x86, um: ... and asm-x86 move

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 178 insertions, 0 deletions

diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
new file mode 100644
index 000000000000..3cdd08b5bdb7
--- /dev/null
+++ b/arch/x86/include/asm/tlbflush.h
@@ -0,0 +1,178 @@
+#ifndef ASM_X86__TLBFLUSH_H
+#define ASM_X86__TLBFLUSH_H
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+
+#include <asm/processor.h>
+#include <asm/system.h>
+
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
+#define __flush_tlb() __native_flush_tlb()
+#define __flush_tlb_global() __native_flush_tlb_global()
+#define __flush_tlb_single(addr) __native_flush_tlb_single(addr)
+#endif
+
+static inline void __native_flush_tlb(void)
+{
+	write_cr3(read_cr3());
+}
+
+static inline void __native_flush_tlb_global(void)
+{
+	unsigned long flags;
+	unsigned long cr4;
+
+	/*
+	 * Read-modify-write to CR4 - protect it from preemption and
+	 * from interrupts. (Use the raw variant because this code can
+	 * be called from deep inside debugging code.)
+	 */
+	raw_local_irq_save(flags);
+
+	cr4 = read_cr4();
+	/* clear PGE */
+	write_cr4(cr4 & ~X86_CR4_PGE);
+	/* write old PGE again and flush TLBs */
+	write_cr4(cr4);
+
+	raw_local_irq_restore(flags);
+}
+
+static inline void __native_flush_tlb_single(unsigned long addr)
+{
+	asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
+}
+
+static inline void __flush_tlb_all(void)
+{
+	if (cpu_has_pge)
+		__flush_tlb_global();
+	else
+		__flush_tlb();
+}
+
+static inline void __flush_tlb_one(unsigned long addr)
+{
+	if (cpu_has_invlpg)
+		__flush_tlb_single(addr);
+	else
+		__flush_tlb();
+}
+
+#ifdef CONFIG_X86_32
+# define TLB_FLUSH_ALL	0xffffffff
+#else
+# define TLB_FLUSH_ALL	-1ULL
+#endif
+
+/*
+ * TLB flushing:
+ *
+ *  - flush_tlb() flushes the current mm struct TLBs
+ *  - flush_tlb_all() flushes all processes TLBs
+ *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
+ *  - flush_tlb_page(vma, vmaddr) flushes one page
+ *  - flush_tlb_range(vma, start, end) flushes a range of pages
+ *  - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
+ *  - flush_tlb_others(cpumask, mm, va) flushes TLBs on other cpus
+ *
+ * ..but the i386 has somewhat limited tlb flushing capabilities,
+ * and page-granular flushes are available only on i486 and up.
+ *
+ * x86-64 can only flush individual pages or full VMs. For a range flush
+ * we always do the full VM. Might be worth trying if for a small
+ * range a few INVLPGs in a row are a win.
+ */
+
+#ifndef CONFIG_SMP
+
+#define flush_tlb() __flush_tlb()
+#define flush_tlb_all() __flush_tlb_all()
+#define local_flush_tlb() __flush_tlb()
+
+static inline void flush_tlb_mm(struct mm_struct *mm)
+{
+	if (mm == current->active_mm)
+		__flush_tlb();
+}
+
+static inline void flush_tlb_page(struct vm_area_struct *vma,
+				  unsigned long addr)
+{
+	if (vma->vm_mm == current->active_mm)
+		__flush_tlb_one(addr);
+}
+
+static inline void flush_tlb_range(struct vm_area_struct *vma,
+				   unsigned long start, unsigned long end)
+{
+	if (vma->vm_mm == current->active_mm)
+		__flush_tlb();
+}
+
+static inline void native_flush_tlb_others(const cpumask_t *cpumask,
+					   struct mm_struct *mm,
+					   unsigned long va)
+{
+}
+
+static inline void reset_lazy_tlbstate(void)
+{
+}
+
+#else  /* SMP */
+
+#include <asm/smp.h>
+
+#define local_flush_tlb() __flush_tlb()
+
+extern void flush_tlb_all(void);
+extern void flush_tlb_current_task(void);
+extern void flush_tlb_mm(struct mm_struct *);
+extern void flush_tlb_page(struct vm_area_struct *, unsigned long);
+
+#define flush_tlb()	flush_tlb_current_task()
+
+static inline void flush_tlb_range(struct vm_area_struct *vma,
+				   unsigned long start, unsigned long end)
+{
+	flush_tlb_mm(vma->vm_mm);
+}
+
+void native_flush_tlb_others(const cpumask_t *cpumask, struct mm_struct *mm,
+			     unsigned long va);
+
+#define TLBSTATE_OK	1
+#define TLBSTATE_LAZY	2
+
+#ifdef CONFIG_X86_32
+struct tlb_state {
+	struct mm_struct *active_mm;
+	int state;
+	char __cacheline_padding[L1_CACHE_BYTES-8];
+};
+DECLARE_PER_CPU(struct tlb_state, cpu_tlbstate);
+
+void reset_lazy_tlbstate(void);
+#else
+static inline void reset_lazy_tlbstate(void)
+{
+}
+#endif
+
+#endif	/* SMP */
+
+#ifndef CONFIG_PARAVIRT
+#define flush_tlb_others(mask, mm, va)	native_flush_tlb_others(&mask, mm, va)
+#endif
+
+static inline void flush_tlb_kernel_range(unsigned long start,
+					  unsigned long end)
+{
+	flush_tlb_all();
+}
+
+#endif /* ASM_X86__TLBFLUSH_H */