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Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/cpu/cpu.c82
1 files changed, 53 insertions, 29 deletions
diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
index 209ff2989..8102fb951 100644
--- a/arch/x86/cpu/cpu.c
+++ b/arch/x86/cpu/cpu.c
@@ -55,35 +55,39 @@ struct gdt_ptr {
u32 ptr;
} __packed;
-static void reload_gdt(void)
+static void load_ds(u32 segment)
{
- /*
- * There are machines which are known to not boot with the GDT
- * being 8-byte unaligned. Intel recommends 16 byte alignment
- */
- static const u64 boot_gdt[] __attribute__((aligned(16))) = {
- /* CS: code, read/execute, 4 GB, base 0 */
- [X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff),
- /* DS: data, read/write, 4 GB, base 0 */
- [X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff),
- /* 16-bit CS: code, read/execute, 64 kB, base 0 */
- [X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff),
- /* 16-bit DS: data, read/write, 64 kB, base 0 */
- [X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff),
- };
- static struct gdt_ptr gdt;
-
- gdt.len = sizeof(boot_gdt)-1;
- gdt.ptr = (u32)&boot_gdt;
-
- asm volatile("lgdtl %0\n" \
- "movl $((2+1)*8), %%ecx\n" \
- "movl %%ecx, %%ds\n" \
- "movl %%ecx, %%es\n" \
- "movl %%ecx, %%fs\n" \
- "movl %%ecx, %%gs\n" \
- "movl %%ecx, %%ss" \
- : : "m" (gdt) : "ecx");
+ asm volatile("movl %0, %%ds" : : "r" (segment * X86_GDT_ENTRY_SIZE));
+}
+
+static void load_es(u32 segment)
+{
+ asm volatile("movl %0, %%es" : : "r" (segment * X86_GDT_ENTRY_SIZE));
+}
+
+static void load_fs(u32 segment)
+{
+ asm volatile("movl %0, %%fs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
+}
+
+static void load_gs(u32 segment)
+{
+ asm volatile("movl %0, %%gs" : : "r" (segment * X86_GDT_ENTRY_SIZE));
+}
+
+static void load_ss(u32 segment)
+{
+ asm volatile("movl %0, %%ss" : : "r" (segment * X86_GDT_ENTRY_SIZE));
+}
+
+static void load_gdt(const u64 *boot_gdt, u16 num_entries)
+{
+ struct gdt_ptr gdt;
+
+ gdt.len = (num_entries * 8) - 1;
+ gdt.ptr = (u32)boot_gdt;
+
+ asm volatile("lgdtl %0\n" : : "m" (gdt));
}
int x86_cpu_init_f(void)
@@ -113,7 +117,27 @@ int x86_cpu_init_r(void)
"movl %%eax, %%cr0\n"
"wbinvd\n" : : "i" (nw_cd_rst) : "eax");
- reload_gdt();
+ /*
+ * There are machines which are known to not boot with the GDT
+ * being 8-byte unaligned. Intel recommends 16 byte alignment
+ */
+ static const u64 boot_gdt[] __aligned(16) = {
+ /* CS: code, read/execute, 4 GB, base 0 */
+ [X86_GDT_ENTRY_32BIT_CS] = GDT_ENTRY(0xc09b, 0, 0xfffff),
+ /* DS: data, read/write, 4 GB, base 0 */
+ [X86_GDT_ENTRY_32BIT_DS] = GDT_ENTRY(0xc093, 0, 0xfffff),
+ /* 16-bit CS: code, read/execute, 64 kB, base 0 */
+ [X86_GDT_ENTRY_16BIT_CS] = GDT_ENTRY(0x109b, 0, 0x0ffff),
+ /* 16-bit DS: data, read/write, 64 kB, base 0 */
+ [X86_GDT_ENTRY_16BIT_DS] = GDT_ENTRY(0x1093, 0, 0x0ffff),
+ };
+
+ load_gdt(boot_gdt, X86_GDT_NUM_ENTRIES);
+ load_ds(X86_GDT_ENTRY_32BIT_DS);
+ load_es(X86_GDT_ENTRY_32BIT_DS);
+ load_fs(X86_GDT_ENTRY_32BIT_DS);
+ load_gs(X86_GDT_ENTRY_32BIT_DS);
+ load_ss(X86_GDT_ENTRY_32BIT_DS);
/* Initialize core interrupt and exception functionality of CPU */
cpu_init_interrupts();