[PATCH] remoteproc: renesas: Synchronize caches across cores

[Marek Vasut]

Explicitly flush icache on the CR52 core before jumping to the next
stage software to make sure it does not contain any invalid content.
Explicitly flash and invalidate dcache on the CA76 core both over the
trampoline buffer and over the CR52 firmware, and then trigger full
system synchronization, to make sure the data surely land in DRAM,
from where the CR52 can surely pick them up.

Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
---
Cc: Nobuhiro Iwamatsu <iwamatsu at nigauri.org>
Cc: Paul Barker <paul.barker.ct at bp.renesas.com>
Cc: Simon Glass <sjg at chromium.org>
Cc: Tom Rini <trini at konsulko.com>
Cc: u-boot at lists.denx.de
---
 arch/arm/mach-renesas/include/mach/boot0.h | 12 +++++++++++-
 drivers/remoteproc/renesas_apmu.c          |  7 +++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-renesas/include/mach/boot0.h b/arch/arm/mach-renesas/include/mach/boot0.h
index fc68ffc0945..b71c157149e 100644
--- a/arch/arm/mach-renesas/include/mach/boot0.h
+++ b/arch/arm/mach-renesas/include/mach/boot0.h
@@ -34,7 +34,7 @@ _start:
 	.inst	0xe380070a	/* orr     r0, r0, #0x280000 */
 
 	/* APMU_RVBARPLC0 = (address of 'b reset' below) | CA_CORE0_VLD_RVBARP */
-	.inst	0xe28f3088	/* add     r3, pc, #0x88 */
+	.inst	0xe28f30a8	/* add     r3, pc, #0xa8 */
 	.inst	0xe3833001	/* orr     r3, r3, #1 */
 	.inst	0xe5843038	/* str     r3, [r4, #56]   @ 0x38 */
 
@@ -75,12 +75,22 @@ _start:
 	.inst	0xe20230ff	/* and     r3, r2, #255    @ 0xff */
 	.inst	0xe3530011	/* cmp     r3, #17 */
 	.inst	0x1afffffb	/* bne     78 <reset-0x28> */
+	/* Invalidate icache before jump to follow up software */
+	.inst	0xe3a00000	/* mov     r0, #0 */
+	.inst	0xee070f15	/* mcr     15, 0, r0, cr7, cr5, {0} */
+	.inst	0xf57ff04f	/* dsb     sy */
+	.inst	0xf57ff06f	/* isb     sy */
+	/* Jump to follow up software */
 	.inst	0xe1a02922	/* lsr     r2, r2, #18 */
 	.inst	0xe1a02902	/* lsl     r2, r2, #18 */
 	.inst	0xe1a0f002	/* mov     pc, r2 */
 	.inst	0xeafffffe	/* b       94 <reset-0xc> */
 	.inst	0xe1a00000	/* nop                     @ (mov r0, r0) */
 	.inst	0xe1a00000	/* nop                     @ (mov r0, r0) */
+	.inst	0xe1a00000	/* nop                     @ (mov r0, r0) */
+	.inst	0xe1a00000	/* nop                     @ (mov r0, r0) */
+	.inst	0xe1a00000	/* nop                     @ (mov r0, r0) */
+	.inst	0xe1a00000	/* nop                     @ (mov r0, r0) */
 	/* Offset 0xa0 */
 #endif
 	b	reset
diff --git a/drivers/remoteproc/renesas_apmu.c b/drivers/remoteproc/renesas_apmu.c
index 32d138e6487..1a50cd3289b 100644
--- a/drivers/remoteproc/renesas_apmu.c
+++ b/drivers/remoteproc/renesas_apmu.c
@@ -68,6 +68,13 @@ static int renesas_apmu_rproc_load(struct udevice *dev, ulong addr, ulong size)
 	flush_dcache_range(trampolineaddr,
 			   trampolineaddr +
 			   sizeof(renesas_apmu_rproc_trampoline));
+	invalidate_dcache_range(trampolineaddr,
+				trampolineaddr +
+				sizeof(renesas_apmu_rproc_trampoline));
+	flush_dcache_range(addr, addr + size);
+	invalidate_dcache_range(addr, addr + size);
+	asm volatile("dsb sy\n");
+	asm volatile("isb sy\n");
 
 	/* CR52 boot address set */
 	writel(trampolineaddr | APMU_CRBARP_CR_VLD_BARP,
-- 
2.45.2