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authorNicholas Piggin <npiggin@gmail.com>2020-06-11 11:12:03 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2020-07-22 16:00:27 +0300
commit7fa95f9adaee7e5cbb195d3359741120829e488b (patch)
tree1ca2d65102ad2c5223afe9a78e3105836982479f /arch/powerpc/xmon
parentb2dc2977cba48990df45e0a96150663d4f342700 (diff)
downloadlinux-7fa95f9adaee7e5cbb195d3359741120829e488b.tar.xz
powerpc/64s: system call support for scv/rfscv instructions
Add support for the scv instruction on POWER9 and later CPUs. For now this implements the zeroth scv vector 'scv 0', as identical to 'sc' system calls, with the exception that LR is not preserved, nor are volatile CR registers, and error is not indicated with CR0[SO], but by returning a negative errno. rfscv is implemented to return from scv type system calls. It can not be used to return from sc system calls because those are defined to preserve LR. getpid syscall throughput on POWER9 is improved by 26% (428 to 318 cycles), largely due to reducing mtmsr and mtspr. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fix ppc64e build] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200611081203.995112-3-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/xmon')
-rw-r--r--arch/powerpc/xmon/xmon.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 7efe4bc3ccf6..3203c3606737 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1593,6 +1593,7 @@ const char *getvecname(unsigned long vec)
case 0x1300: ret = "(Instruction Breakpoint)"; break;
case 0x1500: ret = "(Denormalisation)"; break;
case 0x1700: ret = "(Altivec Assist)"; break;
+ case 0x3000: ret = "(System Call Vectored)"; break;
default: ret = "";
}
return ret;