Commit 2fe2a2c7 authored by Juergen Gross's avatar Juergen Gross Committed by Borislav Petkov
Browse files

x86/alternative: Use ALTERNATIVE_TERNARY() in _static_cpu_has() 



_static_cpu_has() contains a completely open coded version of
ALTERNATIVE_TERNARY(). Replace that with the macro instead.

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210311142319.4723-8-jgross@suse.com
parent e208b3c4

arch/x86/include/asm/cpufeature.h

+9 −32
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 


#include <asm/asm.h>

#include <linux/bitops.h>

#include <asm/alternative.h>



enum cpuid_leafs

{
@@ -175,31 +176,8 @@ extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit); 
 */

static __always_inline bool _static_cpu_has(u16 bit)

{

	asm_volatile_goto("1: jmp 6f\n"

		 "2:\n"

		 ".skip -(((5f-4f) - (2b-1b)) > 0) * "

			 "((5f-4f) - (2b-1b)),0x90\n"

		 "3:\n"

		 ".section .altinstructions,\"a\"\n"

		 " .long 1b - .\n"		/* src offset */

		 " .long 4f - .\n"		/* repl offset */

		 " .word %P[always]\n"		/* always replace */

		 " .byte 3b - 1b\n"		/* src len */

		 " .byte 5f - 4f\n"		/* repl len */

		 " .byte 3b - 2b\n"		/* pad len */

		 ".previous\n"

		 ".section .altinstr_replacement,\"ax\"\n"

		 "4: jmp %l[t_no]\n"

		 "5:\n"

		 ".previous\n"

		 ".section .altinstructions,\"a\"\n"

		 " .long 1b - .\n"		/* src offset */

		 " .long 0\n"			/* no replacement */

		 " .word %P[feature]\n"		/* feature bit */

		 " .byte 3b - 1b\n"		/* src len */

		 " .byte 0\n"			/* repl len */

		 " .byte 0\n"			/* pad len */

		 ".previous\n"

	asm_volatile_goto(

		ALTERNATIVE_TERNARY("jmp 6f", %P[feature], "", "jmp %l[t_no]")

		".section .altinstr_aux,\"ax\"\n"

		"6:\n"

		" testb %[bitnum],%[cap_byte]\n"
@@ -207,7 +185,6 @@ static __always_inline bool _static_cpu_has(u16 bit) 
		" jmp %l[t_no]\n"

		".previous\n"

		 : : [feature]  "i" (bit),

		     [always]   "i" (X86_FEATURE_ALWAYS),

		     [bitnum]   "i" (1 << (bit & 7)),

		     [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])

		 : : t_yes, t_no);