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Subject[PATCH V2 09/22] MIPS: BMIPS: Introduce helper function to change the reset vector
Date
This will need to be called from a few different places, and the logic
is starting to get a bit hairy (with the need for IPIs, CPU bug
workarounds, and hazards).

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
---
arch/mips/kernel/smp-bmips.c | 65 +++++++++++++++++++++++++++++++++++++++-----
1 file changed, 58 insertions(+), 7 deletions(-)

diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
index 4e56911..8383fa4 100644
--- a/arch/mips/kernel/smp-bmips.c
+++ b/arch/mips/kernel/smp-bmips.c
@@ -35,6 +35,7 @@
#include <asm/bmips.h>
#include <asm/traps.h>
#include <asm/barrier.h>
+#include <asm/cpu-features.h>

static int __maybe_unused max_cpus = 1;

@@ -43,6 +44,9 @@ int bmips_smp_enabled = 1;
int bmips_cpu_offset;
cpumask_t bmips_booted_mask;

+#define RESET_FROM_KSEG0 0x80080800
+#define RESET_FROM_KSEG1 0xa0080800
+
#ifdef CONFIG_SMP

/* initial $sp, $gp - used by arch/mips/kernel/bmips_vec.S */
@@ -463,10 +467,61 @@ static inline void bmips_nmi_handler_setup(void)
&bmips_smp_int_vec_end);
}

+struct reset_vec_info {
+ int cpu;
+ u32 val;
+};
+
+static void bmips_set_reset_vec_remote(void *vinfo)
+{
+ struct reset_vec_info *info = vinfo;
+ int shift = info->cpu & 0x01 ? 16 : 0;
+ u32 mask = ~(0xffff << shift), val = info->val >> 16;
+
+ preempt_disable();
+ if (smp_processor_id() > 0) {
+ smp_call_function_single(0, &bmips_set_reset_vec_remote,
+ info, 1);
+ } else {
+ if (info->cpu & 0x02) {
+ /* BMIPS5200 "should" use mask/shift, but it's buggy */
+ bmips_write_zscm_reg(0xa0, (val << 16) | val);
+ bmips_read_zscm_reg(0xa0);
+ } else {
+ write_c0_brcm_bootvec((read_c0_brcm_bootvec() & mask) |
+ (val << shift));
+ }
+ }
+ preempt_enable();
+}
+
+static void bmips_set_reset_vec(int cpu, u32 val)
+{
+ struct reset_vec_info info;
+
+ if (current_cpu_type() == CPU_BMIPS5000) {
+ /* this needs to run from CPU0 (which is always online) */
+ info.cpu = cpu;
+ info.val = val;
+ bmips_set_reset_vec_remote(&info);
+ } else {
+ void __iomem *cbr = BMIPS_GET_CBR();
+
+ if (cpu == 0)
+ __raw_writel(val, cbr + BMIPS_RELO_VECTOR_CONTROL_0);
+ else {
+ if (current_cpu_type() != CPU_BMIPS4380)
+ return;
+ __raw_writel(val, cbr + BMIPS_RELO_VECTOR_CONTROL_1);
+ }
+ }
+ __sync();
+ back_to_back_c0_hazard();
+}
+
void bmips_ebase_setup(void)
{
unsigned long new_ebase = ebase;
- void __iomem __maybe_unused *cbr;

BUG_ON(ebase != CKSEG0);

@@ -492,9 +547,7 @@ void bmips_ebase_setup(void)
* 0x8000_0400: normal vectors
*/
new_ebase = 0x80000400;
- cbr = BMIPS_GET_CBR();
- __raw_writel(0x80080800, cbr + BMIPS_RELO_VECTOR_CONTROL_0);
- __raw_writel(0xa0080800, cbr + BMIPS_RELO_VECTOR_CONTROL_1);
+ bmips_set_reset_vec(0, RESET_FROM_KSEG0);
break;
case CPU_BMIPS5000:
/*
@@ -502,10 +555,8 @@ void bmips_ebase_setup(void)
* 0x8000_1000: normal vectors
*/
new_ebase = 0x80001000;
- write_c0_brcm_bootvec(0xa0088008);
+ bmips_set_reset_vec(0, RESET_FROM_KSEG0);
write_c0_ebase(new_ebase);
- if (max_cpus > 2)
- bmips_write_zscm_reg(0xa0, 0xa008a008);
break;
default:
return;
--
2.1.1


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