ARM: OMAP4: PM: Add L2X0 cache lowpower support
When MPUSS hits off-mode, L2 cache is lost. This patch adds L2X0
necessary maintenance operations and context restoration in the
low power code.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
diff --git a/arch/arm/mach-omap2/sleep44xx.S b/arch/arm/mach-omap2/sleep44xx.S
index e5521945..3154b63 100644
--- a/arch/arm/mach-omap2/sleep44xx.S
+++ b/arch/arm/mach-omap2/sleep44xx.S
@@ -32,6 +32,9 @@
ppa_zero_params:
.word 0x0
+ppa_por_params:
+ .word 1, 0
+
/*
* =============================
* == CPU suspend finisher ==
@@ -132,6 +135,54 @@
mcrne p15, 0, r0, c1, c0, 1
isb
dsb
+#ifdef CONFIG_CACHE_L2X0
+ /*
+ * Clean and invalidate the L2 cache.
+ * Common cache-l2x0.c functions can't be used here since it
+ * uses spinlocks. We are out of coherency here with data cache
+ * disabled. The spinlock implementation uses exclusive load/store
+ * instruction which can fail without data cache being enabled.
+ * OMAP4 hardware doesn't support exclusive monitor which can
+ * overcome exclusive access issue. Because of this, CPU can
+ * lead to deadlock.
+ */
+ bl omap4_get_sar_ram_base
+ mov r8, r0
+ mrc p15, 0, r5, c0, c0, 5 @ Read MPIDR
+ ands r5, r5, #0x0f
+ ldreq r0, [r8, #L2X0_SAVE_OFFSET0] @ Retrieve L2 state from SAR
+ ldrne r0, [r8, #L2X0_SAVE_OFFSET1] @ memory.
+ cmp r0, #3
+ bne do_WFI
+#ifdef CONFIG_PL310_ERRATA_727915
+ mov r0, #0x03
+ mov r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
+ DO_SMC
+#endif
+ bl omap4_get_l2cache_base
+ mov r2, r0
+ ldr r0, =0xffff
+ str r0, [r2, #L2X0_CLEAN_INV_WAY]
+wait:
+ ldr r0, [r2, #L2X0_CLEAN_INV_WAY]
+ ldr r1, =0xffff
+ ands r0, r0, r1
+ bne wait
+#ifdef CONFIG_PL310_ERRATA_727915
+ mov r0, #0x00
+ mov r12, #OMAP4_MON_L2X0_DBG_CTRL_INDEX
+ DO_SMC
+#endif
+l2x_sync:
+ bl omap4_get_l2cache_base
+ mov r2, r0
+ mov r0, #0x0
+ str r0, [r2, #L2X0_CACHE_SYNC]
+sync:
+ ldr r0, [r2, #L2X0_CACHE_SYNC]
+ ands r0, r0, #0x1
+ bne sync
+#endif
do_WFI:
bl omap_do_wfi
@@ -225,6 +276,50 @@
mcreq p15, 0, r0, c1, c0, 1
isb
skip_ns_smp_enable:
+#ifdef CONFIG_CACHE_L2X0
+ /*
+ * Restore the L2 AUXCTRL and enable the L2 cache.
+ * OMAP4_MON_L2X0_AUXCTRL_INDEX = Program the L2X0 AUXCTRL
+ * OMAP4_MON_L2X0_CTRL_INDEX = Enable the L2 using L2X0 CTRL
+ * register r0 contains value to be programmed.
+ * L2 cache is already invalidate by ROM code as part
+ * of MPUSS OFF wakeup path.
+ */
+ ldr r2, =OMAP44XX_L2CACHE_BASE
+ ldr r0, [r2, #L2X0_CTRL]
+ and r0, #0x0f
+ cmp r0, #1
+ beq skip_l2en @ Skip if already enabled
+ ldr r3, =OMAP44XX_SAR_RAM_BASE
+ ldr r1, [r3, #OMAP_TYPE_OFFSET]
+ cmp r1, #0x1 @ Check for HS device
+ bne set_gp_por
+ ldr r0, =OMAP4_PPA_L2_POR_INDEX
+ ldr r1, =OMAP44XX_SAR_RAM_BASE
+ ldr r4, [r1, #L2X0_PREFETCH_CTRL_OFFSET]
+ adr r3, ppa_por_params
+ str r4, [r3, #0x04]
+ mov r1, #0x0 @ Process ID
+ mov r2, #0x4 @ Flag
+ mov r6, #0xff
+ mov r12, #0x00 @ Secure Service ID
+ DO_SMC
+ b set_aux_ctrl
+set_gp_por:
+ ldr r1, =OMAP44XX_SAR_RAM_BASE
+ ldr r0, [r1, #L2X0_PREFETCH_CTRL_OFFSET]
+ ldr r12, =OMAP4_MON_L2X0_PREFETCH_INDEX @ Setup L2 PREFETCH
+ DO_SMC
+set_aux_ctrl:
+ ldr r1, =OMAP44XX_SAR_RAM_BASE
+ ldr r0, [r1, #L2X0_AUXCTRL_OFFSET]
+ ldr r12, =OMAP4_MON_L2X0_AUXCTRL_INDEX @ Setup L2 AUXCTRL
+ DO_SMC
+ mov r0, #0x1
+ ldr r12, =OMAP4_MON_L2X0_CTRL_INDEX @ Enable L2 cache
+ DO_SMC
+skip_l2en:
+#endif
b cpu_resume @ Jump to generic resume
ENDPROC(omap4_cpu_resume)