From 3569d84bb26f6f07d426446da3d2c836180f1565 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Mon, 26 Sep 2022 13:40:57 +1000 Subject: [PATCH] powerpc/64e: provide an addressing macro for use with TOC in alternate register The interrupt entry code carefully saves a minimal number of registers, so in some places the TOC is required, it is loaded into a different register, so provide a macro that can supply an alternate TOC register. This continues to use got addressing because TOC-relative results in "got/toc optimization is not supported" messages by the linker. Having r2 be one of the saved registers and using that for TOC addressing may be the best way to avoid that and switch this to TOC addressing. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220926034057.2360083-6-npiggin@gmail.com --- arch/powerpc/include/asm/ppc_asm.h | 11 +++++++++++ arch/powerpc/kernel/exceptions-64e.S | 14 +++++++------- arch/powerpc/mm/nohash/tlb_low_64e.S | 2 +- 3 files changed, 19 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index cf6bec9..753a275 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -346,6 +346,17 @@ n: addis reg,r2,name@toc@ha; \ addi reg,reg,name@toc@l +#ifdef CONFIG_PPC_BOOK3E_64 +/* + * This is used in register-constrained interrupt handlers. Not to be used + * by BOOK3S. ld complains with "got/toc optimization is not supported" if r2 + * is not used for the TOC offset, so use @got(tocreg). If the interrupt + * handlers saved r2 instead, LOAD_REG_ADDR could be used. + */ +#define LOAD_REG_ADDR_ALTTOC(reg,tocreg,name) \ + ld reg,name@got(tocreg) +#endif + #define LOAD_REG_ADDRBASE(reg,name) LOAD_REG_ADDR(reg,name) #define ADDROFF(name) 0 diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index ece1bd2a..930e360 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -688,8 +688,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) #ifdef CONFIG_RELOCATABLE __LOAD_PACA_TOC(r15) - ld r14,interrupt_base_book3e@got(r15) - ld r15,__end_interrupts@got(r15) + LOAD_REG_ADDR_ALTTOC(r14, r15, interrupt_base_book3e) + LOAD_REG_ADDR_ALTTOC(r15, r15, __end_interrupts) cmpld cr0,r10,r14 cmpld cr1,r10,r15 #else @@ -759,8 +759,8 @@ kernel_dbg_exc: #ifdef CONFIG_RELOCATABLE __LOAD_PACA_TOC(r15) - ld r14,interrupt_base_book3e@got(r15) - ld r15,__end_interrupts@got(r15) + LOAD_REG_ADDR_ALTTOC(r14, r15, interrupt_base_book3e) + LOAD_REG_ADDR_ALTTOC(r15, r15, __end_interrupts) cmpld cr0,r10,r14 cmpld cr1,r10,r15 #else @@ -884,8 +884,8 @@ kernel_dbg_exc: .macro SEARCH_RESTART_TABLE #ifdef CONFIG_RELOCATABLE __LOAD_PACA_TOC(r11) - ld r14,__start___restart_table@got(r11) - ld r15,__stop___restart_table@got(r11) + LOAD_REG_ADDR_ALTTOC(r14, r11, __start___restart_table) + LOAD_REG_ADDR_ALTTOC(r15, r11, __stop___restart_table) #else LOAD_REG_IMMEDIATE_SYM(r14, r11, __start___restart_table) LOAD_REG_IMMEDIATE_SYM(r15, r11, __stop___restart_table) @@ -1303,7 +1303,7 @@ a2_tlbinit_after_linear_map: /* Now we branch the new virtual address mapped by this entry */ #ifdef CONFIG_RELOCATABLE __LOAD_PACA_TOC(r5) - ld r3,1f@got(r5) + LOAD_REG_ADDR_ALTTOC(r3, r5, 1f) #else LOAD_REG_IMMEDIATE_SYM(r3, r5, 1f) #endif diff --git a/arch/powerpc/mm/nohash/tlb_low_64e.S b/arch/powerpc/mm/nohash/tlb_low_64e.S index b3b3dfe..76cf456 100644 --- a/arch/powerpc/mm/nohash/tlb_low_64e.S +++ b/arch/powerpc/mm/nohash/tlb_low_64e.S @@ -1119,7 +1119,7 @@ tlb_load_linear: * final implementation, especially when dealing with hypervisors */ __LOAD_PACA_TOC(r11) - ld r11,linear_map_top@got(r11) + LOAD_REG_ADDR_ALTTOC(r11, r11, linear_map_top) ld r10,0(r11) tovirt(10,10) cmpld cr0,r16,r10 -- 2.7.4