[deliverable/linux.git] / arch / x86 / kernel / xsave.c

/*
 * xsave/xrstor support.
 *
 * Author: Suresh Siddha <suresh.b.siddha@intel.com>
 */
#include <linux/bootmem.h>
#include <linux/compat.h>
#include <asm/i387.h>
#ifdef CONFIG_IA32_EMULATION
#include <asm/sigcontext32.h>
#endif
#include <asm/xcr.h>

/*
 * Supported feature mask by the CPU and the kernel.
 */
u64 pcntxt_mask;

struct _fpx_sw_bytes fx_sw_reserved;
#ifdef CONFIG_IA32_EMULATION
struct _fpx_sw_bytes fx_sw_reserved_ia32;
#endif

static unsigned int *xstate_offsets, *xstate_sizes, xstate_features;

/*
 * Check for the presence of extended state information in the
 * user fpstate pointer in the sigcontext.
 */
int check_for_xstate(struct i387_fxsave_struct __user *buf,
		     void __user *fpstate,
		     struct _fpx_sw_bytes *fx_sw_user)
{
	int min_xstate_size = sizeof(struct i387_fxsave_struct) +
			      sizeof(struct xsave_hdr_struct);
	unsigned int magic2;
	int err;

	err = __copy_from_user(fx_sw_user, &buf->sw_reserved[0],
			       sizeof(struct _fpx_sw_bytes));
	if (err)
		return -EFAULT;

	/*
	 * First Magic check failed.
	 */
	if (fx_sw_user->magic1 != FP_XSTATE_MAGIC1)
		return -EINVAL;

	/*
	 * Check for error scenarios.
	 */
	if (fx_sw_user->xstate_size < min_xstate_size ||
	    fx_sw_user->xstate_size > xstate_size ||
	    fx_sw_user->xstate_size > fx_sw_user->extended_size)
		return -EINVAL;

	err = __get_user(magic2, (__u32 *) (((void *)fpstate) +
					    fx_sw_user->extended_size -
					    FP_XSTATE_MAGIC2_SIZE));
	if (err)
		return err;
	/*
	 * Check for the presence of second magic word at the end of memory
	 * layout. This detects the case where the user just copied the legacy
	 * fpstate layout with out copying the extended state information
	 * in the memory layout.
	 */
	if (magic2 != FP_XSTATE_MAGIC2)
		return -EFAULT;

	return 0;
}

#ifdef CONFIG_X86_64
/*
 * Signal frame handlers.
 */

int save_i387_xstate(void __user *buf)
{
	struct task_struct *tsk = current;
	int err = 0;

	if (!access_ok(VERIFY_WRITE, buf, sig_xstate_size))
		return -EACCES;

	BUG_ON(sig_xstate_size < xstate_size);

	if ((unsigned long)buf % 64)
		printk("save_i387_xstate: bad fpstate %p\n", buf);

	if (!used_math())
		return 0;

	if (task_thread_info(tsk)->status & TS_USEDFPU) {
		/*
	 	 * Start with clearing the user buffer. This will present a
	 	 * clean context for the bytes not touched by the fxsave/xsave.
		 */
		err = __clear_user(buf, sig_xstate_size);
		if (err)
			return err;

		if (use_xsave())
			err = xsave_user(buf);
		else
			err = fxsave_user(buf);

		if (err)
			return err;
		task_thread_info(tsk)->status &= ~TS_USEDFPU;
		stts();
	} else {
		if (__copy_to_user(buf, &tsk->thread.fpu.state->fxsave,
				   xstate_size))
			return -1;
	}

	clear_used_math(); /* trigger finit */

	if (use_xsave()) {
		struct _fpstate __user *fx = buf;
		struct _xstate __user *x = buf;
		u64 xstate_bv;

		err = __copy_to_user(&fx->sw_reserved, &fx_sw_reserved,
				     sizeof(struct _fpx_sw_bytes));

		err |= __put_user(FP_XSTATE_MAGIC2,
				  (__u32 __user *) (buf + sig_xstate_size
						    - FP_XSTATE_MAGIC2_SIZE));

		/*
		 * Read the xstate_bv which we copied (directly from the cpu or
		 * from the state in task struct) to the user buffers and
		 * set the FP/SSE bits.
		 */
		err |= __get_user(xstate_bv, &x->xstate_hdr.xstate_bv);

		/*
		 * For legacy compatible, we always set FP/SSE bits in the bit
		 * vector while saving the state to the user context. This will
		 * enable us capturing any changes(during sigreturn) to
		 * the FP/SSE bits by the legacy applications which don't touch
		 * xstate_bv in the xsave header.
		 *
		 * xsave aware apps can change the xstate_bv in the xsave
		 * header as well as change any contents in the memory layout.
		 * xrestore as part of sigreturn will capture all the changes.
		 */
		xstate_bv |= XSTATE_FPSSE;

		err |= __put_user(xstate_bv, &x->xstate_hdr.xstate_bv);

		if (err)
			return err;
	}

	return 1;
}

/*
 * Restore the extended state if present. Otherwise, restore the FP/SSE
 * state.
 */
static int restore_user_xstate(void __user *buf)
{
	struct _fpx_sw_bytes fx_sw_user;
	u64 mask;
	int err;

	if (((unsigned long)buf % 64) ||
	     check_for_xstate(buf, buf, &fx_sw_user))
		goto fx_only;

	mask = fx_sw_user.xstate_bv;

	/*
	 * restore the state passed by the user.
	 */
	err = xrestore_user(buf, mask);
	if (err)
		return err;

	/*
	 * init the state skipped by the user.
	 */
	mask = pcntxt_mask & ~mask;

	xrstor_state(init_xstate_buf, mask);

	return 0;

fx_only:
	/*
	 * couldn't find the extended state information in the
	 * memory layout. Restore just the FP/SSE and init all
	 * the other extended state.
	 */
	xrstor_state(init_xstate_buf, pcntxt_mask & ~XSTATE_FPSSE);
	return fxrstor_checking((__force struct i387_fxsave_struct *)buf);
}

/*
 * This restores directly out of user space. Exceptions are handled.
 */
int restore_i387_xstate(void __user *buf)
{
	struct task_struct *tsk = current;
	int err = 0;

	if (!buf) {
		if (used_math())
			goto clear;
		return 0;
	} else
		if (!access_ok(VERIFY_READ, buf, sig_xstate_size))
			return -EACCES;

	if (!used_math()) {
		err = init_fpu(tsk);
		if (err)
			return err;
	}

	if (!(task_thread_info(current)->status & TS_USEDFPU)) {
		clts();
		task_thread_info(current)->status |= TS_USEDFPU;
	}
	if (use_xsave())
		err = restore_user_xstate(buf);
	else
		err = fxrstor_checking((__force struct i387_fxsave_struct *)
				       buf);
	if (unlikely(err)) {
		/*
		 * Encountered an error while doing the restore from the
		 * user buffer, clear the fpu state.
		 */
clear:
		clear_fpu(tsk);
		clear_used_math();
	}
	return err;
}
#endif

/*
 * Prepare the SW reserved portion of the fxsave memory layout, indicating
 * the presence of the extended state information in the memory layout
 * pointed by the fpstate pointer in the sigcontext.
 * This will be saved when ever the FP and extended state context is
 * saved on the user stack during the signal handler delivery to the user.
 */
static void prepare_fx_sw_frame(void)
{
	int size_extended = (xstate_size - sizeof(struct i387_fxsave_struct)) +
			     FP_XSTATE_MAGIC2_SIZE;

	sig_xstate_size = sizeof(struct _fpstate) + size_extended;

#ifdef CONFIG_IA32_EMULATION
	sig_xstate_ia32_size = sizeof(struct _fpstate_ia32) + size_extended;
#endif

	memset(&fx_sw_reserved, 0, sizeof(fx_sw_reserved));

	fx_sw_reserved.magic1 = FP_XSTATE_MAGIC1;
	fx_sw_reserved.extended_size = sig_xstate_size;
	fx_sw_reserved.xstate_bv = pcntxt_mask;
	fx_sw_reserved.xstate_size = xstate_size;
#ifdef CONFIG_IA32_EMULATION
	memcpy(&fx_sw_reserved_ia32, &fx_sw_reserved,
	       sizeof(struct _fpx_sw_bytes));
	fx_sw_reserved_ia32.extended_size = sig_xstate_ia32_size;
#endif
}

/*
 * Represents init state for the supported extended state.
 */
struct xsave_struct *init_xstate_buf;

#ifdef CONFIG_X86_64
unsigned int sig_xstate_size = sizeof(struct _fpstate);
#endif

/*
 * Enable the extended processor state save/restore feature
 */
void __cpuinit xsave_init(void)
{
	if (!cpu_has_xsave)
		return;

	set_in_cr4(X86_CR4_OSXSAVE);

	/*
	 * Enable all the features that the HW is capable of
	 * and the Linux kernel is aware of.
	 */
	xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask);
}

/*
 * Record the offsets and sizes of different state managed by the xsave
 * memory layout.
 */
static void setup_xstate_features(void)
{
	int eax, ebx, ecx, edx, leaf = 0x2;

	xstate_features = fls64(pcntxt_mask);
	xstate_offsets = alloc_bootmem(xstate_features * sizeof(int));
	xstate_sizes = alloc_bootmem(xstate_features * sizeof(int));

	do {
		cpuid_count(0xd, leaf, &eax, &ebx, &ecx, &edx);

		if (eax == 0)
			break;

		xstate_offsets[leaf] = ebx;
		xstate_sizes[leaf] = eax;

		leaf++;
	} while (1);
}

/*
 * setup the xstate image representing the init state
 */
static void __init setup_xstate_init(void)
{
	init_xstate_buf = alloc_bootmem(xstate_size);
	init_xstate_buf->i387.mxcsr = MXCSR_DEFAULT;

	setup_xstate_features();
}

/*
 * Enable and initialize the xsave feature.
 */
void __ref xsave_cntxt_init(void)
{
	unsigned int eax, ebx, ecx, edx;

	cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx);
	pcntxt_mask = eax + ((u64)edx << 32);

	if ((pcntxt_mask & XSTATE_FPSSE) != XSTATE_FPSSE) {
		printk(KERN_ERR "FP/SSE not shown under xsave features 0x%llx\n",
		       pcntxt_mask);
		BUG();
	}

	/*
	 * Support only the state known to OS.
	 */
	pcntxt_mask = pcntxt_mask & XCNTXT_MASK;
	xsave_init();

	/*
	 * Recompute the context size for enabled features
	 */
	cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx);
	xstate_size = ebx;

	update_regset_xstate_info(xstate_size, pcntxt_mask);
	prepare_fx_sw_frame();

	setup_xstate_init();

	printk(KERN_INFO "xsave/xrstor: enabled xstate_bv 0x%llx, "
	       "cntxt size 0x%x\n",
	       pcntxt_mask, xstate_size);
}
Commit	Line	Data
dc1e35c6 SS	1	/*
	2	* xsave/xrstor support.
	3	*
	4	* Author: Suresh Siddha <suresh.b.siddha@intel.com>
	5	*/
	6	#include <linux/bootmem.h>
	7	#include <linux/compat.h>
	8	#include <asm/i387.h>
c37b5efe SS	9	#ifdef CONFIG_IA32_EMULATION
	10	#include <asm/sigcontext32.h>
	11	#endif
6152e4b1	12	#include <asm/xcr.h>
dc1e35c6 SS	13
	14	/*
	15	* Supported feature mask by the CPU and the kernel.
	16	*/
6152e4b1	17	u64 pcntxt_mask;
dc1e35c6	18
c37b5efe SS	19	struct _fpx_sw_bytes fx_sw_reserved;
	20	#ifdef CONFIG_IA32_EMULATION
	21	struct _fpx_sw_bytes fx_sw_reserved_ia32;
	22	#endif
	23
a1488f8b SS	24	static unsigned int xstate_offsets, xstate_sizes, xstate_features;
a1488f8b SS	25
c37b5efe SS	26	/*
	27	* Check for the presence of extended state information in the
	28	* user fpstate pointer in the sigcontext.
	29	*/
	30	int check_for_xstate(struct i387_fxsave_struct __user *buf,
	31	void __user *fpstate,
	32	struct _fpx_sw_bytes *fx_sw_user)
	33	{
	34	int min_xstate_size = sizeof(struct i387_fxsave_struct) +
	35	sizeof(struct xsave_hdr_struct);
	36	unsigned int magic2;
	37	int err;
	38
	39	err = __copy_from_user(fx_sw_user, &buf->sw_reserved[0],
	40	sizeof(struct _fpx_sw_bytes));
c37b5efe	41	if (err)
d6d4d420	42	return -EFAULT;
c37b5efe SS	43
	44	/*
	45	* First Magic check failed.
	46	*/
	47	if (fx_sw_user->magic1 != FP_XSTATE_MAGIC1)
d6d4d420	48	return -EINVAL;
c37b5efe SS	49
	50	/*
	51	* Check for error scenarios.
	52	*/
	53	if (fx_sw_user->xstate_size < min_xstate_size \|\|
	54	fx_sw_user->xstate_size > xstate_size \|\|
	55	fx_sw_user->xstate_size > fx_sw_user->extended_size)
d6d4d420	56	return -EINVAL;
c37b5efe SS	57
	58	err = __get_user(magic2, (__u32 ) (((void )fpstate) +
	59	fx_sw_user->extended_size -
	60	FP_XSTATE_MAGIC2_SIZE));
d6d4d420 DC	61	if (err)
d6d4d420 DC	62	return err;
c37b5efe SS	63	/*
	64	* Check for the presence of second magic word at the end of memory
	65	* layout. This detects the case where the user just copied the legacy
	66	* fpstate layout with out copying the extended state information
	67	* in the memory layout.
	68	*/
d6d4d420 DC	69	if (magic2 != FP_XSTATE_MAGIC2)
d6d4d420 DC	70	return -EFAULT;
c37b5efe SS	71
	72	return 0;
	73	}
	74
ab513701 SS	75	#ifdef CONFIG_X86_64
	76	/*
	77	* Signal frame handlers.
	78	*/
	79
	80	int save_i387_xstate(void __user *buf)
	81	{
	82	struct task_struct *tsk = current;
	83	int err = 0;
	84
	85	if (!access_ok(VERIFY_WRITE, buf, sig_xstate_size))
	86	return -EACCES;
	87
f65bc214	88	BUG_ON(sig_xstate_size < xstate_size);
ab513701	89
c37b5efe	90	if ((unsigned long)buf % 64)
ab513701 SS	91	printk("save_i387_xstate: bad fpstate %p\n", buf);
	92
	93	if (!used_math())
	94	return 0;
06c38d5e	95
ab513701	96	if (task_thread_info(tsk)->status & TS_USEDFPU) {
ed405958 SS	97	/*
	98	* Start with clearing the user buffer. This will present a
	99	* clean context for the bytes not touched by the fxsave/xsave.
	100	*/
9f482807 IM	101	err = __clear_user(buf, sig_xstate_size);
	102	if (err)
	103	return err;
ed405958	104
c9ad4882	105	if (use_xsave())
c37b5efe SS	106	err = xsave_user(buf);
	107	else
	108	err = fxsave_user(buf);
	109
ab513701 SS	110	if (err)
	111	return err;
	112	task_thread_info(tsk)->status &= ~TS_USEDFPU;
	113	stts();
	114	} else {
86603283	115	if (__copy_to_user(buf, &tsk->thread.fpu.state->fxsave,
ab513701 SS	116	xstate_size))
	117	return -1;
	118	}
c37b5efe	119
06c38d5e SS	120	clear_used_math(); /* trigger finit */
06c38d5e SS	121
c9ad4882	122	if (use_xsave()) {
c37b5efe	123	struct _fpstate __user *fx = buf;
04944b79 SS	124	struct _xstate __user *x = buf;
04944b79 SS	125	u64 xstate_bv;
c37b5efe SS	126
	127	err = __copy_to_user(&fx->sw_reserved, &fx_sw_reserved,
	128	sizeof(struct _fpx_sw_bytes));
	129
	130	err \|= __put_user(FP_XSTATE_MAGIC2,
	131	(__u32 __user *) (buf + sig_xstate_size
	132	- FP_XSTATE_MAGIC2_SIZE));
04944b79 SS	133
	134	/*
	135	* Read the xstate_bv which we copied (directly from the cpu or
	136	* from the state in task struct) to the user buffers and
	137	* set the FP/SSE bits.
	138	*/
	139	err \|= __get_user(xstate_bv, &x->xstate_hdr.xstate_bv);
	140
	141	/*
	142	* For legacy compatible, we always set FP/SSE bits in the bit
	143	* vector while saving the state to the user context. This will
	144	* enable us capturing any changes(during sigreturn) to
	145	* the FP/SSE bits by the legacy applications which don't touch
	146	* xstate_bv in the xsave header.
	147	*
	148	* xsave aware apps can change the xstate_bv in the xsave
	149	* header as well as change any contents in the memory layout.
	150	* xrestore as part of sigreturn will capture all the changes.
	151	*/
	152	xstate_bv \|= XSTATE_FPSSE;
	153
	154	err \|= __put_user(xstate_bv, &x->xstate_hdr.xstate_bv);
	155
f364eada SS	156	if (err)
f364eada SS	157	return err;
c37b5efe SS	158	}
c37b5efe SS	159
ab513701 SS	160	return 1;
	161	}
	162
c37b5efe SS	163	/*
	164	* Restore the extended state if present. Otherwise, restore the FP/SSE
	165	* state.
	166	*/
7820b756	167	static int restore_user_xstate(void __user *buf)
c37b5efe SS	168	{
c37b5efe SS	169	struct _fpx_sw_bytes fx_sw_user;
6152e4b1	170	u64 mask;
c37b5efe SS	171	int err;
	172
	173	if (((unsigned long)buf % 64) \|\|
	174	check_for_xstate(buf, buf, &fx_sw_user))
	175	goto fx_only;
	176
6152e4b1	177	mask = fx_sw_user.xstate_bv;
c37b5efe SS	178
	179	/*
	180	* restore the state passed by the user.
	181	*/
6152e4b1	182	err = xrestore_user(buf, mask);
c37b5efe SS	183	if (err)
	184	return err;
	185
	186	/*
	187	* init the state skipped by the user.
	188	*/
6152e4b1	189	mask = pcntxt_mask & ~mask;
c37b5efe	190
6152e4b1	191	xrstor_state(init_xstate_buf, mask);
c37b5efe SS	192
	193	return 0;
	194
	195	fx_only:
	196	/*
	197	* couldn't find the extended state information in the
	198	* memory layout. Restore just the FP/SSE and init all
	199	* the other extended state.
	200	*/
6152e4b1	201	xrstor_state(init_xstate_buf, pcntxt_mask & ~XSTATE_FPSSE);
c37b5efe SS	202	return fxrstor_checking((__force struct i387_fxsave_struct *)buf);
	203	}
	204
ab513701 SS	205	/*
	206	* This restores directly out of user space. Exceptions are handled.
	207	*/
	208	int restore_i387_xstate(void __user *buf)
	209	{
	210	struct task_struct *tsk = current;
c37b5efe	211	int err = 0;
ab513701 SS	212
ab513701 SS	213	if (!buf) {
c37b5efe SS	214	if (used_math())
c37b5efe SS	215	goto clear;
ab513701 SS	216	return 0;
	217	} else
	218	if (!access_ok(VERIFY_READ, buf, sig_xstate_size))
	219	return -EACCES;
	220
	221	if (!used_math()) {
	222	err = init_fpu(tsk);
	223	if (err)
	224	return err;
	225	}
	226
	227	if (!(task_thread_info(current)->status & TS_USEDFPU)) {
	228	clts();
	229	task_thread_info(current)->status \|= TS_USEDFPU;
	230	}
c9ad4882	231	if (use_xsave())
c37b5efe SS	232	err = restore_user_xstate(buf);
	233	else
	234	err = fxrstor_checking((__force struct i387_fxsave_struct *)
	235	buf);
ab513701 SS	236	if (unlikely(err)) {
	237	/*
	238	* Encountered an error while doing the restore from the
	239	* user buffer, clear the fpu state.
	240	*/
c37b5efe	241	clear:
ab513701 SS	242	clear_fpu(tsk);
	243	clear_used_math();
	244	}
	245	return err;
	246	}
	247	#endif
	248
c37b5efe SS	249	/*
	250	* Prepare the SW reserved portion of the fxsave memory layout, indicating
	251	* the presence of the extended state information in the memory layout
	252	* pointed by the fpstate pointer in the sigcontext.
	253	* This will be saved when ever the FP and extended state context is
	254	* saved on the user stack during the signal handler delivery to the user.
	255	*/
8bcad30f	256	static void prepare_fx_sw_frame(void)
c37b5efe SS	257	{
	258	int size_extended = (xstate_size - sizeof(struct i387_fxsave_struct)) +
	259	FP_XSTATE_MAGIC2_SIZE;
	260
	261	sig_xstate_size = sizeof(struct _fpstate) + size_extended;
	262
	263	#ifdef CONFIG_IA32_EMULATION
	264	sig_xstate_ia32_size = sizeof(struct _fpstate_ia32) + size_extended;
	265	#endif
	266
	267	memset(&fx_sw_reserved, 0, sizeof(fx_sw_reserved));
	268
	269	fx_sw_reserved.magic1 = FP_XSTATE_MAGIC1;
	270	fx_sw_reserved.extended_size = sig_xstate_size;
6152e4b1	271	fx_sw_reserved.xstate_bv = pcntxt_mask;
c37b5efe SS	272	fx_sw_reserved.xstate_size = xstate_size;
	273	#ifdef CONFIG_IA32_EMULATION
	274	memcpy(&fx_sw_reserved_ia32, &fx_sw_reserved,
	275	sizeof(struct _fpx_sw_bytes));
	276	fx_sw_reserved_ia32.extended_size = sig_xstate_ia32_size;
	277	#endif
	278	}
	279
dc1e35c6 SS	280	/*
	281	* Represents init state for the supported extended state.
	282	*/
	283	struct xsave_struct *init_xstate_buf;
	284
3c1c7f10 SS	285	#ifdef CONFIG_X86_64
	286	unsigned int sig_xstate_size = sizeof(struct _fpstate);
	287	#endif
	288
dc1e35c6 SS	289	/*
	290	* Enable the extended processor state save/restore feature
	291	*/
	292	void __cpuinit xsave_init(void)
	293	{
	294	if (!cpu_has_xsave)
	295	return;
	296
	297	set_in_cr4(X86_CR4_OSXSAVE);
	298
	299	/*
	300	* Enable all the features that the HW is capable of
	301	* and the Linux kernel is aware of.
dc1e35c6	302	*/
6152e4b1	303	xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask);
dc1e35c6 SS	304	}
dc1e35c6 SS	305
a1488f8b SS	306	/*
	307	* Record the offsets and sizes of different state managed by the xsave
	308	* memory layout.
	309	*/
	310	static void setup_xstate_features(void)
	311	{
	312	int eax, ebx, ecx, edx, leaf = 0x2;
	313
	314	xstate_features = fls64(pcntxt_mask);
	315	xstate_offsets = alloc_bootmem(xstate_features * sizeof(int));
	316	xstate_sizes = alloc_bootmem(xstate_features * sizeof(int));
	317
	318	do {
	319	cpuid_count(0xd, leaf, &eax, &ebx, &ecx, &edx);
	320
	321	if (eax == 0)
	322	break;
	323
	324	xstate_offsets[leaf] = ebx;
	325	xstate_sizes[leaf] = eax;
	326
	327	leaf++;
	328	} while (1);
	329	}
	330
dc1e35c6 SS	331	/*
	332	* setup the xstate image representing the init state
	333	*/
a19aac85	334	static void __init setup_xstate_init(void)
dc1e35c6 SS	335	{
	336	init_xstate_buf = alloc_bootmem(xstate_size);
	337	init_xstate_buf->i387.mxcsr = MXCSR_DEFAULT;
a1488f8b SS	338
a1488f8b SS	339	setup_xstate_features();
dc1e35c6 SS	340	}
	341
	342	/*
	343	* Enable and initialize the xsave feature.
	344	*/
bfe085f6	345	void __ref xsave_cntxt_init(void)
dc1e35c6 SS	346	{
	347	unsigned int eax, ebx, ecx, edx;
	348
	349	cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx);
6152e4b1	350	pcntxt_mask = eax + ((u64)edx << 32);
dc1e35c6	351
6152e4b1 PA	352	if ((pcntxt_mask & XSTATE_FPSSE) != XSTATE_FPSSE) {
	353	printk(KERN_ERR "FP/SSE not shown under xsave features 0x%llx\n",
	354	pcntxt_mask);
dc1e35c6 SS	355	BUG();
	356	}
	357
	358	/*
a30469e7	359	* Support only the state known to OS.
dc1e35c6	360	*/
6152e4b1	361	pcntxt_mask = pcntxt_mask & XCNTXT_MASK;
dc1e35c6 SS	362	xsave_init();
	363
	364	/*
	365	* Recompute the context size for enabled features
	366	*/
	367	cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx);
dc1e35c6 SS	368	xstate_size = ebx;
dc1e35c6 SS	369
5b3efd50	370	update_regset_xstate_info(xstate_size, pcntxt_mask);
c37b5efe SS	371	prepare_fx_sw_frame();
c37b5efe SS	372
dc1e35c6 SS	373	setup_xstate_init();
dc1e35c6 SS	374
6152e4b1	375	printk(KERN_INFO "xsave/xrstor: enabled xstate_bv 0x%llx, "
dc1e35c6	376	"cntxt size 0x%x\n",
6152e4b1	377	pcntxt_mask, xstate_size);
dc1e35c6	378	}