powerpc/pseries: Only call start-cpu when a CPU is stopped
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From: Michael Neuling on 1 Jul 2010 20:10 This is not going to work without: f8b67691828321f5c85bb853283aa101ae673130 It'll get a build failure. Mikey In message <20100701172856.882121276(a)clark.site> you wrote: > 2.6.27-stable review patch. If anyone has any objections, please let us know .. > > ------------------ > > From: Michael Neuling <mikey(a)neuling.org> > > commit aef40e87d866355ffd279ab21021de733242d0d5 upstream. > > Currently we always call start-cpu irrespective of if the CPU is > stopped or not. Unfortunatley on POWER7, firmware seems to not like > start-cpu being called when a cpu already been started. This was not > the case on POWER6 and earlier. > > This patch checks to see if the CPU is stopped or not via an > query-cpu-stopped-state call, and only calls start-cpu on CPUs which > are stopped. > > This fixes a bug with kexec on POWER7 on PHYP where only the primary > thread would make it to the second kernel. > > Reported-by: Ankita Garg <ankita(a)linux.vnet.ibm.com> > Signed-off-by: Michael Neuling <mikey(a)neuling.org> > Signed-off-by: Benjamin Herrenschmidt <benh(a)kernel.crashing.org> > Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de> > > --- > arch/powerpc/platforms/pseries/smp.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > --- a/arch/powerpc/platforms/pseries/smp.c > +++ b/arch/powerpc/platforms/pseries/smp.c > @@ -84,6 +84,12 @@ static inline int __devinit smp_startup_ > > pcpu = get_hard_smp_processor_id(lcpu); > > + /* Check to see if the CPU out of FW already for kexec */ > + if (smp_query_cpu_stopped(pcpu) == QCSS_NOT_STOPPED){ > + cpu_set(lcpu, of_spin_map); > + return 1; > + } > + > /* Fixup atomic count: it exited inside IRQ handler. */ > task_thread_info(paca[lcpu].__current)->preempt_count = 0; > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Michael Neuling on 3 Jul 2010 04:00 > > This is not going to work without: > > f8b67691828321f5c85bb853283aa101ae673130 > > > > It'll get a build failure. > > That is because that patch does not apply to the .32 series. If it is > needed, can you please send me a backported version to apply? Sure... Compile and boot tested only. Thanks, Mikey From: Michael Neuling <mikey(a)neuling.org> powerpc/pseries: Make query_cpu_stopped callable outside hotplug cpu This moves query_cpu_stopped() out of the hotplug cpu code and into smp.c so it can called in other places and renames it to smp_query_cpu_stopped(). It also cleans up the return values by adding some #defines Cc: <stable(a)kernel.org> Signed-off-by: Michael Neuling <mikey(a)neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh(a)kernel.crashing.org> Index: clone1/arch/powerpc/platforms/pseries/hotplug-cpu.c =================================================================== --- clone1.orig/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ clone1/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -66,30 +66,6 @@ static void pseries_mach_cpu_die(void) for(;;); } -static int qcss_tok; /* query-cpu-stopped-state token */ - -/* Get state of physical CPU. - * Return codes: - * 0 - The processor is in the RTAS stopped state - * 1 - stop-self is in progress - * 2 - The processor is not in the RTAS stopped state - * -1 - Hardware Error - * -2 - Hardware Busy, Try again later. - */ -static int query_cpu_stopped(unsigned int pcpu) -{ - int cpu_status, status; - - status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu); - if (status != 0) { - printk(KERN_ERR - "RTAS query-cpu-stopped-state failed: %i\n", status); - return status; - } - - return cpu_status; -} - static int pseries_cpu_disable(void) { int cpu = smp_processor_id(); @@ -113,8 +89,9 @@ static void pseries_cpu_die(unsigned int unsigned int pcpu = get_hard_smp_processor_id(cpu); for (tries = 0; tries < 25; tries++) { - cpu_status = query_cpu_stopped(pcpu); - if (cpu_status == 0 || cpu_status == -1) + cpu_status = smp_query_cpu_stopped(pcpu); + if (cpu_status == QCSS_STOPPED || + cpu_status == QCSS_HARDWARE_ERROR) break; cpu_relax(); } @@ -256,6 +233,7 @@ static int __init pseries_cpu_hotplug_in { struct device_node *np; const char *typep; + int qcss_tok; for_each_node_by_name(np, "interrupt-controller") { typep = of_get_property(np, "compatible", NULL); Index: clone1/arch/powerpc/platforms/pseries/plpar_wrappers.h =================================================================== --- clone1.orig/arch/powerpc/platforms/pseries/plpar_wrappers.h +++ clone1/arch/powerpc/platforms/pseries/plpar_wrappers.h @@ -4,6 +4,14 @@ #include <asm/hvcall.h> #include <asm/page.h> +/* Get state of physical CPU from query_cpu_stopped */ +int smp_query_cpu_stopped(unsigned int pcpu); +#define QCSS_STOPPED 0 +#define QCSS_STOPPING 1 +#define QCSS_NOT_STOPPED 2 +#define QCSS_HARDWARE_ERROR -1 +#define QCSS_HARDWARE_BUSY -2 + static inline long poll_pending(void) { return plpar_hcall_norets(H_POLL_PENDING); Index: clone1/arch/powerpc/platforms/pseries/smp.c =================================================================== --- clone1.orig/arch/powerpc/platforms/pseries/smp.c +++ clone1/arch/powerpc/platforms/pseries/smp.c @@ -56,6 +56,28 @@ */ static cpumask_t of_spin_map; +/* Query where a cpu is now. Return codes #defined in plpar_wrappers.h */ +int smp_query_cpu_stopped(unsigned int pcpu) +{ + int cpu_status, status; + int qcss_tok = rtas_token("query-cpu-stopped-state"); + + if (qcss_tok == RTAS_UNKNOWN_SERVICE) { + printk(KERN_INFO "Firmware doesn't support " + "query-cpu-stopped-state\n"); + return QCSS_HARDWARE_ERROR; + } + + status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu); + if (status != 0) { + printk(KERN_ERR + "RTAS query-cpu-stopped-state failed: %i\n", status); + return status; + } + + return cpu_status; +} + /** * smp_startup_cpu() - start the given cpu * -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Michael Neuling on 3 Jul 2010 04:00
In message <20100703015627.GB16229(a)suse.de> you wrote: > On Fri, Jul 02, 2010 at 10:02:48AM +1000, Michael Neuling wrote: > > This is not going to work without: > > f8b67691828321f5c85bb853283aa101ae673130 > > > > It'll get a build failure. > > But that patch does not apply on the .27 series, care to provide a > backported version of it? Sure... Compile and boot tested only. Thanks, Mikey From: Michael Neuling <mikey(a)neuling.org> powerpc/pseries: Make query_cpu_stopped callable outside hotplug cpu This moves query_cpu_stopped() out of the hotplug cpu code and into smp.c so it can called in other places and renames it to smp_query_cpu_stopped(). It also cleans up the return values by adding some #defines Signed-off-by: Michael Neuling <mikey(a)neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh(a)kernel.crashing.org> Index: clone3/arch/powerpc/platforms/pseries/hotplug-cpu.c =================================================================== --- clone3.orig/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ clone3/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -66,30 +66,6 @@ static void pseries_mach_cpu_die(void) for(;;); } -static int qcss_tok; /* query-cpu-stopped-state token */ - -/* Get state of physical CPU. - * Return codes: - * 0 - The processor is in the RTAS stopped state - * 1 - stop-self is in progress - * 2 - The processor is not in the RTAS stopped state - * -1 - Hardware Error - * -2 - Hardware Busy, Try again later. - */ -static int query_cpu_stopped(unsigned int pcpu) -{ - int cpu_status, status; - - status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu); - if (status != 0) { - printk(KERN_ERR - "RTAS query-cpu-stopped-state failed: %i\n", status); - return status; - } - - return cpu_status; -} - static int pseries_cpu_disable(void) { int cpu = smp_processor_id(); @@ -113,8 +89,9 @@ static void pseries_cpu_die(unsigned int unsigned int pcpu = get_hard_smp_processor_id(cpu); for (tries = 0; tries < 25; tries++) { - cpu_status = query_cpu_stopped(pcpu); - if (cpu_status == 0 || cpu_status == -1) + cpu_status = smp_query_cpu_stopped(pcpu); + if (cpu_status == QCSS_STOPPED || + cpu_status == QCSS_HARDWARE_ERROR) break; msleep(200); } @@ -256,6 +233,7 @@ static int __init pseries_cpu_hotplug_in { struct device_node *np; const char *typep; + int qcss_tok; for_each_node_by_name(np, "interrupt-controller") { typep = of_get_property(np, "compatible", NULL); Index: clone3/arch/powerpc/platforms/pseries/plpar_wrappers.h =================================================================== --- clone3.orig/arch/powerpc/platforms/pseries/plpar_wrappers.h +++ clone3/arch/powerpc/platforms/pseries/plpar_wrappers.h @@ -4,6 +4,14 @@ #include <asm/hvcall.h> #include <asm/page.h> +/* Get state of physical CPU from query_cpu_stopped */ +int smp_query_cpu_stopped(unsigned int pcpu); +#define QCSS_STOPPED 0 +#define QCSS_STOPPING 1 +#define QCSS_NOT_STOPPED 2 +#define QCSS_HARDWARE_ERROR -1 +#define QCSS_HARDWARE_BUSY -2 + static inline long poll_pending(void) { return plpar_hcall_norets(H_POLL_PENDING); Index: clone3/arch/powerpc/platforms/pseries/smp.c =================================================================== --- clone3.orig/arch/powerpc/platforms/pseries/smp.c +++ clone3/arch/powerpc/platforms/pseries/smp.c @@ -59,6 +59,28 @@ static cpumask_t of_spin_map; extern void generic_secondary_smp_init(unsigned long); +/* Query where a cpu is now. Return codes #defined in plpar_wrappers.h */ +int smp_query_cpu_stopped(unsigned int pcpu) +{ + int cpu_status, status; + int qcss_tok = rtas_token("query-cpu-stopped-state"); + + if (qcss_tok == RTAS_UNKNOWN_SERVICE) { + printk(KERN_INFO "Firmware doesn't support " + "query-cpu-stopped-state\n"); + return QCSS_HARDWARE_ERROR; + } + + status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu); + if (status != 0) { + printk(KERN_ERR + "RTAS query-cpu-stopped-state failed: %i\n", status); + return status; + } + + return cpu_status; +} + /** * smp_startup_cpu() - start the given cpu * -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |