[PATCH 03/13] csky: Add cpu feature register hint for smp

From: guoren
Date: Fri Jul 31 2020 - 21:14:57 EST


From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>

CPU features registers are setup by customers' bootloader, but
Linux must help transfer them from the primary to secondary cores.
This patch add hint2 CPU feature register supported.

Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/csky/kernel/smp.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c
index b5c5bc3..1945fb2 100644
--- a/arch/csky/kernel/smp.c
+++ b/arch/csky/kernel/smp.c
@@ -156,6 +156,7 @@ void __init setup_smp(void)
extern void _start_smp_secondary(void);

volatile unsigned int secondary_hint;
+volatile unsigned int secondary_hint2;
volatile unsigned int secondary_ccr;
volatile unsigned int secondary_stack;

@@ -168,6 +169,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle)
secondary_stack =
(unsigned int) task_stack_page(tidle) + THREAD_SIZE - 8;
secondary_hint = mfcr("cr31");
+ secondary_hint2 = mfcr("cr<21, 1>");
secondary_ccr = mfcr("cr18");
secondary_msa1 = read_mmu_msa1();

@@ -209,6 +211,7 @@ void csky_start_secondary(void)
unsigned int cpu = smp_processor_id();

mtcr("cr31", secondary_hint);
+ mtcr("cr<21, 1>", secondary_hint2);
mtcr("cr18", secondary_ccr);

mtcr("vbr", vec_base);
--
2.7.4