From 3bd7743f8d6d7171db9897a746038eefd52a1fbd Mon Sep 17 00:00:00 2001 From: Jamie Iles Date: Tue, 15 Nov 2022 20:08:30 +0000 Subject: [PATCH] RISC-V: reduce mcount save space on RV32 For RV32 we can reduce the size of the ABI save+restore state by using SZREG so that register stores are packed rather than on an 8 byte boundary. Signed-off-by: Jamie Iles Reviewed-by: Andrew Jones Link: https://lore.kernel.org/r/20221115200832.706370-3-jamie@jamieiles.com Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/mcount.S | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/arch/riscv/kernel/mcount.S b/arch/riscv/kernel/mcount.S index 9cf0904afd6d..613bd07c6268 100644 --- a/arch/riscv/kernel/mcount.S +++ b/arch/riscv/kernel/mcount.S @@ -15,8 +15,8 @@ .macro SAVE_ABI_STATE addi sp, sp, -16 - REG_S s0, 0(sp) - REG_S ra, 8(sp) + REG_S s0, 0*SZREG(sp) + REG_S ra, 1*SZREG(sp) addi s0, sp, 16 .endm @@ -25,24 +25,24 @@ * register if a0 was not saved. */ .macro SAVE_RET_ABI_STATE - addi sp, sp, -32 - REG_S s0, 16(sp) - REG_S ra, 24(sp) - REG_S a0, 8(sp) - addi s0, sp, 32 + addi sp, sp, -4*SZREG + REG_S s0, 2*SZREG(sp) + REG_S ra, 3*SZREG(sp) + REG_S a0, 1*SZREG(sp) + addi s0, sp, 4*SZREG .endm .macro RESTORE_ABI_STATE - REG_L ra, 8(sp) - REG_L s0, 0(sp) + REG_L ra, 1*SZREG(sp) + REG_L s0, 0*SZREG(sp) addi sp, sp, 16 .endm .macro RESTORE_RET_ABI_STATE - REG_L ra, 24(sp) - REG_L s0, 16(sp) - REG_L a0, 8(sp) - addi sp, sp, 32 + REG_L ra, 3*SZREG(sp) + REG_L s0, 2*SZREG(sp) + REG_L a0, 1*SZREG(sp) + addi sp, sp, 4*SZREG .endm ENTRY(ftrace_stub) @@ -101,10 +101,10 @@ ENTRY(MCOUNT_NAME) * prepare_to_return(&ra_to_caller_of_caller, ra_to_caller) */ do_ftrace_graph_caller: - addi a0, s0, -8 + addi a0, s0, -SZREG mv a1, ra #ifdef HAVE_FUNCTION_GRAPH_FP_TEST - REG_L a2, -16(s0) + REG_L a2, -2*SZREG(s0) #endif SAVE_ABI_STATE call prepare_ftrace_return @@ -117,7 +117,7 @@ do_ftrace_graph_caller: * (*ftrace_trace_function)(ra_to_caller, ra_to_caller_of_caller) */ do_trace: - REG_L a1, -8(s0) + REG_L a1, -SZREG(s0) mv a0, ra SAVE_ABI_STATE