Unverified Commit 914ee966 authored by Palmer Dabbelt's avatar Palmer Dabbelt
Browse files

arm: Use the generic devmem_is_allowed() 



This is exactly the same as the arm64 version, which I recently copied
into lib/ for use by the RISC-V port.

Reviewed-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent 78ed473c

arch/arm/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -5,7 +5,6 @@ config ARM 
	select ARCH_32BIT_OFF_T

	select ARCH_HAS_BINFMT_FLAT

	select ARCH_HAS_DEBUG_VIRTUAL if MMU

	select ARCH_HAS_DEVMEM_IS_ALLOWED

	select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE

	select ARCH_HAS_ELF_RANDOMIZE

	select ARCH_HAS_FORTIFY_SOURCE
@@ -55,6 +54,7 @@ config ARM 
	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_SCHED_CLOCK

	select GENERIC_SMP_IDLE_THREAD

arch/arm/include/asm/io.h

+0 −1
Original line number Diff line number Diff line
@@ -441,7 +441,6 @@ extern void pci_iounmap(struct pci_dev *dev, void __iomem *addr); 
#define ARCH_HAS_VALID_PHYS_ADDR_RANGE

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



/*

arch/arm/mm/mmap.c

+0 −22
Original line number Diff line number Diff line
@@ -165,25 +165,3 @@ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) 
{

	return (pfn + (size >> PAGE_SHIFT)) <= (1 + (PHYS_MASK >> PAGE_SHIFT));

}
 


#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