From: Ralf Baechle Date: Tue, 13 Oct 2009 21:23:28 +0000 (+0200) Subject: MIPS: Avoid potential hazard on Context register X-Git-Tag: v5.15~31671^2~6 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=c2ea1d56eaf084c66177eb5658ff4065e79b36ea;p=mirror_ubuntu-kernels.git MIPS: Avoid potential hazard on Context register set_saved_sp reads Context register. Avoid reading stale value from earlier incomplete write. Issue found and fixed for head.S by Chris Dearman . Signed-off-by: Chris Dearman Signed-off-by: Ralf Baechle --- diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h index ed331c2e4882..6083db586500 100644 --- a/arch/mips/include/asm/mmu_context.h +++ b/arch/mips/include/asm/mmu_context.h @@ -16,6 +16,7 @@ #include #include #include +#include #include #ifdef CONFIG_MIPS_MT_SMTC #include @@ -36,11 +37,13 @@ extern unsigned long pgd_current[]; #ifdef CONFIG_32BIT #define TLBMISS_HANDLER_SETUP() \ write_c0_context((unsigned long) smp_processor_id() << 25); \ + back_to_back_c0_hazard(); \ TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir) #endif #ifdef CONFIG_64BIT #define TLBMISS_HANDLER_SETUP() \ write_c0_context((unsigned long) smp_processor_id() << 26); \ + back_to_back_c0_hazard(); \ TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir) #endif diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S index 531ce7b16124..ea695d9605e9 100644 --- a/arch/mips/kernel/head.S +++ b/arch/mips/kernel/head.S @@ -191,6 +191,7 @@ NESTED(kernel_entry, 16, sp) # kernel entry point /* Set the SP after an empty pt_regs. */ PTR_LI sp, _THREAD_SIZE - 32 - PT_SIZE PTR_ADDU sp, $28 + back_to_back_c0_hazard set_saved_sp sp, t0, t1 PTR_SUBU sp, 4 * SZREG # init stack pointer