diff options
| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2008-07-08 15:06:42 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-16 10:58:13 +0200 |
| commit | 5b09b2876ed1a8e34a0da8f069575fc6174e2077 (patch) | |
| tree | 370750e5c1d4073ed4a7525ccd0348e4154ba0d4 /arch | |
| parent | a9e7062d7339f1a1df2b6d7e5d595c7d55b56bfb (diff) | |
| download | linux-5b09b2876ed1a8e34a0da8f069575fc6174e2077.tar.bz2 | |
x86_64: add workaround for no %gs-based percpu
As a stopgap until Mike Travis's x86-64 gs-based percpu patches are
ready, provide workaround functions for x86_read/write_percpu for
Xen's use.
Specifically, this means that we can't really make use of vcpu
placement, because we can't use a single gs-based memory access to get
to vcpu fields. So disable all that for now.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/head64.c | 11 | ||||
| -rw-r--r-- | arch/x86/xen/enlighten.c | 5 |
2 files changed, 13 insertions, 3 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index c97819829146..1b318e903bf6 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -39,6 +39,13 @@ static struct x8664_pda *__cpu_pda[NR_CPUS] __initdata; static struct x8664_pda *__cpu_pda[NR_CPUS] __read_mostly; #endif +void __init x86_64_init_pda(void) +{ + _cpu_pda = __cpu_pda; + cpu_pda(0) = &_boot_cpu_pda; + pda_init(0); +} + static void __init zap_identity_mappings(void) { pgd_t *pgd = pgd_offset_k(0UL); @@ -102,9 +109,7 @@ void __init x86_64_start_kernel(char * real_mode_data) early_printk("Kernel alive\n"); - _cpu_pda = __cpu_pda; - cpu_pda(0) = &_boot_cpu_pda; - pda_init(0); + x86_64_init_pda(); early_printk("Kernel really alive\n"); diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index a85f447b8d00..f3f11acf7856 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -971,6 +971,7 @@ void xen_setup_vcpu_info_placement(void) /* xen_vcpu_setup managed to place the vcpu_info within the percpu area for all cpus, so make use of it */ +#ifdef CONFIG_X86_32 if (have_vcpu_info_placement) { printk(KERN_INFO "Xen: using vcpu_info placement\n"); @@ -980,6 +981,7 @@ void xen_setup_vcpu_info_placement(void) pv_irq_ops.irq_enable = xen_irq_enable_direct; pv_mmu_ops.read_cr2 = xen_read_cr2_direct; } +#endif } static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf, @@ -1000,10 +1002,12 @@ static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf, goto patch_site switch (type) { +#ifdef CONFIG_X86_32 SITE(pv_irq_ops, irq_enable); SITE(pv_irq_ops, irq_disable); SITE(pv_irq_ops, save_fl); SITE(pv_irq_ops, restore_fl); +#endif /* CONFIG_X86_32 */ #undef SITE patch_site: @@ -1323,6 +1327,7 @@ asmlinkage void __init xen_start_kernel(void) #ifdef CONFIG_X86_64 /* Disable until direct per-cpu data access. */ have_vcpu_info_placement = 0; + x86_64_init_pda(); #endif xen_smp_init(); |