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From: Michael Neuling on 1 Jul 2010 20:20
Greg,

This won't break ppc64, but it pointless without:
aef40e87d866355ffd279ab21021de733242d0d5 powerpc/pseries: Make
query_cpu_stopped callable outside hotplug cpu

There are two patches that can be put in stable, f8b676918 and
aef40e87d. In this batch of stable releases you have:

2.6.27.48 : aef40e87d only (breaks ppc64)
2.6.32.16 : aef40e87d only (breaks ppc64)
2.6.33.6 : aef40e87d & f8b676918 (works!)
2.6.34.1 : f8b676918 only (does nothing)

Mikey

In message <20100701174253.083176764(a)clark.site> you wrote:
> 2.6.34-stable review patch. If anyone has any objections, please let me know
..
>
> ------------------
>
> From: Michael Neuling <mikey(a)neuling.org>
>
> commit f8b67691828321f5c85bb853283aa101ae673130 upstream.
>
> 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>
> Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de>
>
> ---
> arch/powerpc/platforms/pseries/hotplug-cpu.c | 30 +++------------------
---
> arch/powerpc/platforms/pseries/plpar_wrappers.h | 8 ++++++
> arch/powerpc/platforms/pseries/smp.c | 22 +++++++++++++++++
> 3 files changed, 34 insertions(+), 26 deletions(-)
>
> --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
> @@ -154,30 +154,6 @@ 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();
> @@ -224,8 +200,9 @@ static void pseries_cpu_die(unsigned int
> } else if (get_preferred_offline_state(cpu) == CPU_STATE_OFFLINE) {
>
> 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();
> }
> @@ -388,6 +365,7 @@ static int __init pseries_cpu_hotplug_in
> struct device_node *np;
> const char *typep;
> int cpu;
> + int qcss_tok;
>
> for_each_node_by_name(np, "interrupt-controller") {
> typep = of_get_property(np, "compatible", NULL);
> --- a/arch/powerpc/platforms/pseries/plpar_wrappers.h
> +++ b/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);
> --- a/arch/powerpc/platforms/pseries/smp.c
> +++ b/arch/powerpc/platforms/pseries/smp.c
> @@ -57,6 +57,28 @@
> */
> 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
> *
>
>
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From: Michael Neuling on 3 Jul 2010 04:00
> > Greg,
> >
> > This won't break ppc64, but it pointless without:
> > aef40e87d866355ffd279ab21021de733242d0d5 powerpc/pseries: Make
> > query_cpu_stopped callable outside hotplug cpu
>
> That patch does not apply to the .34 tree, as it seems to be already
> included there. If not, can you please send me a backported version?

Sorry, my bad.

aef40e87d866355ffd279ab21021de733242d0d5 is 078/200 in this series
(seemed to escape my inbox). All is good.

Thanks,
Mikey
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