| Paul Mundt | 0ea820c | 2010-01-13 12:51:40 +0900 | [diff] [blame] | 1 | #include <linux/sched.h> |
| Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 2 | #include <linux/slab.h> |
| Paul Mundt | 0ea820c | 2010-01-13 12:51:40 +0900 | [diff] [blame] | 3 | #include <asm/processor.h> |
| 4 | #include <asm/fpu.h> |
| Paul Mundt | f03c486 | 2012-03-30 19:29:57 +0900 | [diff] [blame] | 5 | #include <asm/traps.h> |
| Paul Mundt | 0ea820c | 2010-01-13 12:51:40 +0900 | [diff] [blame] | 6 | |
| 7 | int init_fpu(struct task_struct *tsk) |
| 8 | { |
| 9 | if (tsk_used_math(tsk)) { |
| 10 | if ((boot_cpu_data.flags & CPU_HAS_FPU) && tsk == current) |
| 11 | unlazy_fpu(tsk, task_pt_regs(tsk)); |
| 12 | return 0; |
| 13 | } |
| 14 | |
| 15 | /* |
| 16 | * Memory allocation at the first usage of the FPU and other state. |
| 17 | */ |
| 18 | if (!tsk->thread.xstate) { |
| 19 | tsk->thread.xstate = kmem_cache_alloc(task_xstate_cachep, |
| 20 | GFP_KERNEL); |
| 21 | if (!tsk->thread.xstate) |
| 22 | return -ENOMEM; |
| 23 | } |
| 24 | |
| 25 | if (boot_cpu_data.flags & CPU_HAS_FPU) { |
| 26 | struct sh_fpu_hard_struct *fp = &tsk->thread.xstate->hardfpu; |
| 27 | memset(fp, 0, xstate_size); |
| 28 | fp->fpscr = FPSCR_INIT; |
| 29 | } else { |
| 30 | struct sh_fpu_soft_struct *fp = &tsk->thread.xstate->softfpu; |
| 31 | memset(fp, 0, xstate_size); |
| 32 | fp->fpscr = FPSCR_INIT; |
| 33 | } |
| 34 | |
| 35 | set_stopped_child_used_math(tsk); |
| 36 | return 0; |
| 37 | } |
| 38 | |
| 39 | #ifdef CONFIG_SH_FPU |
| 40 | void __fpu_state_restore(void) |
| 41 | { |
| 42 | struct task_struct *tsk = current; |
| 43 | |
| 44 | restore_fpu(tsk); |
| 45 | |
| 46 | task_thread_info(tsk)->status |= TS_USEDFPU; |
| 47 | tsk->fpu_counter++; |
| 48 | } |
| 49 | |
| 50 | void fpu_state_restore(struct pt_regs *regs) |
| 51 | { |
| 52 | struct task_struct *tsk = current; |
| 53 | |
| 54 | if (unlikely(!user_mode(regs))) { |
| 55 | printk(KERN_ERR "BUG: FPU is used in kernel mode.\n"); |
| 56 | BUG(); |
| 57 | return; |
| 58 | } |
| 59 | |
| 60 | if (!tsk_used_math(tsk)) { |
| Paul Mundt | 4291b73 | 2010-01-18 20:39:49 +0900 | [diff] [blame] | 61 | local_irq_enable(); |
| Paul Mundt | 0ea820c | 2010-01-13 12:51:40 +0900 | [diff] [blame] | 62 | /* |
| 63 | * does a slab alloc which can sleep |
| 64 | */ |
| 65 | if (init_fpu(tsk)) { |
| 66 | /* |
| 67 | * ran out of memory! |
| 68 | */ |
| 69 | do_group_exit(SIGKILL); |
| 70 | return; |
| 71 | } |
| Paul Mundt | 4291b73 | 2010-01-18 20:39:49 +0900 | [diff] [blame] | 72 | local_irq_disable(); |
| Paul Mundt | 0ea820c | 2010-01-13 12:51:40 +0900 | [diff] [blame] | 73 | } |
| 74 | |
| 75 | grab_fpu(regs); |
| 76 | |
| 77 | __fpu_state_restore(); |
| 78 | } |
| 79 | |
| 80 | BUILD_TRAP_HANDLER(fpu_state_restore) |
| 81 | { |
| 82 | TRAP_HANDLER_DECL; |
| 83 | |
| 84 | fpu_state_restore(regs); |
| 85 | } |
| 86 | #endif /* CONFIG_SH_FPU */ |