Changing the Cache Coherency Algorithm (CCA) for kernel mode requires executing from KSEG1. Thus do a jump from KSEG0 to KSEG1 before changing the CCA mode. Jump back to KSEG0 afterwards.
Signed-off-by: Daniel Schwierzeck daniel.schwierzeck@gmail.com ---
arch/mips/lib/cache_init.S | 54 ++++++++++++++++++++++---------------- 1 file changed, 32 insertions(+), 22 deletions(-)
diff --git a/arch/mips/lib/cache_init.S b/arch/mips/lib/cache_init.S index 395bfffdb8..4e956031b3 100644 --- a/arch/mips/lib/cache_init.S +++ b/arch/mips/lib/cache_init.S @@ -84,6 +84,7 @@ 10: .set pop .endm + /* * mips_cache_reset - low level initialisation of the primary caches * @@ -319,19 +320,21 @@ l1_init: PTR_LI t0, INDEX_BASE cache_loop t0, t1, R_IC_LINE, INDEX_STORE_TAG_I #endif - - /* Enable use of the I-cache by setting Config.K0 */ sync - mfc0 t0, CP0_CONFIG - li t1, CONFIG_SYS_MIPS_CACHE_MODE -#if __mips_isa_rev >= 2 - ins t0, t1, 0, 3 -#else - ori t0, t0, CONF_CM_CMASK - xori t0, t0, CONF_CM_CMASK + + /* + * Enable use of the I-cache by setting Config.K0. The code for this + * must be executed from KSEG1. Jump from KSEG0 to KSEG1 to do this. + * Jump back to KSEG0 after caches are enabled and insert an + * instruction hazard barrier. + */ + PTR_LA t0, change_k0_cca + li t1, CPHYSADDR(~0) + and t0, t0, t1 + PTR_LI t1, CKSEG1 or t0, t0, t1 -#endif - mtc0 t0, CP0_CONFIG + li a0, CONFIG_SYS_MIPS_CACHE_MODE + jalr.hb t0
/* * then initialize D-cache. @@ -391,16 +394,9 @@ l2_unbypass: beqz t0, 2f
/* Change Config.K0 to a coherent CCA */ - mfc0 t0, CP0_CONFIG - li t1, CONF_CM_CACHABLE_COW -#if __mips_isa_rev >= 2 - ins t0, t1, 0, 3 -#else - ori t0, t0, CONF_CM_CMASK - xori t0, t0, CONF_CM_CMASK - or t0, t0, t1 -#endif - mtc0 t0, CP0_CONFIG + PTR_LA t0, change_k0_cca + li a0, CONF_CM_CACHABLE_COW + jalr t0
/* * Join the coherent domain such that the caches of this core are kept @@ -421,5 +417,19 @@ l2_unbypass: return: /* Ensure all cache operations complete before returning */ sync - jr ra + jr R_RETURN END(mips_cache_reset) + +LEAF(change_k0_cca) + mfc0 t0, CP0_CONFIG +#if __mips_isa_rev >= 2 + ins t0, a0, 0, 3 +#else + xor a0, a0, t0 + andi a0, a0, CONF_CM_CMASK + xor a0, a0, t0 +#endif + mtc0 a0, CP0_CONFIG + + jr.hb ra + END(change_k0_cca)