Merge tag 'iommu-v4.15-rc7' of git://github.com/awilliam/linux-vfio
[sfrench/cifs-2.6.git] / arch / x86 / kernel / cpu / common.c
index fa998ca8aa5aa5b4899dbe8a57c5b543f927009e..39d7ea865207d102d2f03fc9ca779b2bdbb03c61 100644 (file)
@@ -476,8 +476,8 @@ static const char *table_lookup_model(struct cpuinfo_x86 *c)
        return NULL;            /* Not found */
 }
 
-__u32 cpu_caps_cleared[NCAPINTS];
-__u32 cpu_caps_set[NCAPINTS];
+__u32 cpu_caps_cleared[NCAPINTS + NBUGINTS];
+__u32 cpu_caps_set[NCAPINTS + NBUGINTS];
 
 void load_percpu_segment(int cpu)
 {
@@ -490,28 +490,23 @@ void load_percpu_segment(int cpu)
        load_stack_canary_segment();
 }
 
-/* Setup the fixmap mapping only once per-processor */
-static inline void setup_fixmap_gdt(int cpu)
-{
-#ifdef CONFIG_X86_64
-       /* On 64-bit systems, we use a read-only fixmap GDT. */
-       pgprot_t prot = PAGE_KERNEL_RO;
-#else
-       /*
-        * On native 32-bit systems, the GDT cannot be read-only because
-        * our double fault handler uses a task gate, and entering through
-        * a task gate needs to change an available TSS to busy.  If the GDT
-        * is read-only, that will triple fault.
-        *
-        * On Xen PV, the GDT must be read-only because the hypervisor requires
-        * it.
-        */
-       pgprot_t prot = boot_cpu_has(X86_FEATURE_XENPV) ?
-               PAGE_KERNEL_RO : PAGE_KERNEL;
+#ifdef CONFIG_X86_32
+/* The 32-bit entry code needs to find cpu_entry_area. */
+DEFINE_PER_CPU(struct cpu_entry_area *, cpu_entry_area);
 #endif
 
-       __set_fixmap(get_cpu_gdt_ro_index(cpu), get_cpu_gdt_paddr(cpu), prot);
-}
+#ifdef CONFIG_X86_64
+/*
+ * Special IST stacks which the CPU switches to when it calls
+ * an IST-marked descriptor entry. Up to 7 stacks (hardware
+ * limit), all of them are 4K, except the debug stack which
+ * is 8K.
+ */
+static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
+         [0 ... N_EXCEPTION_STACKS - 1]        = EXCEPTION_STKSZ,
+         [DEBUG_STACK - 1]                     = DEBUG_STKSZ
+};
+#endif
 
 /* Load the original GDT from the per-cpu structure */
 void load_direct_gdt(int cpu)
@@ -747,7 +742,7 @@ static void apply_forced_caps(struct cpuinfo_x86 *c)
 {
        int i;
 
-       for (i = 0; i < NCAPINTS; i++) {
+       for (i = 0; i < NCAPINTS + NBUGINTS; i++) {
                c->x86_capability[i] &= ~cpu_caps_cleared[i];
                c->x86_capability[i] |= cpu_caps_set[i];
        }
@@ -927,6 +922,10 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c)
        }
 
        setup_force_cpu_cap(X86_FEATURE_ALWAYS);
+
+       if (c->x86_vendor != X86_VENDOR_AMD)
+               setup_force_cpu_bug(X86_BUG_CPU_MELTDOWN);
+
        fpu__init_system(c);
 
 #ifdef CONFIG_X86_32
@@ -1250,7 +1249,7 @@ void enable_sep_cpu(void)
                return;
 
        cpu = get_cpu();
-       tss = &per_cpu(cpu_tss, cpu);
+       tss = &per_cpu(cpu_tss_rw, cpu);
 
        /*
         * We cache MSR_IA32_SYSENTER_CS's value in the TSS's ss1 field --
@@ -1259,11 +1258,7 @@ void enable_sep_cpu(void)
 
        tss->x86_tss.ss1 = __KERNEL_CS;
        wrmsr(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1, 0);
-
-       wrmsr(MSR_IA32_SYSENTER_ESP,
-             (unsigned long)tss + offsetofend(struct tss_struct, SYSENTER_stack),
-             0);
-
+       wrmsr(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1), 0);
        wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0);
 
        put_cpu();
@@ -1357,25 +1352,22 @@ DEFINE_PER_CPU(unsigned int, irq_count) __visible = -1;
 DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT;
 EXPORT_PER_CPU_SYMBOL(__preempt_count);
 
-/*
- * Special IST stacks which the CPU switches to when it calls
- * an IST-marked descriptor entry. Up to 7 stacks (hardware
- * limit), all of them are 4K, except the debug stack which
- * is 8K.
- */
-static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
-         [0 ... N_EXCEPTION_STACKS - 1]        = EXCEPTION_STKSZ,
-         [DEBUG_STACK - 1]                     = DEBUG_STKSZ
-};
-
-static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
-       [(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]);
-
 /* May not be marked __init: used by software suspend */
 void syscall_init(void)
 {
+       extern char _entry_trampoline[];
+       extern char entry_SYSCALL_64_trampoline[];
+
+       int cpu = smp_processor_id();
+       unsigned long SYSCALL64_entry_trampoline =
+               (unsigned long)get_cpu_entry_area(cpu)->entry_trampoline +
+               (entry_SYSCALL_64_trampoline - _entry_trampoline);
+
        wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS);
-       wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64);
+       if (static_cpu_has(X86_FEATURE_PTI))
+               wrmsrl(MSR_LSTAR, SYSCALL64_entry_trampoline);
+       else
+               wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64);
 
 #ifdef CONFIG_IA32_EMULATION
        wrmsrl(MSR_CSTAR, (unsigned long)entry_SYSCALL_compat);
@@ -1386,7 +1378,7 @@ void syscall_init(void)
         * AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit).
         */
        wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
-       wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
+       wrmsrl_safe(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1));
        wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat);
 #else
        wrmsrl(MSR_CSTAR, (unsigned long)ignore_sysret);
@@ -1530,7 +1522,7 @@ void cpu_init(void)
        if (cpu)
                load_ucode_ap();
 
-       t = &per_cpu(cpu_tss, cpu);
+       t = &per_cpu(cpu_tss_rw, cpu);
        oist = &per_cpu(orig_ist, cpu);
 
 #ifdef CONFIG_NUMA
@@ -1569,7 +1561,7 @@ void cpu_init(void)
         * set up and load the per-CPU TSS
         */
        if (!oist->ist[0]) {
-               char *estacks = per_cpu(exception_stacks, cpu);
+               char *estacks = get_cpu_entry_area(cpu)->exception_stacks;
 
                for (v = 0; v < N_EXCEPTION_STACKS; v++) {
                        estacks += exception_stack_sizes[v];
@@ -1580,7 +1572,7 @@ void cpu_init(void)
                }
        }
 
-       t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
+       t->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
 
        /*
         * <= is required because the CPU will access up to
@@ -1596,11 +1588,12 @@ void cpu_init(void)
        enter_lazy_tlb(&init_mm, me);
 
        /*
-        * Initialize the TSS.  Don't bother initializing sp0, as the initial
-        * task never enters user mode.
+        * Initialize the TSS.  sp0 points to the entry trampoline stack
+        * regardless of what task is running.
         */
-       set_tss_desc(cpu, t);
+       set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
        load_TR_desc();
+       load_sp0((unsigned long)(cpu_entry_stack(cpu) + 1));
 
        load_mm_ldt(&init_mm);
 
@@ -1612,7 +1605,6 @@ void cpu_init(void)
        if (is_uv_system())
                uv_cpu_init();
 
-       setup_fixmap_gdt(cpu);
        load_fixmap_gdt(cpu);
 }
 
@@ -1622,7 +1614,7 @@ void cpu_init(void)
 {
        int cpu = smp_processor_id();
        struct task_struct *curr = current;
-       struct tss_struct *t = &per_cpu(cpu_tss, cpu);
+       struct tss_struct *t = &per_cpu(cpu_tss_rw, cpu);
 
        wait_for_master_cpu(cpu);
 
@@ -1657,12 +1649,12 @@ void cpu_init(void)
         * Initialize the TSS.  Don't bother initializing sp0, as the initial
         * task never enters user mode.
         */
-       set_tss_desc(cpu, t);
+       set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
        load_TR_desc();
 
        load_mm_ldt(&init_mm);
 
-       t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
+       t->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
 
 #ifdef CONFIG_DOUBLEFAULT
        /* Set up doublefault TSS pointer in the GDT */
@@ -1674,7 +1666,6 @@ void cpu_init(void)
 
        fpu__init_cpu();
 
-       setup_fixmap_gdt(cpu);
        load_fixmap_gdt(cpu);
 }
 #endif