[PATCH v7 051/120] x86/microcode/amd: rdrand: Use standard CPUID(0x1) types

[Ahmed S. Darwish]

Use standard CPUID(0x1) types from x86-cpuid-db instead of doing manual
bitwise operations.

Keep using a direct CPUID query, instead of the CPUID parser API.  At a
later step, clearing a feature bit like X86_FEATURE_RDRAND will also clear
its cached backing CPUID bit, while the code clearly mentions that it wants
to query the CPUID state regardless of the X86_FEATURE_RDRAND bit state.

Signed-off-by: Ahmed S. Darwish <darwi@xxxxxxxxxxxxx>
---
 arch/x86/kernel/cpu/amd.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 0e077a4f2646..5f885fafa238 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -807,6 +807,8 @@ early_param("rdrand", rdrand_cmdline);
 
 static void clear_rdrand_cpuid_bit(struct cpuinfo_x86 *c)
 {
+	struct leaf_0x1_0 l1;
+
 	/*
 	 * Saving of the MSR used to hide the RDRAND support during
 	 * suspend/resume is done by arch/x86/power/cpu.c, which is
@@ -819,7 +821,8 @@ static void clear_rdrand_cpuid_bit(struct cpuinfo_x86 *c)
 	 * The self-test can clear X86_FEATURE_RDRAND, so check for
 	 * RDRAND support using the CPUID function directly.
 	 */
-	if (!(cpuid_ecx(1) & BIT(30)) || rdrand_force)
+	cpuid_read(0x1, &l1);
+	if (!l1.rdrand || rdrand_force)
 		return;
 
 	msr_clear_bit(MSR_AMD64_CPUID_FN_1, 62);
@@ -828,7 +831,8 @@ static void clear_rdrand_cpuid_bit(struct cpuinfo_x86 *c)
 	 * Verify that the CPUID change has occurred in case the kernel is
 	 * running virtualized and the hypervisor doesn't support the MSR.
 	 */
-	if (cpuid_ecx(1) & BIT(30)) {
+	cpuid_read(0x1, &l1);
+	if (l1.rdrand) {
 		pr_info_once("BIOS may not properly restore RDRAND after suspend, but hypervisor does not support hiding RDRAND via CPUID.\n");
 		return;
 	}
-- 
2.54.0