2005-04-04 02:08:31

by Shaohua Li

[permalink] [raw]
Subject: [RFC 1/6]SEP initialization rework


Make SEP init per-cpu, so is hotplug safe.

Thanks,
Shaohua

---

linux-2.6.11-root/arch/i386/kernel/smpboot.c | 6 ++++++
linux-2.6.11-root/arch/i386/kernel/sysenter.c | 10 ++++++----
linux-2.6.11-root/arch/i386/mach-voyager/voyager_smp.c | 6 ++++++
3 files changed, 18 insertions(+), 4 deletions(-)

diff -puN arch/i386/kernel/sysenter.c~sep_init_cleanup arch/i386/kernel/sysenter.c
--- linux-2.6.11/arch/i386/kernel/sysenter.c~sep_init_cleanup 2005-03-28 09:32:30.936304248 +0800
+++ linux-2.6.11-root/arch/i386/kernel/sysenter.c 2005-03-28 09:58:20.703703792 +0800
@@ -26,6 +26,11 @@ void enable_sep_cpu(void *info)
int cpu = get_cpu();
struct tss_struct *tss = &per_cpu(init_tss, cpu);

+ if (!boot_cpu_has(X86_FEATURE_SEP)) {
+ put_cpu();
+ return;
+ }
+
tss->ss1 = __KERNEL_CS;
tss->esp1 = sizeof(struct tss_struct) + (unsigned long) tss;
wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
@@ -41,7 +46,7 @@ void enable_sep_cpu(void *info)
extern const char vsyscall_int80_start, vsyscall_int80_end;
extern const char vsyscall_sysenter_start, vsyscall_sysenter_end;

-static int __init sysenter_setup(void)
+int __init sysenter_setup(void)
{
void *page = (void *)get_zeroed_page(GFP_ATOMIC);

@@ -58,8 +63,5 @@ static int __init sysenter_setup(void)
&vsyscall_sysenter_start,
&vsyscall_sysenter_end - &vsyscall_sysenter_start);

- on_each_cpu(enable_sep_cpu, NULL, 1, 1);
return 0;
}
-
-__initcall(sysenter_setup);
diff -puN arch/i386/kernel/smpboot.c~sep_init_cleanup arch/i386/kernel/smpboot.c
--- linux-2.6.11/arch/i386/kernel/smpboot.c~sep_init_cleanup 2005-03-28 09:33:49.972288952 +0800
+++ linux-2.6.11-root/arch/i386/kernel/smpboot.c 2005-03-28 09:46:01.814032096 +0800
@@ -415,6 +415,8 @@ static void __init smp_callin(void)

static int cpucount;

+extern int sysenter_setup(void);
+extern void enable_sep_cpu(void *);
/*
* Activate a secondary processor.
*/
@@ -445,6 +447,7 @@ static void __init start_secondary(void

/* We can take interrupts now: we're officially "up". */
local_irq_enable();
+ enable_sep_cpu(NULL);

wmb();
cpu_idle();
@@ -913,6 +916,9 @@ static void __init smp_boot_cpus(unsigne
cpus_clear(cpu_sibling_map[0]);
cpu_set(0, cpu_sibling_map[0]);

+ sysenter_setup();
+ enable_sep_cpu(NULL);
+
/*
* If we couldn't find an SMP configuration at boot time,
* get out of here now!
diff -puN arch/i386/mach-voyager/voyager_smp.c~sep_init_cleanup arch/i386/mach-voyager/voyager_smp.c
--- linux-2.6.11/arch/i386/mach-voyager/voyager_smp.c~sep_init_cleanup 2005-03-28 09:48:27.909822160 +0800
+++ linux-2.6.11-root/arch/i386/mach-voyager/voyager_smp.c 2005-03-28 09:51:37.896939728 +0800
@@ -441,6 +441,8 @@ setup_trampoline(void)
return virt_to_phys((__u8 *)trampoline_base);
}

+extern void enable_sep_cpu(void *);
+extern int sysenter_setup(void);
/* Routine initially called when a non-boot CPU is brought online */
static void __init
start_secondary(void *unused)
@@ -499,6 +501,7 @@ start_secondary(void *unused)
while (!cpu_isset(cpuid, smp_commenced_mask))
rep_nop();
local_irq_enable();
+ enable_sep_cpu(NULL);

local_flush_tlb();

@@ -696,6 +699,9 @@ smp_boot_cpus(void)
printk("CPU%d: ", boot_cpu_id);
print_cpu_info(&cpu_data[boot_cpu_id]);

+ sysenter_setup();
+ enable_sep_cpu(NULL);
+
if(is_cpu_quad()) {
/* booting on a Quad CPU */
printk("VOYAGER SMP: Boot CPU is Quad\n");
_



2005-04-04 08:47:17

by Pavel Machek

[permalink] [raw]
Subject: Re: [RFC 1/6]SEP initialization rework

Hi!

> Make SEP init per-cpu, so is hotplug safe.
>
> Thanks,
> Shaohua
>
> ---
>
> linux-2.6.11-root/arch/i386/kernel/smpboot.c | 6 ++++++
> linux-2.6.11-root/arch/i386/kernel/sysenter.c | 10 ++++++----
> linux-2.6.11-root/arch/i386/mach-voyager/voyager_smp.c | 6 ++++++
> 3 files changed, 18 insertions(+), 4 deletions(-)
>
> diff -puN arch/i386/kernel/sysenter.c~sep_init_cleanup arch/i386/kernel/sysenter.c
> --- linux-2.6.11/arch/i386/kernel/sysenter.c~sep_init_cleanup 2005-03-28 09:32:30.936304248 +0800
> +++ linux-2.6.11-root/arch/i386/kernel/sysenter.c 2005-03-28 09:58:20.703703792 +0800
> @@ -26,6 +26,11 @@ void enable_sep_cpu(void *info)
> int cpu = get_cpu();
> struct tss_struct *tss = &per_cpu(init_tss, cpu);
>
> + if (!boot_cpu_has(X86_FEATURE_SEP)) {
> + put_cpu();
> + return;
> + }
> +
> tss->ss1 = __KERNEL_CS;
> tss->esp1 = sizeof(struct tss_struct) + (unsigned long) tss;
> wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
> @@ -41,7 +46,7 @@ void enable_sep_cpu(void *info)
> extern const char vsyscall_int80_start, vsyscall_int80_end;
> extern const char vsyscall_sysenter_start, vsyscall_sysenter_end;
>
> -static int __init sysenter_setup(void)
> +int __init sysenter_setup(void)
> {
> void *page = (void *)get_zeroed_page(GFP_ATOMIC);
>

Can this still be __init? I think you are calling it from hotplug code
now, right?

> diff -puN arch/i386/kernel/smpboot.c~sep_init_cleanup arch/i386/kernel/smpboot.c
> --- linux-2.6.11/arch/i386/kernel/smpboot.c~sep_init_cleanup 2005-03-28 09:33:49.972288952 +0800
> +++ linux-2.6.11-root/arch/i386/kernel/smpboot.c 2005-03-28 09:46:01.814032096 +0800
> @@ -415,6 +415,8 @@ static void __init smp_callin(void)
>
> static int cpucount;
>
> +extern int sysenter_setup(void);
> +extern void enable_sep_cpu(void *);
> /*
> * Activate a secondary processor.
> */

Perhaps these should go to header file somewhere?

Pavel
--
People were complaining that M$ turns users into beta-testers...
...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl!

2005-04-04 08:54:59

by Shaohua Li

[permalink] [raw]
Subject: Re: [RFC 1/6]SEP initialization rework

Hi,

On Mon, 2005-04-04 at 16:46, Pavel Machek wrote:
> > ---
> >
> > linux-2.6.11-root/arch/i386/kernel/smpboot.c | 6 ++++++
> > linux-2.6.11-root/arch/i386/kernel/sysenter.c | 10 ++++++----
> > linux-2.6.11-root/arch/i386/mach-voyager/voyager_smp.c | 6 ++++++
> > 3 files changed, 18 insertions(+), 4 deletions(-)
> >
> > diff -puN arch/i386/kernel/sysenter.c~sep_init_cleanup arch/i386/kernel/sysenter.c
> > --- linux-2.6.11/arch/i386/kernel/sysenter.c~sep_init_cleanup 2005-03-28 09:32:30.936304248 +0800
> > +++ linux-2.6.11-root/arch/i386/kernel/sysenter.c 2005-03-28 09:58:20.703703792 +0800
> > @@ -26,6 +26,11 @@ void enable_sep_cpu(void *info)
> > int cpu = get_cpu();
> > struct tss_struct *tss = &per_cpu(init_tss, cpu);
> >
> > + if (!boot_cpu_has(X86_FEATURE_SEP)) {
> > + put_cpu();
> > + return;
> > + }
> > +
> > tss->ss1 = __KERNEL_CS;
> > tss->esp1 = sizeof(struct tss_struct) + (unsigned long) tss;
> > wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
> > @@ -41,7 +46,7 @@ void enable_sep_cpu(void *info)
> > extern const char vsyscall_int80_start, vsyscall_int80_end;
> > extern const char vsyscall_sysenter_start, vsyscall_sysenter_end;
> >
> > -static int __init sysenter_setup(void)
> > +int __init sysenter_setup(void)
> > {
> > void *page = (void *)get_zeroed_page(GFP_ATOMIC);
> >
>
> Can this still be __init? I think you are calling it from hotplug code
> now, right?
Only BP executes it. AP calls enable_sep_cpu.

>
> > diff -puN arch/i386/kernel/smpboot.c~sep_init_cleanup arch/i386/kernel/smpboot.c
> > --- linux-2.6.11/arch/i386/kernel/smpboot.c~sep_init_cleanup 2005-03-28 09:33:49.972288952 +0800
> > +++ linux-2.6.11-root/arch/i386/kernel/smpboot.c 2005-03-28 09:46:01.814032096 +0800
> > @@ -415,6 +415,8 @@ static void __init smp_callin(void)
> >
> > static int cpucount;
> >
> > +extern int sysenter_setup(void);
> > +extern void enable_sep_cpu(void *);
> > /*
> > * Activate a secondary processor.
> > */
>
> Perhaps these should go to header file somewhere?
in asm-i386/smp.h?

Thanks,
Shaohua

2005-04-04 19:08:42

by Zwane Mwaikambo

[permalink] [raw]
Subject: Re: [RFC 1/6]SEP initialization rework

On Mon, 4 Apr 2005, Li Shaohua wrote:

> linux-2.6.11-root/arch/i386/kernel/smpboot.c | 6 ++++++
> linux-2.6.11-root/arch/i386/kernel/sysenter.c | 10 ++++++----
> linux-2.6.11-root/arch/i386/mach-voyager/voyager_smp.c | 6 ++++++
> 3 files changed, 18 insertions(+), 4 deletions(-)
>
> diff -puN arch/i386/kernel/sysenter.c~sep_init_cleanup arch/i386/kernel/sysenter.c
> --- linux-2.6.11/arch/i386/kernel/sysenter.c~sep_init_cleanup 2005-03-28 09:32:30.936304248 +0800
> +++ linux-2.6.11-root/arch/i386/kernel/sysenter.c 2005-03-28 09:58:20.703703792 +0800
> @@ -26,6 +26,11 @@ void enable_sep_cpu(void *info)
> int cpu = get_cpu();
> struct tss_struct *tss = &per_cpu(init_tss, cpu);
>
> + if (!boot_cpu_has(X86_FEATURE_SEP)) {
> + put_cpu();
> + return;
> + }
> +

Do you have systems like this? Is it really skipping SEP if the boot
processor doesn't have SEP?

2005-04-05 02:03:12

by Shaohua Li

[permalink] [raw]
Subject: Re: [RFC 1/6]SEP initialization rework

On Tue, 2005-04-05 at 03:10, Zwane Mwaikambo wrote:
> On Mon, 4 Apr 2005, Li Shaohua wrote:
>
> > linux-2.6.11-root/arch/i386/kernel/smpboot.c | 6 ++++++
> > linux-2.6.11-root/arch/i386/kernel/sysenter.c | 10 ++++++----
> > linux-2.6.11-root/arch/i386/mach-voyager/voyager_smp.c | 6 ++++++
> > 3 files changed, 18 insertions(+), 4 deletions(-)
> >
> > diff -puN arch/i386/kernel/sysenter.c~sep_init_cleanup arch/i386/kernel/sysenter.c
> > --- linux-2.6.11/arch/i386/kernel/sysenter.c~sep_init_cleanup 2005-03-28 09:32:30.936304248 +0800
> > +++ linux-2.6.11-root/arch/i386/kernel/sysenter.c 2005-03-28 09:58:20.703703792 +0800
> > @@ -26,6 +26,11 @@ void enable_sep_cpu(void *info)
> > int cpu = get_cpu();
> > struct tss_struct *tss = &per_cpu(init_tss, cpu);
> >
> > + if (!boot_cpu_has(X86_FEATURE_SEP)) {
> > + put_cpu();
> > + return;
> > + }
> > +
>
> Do you have systems like this? Is it really skipping SEP if the boot
> processor doesn't have SEP?
No, I haven't such system. This is the logic of original SEP
initialization. If the CPU hasn't SEP, original logic doesn't call
'on_each_cpu(enable_sep_cpu,...)'.

Thanks,
Shaohua

2005-04-05 08:00:43

by Zwane Mwaikambo

[permalink] [raw]
Subject: Re: [RFC 1/6]SEP initialization rework

On Tue, 5 Apr 2005, Li Shaohua wrote:

> On Tue, 2005-04-05 at 03:10, Zwane Mwaikambo wrote:
> > On Mon, 4 Apr 2005, Li Shaohua wrote:
> >
> > > linux-2.6.11-root/arch/i386/kernel/smpboot.c | 6 ++++++
> > > linux-2.6.11-root/arch/i386/kernel/sysenter.c | 10 ++++++----
> > > linux-2.6.11-root/arch/i386/mach-voyager/voyager_smp.c | 6 ++++++
> > > 3 files changed, 18 insertions(+), 4 deletions(-)
> > >
> > > diff -puN arch/i386/kernel/sysenter.c~sep_init_cleanup arch/i386/kernel/sysenter.c
> > > --- linux-2.6.11/arch/i386/kernel/sysenter.c~sep_init_cleanup 2005-03-28 09:32:30.936304248 +0800
> > > +++ linux-2.6.11-root/arch/i386/kernel/sysenter.c 2005-03-28 09:58:20.703703792 +0800
> > > @@ -26,6 +26,11 @@ void enable_sep_cpu(void *info)
> > > int cpu = get_cpu();
> > > struct tss_struct *tss = &per_cpu(init_tss, cpu);
> > >
> > > + if (!boot_cpu_has(X86_FEATURE_SEP)) {
> > > + put_cpu();
> > > + return;
> > > + }
> > > +
> >
> > Do you have systems like this? Is it really skipping SEP if the boot
> > processor doesn't have SEP?
> No, I haven't such system. This is the logic of original SEP
> initialization. If the CPU hasn't SEP, original logic doesn't call
> 'on_each_cpu(enable_sep_cpu,...)'.

Got it, so i misread.

Thanks,
Zwane

2005-04-06 19:33:16

by Martin Waitz

[permalink] [raw]
Subject: Re: [RFC 1/6]SEP initialization rework

hoi :)

On Mon, Apr 04, 2005 at 10:05:56AM +0800, Li Shaohua wrote:
> - on_each_cpu(enable_sep_cpu, NULL, 1, 1);

with this on_each_cpu call gone, you should also be able to remove the
useless info pointer in enable_sep_cpu.

--
Martin Waitz


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