diff options
| -rw-r--r-- | target/linux/generic/pending-5.10/301-MIPS-Add-barriers-between-dcache-icache-flushes.patch | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/target/linux/generic/pending-5.10/301-MIPS-Add-barriers-between-dcache-icache-flushes.patch b/target/linux/generic/pending-5.10/301-MIPS-Add-barriers-between-dcache-icache-flushes.patch new file mode 100644 index 0000000000..726c884027 --- /dev/null +++ b/target/linux/generic/pending-5.10/301-MIPS-Add-barriers-between-dcache-icache-flushes.patch @@ -0,0 +1,71 @@ +From e6e6ef4275978823ec3a84133fc91f4ffbef5c84 Mon Sep 17 00:00:00 2001 +From: Paul Burton <paul.burton@imgtec.com> +Date: Mon, 22 Feb 2016 18:09:44 +0000 +Subject: [PATCH] MIPS: Add barriers between dcache & icache flushes + +Index-based cache operations may be arbitrarily reordered by out of +order CPUs. Thus code which writes back the dcache & then invalidates +the icache using indexed cache ops must include a barrier between +operating on the 2 caches in order to prevent the scenario in which: + + - icache invalidation occurs. + + - icache fetch occurs, due to speculation. + + - dcache writeback occurs. + +If the above were allowed to happen then the icache would contain stale +data. Forcing the dcache writeback to complete before the icache +invalidation avoids this. + +Signed-off-by: Paul Burton <paul.burton@imgtec.com> +Cc: James Hogan <james.hogan@imgtec.com> +--- + arch/mips/mm/c-r4k.c | 13 +++++++++++-- + 1 file changed, 11 insertions(+), 2 deletions(-) + +--- a/arch/mips/mm/c-r4k.c ++++ b/arch/mips/mm/c-r4k.c +@@ -515,6 +515,7 @@ static inline void local_r4k___flush_cac + + default: + r4k_blast_dcache(); ++ mb(); /* cache instructions may be reordered */ + r4k_blast_icache(); + break; + } +@@ -595,8 +596,10 @@ static inline void local_r4k_flush_cache + if (cpu_has_dc_aliases || (exec && !cpu_has_ic_fills_f_dc)) + r4k_blast_dcache(); + /* If executable, blast stale lines from icache */ +- if (exec) ++ if (exec) { ++ mb(); /* cache instructions may be reordered */ + r4k_blast_icache(); ++ } + } + + static void r4k_flush_cache_range(struct vm_area_struct *vma, +@@ -697,8 +700,13 @@ static inline void local_r4k_flush_cache + if (cpu_has_dc_aliases || (exec && !cpu_has_ic_fills_f_dc)) { + vaddr ? r4k_blast_dcache_page(addr) : + r4k_blast_dcache_user_page(addr); +- if (exec && !cpu_icache_snoops_remote_store) ++ if (exec) ++ mb(); /* cache instructions may be reordered */ ++ ++ if (exec && !cpu_icache_snoops_remote_store) { + r4k_blast_scache_page(addr); ++ mb(); /* cache instructions may be reordered */ ++ } + } + if (exec) { + if (vaddr && cpu_has_vtag_icache && mm == current->active_mm) { +@@ -765,6 +773,7 @@ static inline void __local_r4k_flush_ica + else + blast_dcache_range(start, end); + } ++ mb(); /* cache instructions may be reordered */ + } + + if (type == R4K_INDEX || |