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powerpc: Improve the inline asm for syscall wrappers

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Update the inline asm syscall wrappers to match the newer register constraint
usage in INTERNAL_VSYSCALL_CALL_TYPE.  Use the faster mfocrf instruction when
available, rather than the slower mfcr microcoded instruction.
This commit is contained in:
Peter Bergner 2024-11-05 16:05:53 -06:00
parent 7f045c0b48
commit 229265cc2c
1 changed files with 22 additions and 20 deletions
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42
sysdeps/unix/sysv/linux/powerpc/sysdep.h
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@ -32,6 +32,18 @@
#undef SYS_ify
#define SYS_ify(syscall_name) __NR_##syscall_name
#define tostring(s) #s
#define stringify(s) tostring(s)
#ifdef _ARCH_PWR4
/* Power4 and later cpus introduced a faster instruction to copy one
CR field, rather than the slower microcoded mfcr which copies all
CR fields. */
# define MFCR0(REG) "mfocrf " stringify(REG) ",0x80"
#else
# define MFCR0(REG) "mfcr " stringify(REG)
#endif
/* Define a macro which expands inline into the wrapper code for a system
call. This use is for internal calls that do not need to handle errors
normally. It will never touch errno. This returns just what the kernel
@ -52,7 +64,7 @@
__asm__ __volatile__ \
("mtctr %0\n\t" \
"bctrl\n\t" \
"mfcr %0\n\t" \
MFCR0(%0) "\n\t" \
"0:" \
: "+r" (r0), "+r" (r3), "+r" (r4), "+r" (r5), "+r" (r6), \
"+r" (r7), "+r" (r8) \
@ -83,11 +95,10 @@
"scv 0\n\t" \
".machine \"pop\"\n\t" \
"0:" \
: "=&r" (r0), \
"=&r" (r3), "=&r" (r4), "=&r" (r5), \
"=&r" (r6), "=&r" (r7), "=&r" (r8) \
: ASM_INPUT_##nr \
: "r9", "r10", "r11", "r12", \
: "+r" (r0), \
"+r" (r3), "+r" (r4), "+r" (r5), \
"+r" (r6), "+r" (r7), "+r" (r8) \
: : "r9", "r10", "r11", "r12", \
"cr0", "cr1", "cr5", "cr6", "cr7", \
"xer", "lr", "ctr", "memory"); \
r3; \
@ -97,13 +108,12 @@
({ \
__asm__ __volatile__ \
("sc\n\t" \
"mfcr %0\n\t" \
MFCR0(%0) "\n\t" \
"0:" \
: "=&r" (r0), \
"=&r" (r3), "=&r" (r4), "=&r" (r5), \
"=&r" (r6), "=&r" (r7), "=&r" (r8) \
: ASM_INPUT_##nr \
: "r9", "r10", "r11", "r12", \
: "+r" (r0), \
"+r" (r3), "+r" (r4), "+r" (r5), \
"+r" (r6), "+r" (r7), "+r" (r8) \
: : "r9", "r10", "r11", "r12", \
"xer", "cr0", "ctr", "memory"); \
r0 & (1 << 28) ? -r3 : r3; \
})
@ -199,14 +209,6 @@
__illegally_sized_syscall_arg6 (); \
r8 = _arg6
#define ASM_INPUT_0 "0" (r0)
#define ASM_INPUT_1 ASM_INPUT_0, "1" (r3)
#define ASM_INPUT_2 ASM_INPUT_1, "2" (r4)
#define ASM_INPUT_3 ASM_INPUT_2, "3" (r5)
#define ASM_INPUT_4 ASM_INPUT_3, "4" (r6)
#define ASM_INPUT_5 ASM_INPUT_4, "5" (r7)
#define ASM_INPUT_6 ASM_INPUT_5, "6" (r8)
/* List of system calls which are supported as vsyscalls. */
#define VDSO_NAME "LINUX_2.6.15"
#define VDSO_HASH 123718565