[apple/xnu.git] / osfmk / i386 / ucode.c

/*
 *  ucode.c
 *
 *  Microcode updater interface sysctl
 */

#include <kern/locks.h>
#include <i386/ucode.h>
#include <sys/errno.h>
#include <i386/proc_reg.h>
#include <i386/cpuid.h>
#include <vm/vm_kern.h>
#include <i386/mp.h>			// mp_broadcast
#include <machine/cpu_number.h> // cpu_number

#define IA32_BIOS_UPDT_TRIG (0x79) /* microcode update trigger MSR */

struct intel_ucupdate *global_update = NULL;

/* Exceute the actual update! */
static void
update_microcode(void)
{
	/* SDM Example 9-8 code shows that we load the
	 * address of the UpdateData within the microcode blob,
	 * not the address of the header.
	 */
	wrmsr64(IA32_BIOS_UPDT_TRIG, (uint64_t)(uintptr_t)&global_update->data);
}

/* locks */
static lck_grp_attr_t *ucode_slock_grp_attr = NULL;
static lck_grp_t *ucode_slock_grp = NULL;
static lck_attr_t *ucode_slock_attr = NULL;
static lck_spin_t *ucode_slock = NULL;

static kern_return_t
register_locks(void)
{
	/* already allocated? */
	if (ucode_slock_grp_attr && ucode_slock_grp && ucode_slock_attr && ucode_slock)
		return KERN_SUCCESS;

	/* allocate lock group attribute and group */
	if (!(ucode_slock_grp_attr = lck_grp_attr_alloc_init()))
		goto nomem_out;

	lck_grp_attr_setstat(ucode_slock_grp_attr);

	if (!(ucode_slock_grp = lck_grp_alloc_init("uccode_lock", ucode_slock_grp_attr)))
		goto nomem_out;

	/* Allocate lock attribute */
	if (!(ucode_slock_attr = lck_attr_alloc_init()))
		goto nomem_out;

	/* Allocate the spin lock */
	/* We keep one global spin-lock. We could have one per update
	 * request... but srsly, why would you update microcode like that?
	 */
	if (!(ucode_slock = lck_spin_alloc_init(ucode_slock_grp, ucode_slock_attr)))
		goto nomem_out;

	return KERN_SUCCESS;

nomem_out:
	/* clean up */
	if (ucode_slock)
		lck_spin_free(ucode_slock, ucode_slock_grp);
	if (ucode_slock_attr)
		lck_attr_free(ucode_slock_attr);
	if (ucode_slock_grp)
		lck_grp_free(ucode_slock_grp);
	if (ucode_slock_grp_attr)
		lck_grp_attr_free(ucode_slock_grp_attr);

	return KERN_NO_SPACE;
}

/* Copy in an update */
static int
copyin_update(uint64_t inaddr)
{
	struct intel_ucupdate update_header;
	struct intel_ucupdate *update;
	vm_size_t size;
	kern_return_t ret;
	int error;

	/* Copy in enough header to peek at the size */
	error = copyin((user_addr_t)inaddr, (void *)&update_header, sizeof(update_header));
	if (error)
		return error;

	/* Get the actual, alleged size */
	size = update_header.total_size;

	/* huge bogus piece of data that somehow made it through? */
	if (size >= 1024 * 1024)
		return ENOMEM;

	/* Old microcodes? */
	if (size == 0)
		size = 2048; /* default update size; see SDM */

	/*
	 * create the buffer for the update
	 * It need only be aligned to 16-bytes, according to the SDM.
	 * This also wires it down
	 */
	ret = kmem_alloc_kobject(kernel_map, (vm_offset_t *)&update, size);
	if (ret != KERN_SUCCESS)
		return ENOMEM;

	/* Copy it in */
	error = copyin((user_addr_t)inaddr, (void*)update, size);
	if (error) {
		kmem_free(kernel_map, (vm_offset_t)update, size);
		return error;
	}

	global_update = update;
	return 0;
}

/*
 * This is called once by every CPU on a wake from sleep/hibernate
 * and is meant to re-apply a microcode update that got lost
 * by sleeping.
 */
void
ucode_update_wake()
{
	if (global_update) {
		kprintf("ucode: Re-applying update after wake (CPU #%d)\n", cpu_number());
		update_microcode();
#ifdef DEBUG
	} else {
		kprintf("ucode: No update to apply (CPU #%d)\n", cpu_number());
#endif
	}
}

static void
cpu_update(__unused void *arg)
{
	/* grab the lock */
	lck_spin_lock(ucode_slock);

	/* execute the update */
	update_microcode();

	/* if CPU #0, update global CPU information */
	if (!cpu_number())
		cpuid_set_info();

	/* release the lock */
	lck_spin_unlock(ucode_slock);
}

/* Farm an update out to all CPUs */
static void
xcpu_update(void)
{
	if (register_locks() != KERN_SUCCESS)
		return;

	/* Get all CPUs to perform the update */
	mp_broadcast(cpu_update, NULL);
}

/*
 * sysctl function
 *
 */
int
ucode_interface(uint64_t addr)
{
	int error;

#if !DEBUG
	/*
	 * Userland may only call this once per boot. Anything else
	 * would not make sense (all updates are cumulative), and also
	 * leak memory, because we don't free previous updates.
	 */
	if (global_update)
		return EPERM;
#endif

	/* Get the whole microcode */
	error = copyin_update(addr);

	if (error)
		return error;

	/* Farm out the updates */
	xcpu_update();

	return 0;
}
Commit	Line	Data
6d2010ae A	1	/*
	2	* ucode.c
	3	*
	4	* Microcode updater interface sysctl
	5	*/
	6
	7	#include <kern/locks.h>
	8	#include <i386/ucode.h>
	9	#include <sys/errno.h>
	10	#include <i386/proc_reg.h>
	11	#include <i386/cpuid.h>
	12	#include <vm/vm_kern.h>
	13	#include <i386/mp.h> // mp_broadcast
	14	#include <machine/cpu_number.h> // cpu_number
	15
	16	#define IA32_BIOS_UPDT_TRIG (0x79) /* microcode update trigger MSR */
	17
	18	struct intel_ucupdate *global_update = NULL;
	19
	20	/* Exceute the actual update! */
	21	static void
	22	update_microcode(void)
	23	{
	24	/* SDM Example 9-8 code shows that we load the
	25	* address of the UpdateData within the microcode blob,
	26	* not the address of the header.
	27	*/
	28	wrmsr64(IA32_BIOS_UPDT_TRIG, (uint64_t)(uintptr_t)&global_update->data);
	29	}
	30
	31	/* locks */
	32	static lck_grp_attr_t *ucode_slock_grp_attr = NULL;
	33	static lck_grp_t *ucode_slock_grp = NULL;
	34	static lck_attr_t *ucode_slock_attr = NULL;
	35	static lck_spin_t *ucode_slock = NULL;
	36
	37	static kern_return_t
	38	register_locks(void)
	39	{
	40	/* already allocated? */
	41	if (ucode_slock_grp_attr && ucode_slock_grp && ucode_slock_attr && ucode_slock)
	42	return KERN_SUCCESS;
	43
	44	/* allocate lock group attribute and group */
	45	if (!(ucode_slock_grp_attr = lck_grp_attr_alloc_init()))
	46	goto nomem_out;
	47
	48	lck_grp_attr_setstat(ucode_slock_grp_attr);
	49
	50	if (!(ucode_slock_grp = lck_grp_alloc_init("uccode_lock", ucode_slock_grp_attr)))
	51	goto nomem_out;
	52
	53	/* Allocate lock attribute */
	54	if (!(ucode_slock_attr = lck_attr_alloc_init()))
	55	goto nomem_out;
	56
	57	/* Allocate the spin lock */
	58	/* We keep one global spin-lock. We could have one per update
	59	* request... but srsly, why would you update microcode like that?
	60	*/
	61	if (!(ucode_slock = lck_spin_alloc_init(ucode_slock_grp, ucode_slock_attr)))
	62	goto nomem_out;
	63
	64	return KERN_SUCCESS;
65
66	nomem_out:
67	/* clean up */
68	if (ucode_slock)
69	lck_spin_free(ucode_slock, ucode_slock_grp);
70	if (ucode_slock_attr)
71	lck_attr_free(ucode_slock_attr);
72	if (ucode_slock_grp)
73	lck_grp_free(ucode_slock_grp);
74	if (ucode_slock_grp_attr)
75	lck_grp_attr_free(ucode_slock_grp_attr);
76
77	return KERN_NO_SPACE;
78	}
79
80	/* Copy in an update */
81	static int
82	copyin_update(uint64_t inaddr)
83	{
84	struct intel_ucupdate update_header;
85	struct intel_ucupdate *update;
86	vm_size_t size;
87	kern_return_t ret;
88	int error;
89
90	/* Copy in enough header to peek at the size */
91	error = copyin((user_addr_t)inaddr, (void *)&update_header, sizeof(update_header));
92	if (error)
93	return error;
94
95	/* Get the actual, alleged size */
96	size = update_header.total_size;
97
98	/* huge bogus piece of data that somehow made it through? */
99	if (size >= 1024 * 1024)
100	return ENOMEM;
101
102	/* Old microcodes? */
103	if (size == 0)
104	size = 2048; /* default update size; see SDM */
105
106	/*
107	* create the buffer for the update
108	* It need only be aligned to 16-bytes, according to the SDM.
109	* This also wires it down
110	*/
111	ret = kmem_alloc_kobject(kernel_map, (vm_offset_t *)&update, size);
112	if (ret != KERN_SUCCESS)
113	return ENOMEM;
114
115	/* Copy it in */
116	error = copyin((user_addr_t)inaddr, (void*)update, size);
117	if (error) {
118	kmem_free(kernel_map, (vm_offset_t)update, size);
119	return error;
120	}
121
122	global_update = update;
123	return 0;
124	}
125
126	/*
127	* This is called once by every CPU on a wake from sleep/hibernate
128	* and is meant to re-apply a microcode update that got lost
129	* by sleeping.
130	*/
131	void
132	ucode_update_wake()
133	{
134	if (global_update) {
135	kprintf("ucode: Re-applying update after wake (CPU #%d)\n", cpu_number());
136	update_microcode();
137	#ifdef DEBUG
138	} else {
139	kprintf("ucode: No update to apply (CPU #%d)\n", cpu_number());
140	#endif
141	}
142	}
143
144	static void
145	cpu_update(__unused void *arg)
146	{
147	/* grab the lock */
148	lck_spin_lock(ucode_slock);
149
150	/* execute the update */
151	update_microcode();
152
153	/* if CPU #0, update global CPU information */
154	if (!cpu_number())
155	cpuid_set_info();
156
157	/* release the lock */
158	lck_spin_unlock(ucode_slock);
159	}
160
161	/* Farm an update out to all CPUs */
162	static void
163	xcpu_update(void)
164	{
165	if (register_locks() != KERN_SUCCESS)
166	return;
167
168	/* Get all CPUs to perform the update */
169	mp_broadcast(cpu_update, NULL);
170	}
171
172	/*
173	* sysctl function
174	*
175	*/
176	int
177	ucode_interface(uint64_t addr)
178	{
179	int error;
180
181	#if !DEBUG
182	/*
183	* Userland may only call this once per boot. Anything else
184	* would not make sense (all updates are cumulative), and also
185	* leak memory, because we don't free previous updates.
186	*/
187	if (global_update)
188	return EPERM;
189	#endif
190
191	/* Get the whole microcode */
192	error = copyin_update(addr);
193
194	if (error)
195	return error;
196
197	/* Farm out the updates */
198	xcpu_update();
199
200	return 0;
201	}