diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-21 15:38:43 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-21 15:38:43 -0700 |
commit | 5f033bb9bc5cb3bb37a79e3ef131f50ecdcb72b0 (patch) | |
tree | 16c6fdc3fab80d88ea4d8fd7eb302097f97c062c /arch/x86/kernel/process_64.c | |
parent | fd9be4ce2e1eb407a8152f823698cc0d652bbec8 (diff) | |
parent | 34d0559178393547505ec9492321255405f4e441 (diff) |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86: (77 commits)
x86: UV startup of slave cpus
x86: integrate pci-dma.c
x86: don't do dma if mask is NULL.
x86: return conditional to mmu
x86: remove kludge from x86_64
x86: unify gfp masks
x86: retry allocation if failed
x86: don't try to allocate from DMA zone at first
x86: use a fallback dev for i386
x86: use numa allocation function in i386
x86: remove virt_to_bus in pci-dma_64.c
x86: adjust dma_free_coherent for i386
x86: move bad_dma_address
x86: isolate coherent mapping functions
x86: move dma_coherent functions to pci-dma.c
x86: merge iommu initialization parameters
x86: merge dma_supported
x86: move pci fixup to pci-dma.c
x86: move x86_64-specific to common code.
x86: move initialization functions to pci-dma.c
...
Diffstat (limited to 'arch/x86/kernel/process_64.c')
-rw-r--r-- | arch/x86/kernel/process_64.c | 74 |
1 files changed, 73 insertions, 1 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index e75ccc8a2b87..891af1a1b48a 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -36,6 +36,7 @@ #include <linux/kprobes.h> #include <linux/kdebug.h> #include <linux/tick.h> +#include <linux/prctl.h> #include <asm/uaccess.h> #include <asm/pgtable.h> @@ -532,9 +533,71 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp) regs->ss = __USER_DS; regs->flags = 0x200; set_fs(USER_DS); + /* + * Free the old FP and other extended state + */ + free_thread_xstate(current); } EXPORT_SYMBOL_GPL(start_thread); +static void hard_disable_TSC(void) +{ + write_cr4(read_cr4() | X86_CR4_TSD); +} + +void disable_TSC(void) +{ + preempt_disable(); + if (!test_and_set_thread_flag(TIF_NOTSC)) + /* + * Must flip the CPU state synchronously with + * TIF_NOTSC in the current running context. + */ + hard_disable_TSC(); + preempt_enable(); +} + +static void hard_enable_TSC(void) +{ + write_cr4(read_cr4() & ~X86_CR4_TSD); +} + +void enable_TSC(void) +{ + preempt_disable(); + if (test_and_clear_thread_flag(TIF_NOTSC)) + /* + * Must flip the CPU state synchronously with + * TIF_NOTSC in the current running context. + */ + hard_enable_TSC(); + preempt_enable(); +} + +int get_tsc_mode(unsigned long adr) +{ + unsigned int val; + + if (test_thread_flag(TIF_NOTSC)) + val = PR_TSC_SIGSEGV; + else + val = PR_TSC_ENABLE; + + return put_user(val, (unsigned int __user *)adr); +} + +int set_tsc_mode(unsigned int val) +{ + if (val == PR_TSC_SIGSEGV) + disable_TSC(); + else if (val == PR_TSC_ENABLE) + enable_TSC(); + else + return -EINVAL; + + return 0; +} + /* * This special macro can be used to load a debugging register */ @@ -572,6 +635,15 @@ static inline void __switch_to_xtra(struct task_struct *prev_p, loaddebug(next, 7); } + if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^ + test_tsk_thread_flag(next_p, TIF_NOTSC)) { + /* prev and next are different */ + if (test_tsk_thread_flag(next_p, TIF_NOTSC)) + hard_disable_TSC(); + else + hard_enable_TSC(); + } + if (test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) { /* * Copy the relevant range of the IO bitmap. @@ -614,7 +686,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) /* we're going to use this soon, after a few expensive things */ if (next_p->fpu_counter>5) - prefetch(&next->i387.fxsave); + prefetch(next->xstate); /* * Reload esp0, LDT and the page table pointer: |