[PATCH v2 10/12] MIPS: pm-cps: Support CM3 changes to Coherence Enable Register

From: Matt Redfearn
Date: Wed Sep 07 2016 - 05:46:16 EST


MIPS CM3 changed the management of coherence. Instead of a coherence
control register with a bitmask of coherent domains, CM3 simply has a
coherence enable register with a single bit to enable coherence of the
local core. Support this by clearing and setting this single bit to
disable / enable coherence.

Signed-off-by: Matt Redfearn <matt.redfearn@xxxxxxxxxx>
Reviewed-by: Paul Burton <paul.burton@xxxxxxxxxx>
---

Changes in v2: None

arch/mips/include/asm/mips-cm.h | 1 +
arch/mips/kernel/pm-cps.c | 31 ++++++++++++++++++-------------
2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/arch/mips/include/asm/mips-cm.h b/arch/mips/include/asm/mips-cm.h
index 58e7874e9347..ac30981a8360 100644
--- a/arch/mips/include/asm/mips-cm.h
+++ b/arch/mips/include/asm/mips-cm.h
@@ -359,6 +359,7 @@ BUILD_CM_Cx_R_(tcid_8_priority, 0x80)
/* GCR_Cx_COHERENCE register fields */
#define CM_GCR_Cx_COHERENCE_COHDOMAINEN_SHF 0
#define CM_GCR_Cx_COHERENCE_COHDOMAINEN_MSK (_ULCAST_(0xff) << 0)
+#define CM3_GCR_Cx_COHERENCE_COHEN_MSK (_ULCAST_(0x1) << 0)

/* GCR_Cx_CONFIG register fields */
#define CM_GCR_Cx_CONFIG_IOCUTYPE_SHF 10
diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c
index 440e79259566..05bcdedcf9bd 100644
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -480,18 +480,20 @@ static void * __init cps_gen_entry_code(unsigned cpu, enum cps_pm_state state)
uasm_i_sync(&p, STYPE_SYNC);
uasm_i_ehb(&p);

- /*
- * Disable all but self interventions. The load from COHCTL is defined
- * by the interAptiv & proAptiv SUMs as ensuring that the operation
- * resulting from the preceding store is complete.
- */
- uasm_i_addiu(&p, t0, zero, 1 << cpu_data[cpu].core);
- uasm_i_sw(&p, t0, 0, r_pcohctl);
- uasm_i_lw(&p, t0, 0, r_pcohctl);
-
- /* Barrier to ensure write to coherence control is complete */
- uasm_i_sync(&p, STYPE_SYNC);
- uasm_i_ehb(&p);
+ if (mips_cm_revision() < CM_REV_CM3) {
+ /*
+ * Disable all but self interventions. The load from COHCTL is
+ * defined by the interAptiv & proAptiv SUMs as ensuring that the
+ * operation resulting from the preceding store is complete.
+ */
+ uasm_i_addiu(&p, t0, zero, 1 << cpu_data[cpu].core);
+ uasm_i_sw(&p, t0, 0, r_pcohctl);
+ uasm_i_lw(&p, t0, 0, r_pcohctl);
+
+ /* Barrier to ensure write to coherence control is complete */
+ uasm_i_sync(&p, STYPE_SYNC);
+ uasm_i_ehb(&p);
+ }

/* Disable coherence */
uasm_i_sw(&p, zero, 0, r_pcohctl);
@@ -566,7 +568,10 @@ static void * __init cps_gen_entry_code(unsigned cpu, enum cps_pm_state state)
* will run this. The first will actually re-enable coherence & the
* rest will just be performing a rather unusual nop.
*/
- uasm_i_addiu(&p, t0, zero, CM_GCR_Cx_COHERENCE_COHDOMAINEN_MSK);
+ uasm_i_addiu(&p, t0, zero, mips_cm_revision() < CM_REV_CM3
+ ? CM_GCR_Cx_COHERENCE_COHDOMAINEN_MSK
+ : CM3_GCR_Cx_COHERENCE_COHEN_MSK);
+
uasm_i_sw(&p, t0, 0, r_pcohctl);
uasm_i_lw(&p, t0, 0, r_pcohctl);

--
2.7.4