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arm64: Use the generic devmem_is_allowed()

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I recently copied this into lib/ for use by the RISC-V port.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This commit is contained in:
Palmer Dabbelt 2020-07-09 12:05:36 -07:00
parent 914ee96654
commit 6585bd8274
No known key found for this signature in database
GPG key ID: 2E1319F35FBB1889
3 changed files with 1 additions and 24 deletions
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2
arch/arm64/Kconfig
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@ -13,7 +13,6 @@ config ARM64
select ARCH_BINFMT_ELF_STATE
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_DMA_PREP_COHERENT
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
select ARCH_HAS_FAST_MULTIPLIER
@ -110,6 +109,7 @@ 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

2
arch/arm64/include/asm/io.h
View file

@ -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 */

21
arch/arm64/mm/mmap.c
View file

@ -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