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Subject[PATCH v6 1/5] powerpc/85xx: implement hardware timebase sync
Date
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.zhao@freescale.com>
Signed-off-by: Li Yang <leoli@freescale.com>
---
Changes for v6:
* added 85xx_TB_SYNC
* added isync() after set_tb()
* removed extra entries from mpc85xx_smp_guts_ids

arch/powerpc/include/asm/fsl_guts.h | 2 +
arch/powerpc/platforms/85xx/Kconfig | 5 ++
arch/powerpc/platforms/85xx/smp.c | 84 +++++++++++++++++++++++++++++++++++
3 files changed, 91 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/Kconfig b/arch/powerpc/platforms/85xx/Kconfig
index f000d81..8dd7147 100644
--- a/arch/powerpc/platforms/85xx/Kconfig
+++ b/arch/powerpc/platforms/85xx/Kconfig
@@ -8,6 +8,7 @@ menuconfig FSL_SOC_BOOKE
select FSL_PCI if PCI
select SERIAL_8250_EXTENDED if SERIAL_8250
select SERIAL_8250_SHARE_IRQ if SERIAL_8250
+ select 85xx_TB_SYNC if KEXEC
default y

if FSL_SOC_BOOKE
@@ -267,3 +268,7 @@ endif # FSL_SOC_BOOKE

config TQM85xx
bool
+
+config 85xx_TB_SYNC
+ bool
+ default n
diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
index ff42490..edb0cad 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -24,6 +24,7 @@
#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>
@@ -42,6 +43,69 @@ extern void __early_start(void);
#define NUM_BOOT_ENTRY 8
#define SIZE_BOOT_ENTRY (NUM_BOOT_ENTRY * sizeof(u32))

+#ifdef CONFIG_85xx_TB_SYNC
+static struct ccsr_guts __iomem *guts;
+static u64 timebase;
+static int tb_req;
+static int tb_valid;
+
+static void mpc85xx_timebase_freeze(int freeze)
+{
+ unsigned int mask;
+
+ if (!guts)
+ return;
+
+ 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);
+}
+#endif
+
static int __init
smp_85xx_kick_cpu(int nr)
{
@@ -228,6 +292,16 @@ 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 +323,16 @@ 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) {
+#ifdef CONFIG_85xx_TB_SYNC
+ guts = of_iomap(np, 0);
+ smp_85xx_ops.give_timebase = mpc85xx_give_timebase;
+ smp_85xx_ops.take_timebase = mpc85xx_take_timebase;
+#endif
+ of_node_put(np);
+ }
+
smp_ops = &smp_85xx_ops;

#ifdef CONFIG_KEXEC
--
1.6.4.1



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