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

Allocating PDA and GDT at boot is a pain.  Using simple per-cpu variables adds
happiness (although we need the GDT page-aligned for Xen, which we do in a
followup patch).

[akpm@linux-foundation.org: build fix]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 1 insertions, 20 deletions

diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
index 7b14e88b555..b36a5f174cc 100644
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -808,13 +808,7 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu)
 	if (IS_ERR(idle))
 		panic("failed fork for CPU %d", cpu);
 
-	/* Pre-allocate and initialize the CPU's GDT and PDA so it
-	   doesn't have to do any memory allocation during the
-	   delicate CPU-bringup phase. */
-	if (!init_gdt(cpu, idle)) {
-		printk(KERN_INFO "Couldn't allocate GDT/PDA for CPU %d\n", cpu);
-		return -1;	/* ? */
-	}
+	init_gdt(cpu, idle);
 
 	idle->thread.eip = (unsigned long) start_secondary;
 	/* start_eip had better be page-aligned! */
@@ -940,7 +934,6 @@ static int __cpuinit __smp_prepare_cpu(int cpu)
 	DECLARE_COMPLETION_ONSTACK(done);
 	struct warm_boot_cpu_info info;
 	int	apicid, ret;
-	struct Xgt_desc_struct *cpu_gdt_descr = &per_cpu(cpu_gdt_descr, cpu);
 
 	apicid = x86_cpu_to_apicid[cpu];
 	if (apicid == BAD_APICID) {
@@ -948,18 +941,6 @@ static int __cpuinit __smp_prepare_cpu(int cpu)
 		goto exit;
 	}
 
-	/*
-	 * the CPU isn't initialized at boot time, allocate gdt table here.
-	 * cpu_init will initialize it
-	 */
-	if (!cpu_gdt_descr->address) {
-		cpu_gdt_descr->address = get_zeroed_page(GFP_KERNEL);
-		if (!cpu_gdt_descr->address)
-			printk(KERN_CRIT "CPU%d failed to allocate GDT\n", cpu);
-			ret = -ENOMEM;
-			goto exit;
-	}
-
 	info.complete = &done;
 	info.apicid = apicid;
 	info.cpu = cpu;