From d7fb5b18a540efaf05da2b980fc11d50ba775677 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 20 Aug 2019 14:34:14 +0000 Subject: [PATCH] powerpc/64: optimise LOAD_REG_IMMEDIATE_SYM() Optimise LOAD_REG_IMMEDIATE_SYM() using a temporary register to parallelise operations. It reduces the path from 5 to 3 instructions. Suggested-by: Segher Boessenkool Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/bad41ed02531bb0382420cbab50a0d7153b71767.1566311636.git.christophe.leroy@c-s.fr --- arch/powerpc/include/asm/ppc_asm.h | 12 ++++++------ arch/powerpc/kernel/exceptions-64e.S | 22 +++++++++++++--------- arch/powerpc/kernel/head_64.S | 2 +- 3 files changed, 20 insertions(+), 16 deletions(-) diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index 20a00209c965..dd3b191bdcea 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -347,12 +347,12 @@ n: #define LOAD_REG_IMMEDIATE(reg, expr) __LOAD_REG_IMMEDIATE reg, expr -#define LOAD_REG_IMMEDIATE_SYM(reg,expr) \ - lis reg,(expr)@highest; \ - ori reg,reg,(expr)@higher; \ - rldicr reg,reg,32,31; \ - oris reg,reg,(expr)@__AS_ATHIGH; \ - ori reg,reg,(expr)@l; +#define LOAD_REG_IMMEDIATE_SYM(reg, tmp, expr) \ + lis tmp, (expr)@highest; \ + lis reg, (expr)@__AS_ATHIGH; \ + ori tmp, tmp, (expr)@higher; \ + ori reg, reg, (expr)@l; \ + rldimi reg, tmp, 32, 0 #define LOAD_REG_ADDR(reg,name) \ ld reg,name@got(r2) diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index 898aae6da167..829950b96d29 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -750,12 +750,14 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) ld r15,PACATOC(r13) ld r14,interrupt_base_book3e@got(r15) ld r15,__end_interrupts@got(r15) -#else - LOAD_REG_IMMEDIATE_SYM(r14,interrupt_base_book3e) - LOAD_REG_IMMEDIATE_SYM(r15,__end_interrupts) -#endif cmpld cr0,r10,r14 cmpld cr1,r10,r15 +#else + LOAD_REG_IMMEDIATE_SYM(r14, r15, interrupt_base_book3e) + cmpld cr0, r10, r14 + LOAD_REG_IMMEDIATE_SYM(r14, r15, __end_interrupts) + cmpld cr1, r10, r14 +#endif blt+ cr0,1f bge+ cr1,1f @@ -820,12 +822,14 @@ kernel_dbg_exc: ld r15,PACATOC(r13) ld r14,interrupt_base_book3e@got(r15) ld r15,__end_interrupts@got(r15) -#else - LOAD_REG_IMMEDIATE_SYM(r14,interrupt_base_book3e) - LOAD_REG_IMMEDIATE_SYM(r15,__end_interrupts) -#endif cmpld cr0,r10,r14 cmpld cr1,r10,r15 +#else + LOAD_REG_IMMEDIATE_SYM(r14, r15, interrupt_base_book3e) + cmpld cr0, r10, r14 + LOAD_REG_IMMEDIATE_SYM(r14, r15,__end_interrupts) + cmpld cr1, r10, r14 +#endif blt+ cr0,1f bge+ cr1,1f @@ -1449,7 +1453,7 @@ a2_tlbinit_code_start: a2_tlbinit_after_linear_map: /* Now we branch the new virtual address mapped by this entry */ - LOAD_REG_IMMEDIATE_SYM(r3,1f) + LOAD_REG_IMMEDIATE_SYM(r3, r5, 1f) mtctr r3 bctr diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index 1fd44761e997..0f2d61af47cc 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -635,7 +635,7 @@ __after_prom_start: sub r5,r5,r11 #else /* just copy interrupts */ - LOAD_REG_IMMEDIATE_SYM(r5, FIXED_SYMBOL_ABS_ADDR(__end_interrupts)) + LOAD_REG_IMMEDIATE_SYM(r5, r11, FIXED_SYMBOL_ABS_ADDR(__end_interrupts)) #endif b 5f 3: -- 2.39.5