From 9d54a5ce3aa87810f13cd33b314097ac6d28c350 Mon Sep 17 00:00:00 2001 From: Rohan McLure Date: Wed, 21 Sep 2022 16:55:43 +1000 Subject: 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 Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220921065605.1051927-4-rmclure@linux.ibm.com --- arch/powerpc/include/asm/ppc_asm.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'arch/powerpc/include/asm/ppc_asm.h') 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 @@ -33,6 +33,20 @@ .endr .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) -- cgit v1.2.3-59-g8ed1b