Unverified Commit 7d95a88f authored by Palmer Dabbelt's avatar Palmer Dabbelt
Browse files

Add and use a generic version of devmem_is_allowed() 

As part of adding STRICT_DEVMEM support to the RISC-V port, Zong provided an
implementation of devmem_is_allowed() that's exactly the same as the version in
a handful of other ports.  Rather than duplicate code, I've put a generic
version of this in lib/ and used it for the RISC-V port.

* palmer/generic-devmem:
  arm64: Use the generic devmem_is_allowed()
  arm: Use the generic devmem_is_allowed()
  RISC-V: Use the new generic devmem_is_allowed()
  lib: Add a generic version of devmem_is_allowed()
parents 3ae9c3cd 6585bd82

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
@@ -56,6 +55,7 @@ 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

arch/arm64/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -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
@@ -112,6 +111,7 @@ 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

arch/arm64/include/asm/io.h

+0 −2
Original line number Diff line number Diff line
@@ -201,6 +201,4 @@ 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 */

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