kern/amd64: cpu: Make GDT per-cpu to match TSS

Signed-off-by: Ian Moffett <ian@osmora.org>

5 files changed, 22 insertions, 9 deletions

diff --git a/src/sys/arch/amd64/boot/boot_chip.c b/src/sys/arch/amd64/boot/boot_chip.c
index 2ff122c..76753d5 100644
--- a/src/sys/arch/amd64/boot/boot_chip.c
+++ b/src/sys/arch/amd64/boot/boot_chip.c
@@ -61,8 +61,10 @@ static void
 init_tss(struct pcore *pcore)
 {
     struct tss_desc *desc;
+    struct mdcore *mdcore;
 
-    desc = (struct tss_desc *)&g_gdt_data[GDT_TSS_INDEX];
+    mdcore = &pcore->md;
+    desc = (struct tss_desc *)&mdcore->gdt[GDT_TSS_INDEX];
     write_tss(pcore, desc);
     tss_load();
 }
diff --git a/src/sys/arch/amd64/boot/boot_gdt.c b/src/sys/arch/amd64/boot/boot_gdt.c
index 2c1ada6..64b3f2b 100644
--- a/src/sys/arch/amd64/boot/boot_gdt.c
+++ b/src/sys/arch/amd64/boot/boot_gdt.c
@@ -91,8 +91,3 @@ struct gdt_entry g_gdt_data[GDT_ENTRY_COUNT] = {
 
 /* Verify that the GDT is of the correct size */
 __static_assert(sizeof(g_gdt_data) == (8 * GDT_ENTRY_COUNT));
-
-const struct gdtr g_gdtr = {
-    .limit = sizeof(g_gdt_data) - 1,
-    .offset = (uintptr_t)&g_gdt_data[0]
-};
diff --git a/src/sys/arch/amd64/cpu/cpu_conf.c b/src/sys/arch/amd64/cpu/cpu_conf.c
index 5eb1cbe..e462ef3 100644
--- a/src/sys/arch/amd64/cpu/cpu_conf.c
+++ b/src/sys/arch/amd64/cpu/cpu_conf.c
@@ -34,6 +34,7 @@
 #include <machine/trap.h>
 #include <machine/lapic.h>
 #include <machine/gdt.h>
+#include <string.h>
 
 /*
  * Initialize interrupt vectors
@@ -58,8 +59,20 @@ init_vectors(void)
 void
 cpu_conf(struct pcore *pcore)
 {
+    struct mdcore *mdcore;
+    struct gdtr *gdtr;
+
+    /* Copy the template GDT */
+    mdcore = &pcore->md;
+    memcpy(mdcore->gdt, &g_gdt_data, sizeof(g_gdt_data));
+
+    /* Set up the GDTR */
+    gdtr = &mdcore->gdtr;
+    gdtr->offset = (uintptr_t)&mdcore->gdt[0];
+    gdtr->limit = sizeof(g_gdt_data) - 1;
+
     /* We use %GS to store the processor */
-    gdt_load();
+    gdt_load(&mdcore->gdtr);
     pcore->self = pcore;
     wrmsr(IA32_GS_BASE, (uintptr_t)pcore);
 
diff --git a/src/sys/include/arch/amd64/gdt.h b/src/sys/include/arch/amd64/gdt.h
index ee52065..0a22b37 100644
--- a/src/sys/include/arch/amd64/gdt.h
+++ b/src/sys/include/arch/amd64/gdt.h
@@ -87,7 +87,7 @@ extern struct gdt_entry g_gdt_data[GDT_ENTRY_COUNT];
 extern const struct gdtr g_gdtr;
 
 __always_inline static inline void
-gdt_load(void)
+gdt_load(struct gdtr *gdtr)
 {
     __ASMV("lgdt %0\n"
            "push %1\n"              /* Push code segment selector */
@@ -102,7 +102,7 @@ gdt_load(void)
            "  mov %%ax, %%gs\n"
            "  mov %%ax, %%ss\n"
            :
-           : "m" (g_gdtr), "i"(KERNEL_CS), "i"(KERNEL_DS)
+           : "m" (*gdtr), "i"(KERNEL_CS), "i"(KERNEL_DS)
            : "rax", "memory"
     );
 }
diff --git a/src/sys/include/arch/amd64/mdcpu.h b/src/sys/include/arch/amd64/mdcpu.h
index 3fccc42..d72836a 100644
--- a/src/sys/include/arch/amd64/mdcpu.h
+++ b/src/sys/include/arch/amd64/mdcpu.h
@@ -33,6 +33,7 @@
 #include <sys/types.h>
 #include <sys/cdefs.h>
 #include <machine/tss.h>
+#include <machine/gdt.h>
 
 #define md_spinwait() __ASMV("pause")
 #define md_intoff()   __ASMV("cli")
@@ -57,6 +58,8 @@ struct mdcore {
     uint8_t x2apic : 1;
     struct tss_entry tss;
     size_t lapic_tmr_freq;
+    struct gdt_entry gdt[GDT_ENTRY_COUNT];
+    struct gdtr gdtr;
 };
 
 #endif  /* !_MACHINE_MDCPU_H_ */