[linux-2.6-block.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>

/*
 * Supported feature mask by the CPU and the kernel.
 */
unsigned int pcntxt_hmask, pcntxt_lmask;

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

/*
 * 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();
	 */
	asm volatile(".byte 0x0f,0x01,0xd1" : : "c" (0),
		     "a" (pcntxt_lmask), "d" (pcntxt_hmask));
}

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

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

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

	pcntxt_lmask = eax;
	pcntxt_hmask = edx;

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

	/*
	 * for now OS knows only about FP/SSE
	 */
	pcntxt_lmask = pcntxt_lmask & XCNTXT_LMASK;
	pcntxt_hmask = pcntxt_hmask & XCNTXT_HMASK;

	xsave_init();

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

	xstate_size = ebx;

	setup_xstate_init();

	printk(KERN_INFO "xsave/xrstor: enabled xstate_bv 0x%Lx, "
	       "cntxt size 0x%x\n",
	       (pcntxt_lmask | ((u64) pcntxt_hmask << 32)), 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>
	9
	10	/*
	11	* Supported feature mask by the CPU and the kernel.
	12	*/
	13	unsigned int pcntxt_hmask, pcntxt_lmask;
	14
	15	/*
	16	* Represents init state for the supported extended state.
	17	*/
	18	struct xsave_struct *init_xstate_buf;
	19
	20	/*
	21	* Enable the extended processor state save/restore feature
	22	*/
	23	void __cpuinit xsave_init(void)
	24	{
	25	if (!cpu_has_xsave)
	26	return;
	27
	28	set_in_cr4(X86_CR4_OSXSAVE);
	29
	30	/*
	31	* Enable all the features that the HW is capable of
	32	* and the Linux kernel is aware of.
	33	*
	34	* xsetbv();
	35	*/
	36	asm volatile(".byte 0x0f,0x01,0xd1" : : "c" (0),
	37	"a" (pcntxt_lmask), "d" (pcntxt_hmask));
	38	}
	39
	40	/*
	41	* setup the xstate image representing the init state
	42	*/
	43	void setup_xstate_init(void)
	44	{
	45	init_xstate_buf = alloc_bootmem(xstate_size);
	46	init_xstate_buf->i387.mxcsr = MXCSR_DEFAULT;
	47	}
	48
	49	/*
	50	* Enable and initialize the xsave feature.
	51	*/
	52	void __init xsave_cntxt_init(void)
	53	{
	54	unsigned int eax, ebx, ecx, edx;
	55
	56	cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx);
	57
	58	pcntxt_lmask = eax;
	59	pcntxt_hmask = edx;
	60
	61	if ((pcntxt_lmask & XSTATE_FPSSE) != XSTATE_FPSSE) {
	62	printk(KERN_ERR "FP/SSE not shown under xsave features %x\n",
	63	pcntxt_lmask);
	64	BUG();
65	}
66
67	/*
68	* for now OS knows only about FP/SSE
69	*/
70	pcntxt_lmask = pcntxt_lmask & XCNTXT_LMASK;
71	pcntxt_hmask = pcntxt_hmask & XCNTXT_HMASK;
72
73	xsave_init();
74
75	/*
76	* Recompute the context size for enabled features
77	*/
78	cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx);
79
80	xstate_size = ebx;
81
82	setup_xstate_init();
83
84	printk(KERN_INFO "xsave/xrstor: enabled xstate_bv 0x%Lx, "
85	"cntxt size 0x%x\n",
86	(pcntxt_lmask \| ((u64) pcntxt_hmask << 32)), xstate_size);
87	}