x86/fpu: Rename fpu::fpstate_active to fpu::initialized

The x86 FPU code used to have a complex state machine where both the FPU
registers and the FPU state context could be 'active' (or inactive)
independently of each other - which enabled features like lazy FPU restore.

Much of this complexity is gone in the current code: now we basically can
have FPU-less tasks (kernel threads) that don't use (and save/restore) FPU
state at all, plus full FPU users that save/restore directly with no laziness
whatsoever.

But the fpu::fpstate_active still carries bits of the old complexity - meanwhile
this flag has become a simple flag that shows whether the FPU context saving
area in the thread struct is initialized and used, or not.

Rename it to fpu::initialized to express this simplicity in the name as well.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Link: http://lkml.kernel.org/r/20170923130016.21448-30-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

11 files changed, 35 insertions, 35 deletions

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index e0bb46c02857..0e2a5edbce00 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -231,7 +231,7 @@ static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
                  ksig->ka.sa.sa_restorer)
                 sp = (unsigned long) ksig->ka.sa.sa_restorer;
 
-        if (fpu->fpstate_active) {
+        if (fpu->initialized) {
                 unsigned long fx_aligned, math_size;
 
                 sp = fpu__alloc_mathframe(sp, 1, &fx_aligned, &math_size);
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index 508e4181c4af..b26ae05da18a 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -527,7 +527,7 @@ static inline void fpregs_activate(struct fpu *fpu)
 static inline void
 switch_fpu_prepare(struct fpu *old_fpu, int cpu)
 {
-        if (old_fpu->fpstate_active) {
+        if (old_fpu->initialized) {
                 if (!copy_fpregs_to_fpstate(old_fpu))
                         old_fpu->last_cpu = -1;
                 else
@@ -550,7 +550,7 @@ switch_fpu_prepare(struct fpu *old_fpu, int cpu)
 static inline void switch_fpu_finish(struct fpu *new_fpu, int cpu)
 {
         bool preload = static_cpu_has(X86_FEATURE_FPU) &&
-                       new_fpu->fpstate_active;
+                       new_fpu->initialized;
 
         if (preload) {
                 if (!fpregs_state_valid(new_fpu, cpu))
diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h
index 71db45ca8870..a1520575d86b 100644
--- a/arch/x86/include/asm/fpu/types.h
+++ b/arch/x86/include/asm/fpu/types.h
@@ -293,13 +293,13 @@ struct fpu {
         unsigned int                    last_cpu;
 
         /*
-         * @fpstate_active:
+         * @initialized:
          *
-         * This flag indicates whether this context is active: if the task
+         * This flag indicates whether this context is initialized: if the task
          * is not running then we can restore from this context, if the task
          * is running then we should save into this context.
          */
-        unsigned char                   fpstate_active;
+        unsigned char                   initialized;
 
         /*
          * @state:
diff --git a/arch/x86/include/asm/trace/fpu.h b/arch/x86/include/asm/trace/fpu.h
index da565aae9fd2..39f7a27bef13 100644
--- a/arch/x86/include/asm/trace/fpu.h
+++ b/arch/x86/include/asm/trace/fpu.h
@@ -12,22 +12,22 @@ DECLARE_EVENT_CLASS(x86_fpu,
 
         TP_STRUCT__entry(
                 __field(struct fpu *, fpu)
-                __field(bool, fpstate_active)
+                __field(bool, initialized)
                 __field(u64, xfeatures)
                 __field(u64, xcomp_bv)
                 ),
 
         TP_fast_assign(
                 __entry->fpu            = fpu;
-                __entry->fpstate_active = fpu->fpstate_active;
+                __entry->initialized    = fpu->initialized;
                 if (boot_cpu_has(X86_FEATURE_OSXSAVE)) {
                         __entry->xfeatures = fpu->state.xsave.header.xfeatures;
                         __entry->xcomp_bv  = fpu->state.xsave.header.xcomp_bv;
                 }
         ),
-        TP_printk("x86/fpu: %p fpstate_active: %d xfeatures: %llx xcomp_bv: %llx",
+        TP_printk("x86/fpu: %p initialized: %d xfeatures: %llx xcomp_bv: %llx",
                         __entry->fpu,
-                        __entry->fpstate_active,
+                        __entry->initialized,
                         __entry->xfeatures,
                         __entry->xcomp_bv
         )
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index b2cdeb3b1860..c8d6032f04d0 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -100,7 +100,7 @@ void __kernel_fpu_begin(void)
 
         kernel_fpu_disable();
 
-        if (fpu->fpstate_active) {
+        if (fpu->initialized) {
                 /*
                  * Ignore return value -- we don't care if reg state
                  * is clobbered.
@@ -116,7 +116,7 @@ void __kernel_fpu_end(void)
 {
         struct fpu *fpu = &current->thread.fpu;
 
-        if (fpu->fpstate_active)
+        if (fpu->initialized)
                 copy_kernel_to_fpregs(&fpu->state);
 
         kernel_fpu_enable();
@@ -148,7 +148,7 @@ void fpu__save(struct fpu *fpu)
 
         preempt_disable();
         trace_x86_fpu_before_save(fpu);
-        if (fpu->fpstate_active) {
+        if (fpu->initialized) {
                 if (!copy_fpregs_to_fpstate(fpu)) {
                         copy_kernel_to_fpregs(&fpu->state);
                 }
@@ -191,7 +191,7 @@ int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu)
 {
         dst_fpu->last_cpu = -1;
 
-        if (!src_fpu->fpstate_active || !static_cpu_has(X86_FEATURE_FPU))
+        if (!src_fpu->initialized || !static_cpu_has(X86_FEATURE_FPU))
                 return 0;
 
         WARN_ON_FPU(src_fpu != &current->thread.fpu);
@@ -240,13 +240,13 @@ void fpu__activate_curr(struct fpu *fpu)
 {
         WARN_ON_FPU(fpu != &current->thread.fpu);
 
-        if (!fpu->fpstate_active) {
+        if (!fpu->initialized) {
                 fpstate_init(&fpu->state);
                 trace_x86_fpu_init_state(fpu);
 
                 trace_x86_fpu_activate_state(fpu);
                 /* Safe to do for the current task: */
-                fpu->fpstate_active = 1;
+                fpu->initialized = 1;
         }
 }
 EXPORT_SYMBOL_GPL(fpu__activate_curr);
@@ -271,13 +271,13 @@ void fpu__activate_fpstate_read(struct fpu *fpu)
         if (fpu == &current->thread.fpu) {
                 fpu__save(fpu);
         } else {
-                if (!fpu->fpstate_active) {
+                if (!fpu->initialized) {
                         fpstate_init(&fpu->state);
                         trace_x86_fpu_init_state(fpu);
 
                         trace_x86_fpu_activate_state(fpu);
                         /* Safe to do for current and for stopped child tasks: */
-                        fpu->fpstate_active = 1;
+                        fpu->initialized = 1;
                 }
         }
 }
@@ -303,7 +303,7 @@ void fpu__activate_fpstate_write(struct fpu *fpu)
          */
         WARN_ON_FPU(fpu == &current->thread.fpu);
 
-        if (fpu->fpstate_active) {
+        if (fpu->initialized) {
                 /* Invalidate any lazy state: */
                 __fpu_invalidate_fpregs_state(fpu);
         } else {
@@ -312,7 +312,7 @@ void fpu__activate_fpstate_write(struct fpu *fpu)
 
                 trace_x86_fpu_activate_state(fpu);
                 /* Safe to do for stopped child tasks: */
-                fpu->fpstate_active = 1;
+                fpu->initialized = 1;
         }
 }
 
@@ -354,7 +354,7 @@ void fpu__drop(struct fpu *fpu)
         preempt_disable();
 
         if (fpu == &current->thread.fpu) {
-                if (fpu->fpstate_active) {
+                if (fpu->initialized) {
                         /* Ignore delayed exceptions from user space */
                         asm volatile("1: fwait\n"
                                      "2:\n"
@@ -363,7 +363,7 @@ void fpu__drop(struct fpu *fpu)
                 }
         }
 
-        fpu->fpstate_active = 0;
+        fpu->initialized = 0;
 
         trace_x86_fpu_dropped(fpu);
 
diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index d5d44c452624..7affb7e3d9a5 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -240,7 +240,7 @@ static void __init fpu__init_system_ctx_switch(void)
         WARN_ON_FPU(!on_boot_cpu);
         on_boot_cpu = 0;
 
-        WARN_ON_FPU(current->thread.fpu.fpstate_active);
+        WARN_ON_FPU(current->thread.fpu.initialized);
 }
 
 /*
diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c
index c764f7405322..19e82334e811 100644
--- a/arch/x86/kernel/fpu/regset.c
+++ b/arch/x86/kernel/fpu/regset.c
@@ -16,14 +16,14 @@ int regset_fpregs_active(struct task_struct *target, const struct user_regset *r
 {
         struct fpu *target_fpu = &target->thread.fpu;
 
-        return target_fpu->fpstate_active ? regset->n : 0;
+        return target_fpu->initialized ? regset->n : 0;
 }
 
 int regset_xregset_fpregs_active(struct task_struct *target, const struct user_regset *regset)
 {
         struct fpu *target_fpu = &target->thread.fpu;
 
-        if (boot_cpu_has(X86_FEATURE_FXSR) && target_fpu->fpstate_active)
+        if (boot_cpu_has(X86_FEATURE_FXSR) && target_fpu->initialized)
                 return regset->n;
         else
                 return 0;
@@ -380,7 +380,7 @@ int dump_fpu(struct pt_regs *regs, struct user_i387_struct *ufpu)
         struct fpu *fpu = &tsk->thread.fpu;
         int fpvalid;
 
-        fpvalid = fpu->fpstate_active;
+        fpvalid = fpu->initialized;
         if (fpvalid)
                 fpvalid = !fpregs_get(tsk, NULL,
                                       0, sizeof(struct user_i387_ia32_struct),
diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index da68ea1c3a44..ab2dd24cfea4 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -171,7 +171,7 @@ int copy_fpstate_to_sigframe(void __user *buf, void __user *buf_fx, int size)
                         sizeof(struct user_i387_ia32_struct), NULL,
                         (struct _fpstate_32 __user *) buf) ? -1 : 1;
 
-        if (fpu->fpstate_active || using_compacted_format()) {
+        if (fpu->initialized || using_compacted_format()) {
                 /* Save the live register state to the user directly. */
                 if (copy_fpregs_to_sigframe(buf_fx))
                         return -1;
@@ -315,12 +315,12 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
                 int err = 0;
 
                 /*
-                 * Drop the current fpu which clears fpu->fpstate_active. This ensures
+                 * Drop the current fpu which clears fpu->initialized. This ensures
                  * that any context-switch during the copy of the new state,
                  * avoids the intermediate state from getting restored/saved.
                  * Thus avoiding the new restored state from getting corrupted.
                  * We will be ready to restore/save the state only after
-                 * fpu->fpstate_active is again set.
+                 * fpu->initialized is again set.
                  */
                 fpu__drop(fpu);
 
@@ -342,7 +342,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
                         sanitize_restored_xstate(tsk, &env, xfeatures, fx_only);
                 }
 
-                fpu->fpstate_active = 1;
+                fpu->initialized = 1;
                 preempt_disable();
                 fpu__restore(fpu);
                 preempt_enable();
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index fda1109cc355..703e76d027ee 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -867,7 +867,7 @@ const void *get_xsave_field_ptr(int xsave_state)
 {
         struct fpu *fpu = &current->thread.fpu;
 
-        if (!fpu->fpstate_active)
+        if (!fpu->initialized)
                 return NULL;
         /*
          * fpu__save() takes the CPU's xstate registers
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index e04442345fc0..4e188fda5961 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -263,7 +263,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
                 sp = (unsigned long) ka->sa.sa_restorer;
         }
 
-        if (fpu->fpstate_active) {
+        if (fpu->initialized) {
                 sp = fpu__alloc_mathframe(sp, IS_ENABLED(CONFIG_X86_32),
                                           &buf_fx, &math_size);
                 *fpstate = (void __user *)sp;
@@ -279,7 +279,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
                 return (void __user *)-1L;
 
         /* save i387 and extended state */
-        if (fpu->fpstate_active &&
+        if (fpu->initialized &&
             copy_fpstate_to_sigframe(*fpstate, (void __user *)buf_fx, math_size) < 0)
                 return (void __user *)-1L;
 
@@ -755,7 +755,7 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
                 /*
                  * Ensure the signal handler starts with the new fpu state.
                  */
-                if (fpu->fpstate_active)
+                if (fpu->initialized)
                         fpu__clear(fpu);
         }
         signal_setup_done(failed, ksig, stepping);
diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c
index 4d24269c071f..d7bc0eea20a5 100644
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c
@@ -44,7 +44,7 @@ int __execute_only_pkey(struct mm_struct *mm)
          */
         preempt_disable();
         if (!need_to_set_mm_pkey &&
-            current->thread.fpu.fpstate_active &&
+            current->thread.fpu.initialized &&
             !__pkru_allows_read(read_pkru(), execute_only_pkey)) {
                 preempt_enable();
                 return execute_only_pkey;