Re: [PATCH 2/3] arm64/setup: Use ID_AA64ISAR0_EL1_.* macros

From: Suzuki K Poulose
Date: Mon Nov 07 2016 - 11:31:03 EST


On 03/09/15 19:12, Alexander Kuleshov wrote:
The 26d75e67c commit (arm64/cpufeature.h: Add macros for a cpu features
testing) provides set of macros for the testing processor's crypto features.
Let's use these macros instead of direct calculation.




Signed-off-by: Alexander Kuleshov <kuleshovmail@xxxxxxxxx>
---
arch/arm64/kernel/setup.c | 29 +++++++++--------------------
1 file changed, 9 insertions(+), 20 deletions(-)

diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 926ae8d..a3faf4f 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c

This patch doesn't apply on the current mainline tree. Where does this patch apply ?
The elf_hwcap calculation has been moved to a separate function setup_elf_hwcaps()
in arch/arm64/kernel/cpufeature.c, which makes uses of a table of arm64_cpu_capabilities.

Suzuki

@@ -250,33 +250,22 @@ static void __init setup_processor(void)

/*
* 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))
+ if (ID_AA64ISAR0_EL1_AES(features))
+ elf_hwcap |= HWCAP_AES;
+
+ if (ID_AA64ISAR0_EL1_PMULL(features))
+ elf_hwcap |= HWCAP_PMULL;
+
+ if (ID_AA64ISAR0_EL1_SHA1(features))
elf_hwcap |= HWCAP_SHA1;

- block = (features >> 12) & 0xf;
- if (block && !(block & 0x8))
+ if (ID_AA64ISAR0_EL1_SHA2(features))
elf_hwcap |= HWCAP_SHA2;

- block = (features >> 16) & 0xf;
- if (block && !(block & 0x8))
+ if (ID_AA64ISAR0_EL1_CRC32(features))
elf_hwcap |= HWCAP_CRC32;