[PATCH] x86_64: Align and pad x86_64 GDT on page boundary

This patch is on the same lines as Zachary Amsden's i386 GDT page alignemnt
patch in -mm, but for x86_64.

Patch to align and pad x86_64 GDT on page boundries.

[AK: some minor cleanups and fixed incorrect TLS initialization
in CPU init.]

Signed-off-by: Nippun Goel <nippung@calsoftinc.com>
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 5 deletions

diff --git a/include/asm-x86_64/desc.h b/include/asm-x86_64/desc.h
index 5ce0e34f9a0c..eb7723a46790 100644
--- a/include/asm-x86_64/desc.h
+++ b/include/asm-x86_64/desc.h
@@ -25,7 +25,7 @@ struct n_desc_struct {
         unsigned int a,b;
 };      
 
-extern struct desc_struct cpu_gdt_table[NR_CPUS][GDT_ENTRIES];
+extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];
 
 enum { 
         GATE_INTERRUPT = 0xE, 
@@ -79,6 +79,9 @@ extern struct desc_struct default_ldt[];
 extern struct gate_struct idt_table[]; 
 extern struct desc_ptr cpu_gdt_descr[];
 
+/* the cpu gdt accessor */
+#define cpu_gdt(_cpu) ((struct desc_struct *)cpu_gdt_descr[_cpu].address)
+
 static inline void _set_gate(void *adr, unsigned type, unsigned long func, unsigned dpl, unsigned ist)  
 {
         struct gate_struct s;   
@@ -144,20 +147,20 @@ static inline void set_tss_desc(unsigned cpu, void *addr)
          * -1? seg base+limit should be pointing to the address of the
          * last valid byte
          */
-        set_tssldt_descriptor(&cpu_gdt_table[cpu][GDT_ENTRY_TSS],
+        set_tssldt_descriptor(&cpu_gdt(cpu)[GDT_ENTRY_TSS],
                 (unsigned long)addr, DESC_TSS,
                 IO_BITMAP_OFFSET + IO_BITMAP_BYTES + sizeof(unsigned long) - 1);
 } 
 
 static inline void set_ldt_desc(unsigned cpu, void *addr, int size)
 { 
-        set_tssldt_descriptor(&cpu_gdt_table[cpu][GDT_ENTRY_LDT], (unsigned long)addr, 
+        set_tssldt_descriptor(&cpu_gdt(cpu)[GDT_ENTRY_LDT], (unsigned long)addr,
                               DESC_LDT, size * 8 - 1);
 }
 
 static inline void set_seg_base(unsigned cpu, int entry, void *base)
 { 
-        struct desc_struct *d = &cpu_gdt_table[cpu][entry];
+        struct desc_struct *d = &cpu_gdt(cpu)[entry];
         u32 addr = (u32)(u64)base;
         BUG_ON((u64)base >> 32); 
         d->base0 = addr & 0xffff;
@@ -199,7 +202,7 @@ static inline void set_seg_base(unsigned cpu, int entry, void *base)
 
 static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
 {
-        u64 *gdt = (u64 *)(cpu_gdt_table[cpu] + GDT_ENTRY_TLS_MIN);
+        u64 *gdt = (u64 *)(cpu_gdt(cpu) + GDT_ENTRY_TLS_MIN);
         gdt[0] = t->tls_array[0];
         gdt[1] = t->tls_array[1];
         gdt[2] = t->tls_array[2];