[PATCH] i386: Use per-cpu variables for GDT, PDA

[linux-2.6-omap-h63xx.git] / arch / i386 / kernel / cpu / common.c

diff --git a/arch/i386/kernel/cpu/common.c b/arch/i386/kernel/cpu/common.c
index dcbbd0a8bfc2b8b5aa29ce1b7d4b1b78dd47b4e2..2335f4464eada9460f41ae1485e5090c16d2d6d1 100644 (file)
--- a/arch/i386/kernel/cpu/common.c
+++ b/arch/i386/kernel/cpu/common.c
@@ -25,8 +25,10 @@
 DEFINE_PER_CPU(struct Xgt_desc_struct, cpu_gdt_descr);
 EXPORT_PER_CPU_SYMBOL(cpu_gdt_descr);
 
-struct i386_pda *_cpu_pda[NR_CPUS] __read_mostly;
-EXPORT_SYMBOL(_cpu_pda);
+DEFINE_PER_CPU(struct desc_struct, cpu_gdt[GDT_ENTRIES]);
+
+DEFINE_PER_CPU(struct i386_pda, _cpu_pda);
+EXPORT_PER_CPU_SYMBOL(_cpu_pda);
 
 static int cachesize_override __cpuinitdata = -1;
 static int disable_x86_fxsr __cpuinitdata;
@@ -609,52 +611,6 @@ struct pt_regs * __devinit idle_regs(struct pt_regs *regs)
        return regs;
 }
 
-static __cpuinit int alloc_gdt(int cpu)
-{
-       struct Xgt_desc_struct *cpu_gdt_descr = &per_cpu(cpu_gdt_descr, cpu);
-       struct desc_struct *gdt;
-       struct i386_pda *pda;
-
-       gdt = (struct desc_struct *)cpu_gdt_descr->address;
-       pda = cpu_pda(cpu);
-
-       /*
-        * This is a horrible hack to allocate the GDT.  The problem
-        * is that cpu_init() is called really early for the boot CPU
-        * (and hence needs bootmem) but much later for the secondary
-        * CPUs, when bootmem will have gone away
-        */
-       if (NODE_DATA(0)->bdata->node_bootmem_map) {
-               BUG_ON(gdt != NULL || pda != NULL);
-
-               gdt = alloc_bootmem_pages(PAGE_SIZE);
-               pda = alloc_bootmem(sizeof(*pda));
-               /* alloc_bootmem(_pages) panics on failure, so no check */
-
-               memset(gdt, 0, PAGE_SIZE);
-               memset(pda, 0, sizeof(*pda));
-       } else {
-               /* GDT and PDA might already have been allocated if
-                  this is a CPU hotplug re-insertion. */
-               if (gdt == NULL)
-                       gdt = (struct desc_struct *)get_zeroed_page(GFP_KERNEL);
-
-               if (pda == NULL)
-                       pda = kmalloc_node(sizeof(*pda), GFP_KERNEL, cpu_to_node(cpu));
-
-               if (unlikely(!gdt || !pda)) {
-                       free_pages((unsigned long)gdt, 0);
-                       kfree(pda);
-                       return 0;
-               }
-       }
-
-       cpu_gdt_descr->address = (unsigned long)gdt;
-       cpu_pda(cpu) = pda;
-
-       return 1;
-}
-
 /* Initial PDA used by boot CPU */
 struct i386_pda boot_pda = {
        ._pda = &boot_pda,
@@ -670,31 +626,17 @@ static inline void set_kernel_fs(void)
        asm volatile ("mov %0, %%fs" : : "r" (__KERNEL_PDA) : "memory");
 }
 
-/* Initialize the CPU's GDT and PDA.  The boot CPU does this for
-   itself, but secondaries find this done for them. */
-__cpuinit int init_gdt(int cpu, struct task_struct *idle)
+/* Initialize the CPU's GDT and PDA.  This is either the boot CPU doing itself
+   (still using cpu_gdt_table), or a CPU doing it for a secondary which
+   will soon come up. */
+__cpuinit void init_gdt(int cpu, struct task_struct *idle)
 {
        struct Xgt_desc_struct *cpu_gdt_descr = &per_cpu(cpu_gdt_descr, cpu);
-       struct desc_struct *gdt;
-       struct i386_pda *pda;
-
-       /* For non-boot CPUs, the GDT and PDA should already have been
-          allocated. */
-       if (!alloc_gdt(cpu)) {
-               printk(KERN_CRIT "CPU%d failed to allocate GDT or PDA\n", cpu);
-               return 0;
-       }
+       struct desc_struct *gdt = per_cpu(cpu_gdt, cpu);
+       struct i386_pda *pda = &per_cpu(_cpu_pda, cpu);
 
-       gdt = (struct desc_struct *)cpu_gdt_descr->address;
-       pda = cpu_pda(cpu);
-
-       BUG_ON(gdt == NULL || pda == NULL);
-
-       /*
-        * Initialize the per-CPU GDT with the boot GDT,
-        * and set up the GDT descriptor:
-        */
        memcpy(gdt, cpu_gdt_table, GDT_SIZE);
+       cpu_gdt_descr->address = (unsigned long)gdt;
        cpu_gdt_descr->size = GDT_SIZE - 1;
 
        pack_descriptor((u32 *)&gdt[GDT_ENTRY_PDA].a,
@@ -706,17 +648,12 @@ __cpuinit int init_gdt(int cpu, struct task_struct *idle)
        pda->_pda = pda;
        pda->cpu_number = cpu;
        pda->pcurrent = idle;
-
-       return 1;
 }
 
 void __cpuinit cpu_set_gdt(int cpu)
 {
        struct Xgt_desc_struct *cpu_gdt_descr = &per_cpu(cpu_gdt_descr, cpu);
 
-       /* Reinit these anyway, even if they've already been done (on
-          the boot CPU, this will transition from the boot gdt+pda to
-          the real ones). */
        load_gdt(cpu_gdt_descr);
        set_kernel_fs();
 }
@@ -804,13 +741,8 @@ void __cpuinit cpu_init(void)
        struct task_struct *curr = current;
 
        /* Set up the real GDT and PDA, so we can transition from the
-          boot versions. */
-       if (!init_gdt(cpu, curr)) {
-               /* failed to allocate something; not much we can do... */
-               for (;;)
-                       local_irq_enable();
-       }
-
+          boot_gdt_table & boot_pda. */
+       init_gdt(cpu, curr);
        cpu_set_gdt(cpu);
        _cpu_init(cpu, curr);
 }