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arch/x86/include/arch: fix assembly clobber for 64bit

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the "x86 PIC code ebx" workaround done previously
by commit 689e31d18b ("Make cpuid functions usable
when compiled with PIC") does not work for x86_64
(the upper dword of rbx is set to 0)

the GCC bug that needed the workaround was fixed
in version 5 (see GCC bug 54232)

Change-Id: Iff1dd72c7423a3b385a000457bcd065cf7ed6b95
Signed-off-by: Matei Dibu <matdibu@protonmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66345
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
This commit is contained in:
Matei Dibu
2022-08-02 00:48:59 +03:00
committed by Martin L Roth
parent 436f1c471a
commit 516eff01e6
1 changed files with 28 additions and 44 deletions
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72
src/arch/x86/include/arch/cpuid.h
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@@ -15,96 +15,80 @@ struct cpuid_result {
/* /*
* Generic CPUID function * Generic CPUID function
*/ */
static inline struct cpuid_result cpuid(int op) static inline struct cpuid_result cpuid(const uint32_t eax)
{ {
struct cpuid_result result; struct cpuid_result result;
asm volatile( asm volatile(
"mov %%ebx, %%edi;"
"cpuid;" "cpuid;"
"mov %%ebx, %%esi;"
"mov %%edi, %%ebx;"
: "=a" (result.eax), : "=a" (result.eax),
"=S" (result.ebx), "=b" (result.ebx),
"=c" (result.ecx), "=c" (result.ecx),
"=d" (result.edx) "=d" (result.edx)
: "0" (op) : "a" (eax));
: "edi");
return result; return result;
} }
/* /*
* Generic Extended CPUID function * Generic Extended CPUID function
*/ */
static inline struct cpuid_result cpuid_ext(int op, unsigned int ecx) static inline struct cpuid_result cpuid_ext(const uint32_t eax, const uint32_t ecx)
{ {
struct cpuid_result result; struct cpuid_result result;
asm volatile( asm volatile(
"mov %%ebx, %%edi;"
"cpuid;" "cpuid;"
"mov %%ebx, %%esi;"
"mov %%edi, %%ebx;"
: "=a" (result.eax), : "=a" (result.eax),
"=S" (result.ebx), "=b" (result.ebx),
"=c" (result.ecx), "=c" (result.ecx),
"=d" (result.edx) "=d" (result.edx)
: "0" (op), "2" (ecx) : "a" (eax), "c" (ecx));
: "edi");
return result; return result;
} }
/* /*
* CPUID functions returning a single datum * CPUID functions returning a single datum
*/ */
static inline unsigned int cpuid_eax(unsigned int op) static inline uint32_t cpuid_eax(uint32_t eax)
{ {
unsigned int eax; asm volatile(
__asm__("mov %%ebx, %%edi;"
"cpuid;" "cpuid;"
"mov %%edi, %%ebx;" : "+a" (eax)
: "=a" (eax) :: "ebx", "ecx", "edx");
: "0" (op)
: "ecx", "edx", "edi");
return eax; return eax;
} }
static inline unsigned int cpuid_ebx(unsigned int op) static inline uint32_t cpuid_ebx(const uint32_t eax)
{ {
unsigned int eax, ebx; uint32_t ebx;
__asm__("mov %%ebx, %%edi;" asm volatile(
"cpuid;" "cpuid;"
"mov %%ebx, %%esi;" : "=b" (ebx)
"mov %%edi, %%ebx;" : "a" (eax)
: "=a" (eax), "=S" (ebx) : "ecx", "edx");
: "0" (op)
: "ecx", "edx", "edi");
return ebx; return ebx;
} }
static inline unsigned int cpuid_ecx(unsigned int op) static inline uint32_t cpuid_ecx(const uint32_t eax)
{ {
unsigned int eax, ecx; uint32_t ecx;
__asm__("mov %%ebx, %%edi;" asm volatile(
"cpuid;" "cpuid;"
"mov %%edi, %%ebx;" : "=c" (ecx)
: "=a" (eax), "=c" (ecx) : "a" (eax)
: "0" (op) : "ebx", "edx");
: "edx", "edi");
return ecx; return ecx;
} }
static inline unsigned int cpuid_edx(unsigned int op) static inline uint32_t cpuid_edx(const uint32_t eax)
{ {
unsigned int eax, edx; uint32_t edx;
__asm__("mov %%ebx, %%edi;" asm volatile(
"cpuid;" "cpuid;"
"mov %%edi, %%ebx;" : "=d" (edx)
: "=a" (eax), "=d" (edx) : "a" (eax)
: "0" (op) : "ebx", "ecx");
: "ecx", "edi");
return edx; return edx;
} }