x86: cpu/common*.c, make 32-bit have 64-bit only functions

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 150 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 9128ba0c8d33..dcd3ebd5ba62 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -750,6 +750,143 @@ __setup("clearcpuid=", setup_disablecpuid);
 
 cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;
 
+#ifdef CONFIG_X86_64
+struct x8664_pda **_cpu_pda __read_mostly;
+EXPORT_SYMBOL(_cpu_pda);
+
+struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };
+
+char boot_cpu_stack[IRQSTACKSIZE] __page_aligned_bss;
+
+unsigned long __supported_pte_mask __read_mostly = ~0UL;
+EXPORT_SYMBOL_GPL(__supported_pte_mask);
+
+static int do_not_nx __cpuinitdata;
+
+/* noexec=on|off
+Control non executable mappings for 64bit processes.
+
+on      Enable(default)
+off     Disable
+*/
+static int __init nonx_setup(char *str)
+{
+        if (!str)
+                return -EINVAL;
+        if (!strncmp(str, "on", 2)) {
+                __supported_pte_mask |= _PAGE_NX;
+                do_not_nx = 0;
+        } else if (!strncmp(str, "off", 3)) {
+                do_not_nx = 1;
+                __supported_pte_mask &= ~_PAGE_NX;
+        }
+        return 0;
+}
+early_param("noexec", nonx_setup);
+
+int force_personality32;
+
+/* noexec32=on|off
+Control non executable heap for 32bit processes.
+To control the stack too use noexec=off
+
+on      PROT_READ does not imply PROT_EXEC for 32bit processes (default)
+off     PROT_READ implies PROT_EXEC
+*/
+static int __init nonx32_setup(char *str)
+{
+        if (!strcmp(str, "on"))
+                force_personality32 &= ~READ_IMPLIES_EXEC;
+        else if (!strcmp(str, "off"))
+                force_personality32 |= READ_IMPLIES_EXEC;
+        return 1;
+}
+__setup("noexec32=", nonx32_setup);
+
+void pda_init(int cpu)
+{
+        struct x8664_pda *pda = cpu_pda(cpu);
+
+        /* Setup up data that may be needed in __get_free_pages early */
+        loadsegment(fs, 0);
+        loadsegment(gs, 0);
+        /* Memory clobbers used to order PDA accessed */
+        mb();
+        wrmsrl(MSR_GS_BASE, pda);
+        mb();
+
+        pda->cpunumber = cpu;
+        pda->irqcount = -1;
+        pda->kernelstack = (unsigned long)stack_thread_info() -
+                                 PDA_STACKOFFSET + THREAD_SIZE;
+        pda->active_mm = &init_mm;
+        pda->mmu_state = 0;
+
+        if (cpu == 0) {
+                /* others are initialized in smpboot.c */
+                pda->pcurrent = &init_task;
+                pda->irqstackptr = boot_cpu_stack;
+                pda->irqstackptr += IRQSTACKSIZE - 64;
+        } else {
+                if (!pda->irqstackptr) {
+                        pda->irqstackptr = (char *)
+                                __get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
+                        if (!pda->irqstackptr)
+                                panic("cannot allocate irqstack for cpu %d",
+                                      cpu);
+                        pda->irqstackptr += IRQSTACKSIZE - 64;
+                }
+
+                if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE)
+                        pda->nodenumber = cpu_to_node(cpu);
+        }
+}
+
+char boot_exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ +
+                           DEBUG_STKSZ] __page_aligned_bss;
+
+extern asmlinkage void ignore_sysret(void);
+
+/* May not be marked __init: used by software suspend */
+void syscall_init(void)
+{
+        /*
+         * LSTAR and STAR live in a bit strange symbiosis.
+         * They both write to the same internal register. STAR allows to
+         * set CS/DS but only a 32bit target. LSTAR sets the 64bit rip.
+         */
+        wrmsrl(MSR_STAR,  ((u64)__USER32_CS)<<48  | ((u64)__KERNEL_CS)<<32);
+        wrmsrl(MSR_LSTAR, system_call);
+        wrmsrl(MSR_CSTAR, ignore_sysret);
+
+#ifdef CONFIG_IA32_EMULATION
+        syscall32_cpu_init();
+#endif
+
+        /* Flags to clear on syscall */
+        wrmsrl(MSR_SYSCALL_MASK,
+               X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
+}
+
+void __cpuinit check_efer(void)
+{
+        unsigned long efer;
+
+        rdmsrl(MSR_EFER, efer);
+        if (!(efer & EFER_NX) || do_not_nx)
+                __supported_pte_mask &= ~_PAGE_NX;
+}
+
+unsigned long kernel_eflags;
+
+/*
+ * Copies of the original ist values from the tss are only accessed during
+ * debugging, no special alignment required.
+ */
+DEFINE_PER_CPU(struct orig_ist, orig_ist);
+
+#else
+
 /* Make sure %fs is initialized properly in idle threads */
 struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
 {
@@ -757,6 +894,7 @@ struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
         regs->fs = __KERNEL_PERCPU;
         return regs;
 }
+#endif
 
 /*
  * cpu_init() initializes state that is per-CPU. Some data is already
diff --git a/arch/x86/kernel/cpu/common_64.c b/arch/x86/kernel/cpu/common_64.c
index 40c9d89cc14a..9f2a6ece82dd 100644
--- a/arch/x86/kernel/cpu/common_64.c
+++ b/arch/x86/kernel/cpu/common_64.c
@@ -704,6 +704,7 @@ __setup("clearcpuid=", setup_disablecpuid);
 
 cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;
 
+#ifdef CONFIG_X86_64
 struct x8664_pda **_cpu_pda __read_mostly;
 EXPORT_SYMBOL(_cpu_pda);
 
@@ -838,6 +839,17 @@ unsigned long kernel_eflags;
  */
 DEFINE_PER_CPU(struct orig_ist, orig_ist);
 
+#else
+
+/* Make sure %fs is initialized properly in idle threads */
+struct pt_regs * __cpuinit idle_regs(struct pt_regs *regs)
+{
+        memset(regs, 0, sizeof(struct pt_regs));
+        regs->fs = __KERNEL_PERCPU;
+        return regs;
+}
+#endif
+
 /*
  * cpu_init() initializes state that is per-CPU. Some data is already
  * initialized (naturally) in the bootstrap process, such as the GDT