Re: [PATCH v6 1/5] powerpc/85xx: implement hardware timebase sync

On Fri, Jun 29, 2012 at 10:39:24AM -0500, Tabi Timur-B04825 wrote:

On Tue, Jun 26, 2012 at 5:25 AM, Zhao Chenhui
[off-list ref] wrote:

quoted

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 <redacted>
Signed-off-by: Li Yang <redacted>
---
Changes for v6:
=A0* added 85xx_TB_SYNC
=A0* added isync() after set_tb()
=A0* removed extra entries from mpc85xx_smp_guts_ids

=A0arch/powerpc/include/asm/fsl_guts.h | =A0 =A02 +
=A0arch/powerpc/platforms/85xx/Kconfig | =A0 =A05 ++
=A0arch/powerpc/platforms/85xx/smp.c =A0 | =A0 84 +++++++++++++++++++=

++++++++++++++++

quoted

=A03 files changed, 91 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platfor=

ms/85xx/smp.c

quoted

index ff42490..edb0cad 100644

--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c

@@ -24,6 +24,7 @@

=A0#include <asm/mpic.h>
=A0#include <asm/cacheflush.h>
=A0#include <asm/dbell.h>
+#include <asm/fsl_guts.h>

=A0#include <sysdev/fsl_soc.h>
=A0#include <sysdev/mpic.h>

@@ -42,6 +43,69 @@ extern void __early_start(void);

=A0#define NUM_BOOT_ENTRY =A0 =A0 =A0 =A0 8
=A0#define SIZE_BOOT_ENTRY =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0(NUM_BOOT_E=

NTRY * sizeof(u32))

quoted

+#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)
+{
+ =A0 =A0 =A0 unsigned int mask;

=20
'mask' should be uint32_t

OK.

=20

quoted

+
+ =A0 =A0 =A0 if (!guts)
+ =A0 =A0 =A0 =A0 =A0 =A0 =A0 return;

=20
This function should never be called if guts is NULL, so this check
should be unnecessary.

OK.

=20

quoted

+
+ =A0 =A0 =A0 mask =3D CCSR_GUTS_DEVDISR_TB0 | CCSR_GUTS_DEVDISR_TB1;
+ =A0 =A0 =A0 if (freeze)
+ =A0 =A0 =A0 =A0 =A0 =A0 =A0 setbits32(&guts->devdisr, mask);
+ =A0 =A0 =A0 else
+ =A0 =A0 =A0 =A0 =A0 =A0 =A0 clrbits32(&guts->devdisr, mask);
+
+ =A0 =A0 =A0 in_be32(&guts->devdisr);
+}
+

@@ -249,6 +323,16 @@ void __init mpc85xx_smp_init(void)

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0smp_85xx_ops.cause_ipi =3D doorbell_ca=

use_ipi;

quoted

=A0 =A0 =A0 =A0}

+ =A0 =A0 =A0 np =3D of_find_matching_node(NULL, mpc85xx_smp_guts_ids=

);

quoted

+ =A0 =A0 =A0 if (np) {
+#ifdef CONFIG_85xx_TB_SYNC
+ =A0 =A0 =A0 =A0 =A0 =A0 =A0 guts =3D of_iomap(np, 0);

=20
You need to test the return value of of_iomap().  smp_85xx_ops should
be set only if guts is not NULL.

Yes. Thanks.

=20

quoted

+ =A0 =A0 =A0 =A0 =A0 =A0 =A0 smp_85xx_ops.give_timebase =3D mpc85xx_=

give_timebase;

quoted

+ =A0 =A0 =A0 =A0 =A0 =A0 =A0 smp_85xx_ops.take_timebase =3D mpc85xx_=

take_timebase;

quoted

+#endif
+ =A0 =A0 =A0 =A0 =A0 =A0 =A0 of_node_put(np);
+ =A0 =A0 =A0 }
+
=A0 =A0 =A0 =A0smp_ops =3D &smp_85xx_ops;

=A0#ifdef CONFIG_KEXEC
--
1.6.4.1