Commit 4bff28cc authored by Steve Capper's avatar Steve Capper Committed by Catalin Marinas
Browse files

arm64: Add hwcaps for crypto and CRC32 extensions. 



Advertise the optional cryptographic and CRC32 instructions to
user space where present. Several hwcap bits [3-7] are allocated.

Signed-off-by: default avatarSteve Capper <steve.capper@linaro.org>
[bit 2 is taken now so use bits 3-7 instead]
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 148eb0a1

arch/arm64/include/uapi/asm/hwcap.h

+5 −1
Original line number Diff line number Diff line
@@ -22,6 +22,10 @@ 
#define HWCAP_FP		(1 << 0)

#define HWCAP_ASIMD		(1 << 1)

#define HWCAP_EVTSTRM		(1 << 2)



#define HWCAP_AES		(1 << 3)

#define HWCAP_PMULL		(1 << 4)

#define HWCAP_SHA1		(1 << 5)

#define HWCAP_SHA2		(1 << 6)

#define HWCAP_CRC32		(1 << 7)



#endif /* _UAPI__ASM_HWCAP_H */

arch/arm64/kernel/setup.c

+37 −0
Original line number Diff line number Diff line
@@ -126,6 +126,7 @@ bool arch_match_cpu_phys_id(int cpu, u64 phys_id) 
static void __init setup_processor(void)

{

	struct cpu_info *cpu_info;

	u64 features, block;



	cpu_info = lookup_processor_type(read_cpuid_id());

	if (!cpu_info) {
@@ -141,6 +142,37 @@ static void __init setup_processor(void) 


	sprintf(init_utsname()->machine, ELF_PLATFORM);

	elf_hwcap = 0;



	/*

	 * ID_AA64ISAR0_EL1 contains 4-bit wide signed feature blocks.

	 * The blocks we test below represent incremental functionality

	 * for non-negative values. Negative values are reserved.

	 */

	features = read_cpuid(ID_AA64ISAR0_EL1);

	block = (features >> 4) & 0xf;

	if (!(block & 0x8)) {

		switch (block) {

		default:

		case 2:

			elf_hwcap |= HWCAP_PMULL;

		case 1:

			elf_hwcap |= HWCAP_AES;

		case 0:

			break;

		}

	}



	block = (features >> 8) & 0xf;

	if (block && !(block & 0x8))

		elf_hwcap |= HWCAP_SHA1;



	block = (features >> 12) & 0xf;

	if (block && !(block & 0x8))

		elf_hwcap |= HWCAP_SHA2;



	block = (features >> 16) & 0xf;

	if (block && !(block & 0x8))

		elf_hwcap |= HWCAP_CRC32;

}



static void __init setup_machine_fdt(phys_addr_t dt_phys)
@@ -280,6 +312,11 @@ static const char *hwcap_str[] = { 
	"fp",

	"asimd",

	"evtstrm",

	"aes",

	"pmull",

	"sha1",

	"sha2",

	"crc32",

	NULL

};

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