Macros for restoring and saving registers to and from the stack exist. Provide macros with the same interface for clearing a range of gprs by setting each register's value in that range to zero.
The resulting macros are called NULLIFY_GPRS and NULLIFY_NVGPRS, keeping with the naming of the accompanying restore and save macros, and usage of nullify to describe this operation elsewhere in the kernel. Signed-off-by: Rohan McLure <rmcl...@linux.ibm.com> --- V1 -> V2: Change 'ZERO' usage in naming to 'NULLIFY', a more obvious verb --- arch/powerpc/include/asm/ppc_asm.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index 83c02f5a7f2a..d6c46082bf7f 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 NULLIFY_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 NULLIFY_GPRS(start, end) NULLIFY_REGS start, end +#ifdef __powerpc64__ +#define NULLIFY_NVGPRS() NULLIFY_GPRS(14, 31) +#else +#define NULLIFY_NVGPRS() NULLIFY_GPRS(13, 31) +#endif +#define NULLIFY_GPR(n) NULLIFY_GPRS(n, n) + #define SAVE_GPR(n, base) SAVE_GPRS(n, n, base) #define REST_GPR(n, base) REST_GPRS(n, n, base) -- 2.34.1