Commit 402fe0cb authored by Tom Lendacky's avatar Tom Lendacky Committed by Borislav Petkov
Browse files

x86/ioremap: Selectively build arch override encryption functions 



In preparation for other uses of the cc_platform_has() function
besides AMD's memory encryption support, selectively build the
AMD memory encryption architecture override functions only when
CONFIG_AMD_MEM_ENCRYPT=y. These functions are:

- early_memremap_pgprot_adjust()
- arch_memremap_can_ram_remap()

Additionally, routines that are only invoked by these architecture
override functions can also be conditionally built. These functions are:

- memremap_should_map_decrypted()
- memremap_is_efi_data()
- memremap_is_setup_data()
- early_memremap_is_setup_data()

And finally, phys_mem_access_encrypted() is conditionally built as well,
but requires a static inline version of it when CONFIG_AMD_MEM_ENCRYPT is
not set.

Signed-off-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210928191009.32551-2-bp@alien8.de
parent 9e1ff307

arch/x86/include/asm/io.h

+8 −0
Original line number Diff line number Diff line
@@ -391,6 +391,7 @@ extern void arch_io_free_memtype_wc(resource_size_t start, resource_size_t size) 
#define arch_io_reserve_memtype_wc arch_io_reserve_memtype_wc

#endif



#ifdef CONFIG_AMD_MEM_ENCRYPT

extern bool arch_memremap_can_ram_remap(resource_size_t offset,

					unsigned long size,

					unsigned long flags);
@@ -398,6 +399,13 @@ extern bool arch_memremap_can_ram_remap(resource_size_t offset, 


extern bool phys_mem_access_encrypted(unsigned long phys_addr,

				      unsigned long size);

#else

static inline bool phys_mem_access_encrypted(unsigned long phys_addr,

					     unsigned long size)

{

	return true;

}

#endif



/**

 * iosubmit_cmds512 - copy data to single MMIO location, in 512-bit units

arch/x86/mm/ioremap.c

+1 −1
Original line number Diff line number Diff line
@@ -508,6 +508,7 @@ void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr) 
	memunmap((void *)((unsigned long)addr & PAGE_MASK));

}



#ifdef CONFIG_AMD_MEM_ENCRYPT

/*

 * Examine the physical address to determine if it is an area of memory

 * that should be mapped decrypted.  If the memory is not part of the
@@ -746,7 +747,6 @@ bool phys_mem_access_encrypted(unsigned long phys_addr, unsigned long size) 
	return arch_memremap_can_ram_remap(phys_addr, size, 0);

}



#ifdef CONFIG_AMD_MEM_ENCRYPT

/* Remap memory with encryption */

void __init *early_memremap_encrypted(resource_size_t phys_addr,

				      unsigned long size)