MIPS: smp-cps: flush cache after patching mips_cps_core_entry

The start of mips_cps_core_entry is patched in order to provide the code
with the address of the CM register region at a point where it will be
running non-coherent with the rest of the system. However the cache
wasn't being flushed after that patching which could in principle lead
to secondary cores using an invalid CM base address.

The patching is moved to cps_prepare_cpus since local_flush_icache_range
has not been initialised at the point cps_smp_setup is called.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index c7879fbe9f5b..c3661ca5f25c 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -44,7 +44,6 @@ static void __init cps_smp_setup(void)
 {
         unsigned int ncores, nvpes, core_vpes;
         int c, v;
-        u32 *entry_code;
 
         /* Detect & record VPE topology */
         ncores = mips_cm_numcores();
@@ -82,10 +81,6 @@ static void __init cps_smp_setup(void)
         /* Initialise core 0 */
         mips_cps_core_init();
 
-        /* Patch the start of mips_cps_core_entry to provide the CM base */
-        entry_code = (u32 *)&mips_cps_core_entry;
-        UASM_i_LA(&entry_code, 3, (long)mips_cm_base);
-
         /* Make core 0 coherent with everything */
         write_gcr_cl_coherence(0xff);
 }
@@ -93,9 +88,16 @@ static void __init cps_smp_setup(void)
 static void __init cps_prepare_cpus(unsigned int max_cpus)
 {
         unsigned ncores, core_vpes, c;
+        u32 *entry_code;
 
         mips_mt_set_cpuoptions();
 
+        /* Patch the start of mips_cps_core_entry to provide the CM base */
+        entry_code = (u32 *)&mips_cps_core_entry;
+        UASM_i_LA(&entry_code, 3, (long)mips_cm_base);
+        dma_cache_wback_inv((unsigned long)&mips_cps_core_entry,
+                            (void *)entry_code - (void *)&mips_cps_core_entry);
+
         /* Allocate core boot configuration structs */
         ncores = mips_cm_numcores();
         mips_cps_core_bootcfg = kcalloc(ncores, sizeof(*mips_cps_core_bootcfg),