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| author |   Rohan McLure <rmclure@linux.ibm.com> | 2022-09-21 16:55:43 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2022-09-26 23:00:14 +1000 |
| commit | 9d54a5ce3aa87810f13cd33b314097ac6d28c350 (patch) | |
| tree | c313c697f7fbe3c927ba5f126823ba2ff9ddd516 | |
| parent | powerpc: Save caller r3 prior to system_call_exception (diff) | |
| download | linux-dev-9d54a5ce3aa87810f13cd33b314097ac6d28c350.tar.xz linux-dev-9d54a5ce3aa87810f13cd33b314097ac6d28c350.zip | |
powerpc: Add ZEROIZE_GPRS macros for register clears
Provide register zeroing macros, following the same convention as
existing register stack save/restore macros, to be used in later
change to concisely zero a sequence of consecutive gprs.
The resulting macros are called ZEROIZE_GPRS and ZEROIZE_NVGPRS, keeping
with the naming of the accompanying restore and save macros, and usage
of zeroize to describe this operation elsewhere in the kernel.
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-4-rmclure@linux.ibm.com
| -rw-r--r-- | arch/powerpc/include/asm/ppc_asm.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index 7e4fe766e247..eeb7dc8cd45f 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -34,6 +34,20 @@ .endm /* + * This expands to a sequence of register clears for regs start to end + * inclusive, of the form: + * + * li rN, 0 + */ +.macro ZEROIZE_REGS start, end + .Lreg=\start + .rept (\end - \start + 1) + li .Lreg, 0 + .Lreg=.Lreg+1 + .endr +.endm + +/* * Macros for storing registers into and loading registers from * exception frames. */ @@ -49,6 +63,14 @@ #define REST_NVGPRS(base) REST_GPRS(13, 31, base) #endif +#define ZEROIZE_GPRS(start, end) ZEROIZE_REGS start, end +#ifdef __powerpc64__ +#define ZEROIZE_NVGPRS() ZEROIZE_GPRS(14, 31) +#else +#define ZEROIZE_NVGPRS() ZEROIZE_GPRS(13, 31) +#endif +#define ZEROIZE_GPR(n) ZEROIZE_GPRS(n, n) + #define SAVE_GPR(n, base) SAVE_GPRS(n, n, base) #define REST_GPR(n, base) REST_GPRS(n, n, base) |