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

[Suzuki K Poulose]

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 <kuleshovm...@gmail.com>
---
 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;