + size) & ~PHYS_MASK);
}
-
-#ifdef CONFIG_STRICT_DEVMEM
-
-#include <linux/ioport.h>
-
-/*
- * devmem_is_allowed() checks to see if /dev/mem access to a certain address
- * is valid. The argument is a physical page number. We mimic x86 here by
- * disallowing access to system RAM as well as device-exclusive MMIO regions.
- * This effectively disable read()/write() on /dev/mem.
- */
-int devmem_is_allowed(unsigned long pfn)
-{
- if (iomem_is_exclusive(pfn << PAGE_SHIFT))
- return 0;
- if (!page_is_ram(pfn))
- return 1;
- return 0;
-}
-
-#endif
--
2.27.0.383.g050319c2ae-goog
