| Message ID | 1369131215-2920-1-git-send-email-josephl@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/21/2013 04:13 AM, Joseph Lo wrote: > The Tegra114 could hotplug the CPU0, but the common cpu_disable didn't > support that. Adding a Tegra specific cpu_disable function for it. > > Signed-off-by: Joseph Lo <josephl@nvidia.com> > diff --git a/arch/arm/mach-tegra/hotplug.c b/arch/arm/mach-tegra/hotplug.c > +int tegra_cpu_disable(unsigned int cpu) > +{ > + switch (tegra_chip_id) { > + case TEGRA114: > + return 0; > + default: > + return cpu == 0 ? -EPERM : 0; > + } > +} Do we expect all/most future chips to support hotplug of CPU0? Or at least, fewer chips to have the restriction than not? If so, it might be more forward-looking to write that as: if (tegra_chip_id == TEGRA30) return cpu == 0 ? -EPERM : 0; return 0; ?
On Tue, May 21, 2013 at 06:15:48PM +0200, Stephen Warren wrote: > On 05/21/2013 04:13 AM, Joseph Lo wrote: > > The Tegra114 could hotplug the CPU0, but the common cpu_disable didn't > > support that. Adding a Tegra specific cpu_disable function for it. > > > > Signed-off-by: Joseph Lo <josephl@nvidia.com> > > > diff --git a/arch/arm/mach-tegra/hotplug.c b/arch/arm/mach-tegra/hotplug.c > > > +int tegra_cpu_disable(unsigned int cpu) > > +{ > > + switch (tegra_chip_id) { > > + case TEGRA114: > > + return 0; > > + default: > > + return cpu == 0 ? -EPERM : 0; > > + } > > +} > > Do we expect all/most future chips to support hotplug of CPU0? Or at > least, fewer chips to have the restriction than not? If so, it might be Yes. I think we can safely assume future chips will support hotplugging CPU0. > more forward-looking to write that as: > > if (tegra_chip_id == TEGRA30) > return cpu == 0 ? -EPERM : 0; > Also Tegra20 doesn't support hotplugging CPU0? Cheers, Peter.
On 05/22/2013 03:03 AM, Peter De Schrijver wrote: > On Tue, May 21, 2013 at 06:15:48PM +0200, Stephen Warren wrote: >> On 05/21/2013 04:13 AM, Joseph Lo wrote: >>> The Tegra114 could hotplug the CPU0, but the common cpu_disable didn't >>> support that. Adding a Tegra specific cpu_disable function for it. >>> >>> Signed-off-by: Joseph Lo <josephl@nvidia.com> >> >>> diff --git a/arch/arm/mach-tegra/hotplug.c b/arch/arm/mach-tegra/hotplug.c >> >>> +int tegra_cpu_disable(unsigned int cpu) >>> +{ >>> + switch (tegra_chip_id) { >>> + case TEGRA114: >>> + return 0; >>> + default: >>> + return cpu == 0 ? -EPERM : 0; >>> + } >>> +} >> >> Do we expect all/most future chips to support hotplug of CPU0? Or at >> least, fewer chips to have the restriction than not? If so, it might be > > Yes. I think we can safely assume future chips will support hotplugging CPU0. > >> more forward-looking to write that as: >> >> if (tegra_chip_id == TEGRA30) >> return cpu == 0 ? -EPERM : 0; >> > > Also Tegra20 doesn't support hotplugging CPU0? Oh right, this isn't a Tegra30+ file. How about just inverting the switch so it doesn't need to change later: switch (tegra_chip_id) { case TEGRA20: case TEGRA30: return cpu == 0 ? -EPERM : 0; default: return 0; }
On Thu, 2013-05-23 at 05:18 +0800, Stephen Warren wrote: > On 05/22/2013 03:03 AM, Peter De Schrijver wrote: > > On Tue, May 21, 2013 at 06:15:48PM +0200, Stephen Warren wrote: > >> On 05/21/2013 04:13 AM, Joseph Lo wrote: > >>> The Tegra114 could hotplug the CPU0, but the common cpu_disable didn't > >>> support that. Adding a Tegra specific cpu_disable function for it. > >>> > >>> Signed-off-by: Joseph Lo <josephl@nvidia.com> > >> > >>> diff --git a/arch/arm/mach-tegra/hotplug.c b/arch/arm/mach-tegra/hotplug.c > >> > >>> +int tegra_cpu_disable(unsigned int cpu) > >>> +{ > >>> + switch (tegra_chip_id) { > >>> + case TEGRA114: > >>> + return 0; > >>> + default: > >>> + return cpu == 0 ? -EPERM : 0; > >>> + } > >>> +} > >> > >> Do we expect all/most future chips to support hotplug of CPU0? Or at > >> least, fewer chips to have the restriction than not? If so, it might be > > > > Yes. I think we can safely assume future chips will support hotplugging CPU0. > > > >> more forward-looking to write that as: > >> > >> if (tegra_chip_id == TEGRA30) > >> return cpu == 0 ? -EPERM : 0; > >> > > > > Also Tegra20 doesn't support hotplugging CPU0? > > Oh right, this isn't a Tegra30+ file. How about just inverting the > switch so it doesn't need to change later: > > switch (tegra_chip_id) { > case TEGRA20: > case TEGRA30: > return cpu == 0 ? -EPERM : 0; > default: > return 0; > } > OK. Will update a newer version later. Thanks, Joseph
diff --git a/arch/arm/mach-tegra/common.h b/arch/arm/mach-tegra/common.h index 5900cc4..32f8eb3 100644 --- a/arch/arm/mach-tegra/common.h +++ b/arch/arm/mach-tegra/common.h @@ -2,3 +2,4 @@ extern struct smp_operations tegra_smp_ops; extern int tegra_cpu_kill(unsigned int cpu); extern void tegra_cpu_die(unsigned int cpu); +extern int tegra_cpu_disable(unsigned int cpu); diff --git a/arch/arm/mach-tegra/hotplug.c b/arch/arm/mach-tegra/hotplug.c index d07f152..9695b63 100644 --- a/arch/arm/mach-tegra/hotplug.c +++ b/arch/arm/mach-tegra/hotplug.c @@ -46,6 +46,16 @@ void __ref tegra_cpu_die(unsigned int cpu) BUG(); } +int tegra_cpu_disable(unsigned int cpu) +{ + switch (tegra_chip_id) { + case TEGRA114: + return 0; + default: + return cpu == 0 ? -EPERM : 0; + } +} + void __init tegra_hotplug_init(void) { if (!IS_ENABLED(CONFIG_HOTPLUG_CPU)) diff --git a/arch/arm/mach-tegra/platsmp.c b/arch/arm/mach-tegra/platsmp.c index 554aedc..24db4ac 100644 --- a/arch/arm/mach-tegra/platsmp.c +++ b/arch/arm/mach-tegra/platsmp.c @@ -196,5 +196,6 @@ struct smp_operations tegra_smp_ops __initdata = { #ifdef CONFIG_HOTPLUG_CPU .cpu_kill = tegra_cpu_kill, .cpu_die = tegra_cpu_die, + .cpu_disable = tegra_cpu_disable, #endif };
The Tegra114 could hotplug the CPU0, but the common cpu_disable didn't support that. Adding a Tegra specific cpu_disable function for it. Signed-off-by: Joseph Lo <josephl@nvidia.com> --- This patch depends on the series of "ARM: tegra114: add CPU hotplug support". --- arch/arm/mach-tegra/common.h | 1 + arch/arm/mach-tegra/hotplug.c | 10 ++++++++++ arch/arm/mach-tegra/platsmp.c | 1 + 3 files changed, 12 insertions(+)