diff options
| author | Paul Burton <paul.burton@imgtec.com> | 2016-09-21 11:18:55 +0100 |
|---|---|---|
| committer | Daniel Schwierzeck <daniel.schwierzeck@gmail.com> | 2016-09-21 15:04:04 +0200 |
| commit | 7953354b07bba8fa9599bf5d212308e6cdf9cbe2 (patch) | |
| tree | ea7c5e9e3bb9f02a999f0c4c39392fbabb1607d3 /arch/mips | |
| parent | 4baa0ab67d504f3b4318f999631e3f83d0c52c4a (diff) | |
MIPS: Join the coherent domain when a CM is present
MIPS Linux expects the bootloader to leave the boot CPU a member of the
coherent domain when running on a system with a CM, and we will need to
do so if we wish to make use of IOCUs to have cache-coherent DMA in
U-Boot (and on some systems there is no choice in that matter). When a
CM is present, join the coherent domain after completing cache
initialisation.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Diffstat (limited to 'arch/mips')
| -rw-r--r-- | arch/mips/include/asm/cm.h | 5 | ||||
| -rw-r--r-- | arch/mips/lib/cache_init.S | 38 |
2 files changed, 43 insertions, 0 deletions
diff --git a/arch/mips/include/asm/cm.h b/arch/mips/include/asm/cm.h index 62ecef20fc..b9ab0c65e6 100644 --- a/arch/mips/include/asm/cm.h +++ b/arch/mips/include/asm/cm.h @@ -19,6 +19,7 @@ #define GCR_L2_TAG_STATE_UPPER 0x060c #define GCR_L2_DATA 0x0610 #define GCR_L2_DATA_UPPER 0x0614 +#define GCR_Cx_COHERENCE 0x2008 /* GCR_REV CM versions */ #define GCR_REV_CM3 0x0800 @@ -32,6 +33,10 @@ #define GCR_L2_CONFIG_SETSZ_BITS 4 #define GCR_L2_CONFIG_BYPASS (1 << 20) +/* GCR_Cx_COHERENCE */ +#define GCR_Cx_COHERENCE_DOM_EN (0xff << 0) +#define GCR_Cx_COHERENCE_EN (0x1 << 0) + #ifndef __ASSEMBLY__ #include <asm/io.h> diff --git a/arch/mips/lib/cache_init.S b/arch/mips/lib/cache_init.S index ecb88e5683..e61432ee9c 100644 --- a/arch/mips/lib/cache_init.S +++ b/arch/mips/lib/cache_init.S @@ -378,6 +378,44 @@ l2_unbypass: ehb 2: +# ifdef CONFIG_MIPS_CM + /* Config3 must exist for a CM to be present */ + mfc0 t0, CP0_CONFIG, 1 + bgez t0, 2f + mfc0 t0, CP0_CONFIG, 2 + bgez t0, 2f + + /* Check Config3.CMGCR to determine CM presence */ + mfc0 t0, CP0_CONFIG, 3 + and t0, t0, MIPS_CONF3_CMGCR + 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 + + /* + * Join the coherent domain such that the caches of this core are kept + * coherent with those of other cores. + */ + PTR_LI t0, CKSEG1ADDR(CONFIG_MIPS_CM_BASE) + lw t1, GCR_REV(t0) + li t2, GCR_REV_CM3 + li t3, GCR_Cx_COHERENCE_EN + bge t1, t2, 1f + li t3, GCR_Cx_COHERENCE_DOM_EN +1: sw t3, GCR_Cx_COHERENCE(t0) + ehb +2: +# endif #endif return: |