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-rw-r--r--arch/x86/mm/Makefile2
-rw-r--r--arch/x86/mm/fault.c446
-rw-r--r--arch/x86/mm/init_32.c1
-rw-r--r--arch/x86/mm/srat_64.c1
-rw-r--r--arch/x86/mm/tlb.c296
5 files changed, 562 insertions, 184 deletions
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index d8cc96a2738..9f05157220f 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -1,6 +1,8 @@
obj-y := init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
pat.o pgtable.o gup.o
+obj-$(CONFIG_X86_SMP) += tlb.o
+
obj-$(CONFIG_X86_32) += pgtable_32.o iomap_32.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index c76ef1d701c..8c3f3113a6e 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -26,6 +26,7 @@
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/kdebug.h>
+#include <linux/magic.h>
#include <asm/system.h>
#include <asm/desc.h>
@@ -91,8 +92,8 @@ static inline int notify_page_fault(struct pt_regs *regs)
*
* Opcode checker based on code by Richard Brunner
*/
-static int is_prefetch(struct pt_regs *regs, unsigned long addr,
- unsigned long error_code)
+static int is_prefetch(struct pt_regs *regs, unsigned long error_code,
+ unsigned long addr)
{
unsigned char *instr;
int scan_more = 1;
@@ -409,15 +410,15 @@ static void show_fault_oops(struct pt_regs *regs, unsigned long error_code,
}
#ifdef CONFIG_X86_64
-static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
- unsigned long error_code)
+static noinline void pgtable_bad(struct pt_regs *regs,
+ unsigned long error_code, unsigned long address)
{
unsigned long flags = oops_begin();
int sig = SIGKILL;
- struct task_struct *tsk;
+ struct task_struct *tsk = current;
printk(KERN_ALERT "%s: Corrupted page table at address %lx\n",
- current->comm, address);
+ tsk->comm, address);
dump_pagetable(address);
tsk = current;
tsk->thread.cr2 = address;
@@ -429,6 +430,196 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
}
#endif
+static noinline void no_context(struct pt_regs *regs,
+ unsigned long error_code, unsigned long address)
+{
+ struct task_struct *tsk = current;
+ unsigned long *stackend;
+
+#ifdef CONFIG_X86_64
+ unsigned long flags;
+ int sig;
+#endif
+
+ /* Are we prepared to handle this kernel fault? */
+ if (fixup_exception(regs))
+ return;
+
+ /*
+ * X86_32
+ * Valid to do another page fault here, because if this fault
+ * had been triggered by is_prefetch fixup_exception would have
+ * handled it.
+ *
+ * X86_64
+ * Hall of shame of CPU/BIOS bugs.
+ */
+ if (is_prefetch(regs, error_code, address))
+ return;
+
+ if (is_errata93(regs, address))
+ return;
+
+ /*
+ * Oops. The kernel tried to access some bad page. We'll have to
+ * terminate things with extreme prejudice.
+ */
+#ifdef CONFIG_X86_32
+ bust_spinlocks(1);
+#else
+ flags = oops_begin();
+#endif
+
+ show_fault_oops(regs, error_code, address);
+
+ stackend = end_of_stack(tsk);
+ if (*stackend != STACK_END_MAGIC)
+ printk(KERN_ALERT "Thread overran stack, or stack corrupted\n");
+
+ tsk->thread.cr2 = address;
+ tsk->thread.trap_no = 14;
+ tsk->thread.error_code = error_code;
+
+#ifdef CONFIG_X86_32
+ die("Oops", regs, error_code);
+ bust_spinlocks(0);
+ do_exit(SIGKILL);
+#else
+ sig = SIGKILL;
+ if (__die("Oops", regs, error_code))
+ sig = 0;
+ /* Executive summary in case the body of the oops scrolled away */
+ printk(KERN_EMERG "CR2: %016lx\n", address);
+ oops_end(flags, regs, sig);
+#endif
+}
+
+static void __bad_area_nosemaphore(struct pt_regs *regs,
+ unsigned long error_code, unsigned long address,
+ int si_code)
+{
+ struct task_struct *tsk = current;
+
+ /* User mode accesses just cause a SIGSEGV */
+ if (error_code & PF_USER) {
+ /*
+ * It's possible to have interrupts off here.
+ */
+ local_irq_enable();
+
+ /*
+ * Valid to do another page fault here because this one came
+ * from user space.
+ */
+ if (is_prefetch(regs, error_code, address))
+ return;
+
+ if (is_errata100(regs, address))
+ return;
+
+ if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
+ printk_ratelimit()) {
+ printk(
+ "%s%s[%d]: segfault at %lx ip %p sp %p error %lx",
+ task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
+ tsk->comm, task_pid_nr(tsk), address,
+ (void *) regs->ip, (void *) regs->sp, error_code);
+ print_vma_addr(" in ", regs->ip);
+ printk("\n");
+ }
+
+ tsk->thread.cr2 = address;
+ /* Kernel addresses are always protection faults */
+ tsk->thread.error_code = error_code | (address >= TASK_SIZE);
+ tsk->thread.trap_no = 14;
+ force_sig_info_fault(SIGSEGV, si_code, address, tsk);
+ return;
+ }
+
+ if (is_f00f_bug(regs, address))
+ return;
+
+ no_context(regs, error_code, address);
+}
+
+static noinline void bad_area_nosemaphore(struct pt_regs *regs,
+ unsigned long error_code, unsigned long address)
+{
+ __bad_area_nosemaphore(regs, error_code, address, SEGV_MAPERR);
+}
+
+static void __bad_area(struct pt_regs *regs,
+ unsigned long error_code, unsigned long address,
+ int si_code)
+{
+ struct mm_struct *mm = current->mm;
+
+ /*
+ * Something tried to access memory that isn't in our memory map..
+ * Fix it, but check if it's kernel or user first..
+ */
+ up_read(&mm->mmap_sem);
+
+ __bad_area_nosemaphore(regs, error_code, address, si_code);
+}
+
+static noinline void bad_area(struct pt_regs *regs,
+ unsigned long error_code, unsigned long address)
+{
+ __bad_area(regs, error_code, address, SEGV_MAPERR);
+}
+
+static noinline void bad_area_access_error(struct pt_regs *regs,
+ unsigned long error_code, unsigned long address)
+{
+ __bad_area(regs, error_code, address, SEGV_ACCERR);
+}
+
+/* TODO: fixup for "mm-invoke-oom-killer-from-page-fault.patch" */
+static void out_of_memory(struct pt_regs *regs,
+ unsigned long error_code, unsigned long address)
+{
+ /*
+ * We ran out of memory, call the OOM killer, and return the userspace
+ * (which will retry the fault, or kill us if we got oom-killed).
+ */
+ up_read(&current->mm->mmap_sem);
+ pagefault_out_of_memory();
+}
+
+static void do_sigbus(struct pt_regs *regs,
+ unsigned long error_code, unsigned long address)
+{
+ struct task_struct *tsk = current;
+ struct mm_struct *mm = tsk->mm;
+
+ up_read(&mm->mmap_sem);
+
+ /* Kernel mode? Handle exceptions or die */
+ if (!(error_code & PF_USER))
+ no_context(regs, error_code, address);
+#ifdef CONFIG_X86_32
+ /* User space => ok to do another page fault */
+ if (is_prefetch(regs, error_code, address))
+ return;
+#endif
+ tsk->thread.cr2 = address;
+ tsk->thread.error_code = error_code;
+ tsk->thread.trap_no = 14;
+ force_sig_info_fault(SIGBUS, BUS_ADRERR, address, tsk);
+}
+
+static noinline void mm_fault_error(struct pt_regs *regs,
+ unsigned long error_code, unsigned long address, unsigned int fault)
+{
+ if (fault & VM_FAULT_OOM)
+ out_of_memory(regs, error_code, address);
+ else if (fault & VM_FAULT_SIGBUS)
+ do_sigbus(regs, error_code, address);
+ else
+ BUG();
+}
+
static int spurious_fault_check(unsigned long error_code, pte_t *pte)
{
if ((error_code & PF_WRITE) && !pte_write(*pte))
@@ -448,8 +639,8 @@ static int spurious_fault_check(unsigned long error_code, pte_t *pte)
* There are no security implications to leaving a stale TLB when
* increasing the permissions on a page.
*/
-static int spurious_fault(unsigned long address,
- unsigned long error_code)
+static noinline int spurious_fault(unsigned long error_code,
+ unsigned long address)
{
pgd_t *pgd;
pud_t *pud;
@@ -494,7 +685,7 @@ static int spurious_fault(unsigned long address,
*
* This assumes no large pages in there.
*/
-static int vmalloc_fault(unsigned long address)
+static noinline int vmalloc_fault(unsigned long address)
{
#ifdef CONFIG_X86_32
unsigned long pgd_paddr;
@@ -573,6 +764,25 @@ static int vmalloc_fault(unsigned long address)
int show_unhandled_signals = 1;
+static inline int access_error(unsigned long error_code, int write,
+ struct vm_area_struct *vma)
+{
+ if (write) {
+ /* write, present and write, not present */
+ if (unlikely(!(vma->vm_flags & VM_WRITE)))
+ return 1;
+ } else if (unlikely(error_code & PF_PROT)) {
+ /* read, present */
+ return 1;
+ } else {
+ /* read, not present */
+ if (unlikely(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))))
+ return 1;
+ }
+
+ return 0;
+}
+
/*
* This routine handles page faults. It determines the address,
* and the problem, and then passes it off to one of the appropriate
@@ -583,16 +793,12 @@ asmlinkage
#endif
void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
{
+ unsigned long address;
struct task_struct *tsk;
struct mm_struct *mm;
struct vm_area_struct *vma;
- unsigned long address;
- int write, si_code;
+ int write;
int fault;
-#ifdef CONFIG_X86_64
- unsigned long flags;
- int sig;
-#endif
tsk = current;
mm = tsk->mm;
@@ -601,8 +807,6 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
/* get the address */
address = read_cr2();
- si_code = SEGV_MAPERR;
-
if (unlikely(kmmio_fault(regs, address)))
return;
@@ -629,7 +833,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
return;
/* Can handle a stale RO->RW TLB */
- if (spurious_fault(address, error_code))
+ if (spurious_fault(error_code, address))
return;
/* kprobes don't want to hook the spurious faults. */
@@ -639,13 +843,12 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
* Don't take the mm semaphore here. If we fixup a prefetch
* fault we could otherwise deadlock.
*/
- goto bad_area_nosemaphore;
+ bad_area_nosemaphore(regs, error_code, address);
+ return;
}
- /* kprobes don't want to hook the spurious faults. */
- if (notify_page_fault(regs))
+ if (unlikely(notify_page_fault(regs)))
return;
-
/*
* It's safe to allow irq's after cr2 has been saved and the
* vmalloc fault has been handled.
@@ -661,15 +864,17 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
#ifdef CONFIG_X86_64
if (unlikely(error_code & PF_RSVD))
- pgtable_bad(address, regs, error_code);
+ pgtable_bad(regs, error_code, address);
#endif
/*
* If we're in an interrupt, have no user context or are running in an
* atomic region then we must not take the fault.
*/
- if (unlikely(in_atomic() || !mm))
- goto bad_area_nosemaphore;
+ if (unlikely(in_atomic() || !mm)) {
+ bad_area_nosemaphore(regs, error_code, address);
+ return;
+ }
/*
* When running in the kernel we expect faults to occur only to
@@ -687,20 +892,26 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
* source. If this is invalid we can skip the address space check,
* thus avoiding the deadlock.
*/
- if (!down_read_trylock(&mm->mmap_sem)) {
+ if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
if ((error_code & PF_USER) == 0 &&
- !search_exception_tables(regs->ip))
- goto bad_area_nosemaphore;
+ !search_exception_tables(regs->ip)) {
+ bad_area_nosemaphore(regs, error_code, address);
+ return;
+ }
down_read(&mm->mmap_sem);
}
vma = find_vma(mm, address);
- if (!vma)
- goto bad_area;
- if (vma->vm_start <= address)
+ if (unlikely(!vma)) {
+ bad_area(regs, error_code, address);
+ return;
+ }
+ if (likely(vma->vm_start <= address))
goto good_area;
- if (!(vma->vm_flags & VM_GROWSDOWN))
- goto bad_area;
+ if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) {
+ bad_area(regs, error_code, address);
+ return;
+ }
if (error_code & PF_USER) {
/*
* Accessing the stack below %sp is always a bug.
@@ -708,31 +919,25 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
* and pusha to work. ("enter $65535,$31" pushes
* 32 pointers and then decrements %sp by 65535.)
*/
- if (address + 65536 + 32 * sizeof(unsigned long) < regs->sp)
- goto bad_area;
+ if (unlikely(address + 65536 + 32 * sizeof(unsigned long) < regs->sp)) {
+ bad_area(regs, error_code, address);
+ return;
+ }
}
- if (expand_stack(vma, address))
- goto bad_area;
-/*
- * Ok, we have a good vm_area for this memory access, so
- * we can handle it..
- */
+ if (unlikely(expand_stack(vma, address))) {
+ bad_area(regs, error_code, address);
+ return;
+ }
+
+ /*
+ * Ok, we have a good vm_area for this memory access, so
+ * we can handle it..
+ */
good_area:
- si_code = SEGV_ACCERR;
- write = 0;
- switch (error_code & (PF_PROT|PF_WRITE)) {
- default: /* 3: write, present */
- /* fall through */
- case PF_WRITE: /* write, not present */
- if (!(vma->vm_flags & VM_WRITE))
- goto bad_area;
- write++;
- break;
- case PF_PROT: /* read, present */
- goto bad_area;
- case 0: /* read, not present */
- if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
- goto bad_area;
+ write = error_code & PF_WRITE;
+ if (unlikely(access_error(error_code, write, vma))) {
+ bad_area_access_error(regs, error_code, address);
+ return;
}
/*
@@ -742,11 +947,8 @@ good_area:
*/
fault = handle_mm_fault(mm, vma, address, write);
if (unlikely(fault & VM_FAULT_ERROR)) {
- if (fault & VM_FAULT_OOM)
- goto out_of_memory;
- else if (fault & VM_FAULT_SIGBUS)
- goto do_sigbus;
- BUG();
+ mm_fault_error(regs, error_code, address, fault);
+ return;
}
if (fault & VM_FAULT_MAJOR)
tsk->maj_flt++;
@@ -764,128 +966,6 @@ good_area:
}
#endif
up_read(&mm->mmap_sem);
- return;
-
-/*
- * Something tried to access memory that isn't in our memory map..
- * Fix it, but check if it's kernel or user first..
- */
-bad_area:
- up_read(&mm->mmap_sem);
-
-bad_area_nosemaphore:
- /* User mode accesses just cause a SIGSEGV */
- if (error_code & PF_USER) {
- /*
- * It's possible to have interrupts off here.
- */
- local_irq_enable();
-
- /*
- * Valid to do another page fault here because this one came
- * from user space.
- */
- if (is_prefetch(regs, address, error_code))
- return;
-
- if (is_errata100(regs, address))
- return;
-
- if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
- printk_ratelimit()) {
- printk(
- "%s%s[%d]: segfault at %lx ip %p sp %p error %lx",
- task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
- tsk->comm, task_pid_nr(tsk), address,
- (void *) regs->ip, (void *) regs->sp, error_code);
- print_vma_addr(" in ", regs->ip);
- printk("\n");
- }
-
- tsk->thread.cr2 = address;
- /* Kernel addresses are always protection faults */
- tsk->thread.error_code = error_code | (address >= TASK_SIZE);
- tsk->thread.trap_no = 14;
- force_sig_info_fault(SIGSEGV, si_code, address, tsk);
- return;
- }
-
- if (is_f00f_bug(regs, address))
- return;
-
-no_context:
- /* Are we prepared to handle this kernel fault? */
- if (fixup_exception(regs))
- return;
-
- /*
- * X86_32
- * Valid to do another page fault here, because if this fault
- * had been triggered by is_prefetch fixup_exception would have
- * handled it.
- *
- * X86_64
- * Hall of shame of CPU/BIOS bugs.
- */
- if (is_prefetch(regs, address, error_code))
- return;
-
- if (is_errata93(regs, address))
- return;
-
-/*
- * Oops. The kernel tried to access some bad page. We'll have to
- * terminate things with extreme prejudice.
- */
-#ifdef CONFIG_X86_32
- bust_spinlocks(1);
-#else
- flags = oops_begin();
-#endif
-
- show_fault_oops(regs, error_code, address);
-
- tsk->thread.cr2 = address;
- tsk->thread.trap_no = 14;
- tsk->thread.error_code = error_code;
-
-#ifdef CONFIG_X86_32
- die("Oops", regs, error_code);
- bust_spinlocks(0);
- do_exit(SIGKILL);
-#else
- sig = SIGKILL;
- if (__die("Oops", regs, error_code))
- sig = 0;
- /* Executive summary in case the body of the oops scrolled away */
- printk(KERN_EMERG "CR2: %016lx\n", address);
- oops_end(flags, regs, sig);
-#endif
-
-out_of_memory:
- /*
- * We ran out of memory, call the OOM killer, and return the userspace
- * (which will retry the fault, or kill us if we got oom-killed).
- */
- up_read(&mm->mmap_sem);
- pagefault_out_of_memory();
- return;
-
-do_sigbus:
- up_read(&mm->mmap_sem);
-
- /* Kernel mode? Handle exceptions or die */
- if (!(error_code & PF_USER))
- goto no_context;
-#ifdef CONFIG_X86_32
- /* User space => ok to do another page fault */
- if (is_prefetch(regs, address, error_code))
- return;
-#endif
- tsk->thread.cr2 = address;
- tsk->thread.error_code = error_code;
- tsk->thread.trap_no = 14;
- force_sig_info_fault(SIGBUS, BUS_ADRERR, address, tsk);
}
DEFINE_SPINLOCK(pgd_lock);
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 2cef0507441..00263bf07a8 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -49,7 +49,6 @@
#include <asm/paravirt.h>
#include <asm/setup.h>
#include <asm/cacheflush.h>
-#include <asm/smp.h>
unsigned int __VMALLOC_RESERVE = 128 << 20;
diff --git a/arch/x86/mm/srat_64.c b/arch/x86/mm/srat_64.c
index 09737c8af07..15df1baee10 100644
--- a/arch/x86/mm/srat_64.c
+++ b/arch/x86/mm/srat_64.c
@@ -21,6 +21,7 @@
#include <asm/numa.h>
#include <asm/e820.h>
#include <asm/genapic.h>
+#include <asm/uv/uv.h>
int acpi_numa __initdata;
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
new file mode 100644
index 00000000000..72a6d4ebe34
--- /dev/null
+++ b/arch/x86/mm/tlb.c
@@ -0,0 +1,296 @@
+#include <linux/init.h>
+
+#include <linux/mm.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+#include <asm/apic.h>
+#include <asm/uv/uv.h>
+
+DEFINE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate)
+ = { &init_mm, 0, };
+
+#include <mach_ipi.h>
+/*
+ * Smarter SMP flushing macros.
+ * c/o Linus Torvalds.
+ *
+ * These mean you can really definitely utterly forget about
+ * writing to user space from interrupts. (Its not allowed anyway).
+ *
+ * Optimizations Manfred Spraul <manfred@colorfullife.com>
+ *
+ * More scalable flush, from Andi Kleen
+ *
+ * To avoid global state use 8 different call vectors.
+ * Each CPU uses a specific vector to trigger flushes on other
+ * CPUs. Depending on the received vector the target CPUs look into
+ * the right array slot for the flush data.
+ *
+ * With more than 8 CPUs they are hashed to the 8 available
+ * vectors. The limited global vector space forces us to this right now.
+ * In future when interrupts are split into per CPU domains this could be
+ * fixed, at the cost of triggering multiple IPIs in some cases.
+ */
+
+union smp_flush_state {
+ struct {
+ struct mm_struct *flush_mm;
+ unsigned long flush_va;
+ spinlock_t tlbstate_lock;
+ DECLARE_BITMAP(flush_cpumask, NR_CPUS);
+ };
+ char pad[CONFIG_X86_INTERNODE_CACHE_BYTES];
+} ____cacheline_internodealigned_in_smp;
+
+/* State is put into the per CPU data section, but padded
+ to a full cache line because other CPUs can access it and we don't
+ want false sharing in the per cpu data segment. */
+static union smp_flush_state flush_state[NUM_INVALIDATE_TLB_VECTORS];
+
+/*
+ * We cannot call mmdrop() because we are in interrupt context,
+ * instead update mm->cpu_vm_mask.
+ */
+void leave_mm(int cpu)
+{
+ if (percpu_read(cpu_tlbstate.state) == TLBSTATE_OK)
+ BUG();
+ cpu_clear(cpu, percpu_read(cpu_tlbstate.active_mm)->cpu_vm_mask);
+ load_cr3(swapper_pg_dir);
+}
+EXPORT_SYMBOL_GPL(leave_mm);
+
+/*
+ *
+ * The flush IPI assumes that a thread switch happens in this order:
+ * [cpu0: the cpu that switches]
+ * 1) switch_mm() either 1a) or 1b)
+ * 1a) thread switch to a different mm
+ * 1a1) cpu_clear(cpu, old_mm->cpu_vm_mask);
+ * Stop ipi delivery for the old mm. This is not synchronized with
+ * the other cpus, but smp_invalidate_interrupt ignore flush ipis
+ * for the wrong mm, and in the worst case we perform a superfluous
+ * tlb flush.
+ * 1a2) set cpu mmu_state to TLBSTATE_OK
+ * Now the smp_invalidate_interrupt won't call leave_mm if cpu0
+ * was in lazy tlb mode.
+ * 1a3) update cpu active_mm
+ * Now cpu0 accepts tlb flushes for the new mm.
+ * 1a4) cpu_set(cpu, new_mm->cpu_vm_mask);
+ * Now the other cpus will send tlb flush ipis.
+ * 1a4) change cr3.
+ * 1b) thread switch without mm change
+ * cpu active_mm is correct, cpu0 already handles
+ * flush ipis.
+ * 1b1) set cpu mmu_state to TLBSTATE_OK
+ * 1b2) test_and_set the cpu bit in cpu_vm_mask.
+ * Atomically set the bit [other cpus will start sending flush ipis],
+ * and test the bit.
+ * 1b3) if the bit was 0: leave_mm was called, flush the tlb.
+ * 2) switch %%esp, ie current
+ *
+ * The interrupt must handle 2 special cases:
+ * - cr3 is changed before %%esp, ie. it cannot use current->{active_,}mm.
+ * - the cpu performs speculative tlb reads, i.e. even if the cpu only
+ * runs in kernel space, the cpu could load tlb entries for user space
+ * pages.
+ *
+ * The good news is that cpu mmu_state is local to each cpu, no
+ * write/read ordering problems.
+ */
+
+/*
+ * TLB flush IPI:
+ *
+ * 1) Flush the tlb entries if the cpu uses the mm that's being flushed.
+ * 2) Leave the mm if we are in the lazy tlb mode.
+ *
+ * Interrupts are disabled.
+ */
+
+/*
+ * FIXME: use of asmlinkage is not consistent. On x86_64 it's noop
+ * but still used for documentation purpose but the usage is slightly
+ * inconsistent. On x86_32, asmlinkage is regparm(0) but interrupt
+ * entry calls in with the first parameter in %eax. Maybe define
+ * intrlinkage?
+ */
+#ifdef CONFIG_X86_64
+asmlinkage
+#endif
+void smp_invalidate_interrupt(struct pt_regs *regs)
+{
+ unsigned int cpu;
+ unsigned int sender;
+ union smp_flush_state *f;
+
+ cpu = smp_processor_id();
+ /*
+ * orig_rax contains the negated interrupt vector.
+ * Use that to determine where the sender put the data.
+ */
+ sender = ~regs->orig_ax - INVALIDATE_TLB_VECTOR_START;
+ f = &flush_state[sender];
+
+ if (!cpumask_test_cpu(cpu, to_cpumask(f->flush_cpumask)))
+ goto out;
+ /*
+ * This was a BUG() but until someone can quote me the
+ * line from the intel manual that guarantees an IPI to
+ * multiple CPUs is retried _only_ on the erroring CPUs
+ * its staying as a return
+ *
+ * BUG();
+ */
+
+ if (f->flush_mm == percpu_read(cpu_tlbstate.active_mm)) {
+ if (percpu_read(cpu_tlbstate.state) == TLBSTATE_OK) {
+ if (f->flush_va == TLB_FLUSH_ALL)
+ local_flush_tlb();
+ else
+ __flush_tlb_one(f->flush_va);
+ } else
+ leave_mm(cpu);
+ }
+out:
+ ack_APIC_irq();
+ smp_mb__before_clear_bit();
+ cpumask_clear_cpu(cpu, to_cpumask(f->flush_cpumask));
+ smp_mb__after_clear_bit();
+ inc_irq_stat(irq_tlb_count);
+}
+
+static void flush_tlb_others_ipi(const struct cpumask *cpumask,
+ struct mm_struct *mm, unsigned long va)
+{
+ unsigned int sender;
+ union smp_flush_state *f;
+
+ /* Caller has disabled preemption */
+ sender = smp_processor_id() % NUM_INVALIDATE_TLB_VECTORS;
+ f = &flush_state[sender];
+
+ /*
+ * Could avoid this lock when
+ * num_online_cpus() <= NUM_INVALIDATE_TLB_VECTORS, but it is
+ * probably not worth checking this for a cache-hot lock.
+ */
+ spin_lock(&f->tlbstate_lock);
+
+ f->flush_mm = mm;
+ f->flush_va = va;
+ cpumask_andnot(to_cpumask(f->flush_cpumask),
+ cpumask, cpumask_of(smp_processor_id()));
+
+ /*
+ * Make the above memory operations globally visible before
+ * sending the IPI.
+ */
+ smp_mb();
+ /*
+ * We have to send the IPI only to
+ * CPUs affected.
+ */
+ send_IPI_mask(to_cpumask(f->flush_cpumask),
+ INVALIDATE_TLB_VECTOR_START + sender);
+
+ while (!cpumask_empty(to_cpumask(f->flush_cpumask)))
+ cpu_relax();
+
+ f->flush_mm = NULL;
+ f->flush_va = 0;
+ spin_unlock(&f->tlbstate_lock);
+}
+
+void native_flush_tlb_others(const struct cpumask *cpumask,
+ struct mm_struct *mm, unsigned long va)
+{
+ if (is_uv_system()) {
+ unsigned int cpu;
+
+ cpu = get_cpu();
+ cpumask = uv_flush_tlb_others(cpumask, mm, va, cpu);
+ if (cpumask)
+ flush_tlb_others_ipi(cpumask, mm, va);
+ put_cpu();
+ return;
+ }
+ flush_tlb_others_ipi(cpumask, mm, va);
+}
+
+static int __cpuinit init_smp_flush(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(flush_state); i++)
+ spin_lock_init(&flush_state[i].tlbstate_lock);
+
+ return 0;
+}
+core_initcall(init_smp_flush);
+
+void flush_tlb_current_task(void)
+{
+ struct mm_struct *mm = current->mm;
+
+ preempt_disable();
+
+ local_flush_tlb();
+ if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids)
+ flush_tlb_others(&mm->cpu_vm_mask, mm, TLB_FLUSH_ALL);
+ preempt_enable();
+}
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+ preempt_disable();
+
+ if (current->active_mm == mm) {
+ if (current->mm)
+ local_flush_tlb();
+ else
+ leave_mm(smp_processor_id());
+ }
+ if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids)
+ flush_tlb_others(&mm->cpu_vm_mask, mm, TLB_FLUSH_ALL);
+
+ preempt_enable();
+}
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long va)
+{
+ struct mm_struct *mm = vma->vm_mm;
+
+ preempt_disable();
+
+ if (current->active_mm == mm) {
+ if (current->mm)
+ __flush_tlb_one(va);
+ else
+ leave_mm(smp_processor_id());
+ }
+
+ if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids)
+ flush_tlb_others(&mm->cpu_vm_mask, mm, va);
+
+ preempt_enable();
+}
+
+static void do_flush_tlb_all(void *info)
+{
+ unsigned long cpu = smp_processor_id();
+
+ __flush_tlb_all();
+ if (percpu_read(cpu_tlbstate.state) == TLBSTATE_LAZY)
+ leave_mm(cpu);
+}
+
+void flush_tlb_all(void)
+{
+ on_each_cpu(do_flush_tlb_all, NULL, 1);
+}