* [PATCH] powerpc: Add support for using doorbells for SMP IPI
@ 2009-02-12 23:54 Kumar Gala
2009-02-13 2:46 ` Benjamin Herrenschmidt
2009-02-23 2:43 ` Benjamin Herrenschmidt
0 siblings, 2 replies; 6+ messages in thread
From: Kumar Gala @ 2009-02-12 23:54 UTC (permalink / raw)
To: linuxppc-dev
The e500mc supports the new msgsnd/doorbell mechanisms that were added in
the Power ISA 2.05 architecture. We use the normal level doorbell for
doing SMP IPIs at this point.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
arch/powerpc/include/asm/cputable.h | 4 ++-
arch/powerpc/include/asm/dbell.h | 43 +++++++++++++++++++++++++++++++++
arch/powerpc/kernel/Makefile | 2 +-
arch/powerpc/kernel/dbell.c | 44 ++++++++++++++++++++++++++++++++++
arch/powerpc/kernel/head_fsl_booke.S | 6 ++++-
arch/powerpc/kernel/traps.c | 21 ++++++++++++++++
6 files changed, 117 insertions(+), 3 deletions(-)
create mode 100644 arch/powerpc/include/asm/dbell.h
create mode 100644 arch/powerpc/kernel/dbell.c
diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
index 4911104..fca1611 100644
--- a/arch/powerpc/include/asm/cputable.h
+++ b/arch/powerpc/include/asm/cputable.h
@@ -145,6 +145,7 @@ extern const char *powerpc_base_platform;
#define CPU_FTR_USE_TB ASM_CONST(0x0000000000000040)
#define CPU_FTR_L2CSR ASM_CONST(0x0000000000000080)
#define CPU_FTR_601 ASM_CONST(0x0000000000000100)
+#define CPU_FTR_DBELL ASM_CONST(0x0000000000000200)
#define CPU_FTR_CAN_NAP ASM_CONST(0x0000000000000400)
#define CPU_FTR_L3CR ASM_CONST(0x0000000000000800)
#define CPU_FTR_L3_DISABLE_NAP ASM_CONST(0x0000000000001000)
@@ -373,7 +374,8 @@ extern const char *powerpc_base_platform;
CPU_FTR_NODSISRALIGN | CPU_FTR_NOEXECUTE)
#define CPU_FTRS_E500MC (CPU_FTR_MAYBE_CAN_DOZE | CPU_FTR_USE_TB | \
CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_NODSISRALIGN | \
- CPU_FTR_L2CSR | CPU_FTR_LWSYNC | CPU_FTR_NOEXECUTE)
+ CPU_FTR_L2CSR | CPU_FTR_LWSYNC | CPU_FTR_NOEXECUTE | \
+ CPU_FTR_DBELL)
#define CPU_FTRS_GENERIC_32 (CPU_FTR_COMMON | CPU_FTR_NODSISRALIGN)
/* 64-bit CPUs */
diff --git a/arch/powerpc/include/asm/dbell.h b/arch/powerpc/include/asm/dbell.h
new file mode 100644
index 0000000..501189a
--- /dev/null
+++ b/arch/powerpc/include/asm/dbell.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2009 Freescale Semicondutor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * provides masks and opcode images for use by code generation, emulation
+ * and for instructions that older assemblers might not know about
+ */
+#ifndef _ASM_POWERPC_DBELL_H
+#define _ASM_POWERPC_DBELL_H
+
+#include <linux/smp.h>
+#include <linux/threads.h>
+
+#include <asm/ppc-opcode.h>
+
+#define PPC_DBELL_MSG_BRDCAST (0x04000000)
+#define PPC_DBELL_TYPE(x) (((x) & 0xf) << 28)
+enum ppc_dbell {
+ PPC_DBELL = 0, /* doorbell */
+ PPC_DBELL_CRIT = 1, /* critical doorbell */
+ PPC_G_DBELL = 2, /* guest doorbell */
+ PPC_G_DBELL_CRIT = 3, /* guest critical doorbell */
+ PPC_G_DBELL_MC = 4, /* guest mcheck doorbell */
+};
+
+#ifdef CONFIG_SMP
+extern unsigned long dbell_smp_message[NR_CPUS];
+extern void smp_dbell_message_pass(int target, int msg);
+#endif
+
+static inline void ppc_msgsnd(enum ppc_dbell type, u32 flags, u32 tag)
+{
+ u32 msg = PPC_DBELL_TYPE(type) | (flags & PPC_DBELL_MSG_BRDCAST) |
+ (tag & 0x07ffffff);
+
+ __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
+}
+
+#endif /* _ASM_POWERPC_DBELL_H */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index d159921..f420844 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -61,7 +61,7 @@ obj-$(CONFIG_HIBERNATION) += swsusp.o suspend.o \
obj64-$(CONFIG_HIBERNATION) += swsusp_asm64.o
obj-$(CONFIG_MODULES) += module.o module_$(CONFIG_WORD_SIZE).o
obj-$(CONFIG_44x) += cpu_setup_44x.o
-obj-$(CONFIG_FSL_BOOKE) += cpu_setup_fsl_booke.o
+obj-$(CONFIG_FSL_BOOKE) += cpu_setup_fsl_booke.o dbell.o
extra-$(CONFIG_PPC_STD_MMU) := head_32.o
extra-$(CONFIG_PPC64) := head_64.o
diff --git a/arch/powerpc/kernel/dbell.c b/arch/powerpc/kernel/dbell.c
new file mode 100644
index 0000000..1493734
--- /dev/null
+++ b/arch/powerpc/kernel/dbell.c
@@ -0,0 +1,44 @@
+/*
+ * Author: Kumar Gala <galak@kernel.crashing.org>
+ *
+ * Copyright 2009 Freescale Semiconductor Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/threads.h>
+
+#include <asm/dbell.h>
+
+#ifdef CONFIG_SMP
+unsigned long dbell_smp_message[NR_CPUS];
+
+void smp_dbell_message_pass(int target, int msg)
+{
+ int i;
+
+ if(target < NR_CPUS) {
+ set_bit(msg, &dbell_smp_message[target]);
+ ppc_msgsnd(PPC_DBELL, 0, target);
+ }
+ else if(target == MSG_ALL_BUT_SELF) {
+ for_each_online_cpu(i) {
+ if (i == smp_processor_id())
+ continue;
+ set_bit(msg, &dbell_smp_message[i]);
+ ppc_msgsnd(PPC_DBELL, 0, i);
+ }
+ }
+ else { /* target == MSG_ALL */
+ for_each_online_cpu(i)
+ set_bit(msg, &dbell_smp_message[i]);
+ ppc_msgsnd(PPC_DBELL, PPC_DBELL_MSG_BRDCAST, 0);
+ }
+}
+#endif
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 4ea6e1a..4c22620 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -698,7 +698,9 @@ interrupt_base:
/* Performance Monitor */
EXCEPTION(0x2060, PerformanceMonitor, performance_monitor_exception, EXC_XFER_STD)
- EXCEPTION(0x2070, Doorbell, unknown_exception, EXC_XFER_STD)
+ EXCEPTION(0x2070, Doorbell, doorbell_exception, EXC_XFER_STD)
+
+ CRITICAL_EXCEPTION(0x2080, CriticalDoorbell, unknown_exception)
/* Debug Interrupt */
DEBUG_DEBUG_EXCEPTION
@@ -921,6 +923,8 @@ _GLOBAL(__setup_e500mc_ivors)
mtspr SPRN_IVOR35,r3
li r3,Doorbell@l
mtspr SPRN_IVOR36,r3
+ li r3,CriticalDoorbell@l
+ mtspr SPRN_IVOR37,r3
sync
blr
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 970d66e..678fbff 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -53,6 +53,9 @@
#endif
#include <asm/kexec.h>
#include <asm/ppc-opcode.h>
+#ifdef CONFIG_FSL_BOOKE
+#include <asm/dbell.h>
+#endif
#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
int (*__debugger)(struct pt_regs *regs);
@@ -1122,6 +1125,24 @@ void vsx_assist_exception(struct pt_regs *regs)
#endif /* CONFIG_VSX */
#ifdef CONFIG_FSL_BOOKE
+
+void doorbell_exception(struct pt_regs *regs)
+{
+#ifdef CONFIG_SMP
+ int cpu = smp_processor_id();
+ int msg;
+
+ if (num_online_cpus() < 2)
+ return;
+
+ for (msg = 0; msg < 4; msg++)
+ if (test_and_clear_bit(msg, &dbell_smp_message[cpu]))
+ smp_message_recv(msg);
+#else
+ printk(KERN_WARNING "Received doorbell on non-smp system\n");
+#endif
+}
+
void CacheLockingException(struct pt_regs *regs, unsigned long address,
unsigned long error_code)
{
--
1.5.6.6
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] powerpc: Add support for using doorbells for SMP IPI
2009-02-12 23:54 [PATCH] powerpc: Add support for using doorbells for SMP IPI Kumar Gala
@ 2009-02-13 2:46 ` Benjamin Herrenschmidt
2009-02-13 5:10 ` Kumar Gala
2009-02-23 2:43 ` Benjamin Herrenschmidt
1 sibling, 1 reply; 6+ messages in thread
From: Benjamin Herrenschmidt @ 2009-02-13 2:46 UTC (permalink / raw)
To: Kumar Gala; +Cc: linuxppc-dev
On Thu, 2009-02-12 at 17:54 -0600, Kumar Gala wrote:
> The e500mc supports the new msgsnd/doorbell mechanisms that were added in
> the Power ISA 2.05 architecture. We use the normal level doorbell for
> doing SMP IPIs at this point.
>
Cool stuff. Haven't reviewed in details yet tho :-) But I was
thinking...
We should introduce a special xmon variant of local_irq_save/restore for
use by xmon that masks MSR:CE and use a crit doorbell for xmon IPI, that
would increase significantly the ability of xmon to catch deadlocked
CPUs, and we could use external CRITs as a more generic way of doing
IPIs, no ?
In fact, we should expose a local_crit_irq_save/restore (disable/enable)
too for things like watchdog drivers etc... which may want to use these.
Cheers,
Ben.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] powerpc: Add support for using doorbells for SMP IPI
2009-02-13 2:46 ` Benjamin Herrenschmidt
@ 2009-02-13 5:10 ` Kumar Gala
2009-02-13 5:25 ` Benjamin Herrenschmidt
0 siblings, 1 reply; 6+ messages in thread
From: Kumar Gala @ 2009-02-13 5:10 UTC (permalink / raw)
To: Benjamin Herrenschmidt; +Cc: linuxppc-dev
On Feb 12, 2009, at 8:46 PM, Benjamin Herrenschmidt wrote:
> On Thu, 2009-02-12 at 17:54 -0600, Kumar Gala wrote:
>> The e500mc supports the new msgsnd/doorbell mechanisms that were
>> added in
>> the Power ISA 2.05 architecture. We use the normal level doorbell
>> for
>> doing SMP IPIs at this point.
>>
>
> Cool stuff. Haven't reviewed in details yet tho :-) But I was
> thinking...
>
> We should introduce a special xmon variant of local_irq_save/restore
> for
> use by xmon that masks MSR:CE and use a crit doorbell for xmon IPI,
> that
> would increase significantly the ability of xmon to catch deadlocked
> CPUs, and we could use external CRITs as a more generic way of doing
> IPIs, no ?
crit doorbell for xmon IPI sounds interesting. However, I don't
following about use of external CRITs for IPIs.
> In fact, we should expose a local_crit_irq_save/restore (disable/
> enable)
> too for things like watchdog drivers etc... which may want to use
> these.
Yeah, probably a good thing for us to add.
- k
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] powerpc: Add support for using doorbells for SMP IPI
2009-02-13 5:10 ` Kumar Gala
@ 2009-02-13 5:25 ` Benjamin Herrenschmidt
0 siblings, 0 replies; 6+ messages in thread
From: Benjamin Herrenschmidt @ 2009-02-13 5:25 UTC (permalink / raw)
To: Kumar Gala; +Cc: linuxppc-dev
> crit doorbell for xmon IPI sounds interesting. However, I don't
> following about use of external CRITs for IPIs.
Just a finger not following the brain :-) I meant for NMI's
Cheers,
Ben.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] powerpc: Add support for using doorbells for SMP IPI
2009-02-12 23:54 [PATCH] powerpc: Add support for using doorbells for SMP IPI Kumar Gala
2009-02-13 2:46 ` Benjamin Herrenschmidt
@ 2009-02-23 2:43 ` Benjamin Herrenschmidt
2009-02-23 16:23 ` Kumar Gala
1 sibling, 1 reply; 6+ messages in thread
From: Benjamin Herrenschmidt @ 2009-02-23 2:43 UTC (permalink / raw)
To: Kumar Gala; +Cc: linuxppc-dev
On Thu, 2009-02-12 at 17:54 -0600, Kumar Gala wrote:
> The e500mc supports the new msgsnd/doorbell mechanisms that were added in
> the Power ISA 2.05 architecture. We use the normal level doorbell for
> doing SMP IPIs at this point.
Any reason why you don't use the tag ? I'm not too familiar with the
doorbell stuff just yet but can't you use that instead of doing those
atomics ?
On thing we also need to look at is change our low level msg send to
take a CPU mask.
This will be better generically and we need a good cpu mask based IPI
for the TLB stuff anyway. Volunteer ? :-)
Cheers,
Ben.
> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
> ---
> arch/powerpc/include/asm/cputable.h | 4 ++-
> arch/powerpc/include/asm/dbell.h | 43 +++++++++++++++++++++++++++++++++
> arch/powerpc/kernel/Makefile | 2 +-
> arch/powerpc/kernel/dbell.c | 44 ++++++++++++++++++++++++++++++++++
> arch/powerpc/kernel/head_fsl_booke.S | 6 ++++-
> arch/powerpc/kernel/traps.c | 21 ++++++++++++++++
> 6 files changed, 117 insertions(+), 3 deletions(-)
> create mode 100644 arch/powerpc/include/asm/dbell.h
> create mode 100644 arch/powerpc/kernel/dbell.c
>
> diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
> index 4911104..fca1611 100644
> --- a/arch/powerpc/include/asm/cputable.h
> +++ b/arch/powerpc/include/asm/cputable.h
> @@ -145,6 +145,7 @@ extern const char *powerpc_base_platform;
> #define CPU_FTR_USE_TB ASM_CONST(0x0000000000000040)
> #define CPU_FTR_L2CSR ASM_CONST(0x0000000000000080)
> #define CPU_FTR_601 ASM_CONST(0x0000000000000100)
> +#define CPU_FTR_DBELL ASM_CONST(0x0000000000000200)
> #define CPU_FTR_CAN_NAP ASM_CONST(0x0000000000000400)
> #define CPU_FTR_L3CR ASM_CONST(0x0000000000000800)
> #define CPU_FTR_L3_DISABLE_NAP ASM_CONST(0x0000000000001000)
> @@ -373,7 +374,8 @@ extern const char *powerpc_base_platform;
> CPU_FTR_NODSISRALIGN | CPU_FTR_NOEXECUTE)
> #define CPU_FTRS_E500MC (CPU_FTR_MAYBE_CAN_DOZE | CPU_FTR_USE_TB | \
> CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_NODSISRALIGN | \
> - CPU_FTR_L2CSR | CPU_FTR_LWSYNC | CPU_FTR_NOEXECUTE)
> + CPU_FTR_L2CSR | CPU_FTR_LWSYNC | CPU_FTR_NOEXECUTE | \
> + CPU_FTR_DBELL)
> #define CPU_FTRS_GENERIC_32 (CPU_FTR_COMMON | CPU_FTR_NODSISRALIGN)
>
> /* 64-bit CPUs */
> diff --git a/arch/powerpc/include/asm/dbell.h b/arch/powerpc/include/asm/dbell.h
> new file mode 100644
> index 0000000..501189a
> --- /dev/null
> +++ b/arch/powerpc/include/asm/dbell.h
> @@ -0,0 +1,43 @@
> +/*
> + * Copyright 2009 Freescale Semicondutor, Inc.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + *
> + * provides masks and opcode images for use by code generation, emulation
> + * and for instructions that older assemblers might not know about
> + */
> +#ifndef _ASM_POWERPC_DBELL_H
> +#define _ASM_POWERPC_DBELL_H
> +
> +#include <linux/smp.h>
> +#include <linux/threads.h>
> +
> +#include <asm/ppc-opcode.h>
> +
> +#define PPC_DBELL_MSG_BRDCAST (0x04000000)
> +#define PPC_DBELL_TYPE(x) (((x) & 0xf) << 28)
> +enum ppc_dbell {
> + PPC_DBELL = 0, /* doorbell */
> + PPC_DBELL_CRIT = 1, /* critical doorbell */
> + PPC_G_DBELL = 2, /* guest doorbell */
> + PPC_G_DBELL_CRIT = 3, /* guest critical doorbell */
> + PPC_G_DBELL_MC = 4, /* guest mcheck doorbell */
> +};
> +
> +#ifdef CONFIG_SMP
> +extern unsigned long dbell_smp_message[NR_CPUS];
> +extern void smp_dbell_message_pass(int target, int msg);
> +#endif
> +
> +static inline void ppc_msgsnd(enum ppc_dbell type, u32 flags, u32 tag)
> +{
> + u32 msg = PPC_DBELL_TYPE(type) | (flags & PPC_DBELL_MSG_BRDCAST) |
> + (tag & 0x07ffffff);
> +
> + __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
> +}
> +
> +#endif /* _ASM_POWERPC_DBELL_H */
> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
> index d159921..f420844 100644
> --- a/arch/powerpc/kernel/Makefile
> +++ b/arch/powerpc/kernel/Makefile
> @@ -61,7 +61,7 @@ obj-$(CONFIG_HIBERNATION) += swsusp.o suspend.o \
> obj64-$(CONFIG_HIBERNATION) += swsusp_asm64.o
> obj-$(CONFIG_MODULES) += module.o module_$(CONFIG_WORD_SIZE).o
> obj-$(CONFIG_44x) += cpu_setup_44x.o
> -obj-$(CONFIG_FSL_BOOKE) += cpu_setup_fsl_booke.o
> +obj-$(CONFIG_FSL_BOOKE) += cpu_setup_fsl_booke.o dbell.o
>
> extra-$(CONFIG_PPC_STD_MMU) := head_32.o
> extra-$(CONFIG_PPC64) := head_64.o
> diff --git a/arch/powerpc/kernel/dbell.c b/arch/powerpc/kernel/dbell.c
> new file mode 100644
> index 0000000..1493734
> --- /dev/null
> +++ b/arch/powerpc/kernel/dbell.c
> @@ -0,0 +1,44 @@
> +/*
> + * Author: Kumar Gala <galak@kernel.crashing.org>
> + *
> + * Copyright 2009 Freescale Semiconductor Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation; either version 2 of the License, or (at your
> + * option) any later version.
> + */
> +
> +#include <linux/stddef.h>
> +#include <linux/kernel.h>
> +#include <linux/smp.h>
> +#include <linux/threads.h>
> +
> +#include <asm/dbell.h>
> +
> +#ifdef CONFIG_SMP
> +unsigned long dbell_smp_message[NR_CPUS];
> +
> +void smp_dbell_message_pass(int target, int msg)
> +{
> + int i;
> +
> + if(target < NR_CPUS) {
> + set_bit(msg, &dbell_smp_message[target]);
> + ppc_msgsnd(PPC_DBELL, 0, target);
> + }
> + else if(target == MSG_ALL_BUT_SELF) {
> + for_each_online_cpu(i) {
> + if (i == smp_processor_id())
> + continue;
> + set_bit(msg, &dbell_smp_message[i]);
> + ppc_msgsnd(PPC_DBELL, 0, i);
> + }
> + }
> + else { /* target == MSG_ALL */
> + for_each_online_cpu(i)
> + set_bit(msg, &dbell_smp_message[i]);
> + ppc_msgsnd(PPC_DBELL, PPC_DBELL_MSG_BRDCAST, 0);
> + }
> +}
> +#endif
> diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
> index 4ea6e1a..4c22620 100644
> --- a/arch/powerpc/kernel/head_fsl_booke.S
> +++ b/arch/powerpc/kernel/head_fsl_booke.S
> @@ -698,7 +698,9 @@ interrupt_base:
> /* Performance Monitor */
> EXCEPTION(0x2060, PerformanceMonitor, performance_monitor_exception, EXC_XFER_STD)
>
> - EXCEPTION(0x2070, Doorbell, unknown_exception, EXC_XFER_STD)
> + EXCEPTION(0x2070, Doorbell, doorbell_exception, EXC_XFER_STD)
> +
> + CRITICAL_EXCEPTION(0x2080, CriticalDoorbell, unknown_exception)
>
> /* Debug Interrupt */
> DEBUG_DEBUG_EXCEPTION
> @@ -921,6 +923,8 @@ _GLOBAL(__setup_e500mc_ivors)
> mtspr SPRN_IVOR35,r3
> li r3,Doorbell@l
> mtspr SPRN_IVOR36,r3
> + li r3,CriticalDoorbell@l
> + mtspr SPRN_IVOR37,r3
> sync
> blr
>
> diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
> index 970d66e..678fbff 100644
> --- a/arch/powerpc/kernel/traps.c
> +++ b/arch/powerpc/kernel/traps.c
> @@ -53,6 +53,9 @@
> #endif
> #include <asm/kexec.h>
> #include <asm/ppc-opcode.h>
> +#ifdef CONFIG_FSL_BOOKE
> +#include <asm/dbell.h>
> +#endif
>
> #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
> int (*__debugger)(struct pt_regs *regs);
> @@ -1122,6 +1125,24 @@ void vsx_assist_exception(struct pt_regs *regs)
> #endif /* CONFIG_VSX */
>
> #ifdef CONFIG_FSL_BOOKE
> +
> +void doorbell_exception(struct pt_regs *regs)
> +{
> +#ifdef CONFIG_SMP
> + int cpu = smp_processor_id();
> + int msg;
> +
> + if (num_online_cpus() < 2)
> + return;
> +
> + for (msg = 0; msg < 4; msg++)
> + if (test_and_clear_bit(msg, &dbell_smp_message[cpu]))
> + smp_message_recv(msg);
> +#else
> + printk(KERN_WARNING "Received doorbell on non-smp system\n");
> +#endif
> +}
> +
> void CacheLockingException(struct pt_regs *regs, unsigned long address,
> unsigned long error_code)
> {
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] powerpc: Add support for using doorbells for SMP IPI
2009-02-23 2:43 ` Benjamin Herrenschmidt
@ 2009-02-23 16:23 ` Kumar Gala
0 siblings, 0 replies; 6+ messages in thread
From: Kumar Gala @ 2009-02-23 16:23 UTC (permalink / raw)
To: Benjamin Herrenschmidt; +Cc: linuxppc-dev
On Feb 22, 2009, at 8:43 PM, Benjamin Herrenschmidt wrote:
> On Thu, 2009-02-12 at 17:54 -0600, Kumar Gala wrote:
>> The e500mc supports the new msgsnd/doorbell mechanisms that were
>> added in
>> the Power ISA 2.05 architecture. We use the normal level doorbell
>> for
>> doing SMP IPIs at this point.
>
> Any reason why you don't use the tag ? I'm not too familiar with the
> doorbell stuff just yet but can't you use that instead of doing those
> atomics ?
tag just conveys the type of doorbell (normal, critical, etc.). So
for the 4 IPI msgs we support we need software to keep track.
> On thing we also need to look at is change our low level msg send to
> take a CPU mask.
>
> This will be better generically and we need a good cpu mask based IPI
> for the TLB stuff anyway. Volunteer ? :-)
yeah.. It something on the list :)
- k
>> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
>> ---
>> arch/powerpc/include/asm/cputable.h | 4 ++-
>> arch/powerpc/include/asm/dbell.h | 43 ++++++++++++++++++++++++
>> +++++++++
>> arch/powerpc/kernel/Makefile | 2 +-
>> arch/powerpc/kernel/dbell.c | 44 ++++++++++++++++++++++++
>> ++++++++++
>> arch/powerpc/kernel/head_fsl_booke.S | 6 ++++-
>> arch/powerpc/kernel/traps.c | 21 ++++++++++++++++
>> 6 files changed, 117 insertions(+), 3 deletions(-)
>> create mode 100644 arch/powerpc/include/asm/dbell.h
>> create mode 100644 arch/powerpc/kernel/dbell.c
>>
>> diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/
>> include/asm/cputable.h
>> index 4911104..fca1611 100644
>> --- a/arch/powerpc/include/asm/cputable.h
>> +++ b/arch/powerpc/include/asm/cputable.h
>> @@ -145,6 +145,7 @@ extern const char *powerpc_base_platform;
>> #define CPU_FTR_USE_TB ASM_CONST(0x0000000000000040)
>> #define CPU_FTR_L2CSR ASM_CONST(0x0000000000000080)
>> #define CPU_FTR_601 ASM_CONST(0x0000000000000100)
>> +#define CPU_FTR_DBELL ASM_CONST(0x0000000000000200)
>> #define CPU_FTR_CAN_NAP ASM_CONST(0x0000000000000400)
>> #define CPU_FTR_L3CR ASM_CONST(0x0000000000000800)
>> #define CPU_FTR_L3_DISABLE_NAP ASM_CONST(0x0000000000001000)
>> @@ -373,7 +374,8 @@ extern const char *powerpc_base_platform;
>> CPU_FTR_NODSISRALIGN | CPU_FTR_NOEXECUTE)
>> #define CPU_FTRS_E500MC (CPU_FTR_MAYBE_CAN_DOZE | CPU_FTR_USE_TB | \
>> CPU_FTR_MAYBE_CAN_NAP | CPU_FTR_NODSISRALIGN | \
>> - CPU_FTR_L2CSR | CPU_FTR_LWSYNC | CPU_FTR_NOEXECUTE)
>> + CPU_FTR_L2CSR | CPU_FTR_LWSYNC | CPU_FTR_NOEXECUTE | \
>> + CPU_FTR_DBELL)
>> #define CPU_FTRS_GENERIC_32 (CPU_FTR_COMMON | CPU_FTR_NODSISRALIGN)
>>
>> /* 64-bit CPUs */
>> diff --git a/arch/powerpc/include/asm/dbell.h b/arch/powerpc/
>> include/asm/dbell.h
>> new file mode 100644
>> index 0000000..501189a
>> --- /dev/null
>> +++ b/arch/powerpc/include/asm/dbell.h
>> @@ -0,0 +1,43 @@
>> +/*
>> + * Copyright 2009 Freescale Semicondutor, Inc.
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License
>> + * as published by the Free Software Foundation; either version
>> + * 2 of the License, or (at your option) any later version.
>> + *
>> + * provides masks and opcode images for use by code generation,
>> emulation
>> + * and for instructions that older assemblers might not know about
>> + */
>> +#ifndef _ASM_POWERPC_DBELL_H
>> +#define _ASM_POWERPC_DBELL_H
>> +
>> +#include <linux/smp.h>
>> +#include <linux/threads.h>
>> +
>> +#include <asm/ppc-opcode.h>
>> +
>> +#define PPC_DBELL_MSG_BRDCAST (0x04000000)
>> +#define PPC_DBELL_TYPE(x) (((x) & 0xf) << 28)
>> +enum ppc_dbell {
>> + PPC_DBELL = 0, /* doorbell */
>> + PPC_DBELL_CRIT = 1, /* critical doorbell */
>> + PPC_G_DBELL = 2, /* guest doorbell */
>> + PPC_G_DBELL_CRIT = 3, /* guest critical doorbell */
>> + PPC_G_DBELL_MC = 4, /* guest mcheck doorbell */
>> +};
>> +
>> +#ifdef CONFIG_SMP
>> +extern unsigned long dbell_smp_message[NR_CPUS];
>> +extern void smp_dbell_message_pass(int target, int msg);
>> +#endif
>> +
>> +static inline void ppc_msgsnd(enum ppc_dbell type, u32 flags, u32
>> tag)
>> +{
>> + u32 msg = PPC_DBELL_TYPE(type) | (flags & PPC_DBELL_MSG_BRDCAST) |
>> + (tag & 0x07ffffff);
>> +
>> + __asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
>> +}
>> +
>> +#endif /* _ASM_POWERPC_DBELL_H */
>> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/
>> Makefile
>> index d159921..f420844 100644
>> --- a/arch/powerpc/kernel/Makefile
>> +++ b/arch/powerpc/kernel/Makefile
>> @@ -61,7 +61,7 @@ obj-$(CONFIG_HIBERNATION) += swsusp.o suspend.o \
>> obj64-$(CONFIG_HIBERNATION) += swsusp_asm64.o
>> obj-$(CONFIG_MODULES) += module.o module_$(CONFIG_WORD_SIZE).o
>> obj-$(CONFIG_44x) += cpu_setup_44x.o
>> -obj-$(CONFIG_FSL_BOOKE) += cpu_setup_fsl_booke.o
>> +obj-$(CONFIG_FSL_BOOKE) += cpu_setup_fsl_booke.o dbell.o
>>
>> extra-$(CONFIG_PPC_STD_MMU) := head_32.o
>> extra-$(CONFIG_PPC64) := head_64.o
>> diff --git a/arch/powerpc/kernel/dbell.c b/arch/powerpc/kernel/
>> dbell.c
>> new file mode 100644
>> index 0000000..1493734
>> --- /dev/null
>> +++ b/arch/powerpc/kernel/dbell.c
>> @@ -0,0 +1,44 @@
>> +/*
>> + * Author: Kumar Gala <galak@kernel.crashing.org>
>> + *
>> + * Copyright 2009 Freescale Semiconductor Inc.
>> + *
>> + * This program is free software; you can redistribute it and/or
>> modify it
>> + * under the terms of the GNU General Public License as
>> published by the
>> + * Free Software Foundation; either version 2 of the License, or
>> (at your
>> + * option) any later version.
>> + */
>> +
>> +#include <linux/stddef.h>
>> +#include <linux/kernel.h>
>> +#include <linux/smp.h>
>> +#include <linux/threads.h>
>> +
>> +#include <asm/dbell.h>
>> +
>> +#ifdef CONFIG_SMP
>> +unsigned long dbell_smp_message[NR_CPUS];
>> +
>> +void smp_dbell_message_pass(int target, int msg)
>> +{
>> + int i;
>> +
>> + if(target < NR_CPUS) {
>> + set_bit(msg, &dbell_smp_message[target]);
>> + ppc_msgsnd(PPC_DBELL, 0, target);
>> + }
>> + else if(target == MSG_ALL_BUT_SELF) {
>> + for_each_online_cpu(i) {
>> + if (i == smp_processor_id())
>> + continue;
>> + set_bit(msg, &dbell_smp_message[i]);
>> + ppc_msgsnd(PPC_DBELL, 0, i);
>> + }
>> + }
>> + else { /* target == MSG_ALL */
>> + for_each_online_cpu(i)
>> + set_bit(msg, &dbell_smp_message[i]);
>> + ppc_msgsnd(PPC_DBELL, PPC_DBELL_MSG_BRDCAST, 0);
>> + }
>> +}
>> +#endif
>> diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/
>> kernel/head_fsl_booke.S
>> index 4ea6e1a..4c22620 100644
>> --- a/arch/powerpc/kernel/head_fsl_booke.S
>> +++ b/arch/powerpc/kernel/head_fsl_booke.S
>> @@ -698,7 +698,9 @@ interrupt_base:
>> /* Performance Monitor */
>> EXCEPTION(0x2060, PerformanceMonitor,
>> performance_monitor_exception, EXC_XFER_STD)
>>
>> - EXCEPTION(0x2070, Doorbell, unknown_exception, EXC_XFER_STD)
>> + EXCEPTION(0x2070, Doorbell, doorbell_exception, EXC_XFER_STD)
>> +
>> + CRITICAL_EXCEPTION(0x2080, CriticalDoorbell, unknown_exception)
>>
>> /* Debug Interrupt */
>> DEBUG_DEBUG_EXCEPTION
>> @@ -921,6 +923,8 @@ _GLOBAL(__setup_e500mc_ivors)
>> mtspr SPRN_IVOR35,r3
>> li r3,Doorbell@l
>> mtspr SPRN_IVOR36,r3
>> + li r3,CriticalDoorbell@l
>> + mtspr SPRN_IVOR37,r3
>> sync
>> blr
>>
>> diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/
>> traps.c
>> index 970d66e..678fbff 100644
>> --- a/arch/powerpc/kernel/traps.c
>> +++ b/arch/powerpc/kernel/traps.c
>> @@ -53,6 +53,9 @@
>> #endif
>> #include <asm/kexec.h>
>> #include <asm/ppc-opcode.h>
>> +#ifdef CONFIG_FSL_BOOKE
>> +#include <asm/dbell.h>
>> +#endif
>>
>> #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
>> int (*__debugger)(struct pt_regs *regs);
>> @@ -1122,6 +1125,24 @@ void vsx_assist_exception(struct pt_regs
>> *regs)
>> #endif /* CONFIG_VSX */
>>
>> #ifdef CONFIG_FSL_BOOKE
>> +
>> +void doorbell_exception(struct pt_regs *regs)
>> +{
>> +#ifdef CONFIG_SMP
>> + int cpu = smp_processor_id();
>> + int msg;
>> +
>> + if (num_online_cpus() < 2)
>> + return;
>> +
>> + for (msg = 0; msg < 4; msg++)
>> + if (test_and_clear_bit(msg, &dbell_smp_message[cpu]))
>> + smp_message_recv(msg);
>> +#else
>> + printk(KERN_WARNING "Received doorbell on non-smp system\n");
>> +#endif
>> +}
>> +
>> void CacheLockingException(struct pt_regs *regs, unsigned long
>> address,
>> unsigned long error_code)
>> {
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2009-02-23 16:23 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-02-12 23:54 [PATCH] powerpc: Add support for using doorbells for SMP IPI Kumar Gala
2009-02-13 2:46 ` Benjamin Herrenschmidt
2009-02-13 5:10 ` Kumar Gala
2009-02-13 5:25 ` Benjamin Herrenschmidt
2009-02-23 2:43 ` Benjamin Herrenschmidt
2009-02-23 16:23 ` Kumar Gala
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