[PATCH v1] generic: mips: support harts to boot from mips_warm_boot

[Chao-ying Fu <icebergfu@gmail.com>]

We program reset base for harts (other than hart 0) to boot at
mips_warm_boot that jumps to _start_warm. This helps to skip some code
sequence to speed up.

Signed-off-by: Chao-ying Fu <cfu@mips.com>
---
 platform/generic/mips/p8700.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/platform/generic/mips/p8700.c b/platform/generic/mips/p8700.c
index 888a45c..687912a 100644
--- a/platform/generic/mips/p8700.c
+++ b/platform/generic/mips/p8700.c
@@ -140,6 +140,22 @@ static void power_up_other_cluster(u32 hartid)
 }
 #endif
 
+static void __attribute__((naked,no_instrument_function,aligned(4096)))
+mips_warm_boot(void)
+{
+  __asm__ __volatile__(
+	"	j	1f\n"
+	"	.align	2\n"
+	"	j	1f\n"
+	"	.align	2\n"
+	"	j	1f\n"
+	"	.align	2\n"
+	"	j	1f\n"
+	"1:	lla	t0, _start_warm\n"
+	"	jr	t0\n"
+	);
+}
+
 static int mips_hart_start(u32 hartid, ulong saddr)
 {
 	unsigned int stat;
@@ -150,6 +166,9 @@ static int mips_hart_start(u32 hartid, ulong saddr)
 	if (hartid == 0)
 		return SBI_ENOTSUPP;
 
+	/* Change reset base to mips_warm_boot */
+	write_gcr_co_reset_base(hartid, (unsigned long)mips_warm_boot, local_p);
+
 	if (cpu_hart(hartid) == 0) {
 		/* Ensure its coherency is disabled */
 		write_gcr_co_coherence(hartid, 0, local_p);
-- 
2.47.1


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