#include <asm/processor.h>
#include <asm/system.h>
+#include <asm/smp.h>
+
+static inline void __invpcid(unsigned long pcid, unsigned long addr,
+ unsigned long type)
+{
+ struct { u64 d[2]; } desc = { { pcid, addr } };
+
+ /*
+ * The memory clobber is because the whole point is to invalidate
+ * stale TLB entries and, especially if we're flushing global
+ * mappings, we don't want the compiler to reorder any subsequent
+ * memory accesses before the TLB flush.
+ *
+ * The hex opcode is invpcid (%ecx), %eax in 32-bit mode and
+ * invpcid (%rcx), %rax in long mode.
+ */
+ asm volatile (".byte 0x66, 0x0f, 0x38, 0x82, 0x01"
+ : : "m" (desc), "a" (type), "c" (&desc) : "memory");
+}
+
+#define INVPCID_TYPE_INDIV_ADDR 0
+#define INVPCID_TYPE_SINGLE_CTXT 1
+#define INVPCID_TYPE_ALL_INCL_GLOBAL 2
+#define INVPCID_TYPE_ALL_NON_GLOBAL 3
+
+/* Flush all mappings for a given pcid and addr, not including globals. */
+static inline void invpcid_flush_one(unsigned long pcid,
+ unsigned long addr)
+{
+ __invpcid(pcid, addr, INVPCID_TYPE_INDIV_ADDR);
+}
+
+/* Flush all mappings for a given PCID, not including globals. */
+static inline void invpcid_flush_single_context(unsigned long pcid)
+{
+ __invpcid(pcid, 0, INVPCID_TYPE_SINGLE_CTXT);
+}
+
+/* Flush all mappings, including globals, for all PCIDs. */
+static inline void invpcid_flush_all(void)
+{
+ __invpcid(0, 0, INVPCID_TYPE_ALL_INCL_GLOBAL);
+}
+
+/* Flush all mappings for all PCIDs except globals. */
+static inline void invpcid_flush_all_nonglobals(void)
+{
+ __invpcid(0, 0, INVPCID_TYPE_ALL_NON_GLOBAL);
+}
#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#define __flush_tlb_single(addr) __native_flush_tlb_single(addr)
#endif
+/*
+ * Declare a couple of kaiser interfaces here for convenience,
+ * to avoid the need for asm/kaiser.h in unexpected places.
+ */
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+extern int kaiser_enabled;
+extern void kaiser_setup_pcid(void);
+extern void kaiser_flush_tlb_on_return_to_user(void);
+#else
+#define kaiser_enabled 0
+static inline void kaiser_setup_pcid(void)
+{
+}
+static inline void kaiser_flush_tlb_on_return_to_user(void)
+{
+}
+#endif
+
static inline void __native_flush_tlb(void)
{
+ /*
+ * If current->mm == NULL then we borrow a mm which may change during a
+ * task switch and therefore we must not be preempted while we write CR3
+ * back:
+ */
+ preempt_disable();
+ if (kaiser_enabled)
+ kaiser_flush_tlb_on_return_to_user();
native_write_cr3(native_read_cr3());
+ preempt_enable();
}
static inline void __native_flush_tlb_global(void)
unsigned long flags;
unsigned long cr4;
+ if (this_cpu_has(X86_FEATURE_INVPCID)) {
+ /*
+ * Using INVPCID is considerably faster than a pair of writes
+ * to CR4 sandwiched inside an IRQ flag save/restore.
+ *
+ * Note, this works with CR4.PCIDE=0 or 1.
+ */
+ invpcid_flush_all();
+ return;
+ }
+
/*
* Read-modify-write to CR4 - protect it from preemption and
* from interrupts. (Use the raw variant because this code can
raw_local_irq_save(flags);
cr4 = native_read_cr4();
- /* clear PGE */
- native_write_cr4(cr4 & ~X86_CR4_PGE);
- /* write old PGE again and flush TLBs */
- native_write_cr4(cr4);
+ if (cr4 & X86_CR4_PGE) {
+ /* clear PGE and flush TLB of all entries */
+ native_write_cr4(cr4 & ~X86_CR4_PGE);
+ /* restore PGE as it was before */
+ native_write_cr4(cr4);
+ } else {
+ /* do it with cr3, letting kaiser flush user PCID */
+ __native_flush_tlb();
+ }
raw_local_irq_restore(flags);
}
static inline void __native_flush_tlb_single(unsigned long addr)
{
- asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
+ /*
+ * SIMICS #GP's if you run INVPCID with type 2/3
+ * and X86_CR4_PCIDE clear. Shame!
+ *
+ * The ASIDs used below are hard-coded. But, we must not
+ * call invpcid(type=1/2) before CR4.PCIDE=1. Just call
+ * invlpg in the case we are called early.
+ */
+
+ if (!this_cpu_has(X86_FEATURE_INVPCID_SINGLE)) {
+ if (kaiser_enabled)
+ kaiser_flush_tlb_on_return_to_user();
+ asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
+ return;
+ }
+ /* Flush the address out of both PCIDs. */
+ /*
+ * An optimization here might be to determine addresses
+ * that are only kernel-mapped and only flush the kernel
+ * ASID. But, userspace flushes are probably much more
+ * important performance-wise.
+ *
+ * Make sure to do only a single invpcid when KAISER is
+ * disabled and we have only a single ASID.
+ */
+ if (kaiser_enabled)
+ invpcid_flush_one(X86_CR3_PCID_ASID_USER, addr);
+ invpcid_flush_one(X86_CR3_PCID_ASID_KERN, addr);
}
static inline void __flush_tlb_all(void)
{
- if (cpu_has_pge)
- __flush_tlb_global();
- else
- __flush_tlb();
+ __flush_tlb_global();
+ /*
+ * Note: if we somehow had PCID but not PGE, then this wouldn't work --
+ * we'd end up flushing kernel translations for the current ASID but
+ * we might fail to flush kernel translations for other cached ASIDs.
+ *
+ * To avoid this issue, we force PCID off if PGE is off.
+ */
}
static inline void __flush_tlb_one(unsigned long addr)
*
* ..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 struct cpumask *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);
percpu_write(cpu_tlbstate.active_mm, &init_mm);
}
-#endif /* SMP */
-
#ifndef CONFIG_PARAVIRT
#define flush_tlb_others(mask, mm, va) native_flush_tlb_others(mask, mm, va)
#endif
git.openpandora.org / pandora-kernel.git / blobdiff