diff options
| -rw-r--r-- | arch/x86/include/asm/xsave.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/xsave.c | 64 |
3 files changed, 68 insertions, 0 deletions
diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h index aa3ff0cca9a1..1ba577c670ad 100644 --- a/arch/x86/include/asm/xsave.h +++ b/arch/x86/include/asm/xsave.h @@ -255,4 +255,7 @@ static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask) return err; } +void *get_xsave_addr(struct xsave_struct *xsave, int xstate); +void setup_xstate_comp(void); + #endif diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 4505e2a950d8..f804dc935d2a 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -93,6 +93,7 @@ void arch_task_cache_init(void) kmem_cache_create("task_xstate", xstate_size, __alignof__(union thread_xstate), SLAB_PANIC | SLAB_NOTRACK, NULL); + setup_xstate_comp(); } /* diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index f930f8ab92d1..a6cb8233f628 100644 --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -482,6 +482,47 @@ static void __init setup_xstate_features(void) } /* + * This function sets up offsets and sizes of all extended states in + * xsave area. This supports both standard format and compacted format + * of the xsave aread. + * + * Input: void + * Output: void + */ +void setup_xstate_comp(void) +{ + int i; + + xstate_comp_offsets = kmalloc(xstate_features * sizeof(int), + GFP_KERNEL); + xstate_comp_sizes = kmalloc(xstate_features * sizeof(int), GFP_KERNEL); + + if (!cpu_has_xsaves) { + for (i = 2; i < xstate_features; i++) { + if (test_bit(i, (unsigned long *)&pcntxt_mask)) { + xstate_comp_offsets[i] = xstate_offsets[i]; + xstate_comp_sizes[i] = xstate_sizes[i]; + } + } + return; + } + + xstate_comp_offsets[2] = FXSAVE_SIZE + XSAVE_HDR_SIZE; + + for (i = 2; i < xstate_features; i++) { + if (test_bit(i, (unsigned long *)&pcntxt_mask)) + xstate_comp_sizes[i] = xstate_sizes[i]; + else + xstate_comp_sizes[i] = 0; + + if (i > 2) + xstate_comp_offsets[i] = xstate_comp_offsets[i-1] + + xstate_comp_sizes[i-1]; + + } +} + +/* * setup the xstate image representing the init state */ static void __init setup_init_fpu_buf(void) @@ -668,3 +709,26 @@ void eager_fpu_init(void) else fxrstor_checking(&init_xstate_buf->i387); } + +/* + * Given the xsave area and a state inside, this function returns the + * address of the state. + * + * This is the API that is called to get xstate address in either + * standard format or compacted format of xsave area. + * + * Inputs: + * xsave: base address of the xsave area; + * xstate: state which is defined in xsave.h (e.g. XSTATE_FP, XSTATE_SSE, + * etc.) + * Output: + * address of the state in the xsave area. + */ +void *get_xsave_addr(struct xsave_struct *xsave, int xstate) +{ + int feature = fls64(xstate) - 1; + if (!test_bit(feature, (unsigned long *)&pcntxt_mask)) + return NULL; + + return (void *)xsave + xstate_comp_offsets[feature]; +} |