Do hardware timebase sync. Firstly, stop all timebases, and transfer
the timebase value of the boot core to the other core. Finally,
start all timebases.
Only apply to dual-core chips, such as MPC8572, P2020, etc.
Signed-off-by: Zhao Chenhui <chenhui.z...@freescale.com>
Signed-off-by: Li Yang <le...@freescale.com>
---
arch/powerpc/include/asm/fsl_guts.h | 2 +
arch/powerpc/platforms/85xx/smp.c | 82 +++++++++++++++++++++++++++++++++++
2 files changed, 84 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/include/asm/fsl_guts.h
b/arch/powerpc/include/asm/fsl_guts.h
index aa4c488..dd5ba2c 100644
--- a/arch/powerpc/include/asm/fsl_guts.h
+++ b/arch/powerpc/include/asm/fsl_guts.h
@@ -48,6 +48,8 @@ struct ccsr_guts {
__be32 dmuxcr; /* 0x.0068 - DMA Mux Control Register */
u8 res06c[0x70 - 0x6c];
__be32 devdisr; /* 0x.0070 - Device Disable Control */
+#define CCSR_GUTS_DEVDISR_TB1 0x00001000
+#define CCSR_GUTS_DEVDISR_TB0 0x00004000
__be32 devdisr2; /* 0x.0074 - Device Disable Control 2 */
u8 res078[0x7c - 0x78];
__be32 pmjcr; /* 0x.007c - 4 Power Management Jog Control
Register */
diff --git a/arch/powerpc/platforms/85xx/smp.c
b/arch/powerpc/platforms/85xx/smp.c
index 4827709..7ed52a6 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -25,6 +25,7 @@
#include <asm/mpic.h>
#include <asm/cacheflush.h>
#include <asm/dbell.h>
+#include <asm/fsl_guts.h>
#include <sysdev/fsl_soc.h>
#include <sysdev/mpic.h>
@@ -41,6 +42,64 @@ struct epapr_spin_table {
u32 pir;
};
+static struct ccsr_guts __iomem *guts;
+static u64 timebase;
+static int tb_req;
+static int tb_valid;
+
+static void mpc85xx_timebase_freeze(int freeze)
+{
+ uint32_t mask;
+
+ mask = CCSR_GUTS_DEVDISR_TB0 | CCSR_GUTS_DEVDISR_TB1;
+ if (freeze)
+ setbits32(&guts->devdisr, mask);
+ else
+ clrbits32(&guts->devdisr, mask);
+
+ in_be32(&guts->devdisr);
+}
+
+static void mpc85xx_give_timebase(void)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ while (!tb_req)
+ barrier();
+ tb_req = 0;
+
+ mpc85xx_timebase_freeze(1);
+ timebase = get_tb();
+ mb();
+ tb_valid = 1;
+
+ while (tb_valid)
+ barrier();
+
+ mpc85xx_timebase_freeze(0);
+
+ local_irq_restore(flags);
+}
+
+static void mpc85xx_take_timebase(void)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ tb_req = 1;
+ while (!tb_valid)
+ barrier();
+
+ set_tb(timebase >> 32, timebase & 0xffffffff);
+ isync();
+ tb_valid = 0;
+
+ local_irq_restore(flags);
+}
+
static int __init
smp_85xx_kick_cpu(int nr)
{
@@ -228,6 +287,16 @@ smp_85xx_setup_cpu(int cpu_nr)
doorbell_setup_this_cpu();
}
+static const struct of_device_id mpc85xx_smp_guts_ids[] = {
+ { .compatible = "fsl,mpc8572-guts", },
+ { .compatible = "fsl,p1020-guts", },
+ { .compatible = "fsl,p1021-guts", },
+ { .compatible = "fsl,p1022-guts", },
+ { .compatible = "fsl,p1023-guts", },
+ { .compatible = "fsl,p2020-guts", },
+ {},
+};
+
void __init mpc85xx_smp_init(void)
{
struct device_node *np;
@@ -249,6 +318,19 @@ void __init mpc85xx_smp_init(void)
smp_85xx_ops.cause_ipi = doorbell_cause_ipi;
}
+ np = of_find_matching_node(NULL, mpc85xx_smp_guts_ids);
+ if (np) {
+ guts = of_iomap(np, 0);
+ of_node_put(np);
+ if (!guts) {
+ pr_err("%s: Could not map guts node address\n",
+ __func__);
+ return;
+ }
+ smp_85xx_ops.give_timebase = mpc85xx_give_timebase;
+ smp_85xx_ops.take_timebase = mpc85xx_take_timebase;
+ }
+
smp_ops = &smp_85xx_ops;
#ifdef CONFIG_KEXEC
--
1.6.4.1
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