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Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-android

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This commit is contained in:
Mark Brown 2014-06-26 10:50:14 +01:00
commit afe6ba0684
12 changed files with 34 additions and 288 deletions
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3
arch/arm64/Kconfig
View File

@ -118,9 +118,6 @@ config IOMMU_HELPER
config FIX_EARLYCON_MEM
def_bool y
config KERNEL_MODE_NEON
def_bool y
source "init/Kconfig"
source "kernel/Kconfig.freezer"

23
arch/arm64/include/asm/fpsimd.h
View File

@ -37,21 +37,8 @@ struct fpsimd_state {
u32 fpcr;
};
};
/* the id of the last cpu to have restored this state */
unsigned int cpu;
};
/*
* Struct for stacking the bottom 'n' FP/SIMD registers.
*/
struct fpsimd_partial_state {
u32 fpsr;
u32 fpcr;
u32 num_regs;
__uint128_t vregs[32];
};
#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
/* Masks for extracting the FPSR and FPCR from the FPSCR */
#define VFP_FPSCR_STAT_MASK 0xf800009f
@ -71,16 +58,6 @@ extern void fpsimd_load_state(struct fpsimd_state *state);
extern void fpsimd_thread_switch(struct task_struct *next);
extern void fpsimd_flush_thread(void);
extern void fpsimd_preserve_current_state(void);
extern void fpsimd_restore_current_state(void);
extern void fpsimd_update_current_state(struct fpsimd_state *state);
extern void fpsimd_flush_task_state(struct task_struct *target);
extern void fpsimd_save_partial_state(struct fpsimd_partial_state *state,
u32 num_regs);
extern void fpsimd_load_partial_state(struct fpsimd_partial_state *state);
#endif
#endif

35
arch/arm64/include/asm/fpsimdmacros.h
View File

@ -62,38 +62,3 @@
ldr w\tmpnr, [\state, #16 * 2 + 4]
msr fpcr, x\tmpnr
.endm
.altmacro
.macro fpsimd_save_partial state, numnr, tmpnr1, tmpnr2
mrs x\tmpnr1, fpsr
str w\numnr, [\state, #8]
mrs x\tmpnr2, fpcr
stp w\tmpnr1, w\tmpnr2, [\state]
adr x\tmpnr1, 0f
add \state, \state, x\numnr, lsl #4
sub x\tmpnr1, x\tmpnr1, x\numnr, lsl #1
br x\tmpnr1
.irp qa, 30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 0
.irp qb, %(qa + 1)
stp q\qa, q\qb, [\state, # -16 * \qa - 16]
.endr
.endr
0:
.endm
.macro fpsimd_restore_partial state, tmpnr1, tmpnr2
ldp w\tmpnr1, w\tmpnr2, [\state]
msr fpsr, x\tmpnr1
msr fpcr, x\tmpnr2
adr x\tmpnr1, 0f
ldr w\tmpnr2, [\state, #8]
add \state, \state, x\tmpnr2, lsl #4
sub x\tmpnr1, x\tmpnr1, x\tmpnr2, lsl #1
br x\tmpnr1
.irp qa, 30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 0
.irp qb, %(qa + 1)
ldp q\qa, q\qb, [\state, # -16 * \qa - 16]
.endr
.endr
0:
.endm

18
arch/arm64/include/asm/neon.h
View File

@ -1,18 +0,0 @@
/*
* linux/arch/arm64/include/asm/neon.h
*
* Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/types.h>
#define cpu_has_neon() (1)
#define kernel_neon_begin() kernel_neon_begin_partial(32)
void kernel_neon_begin_partial(u32 num_regs);
void kernel_neon_end(void);

4
arch/arm64/include/asm/thread_info.h
View File

@ -109,7 +109,6 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_SIGPENDING 0
#define TIF_NEED_RESCHED 1
#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
#define TIF_FOREIGN_FPSTATE 3 /* CPU's FP state is not current's */
#define TIF_SYSCALL_TRACE 8
#define TIF_SYSCALL_AUDIT 9
#define TIF_SYSCALL_TRACEPOINT 10
@ -125,7 +124,6 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_FOREIGN_FPSTATE (1 << TIF_FOREIGN_FPSTATE)
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
@ -133,7 +131,7 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_32BIT (1 << TIF_32BIT)
#define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
_TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE)
_TIF_NOTIFY_RESUME)
#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
_TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP)

24
arch/arm64/kernel/entry-fpsimd.S
View File

@ -41,27 +41,3 @@ ENTRY(fpsimd_load_state)
fpsimd_restore x0, 8
ret
ENDPROC(fpsimd_load_state)
#ifdef CONFIG_KERNEL_MODE_NEON
/*
* Save the bottom n FP registers.
*
* x0 - pointer to struct fpsimd_partial_state
*/
ENTRY(fpsimd_save_partial_state)
fpsimd_save_partial x0, 1, 8, 9
ret
ENDPROC(fpsimd_load_partial_state)
/*
* Load the bottom n FP registers.
*
* x0 - pointer to struct fpsimd_partial_state
*/
ENTRY(fpsimd_load_partial_state)
fpsimd_restore_partial x0, 8, 9
ret
ENDPROC(fpsimd_load_partial_state)
#endif

2
arch/arm64/kernel/entry.S
View File

@ -591,7 +591,7 @@ fast_work_pending:
str x0, [sp, #S_X0] // returned x0
work_pending:
tbnz x1, #TIF_NEED_RESCHED, work_resched
/* TIF_SIGPENDING, TIF_NOTIFY_RESUME or TIF_FOREIGN_FPSTATE case */
/* TIF_SIGPENDING or TIF_NOTIFY_RESUME case */
ldr x2, [sp, #S_PSTATE]
mov x0, sp // 'regs'
tst x2, #PSR_MODE_MASK // user mode regs?

187
arch/arm64/kernel/fpsimd.c
View File

@ -22,7 +22,6 @@
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/hardirq.h>
#include <asm/fpsimd.h>
#include <asm/cputype.h>
@ -34,60 +33,6 @@
#define FPEXC_IXF (1 << 4)
#define FPEXC_IDF (1 << 7)
/*
* In order to reduce the number of times the FPSIMD state is needlessly saved
* and restored, we need to keep track of two things:
* (a) for each task, we need to remember which CPU was the last one to have
* the task's FPSIMD state loaded into its FPSIMD registers;
* (b) for each CPU, we need to remember which task's userland FPSIMD state has
* been loaded into its FPSIMD registers most recently, or whether it has
* been used to perform kernel mode NEON in the meantime.
*
* For (a), we add a 'cpu' field to struct fpsimd_state, which gets updated to
* the id of the current CPU everytime the state is loaded onto a CPU. For (b),
* we add the per-cpu variable 'fpsimd_last_state' (below), which contains the
* address of the userland FPSIMD state of the task that was loaded onto the CPU
* the most recently, or NULL if kernel mode NEON has been performed after that.
*
* With this in place, we no longer have to restore the next FPSIMD state right
* when switching between tasks. Instead, we can defer this check to userland
* resume, at which time we verify whether the CPU's fpsimd_last_state and the
* task's fpsimd_state.cpu are still mutually in sync. If this is the case, we
* can omit the FPSIMD restore.
*
* As an optimization, we use the thread_info flag TIF_FOREIGN_FPSTATE to
* indicate whether or not the userland FPSIMD state of the current task is
* present in the registers. The flag is set unless the FPSIMD registers of this
* CPU currently contain the most recent userland FPSIMD state of the current
* task.
*
* For a certain task, the sequence may look something like this:
* - the task gets scheduled in; if both the task's fpsimd_state.cpu field
* contains the id of the current CPU, and the CPU's fpsimd_last_state per-cpu
* variable points to the task's fpsimd_state, the TIF_FOREIGN_FPSTATE flag is
* cleared, otherwise it is set;
*
* - the task returns to userland; if TIF_FOREIGN_FPSTATE is set, the task's
* userland FPSIMD state is copied from memory to the registers, the task's
* fpsimd_state.cpu field is set to the id of the current CPU, the current
* CPU's fpsimd_last_state pointer is set to this task's fpsimd_state and the
* TIF_FOREIGN_FPSTATE flag is cleared;
*
* - the task executes an ordinary syscall; upon return to userland, the
* TIF_FOREIGN_FPSTATE flag will still be cleared, so no FPSIMD state is
* restored;
*
* - the task executes a syscall which executes some NEON instructions; this is
* preceded by a call to kernel_neon_begin(), which copies the task's FPSIMD
* register contents to memory, clears the fpsimd_last_state per-cpu variable
* and sets the TIF_FOREIGN_FPSTATE flag;
*
* - the task gets preempted after kernel_neon_end() is called; as we have not
* returned from the 2nd syscall yet, TIF_FOREIGN_FPSTATE is still set so
* whatever is in the FPSIMD registers is not saved to memory, but discarded.
*/
static DEFINE_PER_CPU(struct fpsimd_state *, fpsimd_last_state);
/*
* Trapped FP/ASIMD access.
*/
@ -126,137 +71,43 @@ void do_fpsimd_exc(unsigned int esr, struct pt_regs *regs)
void fpsimd_thread_switch(struct task_struct *next)
{
/*
* Save the current FPSIMD state to memory, but only if whatever is in
* the registers is in fact the most recent userland FPSIMD state of
* 'current'.
*/
if (current->mm && !test_thread_flag(TIF_FOREIGN_FPSTATE))
/* check if not kernel threads */
if (current->mm)
fpsimd_save_state(&current->thread.fpsimd_state);
if (next->mm) {
/*
* If we are switching to a task whose most recent userland
* FPSIMD state is already in the registers of *this* cpu,
* we can skip loading the state from memory. Otherwise, set
* the TIF_FOREIGN_FPSTATE flag so the state will be loaded
* upon the next return to userland.
*/
struct fpsimd_state *st = &next->thread.fpsimd_state;
if (__this_cpu_read(fpsimd_last_state) == st
&& st->cpu == smp_processor_id())
clear_ti_thread_flag(task_thread_info(next),
TIF_FOREIGN_FPSTATE);
else
set_ti_thread_flag(task_thread_info(next),
TIF_FOREIGN_FPSTATE);
}
if (next->mm)
fpsimd_load_state(&next->thread.fpsimd_state);
}
void fpsimd_flush_thread(void)
{
preempt_disable();
memset(&current->thread.fpsimd_state, 0, sizeof(struct fpsimd_state));
set_thread_flag(TIF_FOREIGN_FPSTATE);
}
/*
* Save the userland FPSIMD state of 'current' to memory, but only if the state
* currently held in the registers does in fact belong to 'current'
*/
void fpsimd_preserve_current_state(void)
{
preempt_disable();
if (!test_thread_flag(TIF_FOREIGN_FPSTATE))
fpsimd_save_state(&current->thread.fpsimd_state);
fpsimd_load_state(&current->thread.fpsimd_state);
preempt_enable();
}
/*
* Load the userland FPSIMD state of 'current' from memory, but only if the
* FPSIMD state already held in the registers is /not/ the most recent FPSIMD
* state of 'current'
*/
void fpsimd_restore_current_state(void)
{
preempt_disable();
if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) {
struct fpsimd_state *st = &current->thread.fpsimd_state;
fpsimd_load_state(st);
this_cpu_write(fpsimd_last_state, st);
st->cpu = smp_processor_id();
}
preempt_enable();
}
/*
* Load an updated userland FPSIMD state for 'current' from memory and set the
* flag that indicates that the FPSIMD register contents are the most recent
* FPSIMD state of 'current'
*/
void fpsimd_update_current_state(struct fpsimd_state *state)
{
preempt_disable();
fpsimd_load_state(state);
if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) {
struct fpsimd_state *st = &current->thread.fpsimd_state;
this_cpu_write(fpsimd_last_state, st);
st->cpu = smp_processor_id();
}
preempt_enable();
}
/*
* Invalidate live CPU copies of task t's FPSIMD state
*/
void fpsimd_flush_task_state(struct task_struct *t)
{
t->thread.fpsimd_state.cpu = NR_CPUS;
}
#ifdef CONFIG_KERNEL_MODE_NEON
static DEFINE_PER_CPU(struct fpsimd_partial_state, hardirq_fpsimdstate);
static DEFINE_PER_CPU(struct fpsimd_partial_state, softirq_fpsimdstate);
/*
* Kernel-side NEON support functions
*/
void kernel_neon_begin_partial(u32 num_regs)
void kernel_neon_begin(void)
{
if (in_interrupt()) {
struct fpsimd_partial_state *s = this_cpu_ptr(
in_irq() ? &hardirq_fpsimdstate : &softirq_fpsimdstate);
/* Avoid using the NEON in interrupt context */
BUG_ON(in_interrupt());
preempt_disable();
BUG_ON(num_regs > 32);
fpsimd_save_partial_state(s, roundup(num_regs, 2));
} else {
/*
* Save the userland FPSIMD state if we have one and if we
* haven't done so already. Clear fpsimd_last_state to indicate
* that there is no longer userland FPSIMD state in the
* registers.
*/
preempt_disable();
if (current->mm &&
!test_and_set_thread_flag(TIF_FOREIGN_FPSTATE))
fpsimd_save_state(&current->thread.fpsimd_state);
this_cpu_write(fpsimd_last_state, NULL);
}
if (current->mm)
fpsimd_save_state(&current->thread.fpsimd_state);
}
EXPORT_SYMBOL(kernel_neon_begin_partial);
EXPORT_SYMBOL(kernel_neon_begin);
void kernel_neon_end(void)
{
if (in_interrupt()) {
struct fpsimd_partial_state *s = this_cpu_ptr(
in_irq() ? &hardirq_fpsimdstate : &softirq_fpsimdstate);
fpsimd_load_partial_state(s);
} else {
preempt_enable();
}
if (current->mm)
fpsimd_load_state(&current->thread.fpsimd_state);
preempt_enable();
}
EXPORT_SYMBOL(kernel_neon_end);
@ -268,12 +119,12 @@ static int fpsimd_cpu_pm_notifier(struct notifier_block *self,
{
switch (cmd) {
case CPU_PM_ENTER:
if (current->mm && !test_thread_flag(TIF_FOREIGN_FPSTATE))
if (current->mm)
fpsimd_save_state(&current->thread.fpsimd_state);
break;
case CPU_PM_EXIT:
if (current->mm)
set_thread_flag(TIF_FOREIGN_FPSTATE);
fpsimd_load_state(&current->thread.fpsimd_state);
break;
case CPU_PM_ENTER_FAILED:
default:

2
arch/arm64/kernel/process.c
View File

@ -215,7 +215,7 @@ void release_thread(struct task_struct *dead_task)
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
{
fpsimd_preserve_current_state();
fpsimd_save_state(&current->thread.fpsimd_state);
*dst = *src;
return 0;
}

2
arch/arm64/kernel/ptrace.c
View File

@ -521,7 +521,6 @@ static int fpr_set(struct task_struct *target, const struct user_regset *regset,
return ret;
target->thread.fpsimd_state.user_fpsimd = newstate;
fpsimd_flush_task_state(target);
return ret;
}
@ -769,7 +768,6 @@ static int compat_vfp_set(struct task_struct *target,
uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
}
fpsimd_flush_task_state(target);
return ret;
}

13
arch/arm64/kernel/signal.c
View File

@ -51,7 +51,7 @@ static int preserve_fpsimd_context(struct fpsimd_context __user *ctx)
int err;
/* dump the hardware registers to the fpsimd_state structure */
fpsimd_preserve_current_state();
fpsimd_save_state(fpsimd);
/* copy the FP and status/control registers */
err = __copy_to_user(ctx->vregs, fpsimd->vregs, sizeof(fpsimd->vregs));
@ -86,8 +86,11 @@ static int restore_fpsimd_context(struct fpsimd_context __user *ctx)
__get_user_error(fpsimd.fpcr, &ctx->fpcr, err);
/* load the hardware registers from the fpsimd_state structure */
if (!err)
fpsimd_update_current_state(&fpsimd);
if (!err) {
preempt_disable();
fpsimd_load_state(&fpsimd);
preempt_enable();
}
return err ? -EFAULT : 0;
}
@ -420,8 +423,4 @@ asmlinkage void do_notify_resume(struct pt_regs *regs,
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
if (thread_flags & _TIF_FOREIGN_FPSTATE)
fpsimd_restore_current_state();
}

9
arch/arm64/kernel/signal32.c
View File

@ -219,7 +219,7 @@ static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
* Note that this also saves V16-31, which aren't visible
* in AArch32.
*/
fpsimd_preserve_current_state();
fpsimd_save_state(fpsimd);
/* Place structure header on the stack */
__put_user_error(magic, &frame->magic, err);
@ -282,8 +282,11 @@ static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
* We don't need to touch the exception register, so
* reload the hardware state.
*/
if (!err)
fpsimd_update_current_state(&fpsimd);
if (!err) {
preempt_disable();
fpsimd_load_state(&fpsimd);
preempt_enable();
}
return err ? -EFAULT : 0;
}