lkml.org 
[lkml]   [2016]   [Oct]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 8/8] x86/fpu: Remove clts()
    Date
    The kernel doesn't use clts() any more.  Remove it and all of its
    paravirt infrastructure.

    A careful reader may notice that xen_clts() appears to have been
    buggy -- it didn't update xen_cr0_value.

    Signed-off-by: Andy Lutomirski <luto@kernel.org>
    ---
    arch/x86/include/asm/paravirt.h | 5 -----
    arch/x86/include/asm/paravirt_types.h | 2 --
    arch/x86/include/asm/special_insns.h | 11 -----------
    arch/x86/kernel/paravirt.c | 1 -
    arch/x86/kernel/paravirt_patch_32.c | 2 --
    arch/x86/kernel/paravirt_patch_64.c | 2 --
    arch/x86/lguest/boot.c | 12 ------------
    arch/x86/xen/enlighten.c | 13 -------------
    8 files changed, 48 deletions(-)

    diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
    index ce932812f142..f1fb4dbe9a3e 100644
    --- a/arch/x86/include/asm/paravirt.h
    +++ b/arch/x86/include/asm/paravirt.h
    @@ -41,11 +41,6 @@ static inline void set_debugreg(unsigned long val, int reg)
    PVOP_VCALL2(pv_cpu_ops.set_debugreg, reg, val);
    }

    -static inline void clts(void)
    -{
    - PVOP_VCALL0(pv_cpu_ops.clts);
    -}
    -
    static inline unsigned long read_cr0(void)
    {
    return PVOP_CALL0(unsigned long, pv_cpu_ops.read_cr0);
    diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
    index 0f400c0e4979..545426aa61ef 100644
    --- a/arch/x86/include/asm/paravirt_types.h
    +++ b/arch/x86/include/asm/paravirt_types.h
    @@ -103,8 +103,6 @@ struct pv_cpu_ops {
    unsigned long (*get_debugreg)(int regno);
    void (*set_debugreg)(int regno, unsigned long value);

    - void (*clts)(void);
    -
    unsigned long (*read_cr0)(void);
    void (*write_cr0)(unsigned long);

    diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
    index 29b417bd8a68..12af3e35edfa 100644
    --- a/arch/x86/include/asm/special_insns.h
    +++ b/arch/x86/include/asm/special_insns.h
    @@ -6,11 +6,6 @@

    #include <asm/nops.h>

    -static inline void native_clts(void)
    -{
    - asm volatile("clts");
    -}
    -
    /*
    * Volatile isn't enough to prevent the compiler from reordering the
    * read/write functions for the control registers and messing everything up.
    @@ -208,12 +203,6 @@ static inline void load_gs_index(unsigned selector)

    #endif

    -/* Clear the 'TS' bit */
    -static inline void clts(void)
    -{
    - native_clts();
    -}
    -
    #endif/* CONFIG_PARAVIRT */

    static inline void clflush(volatile void *__p)
    diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
    index bbf3d5933eaa..a1bfba0f7234 100644
    --- a/arch/x86/kernel/paravirt.c
    +++ b/arch/x86/kernel/paravirt.c
    @@ -328,7 +328,6 @@ __visible struct pv_cpu_ops pv_cpu_ops = {
    .cpuid = native_cpuid,
    .get_debugreg = native_get_debugreg,
    .set_debugreg = native_set_debugreg,
    - .clts = native_clts,
    .read_cr0 = native_read_cr0,
    .write_cr0 = native_write_cr0,
    .read_cr4 = native_read_cr4,
    diff --git a/arch/x86/kernel/paravirt_patch_32.c b/arch/x86/kernel/paravirt_patch_32.c
    index 920c6ae08592..d3f7f14bb328 100644
    --- a/arch/x86/kernel/paravirt_patch_32.c
    +++ b/arch/x86/kernel/paravirt_patch_32.c
    @@ -8,7 +8,6 @@ DEF_NATIVE(pv_cpu_ops, iret, "iret");
    DEF_NATIVE(pv_mmu_ops, read_cr2, "mov %cr2, %eax");
    DEF_NATIVE(pv_mmu_ops, write_cr3, "mov %eax, %cr3");
    DEF_NATIVE(pv_mmu_ops, read_cr3, "mov %cr3, %eax");
    -DEF_NATIVE(pv_cpu_ops, clts, "clts");

    #if defined(CONFIG_PARAVIRT_SPINLOCKS)
    DEF_NATIVE(pv_lock_ops, queued_spin_unlock, "movb $0, (%eax)");
    @@ -48,7 +47,6 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
    PATCH_SITE(pv_mmu_ops, read_cr2);
    PATCH_SITE(pv_mmu_ops, read_cr3);
    PATCH_SITE(pv_mmu_ops, write_cr3);
    - PATCH_SITE(pv_cpu_ops, clts);
    #if defined(CONFIG_PARAVIRT_SPINLOCKS)
    case PARAVIRT_PATCH(pv_lock_ops.queued_spin_unlock):
    if (pv_is_native_spin_unlock()) {
    diff --git a/arch/x86/kernel/paravirt_patch_64.c b/arch/x86/kernel/paravirt_patch_64.c
    index bb3840cedb4f..915a4c0b217c 100644
    --- a/arch/x86/kernel/paravirt_patch_64.c
    +++ b/arch/x86/kernel/paravirt_patch_64.c
    @@ -10,7 +10,6 @@ DEF_NATIVE(pv_mmu_ops, read_cr2, "movq %cr2, %rax");
    DEF_NATIVE(pv_mmu_ops, read_cr3, "movq %cr3, %rax");
    DEF_NATIVE(pv_mmu_ops, write_cr3, "movq %rdi, %cr3");
    DEF_NATIVE(pv_mmu_ops, flush_tlb_single, "invlpg (%rdi)");
    -DEF_NATIVE(pv_cpu_ops, clts, "clts");
    DEF_NATIVE(pv_cpu_ops, wbinvd, "wbinvd");

    DEF_NATIVE(pv_cpu_ops, usergs_sysret64, "swapgs; sysretq");
    @@ -58,7 +57,6 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
    PATCH_SITE(pv_mmu_ops, read_cr2);
    PATCH_SITE(pv_mmu_ops, read_cr3);
    PATCH_SITE(pv_mmu_ops, write_cr3);
    - PATCH_SITE(pv_cpu_ops, clts);
    PATCH_SITE(pv_mmu_ops, flush_tlb_single);
    PATCH_SITE(pv_cpu_ops, wbinvd);
    #if defined(CONFIG_PARAVIRT_SPINLOCKS)
    diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
    index d74afcdbc580..4ca0d78adcf0 100644
    --- a/arch/x86/lguest/boot.c
    +++ b/arch/x86/lguest/boot.c
    @@ -518,17 +518,6 @@ static unsigned long lguest_read_cr0(void)
    }

    /*
    - * Intel provided a special instruction to clear the TS bit for people too cool
    - * to use write_cr0() to do it. This "clts" instruction is faster, because all
    - * the vowels have been optimized out.
    - */
    -static void lguest_clts(void)
    -{
    - lazy_hcall1(LHCALL_TS, 0);
    - current_cr0 &= ~X86_CR0_TS;
    -}
    -
    -/*
    * cr2 is the virtual address of the last page fault, which the Guest only ever
    * reads. The Host kindly writes this into our "struct lguest_data", so we
    * just read it out of there.
    @@ -1429,7 +1418,6 @@ __init void lguest_init(void)
    pv_cpu_ops.load_tls = lguest_load_tls;
    pv_cpu_ops.get_debugreg = lguest_get_debugreg;
    pv_cpu_ops.set_debugreg = lguest_set_debugreg;
    - pv_cpu_ops.clts = lguest_clts;
    pv_cpu_ops.read_cr0 = lguest_read_cr0;
    pv_cpu_ops.write_cr0 = lguest_write_cr0;
    pv_cpu_ops.read_cr4 = lguest_read_cr4;
    diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
    index c0fdd57da7aa..69f22f7e80ed 100644
    --- a/arch/x86/xen/enlighten.c
    +++ b/arch/x86/xen/enlighten.c
    @@ -980,17 +980,6 @@ static void xen_io_delay(void)
    {
    }

    -static void xen_clts(void)
    -{
    - struct multicall_space mcs;
    -
    - mcs = xen_mc_entry(0);
    -
    - MULTI_fpu_taskswitch(mcs.mc, 0);
    -
    - xen_mc_issue(PARAVIRT_LAZY_CPU);
    -}
    -
    static DEFINE_PER_CPU(unsigned long, xen_cr0_value);

    static unsigned long xen_read_cr0(void)
    @@ -1233,8 +1222,6 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = {
    .set_debugreg = xen_set_debugreg,
    .get_debugreg = xen_get_debugreg,

    - .clts = xen_clts,
    -
    .read_cr0 = xen_read_cr0,
    .write_cr0 = xen_write_cr0,

    --
    2.7.4
    \
     
     \ /
      Last update: 2016-10-31 23:21    [W:2.214 / U:0.700 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site