lkml.org 
[lkml]   [2012]   [Jul]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v7 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>
---
v7:
* removed CONFIG_85xx_TB_SYNC
* incorporated Timur's comments
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 ff42490..2e65fe8 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 +43,64 @@ extern void __early_start(void);
#define NUM_BOOT_ENTRY 8
#define SIZE_BOOT_ENTRY (NUM_BOOT_ENTRY * sizeof(u32))

+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



\
 
 \ /
  Last update: 2012-07-03 13:21    [from the cache]
©2003-2011 Jasper Spaans