[linux-2.6-block.git] / arch / s390 / kernel / suspend.c

/*
 * Suspend support specific for s390.
 *
 * Copyright IBM Corp. 2009
 *
 * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
 */

#include <linux/pfn.h>
#include <linux/suspend.h>
#include <linux/mm.h>
#include <linux/pci.h>
#include <asm/ctl_reg.h>
#include <asm/ipl.h>
#include <asm/cio.h>
#include <asm/sections.h>
#include "entry.h"

/*
 * The restore of the saved pages in an hibernation image will set
 * the change and referenced bits in the storage key for each page.
 * Overindication of the referenced bits after an hibernation cycle
 * does not cause any harm but the overindication of the change bits
 * would cause trouble.
 * Use the ARCH_SAVE_PAGE_KEYS hooks to save the storage key of each
 * page to the most significant byte of the associated page frame
 * number in the hibernation image.
 */

/*
 * Key storage is allocated as a linked list of pages.
 * The size of the keys array is (PAGE_SIZE - sizeof(long))
 */
struct page_key_data {
	struct page_key_data *next;
	unsigned char data[];
};

#define PAGE_KEY_DATA_SIZE	(PAGE_SIZE - sizeof(struct page_key_data *))

static struct page_key_data *page_key_data;
static struct page_key_data *page_key_rp, *page_key_wp;
static unsigned long page_key_rx, page_key_wx;
unsigned long suspend_zero_pages;

/*
 * For each page in the hibernation image one additional byte is
 * stored in the most significant byte of the page frame number.
 * On suspend no additional memory is required but on resume the
 * keys need to be memorized until the page data has been restored.
 * Only then can the storage keys be set to their old state.
 */
unsigned long page_key_additional_pages(unsigned long pages)
{
	return DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE);
}

/*
 * Free page_key_data list of arrays.
 */
void page_key_free(void)
{
	struct page_key_data *pkd;

	while (page_key_data) {
		pkd = page_key_data;
		page_key_data = pkd->next;
		free_page((unsigned long) pkd);
	}
}

/*
 * Allocate page_key_data list of arrays with enough room to store
 * one byte for each page in the hibernation image.
 */
int page_key_alloc(unsigned long pages)
{
	struct page_key_data *pk;
	unsigned long size;

	size = DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE);
	while (size--) {
		pk = (struct page_key_data *) get_zeroed_page(GFP_KERNEL);
		if (!pk) {
			page_key_free();
			return -ENOMEM;
		}
		pk->next = page_key_data;
		page_key_data = pk;
	}
	page_key_rp = page_key_wp = page_key_data;
	page_key_rx = page_key_wx = 0;
	return 0;
}

/*
 * Save the storage key into the upper 8 bits of the page frame number.
 */
void page_key_read(unsigned long *pfn)
{
	unsigned long addr;

	addr = (unsigned long) page_address(pfn_to_page(*pfn));
	*(unsigned char *) pfn = (unsigned char) page_get_storage_key(addr);
}

/*
 * Extract the storage key from the upper 8 bits of the page frame number
 * and store it in the page_key_data list of arrays.
 */
void page_key_memorize(unsigned long *pfn)
{
	page_key_wp->data[page_key_wx] = *(unsigned char *) pfn;
	*(unsigned char *) pfn = 0;
	if (++page_key_wx < PAGE_KEY_DATA_SIZE)
		return;
	page_key_wp = page_key_wp->next;
	page_key_wx = 0;
}

/*
 * Get the next key from the page_key_data list of arrays and set the
 * storage key of the page referred by @address. If @address refers to
 * a "safe" page the swsusp_arch_resume code will transfer the storage
 * key from the buffer page to the original page.
 */
void page_key_write(void *address)
{
	page_set_storage_key((unsigned long) address,
			     page_key_rp->data[page_key_rx], 0);
	if (++page_key_rx >= PAGE_KEY_DATA_SIZE)
		return;
	page_key_rp = page_key_rp->next;
	page_key_rx = 0;
}

int pfn_is_nosave(unsigned long pfn)
{
	unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin));
	unsigned long nosave_end_pfn = PFN_DOWN(__pa(&__nosave_end));
	unsigned long eshared_pfn = PFN_DOWN(__pa(&_eshared)) - 1;
	unsigned long stext_pfn = PFN_DOWN(__pa(&_stext));

	/* Always save lowcore pages (LC protection might be enabled). */
	if (pfn <= LC_PAGES)
		return 0;
	if (pfn >= nosave_begin_pfn && pfn < nosave_end_pfn)
		return 1;
	/* Skip memory holes and read-only pages (NSS, DCSS, ...). */
	if (pfn >= stext_pfn && pfn <= eshared_pfn)
		return ipl_info.type == IPL_TYPE_NSS ? 1 : 0;
	if (tprot(PFN_PHYS(pfn)))
		return 1;
	return 0;
}

/*
 * PM notifier callback for suspend
 */
static int suspend_pm_cb(struct notifier_block *nb, unsigned long action,
			 void *ptr)
{
	switch (action) {
	case PM_SUSPEND_PREPARE:
	case PM_HIBERNATION_PREPARE:
		suspend_zero_pages = __get_free_pages(GFP_KERNEL, LC_ORDER);
		if (!suspend_zero_pages)
			return NOTIFY_BAD;
		break;
	case PM_POST_SUSPEND:
	case PM_POST_HIBERNATION:
		free_pages(suspend_zero_pages, LC_ORDER);
		break;
	default:
		return NOTIFY_DONE;
	}
	return NOTIFY_OK;
}

static int __init suspend_pm_init(void)
{
	pm_notifier(suspend_pm_cb, 0);
	return 0;
}
arch_initcall(suspend_pm_init);

void save_processor_state(void)
{
	/* swsusp_arch_suspend() actually saves all cpu register contents.
	 * Machine checks must be disabled since swsusp_arch_suspend() stores
	 * register contents to their lowcore save areas. That's the same
	 * place where register contents on machine checks would be saved.
	 * To avoid register corruption disable machine checks.
	 * We must also disable machine checks in the new psw mask for
	 * program checks, since swsusp_arch_suspend() may generate program
	 * checks. Disabling machine checks for all other new psw masks is
	 * just paranoia.
	 */
	local_mcck_disable();
	/* Disable lowcore protection */
	__ctl_clear_bit(0,28);
	S390_lowcore.external_new_psw.mask &= ~PSW_MASK_MCHECK;
	S390_lowcore.svc_new_psw.mask &= ~PSW_MASK_MCHECK;
	S390_lowcore.io_new_psw.mask &= ~PSW_MASK_MCHECK;
	S390_lowcore.program_new_psw.mask &= ~PSW_MASK_MCHECK;
}

void restore_processor_state(void)
{
	S390_lowcore.external_new_psw.mask |= PSW_MASK_MCHECK;
	S390_lowcore.svc_new_psw.mask |= PSW_MASK_MCHECK;
	S390_lowcore.io_new_psw.mask |= PSW_MASK_MCHECK;
	S390_lowcore.program_new_psw.mask |= PSW_MASK_MCHECK;
	/* Enable lowcore protection */
	__ctl_set_bit(0,28);
	local_mcck_enable();
}

/* Called at the end of swsusp_arch_resume */
void s390_early_resume(void)
{
	lgr_info_log();
	channel_subsystem_reinit();
	zpci_rescan();
}
Commit	Line	Data
155af2f9	1	/*
c48ff644	2	* Suspend support specific for s390.
155af2f9 HJP	3	*
	4	* Copyright IBM Corp. 2009
	5	*
	6	* Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
155af2f9 HJP	7	*/
155af2f9 HJP	8
c48ff644	9	#include <linux/pfn.h>
638ad34a	10	#include <linux/suspend.h>
85055dd8	11	#include <linux/mm.h>
cd11433e	12	#include <linux/pci.h>
a0616cde	13	#include <asm/ctl_reg.h>
77e844b9 SO	14	#include <asm/ipl.h>
77e844b9 SO	15	#include <asm/cio.h>
7f8998c7	16	#include <asm/sections.h>
63df41d6	17	#include "entry.h"
c48ff644	18
85055dd8 MS	19	/*
	20	* The restore of the saved pages in an hibernation image will set
	21	* the change and referenced bits in the storage key for each page.
	22	* Overindication of the referenced bits after an hibernation cycle
	23	* does not cause any harm but the overindication of the change bits
	24	* would cause trouble.
	25	* Use the ARCH_SAVE_PAGE_KEYS hooks to save the storage key of each
	26	* page to the most significant byte of the associated page frame
	27	* number in the hibernation image.
	28	*/
	29
	30	/*
	31	* Key storage is allocated as a linked list of pages.
	32	* The size of the keys array is (PAGE_SIZE - sizeof(long))
	33	*/
	34	struct page_key_data {
	35	struct page_key_data *next;
	36	unsigned char data[];
	37	};
	38
	39	#define PAGE_KEY_DATA_SIZE (PAGE_SIZE - sizeof(struct page_key_data *))
	40
	41	static struct page_key_data *page_key_data;
	42	static struct page_key_data page_key_rp, page_key_wp;
	43	static unsigned long page_key_rx, page_key_wx;
91c15a95	44	unsigned long suspend_zero_pages;
85055dd8 MS	45
	46	/*
	47	* For each page in the hibernation image one additional byte is
	48	* stored in the most significant byte of the page frame number.
	49	* On suspend no additional memory is required but on resume the
	50	* keys need to be memorized until the page data has been restored.
	51	* Only then can the storage keys be set to their old state.
	52	*/
	53	unsigned long page_key_additional_pages(unsigned long pages)
	54	{
	55	return DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE);
	56	}
	57
	58	/*
	59	* Free page_key_data list of arrays.
	60	*/
	61	void page_key_free(void)
	62	{
	63	struct page_key_data *pkd;
	64
	65	while (page_key_data) {
	66	pkd = page_key_data;
	67	page_key_data = pkd->next;
	68	free_page((unsigned long) pkd);
	69	}
	70	}
	71
	72	/*
	73	* Allocate page_key_data list of arrays with enough room to store
	74	* one byte for each page in the hibernation image.
	75	*/
	76	int page_key_alloc(unsigned long pages)
	77	{
	78	struct page_key_data *pk;
	79	unsigned long size;
	80
	81	size = DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE);
	82	while (size--) {
	83	pk = (struct page_key_data *) get_zeroed_page(GFP_KERNEL);
	84	if (!pk) {
	85	page_key_free();
	86	return -ENOMEM;
	87	}
	88	pk->next = page_key_data;
	89	page_key_data = pk;
	90	}
	91	page_key_rp = page_key_wp = page_key_data;
	92	page_key_rx = page_key_wx = 0;
	93	return 0;
	94	}
	95
	96	/*
	97	* Save the storage key into the upper 8 bits of the page frame number.
	98	*/
	99	void page_key_read(unsigned long *pfn)
	100	{
	101	unsigned long addr;
	102
	103	addr = (unsigned long) page_address(pfn_to_page(*pfn));
	104	(unsigned char ) pfn = (unsigned char) page_get_storage_key(addr);
	105	}
	106
	107	/*
	108	* Extract the storage key from the upper 8 bits of the page frame number
109	* and store it in the page_key_data list of arrays.
110	*/
111	void page_key_memorize(unsigned long *pfn)
112	{
113	page_key_wp->data[page_key_wx] = (unsigned char ) pfn;
114	(unsigned char ) pfn = 0;
115	if (++page_key_wx < PAGE_KEY_DATA_SIZE)
116	return;
117	page_key_wp = page_key_wp->next;
118	page_key_wx = 0;
119	}
120
121	/*
122	* Get the next key from the page_key_data list of arrays and set the
123	* storage key of the page referred by @address. If @address refers to
124	* a "safe" page the swsusp_arch_resume code will transfer the storage
125	* key from the buffer page to the original page.
126	*/
127	void page_key_write(void *address)
128	{
129	page_set_storage_key((unsigned long) address,
130	page_key_rp->data[page_key_rx], 0);
131	if (++page_key_rx >= PAGE_KEY_DATA_SIZE)
132	return;
133	page_key_rp = page_key_rp->next;
134	page_key_rx = 0;
135	}
136
c48ff644 HC	137	int pfn_is_nosave(unsigned long pfn)
c48ff644 HC	138	{
2573a575 HC	139	unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin));
2573a575 HC	140	unsigned long nosave_end_pfn = PFN_DOWN(__pa(&__nosave_end));
d7441949 HC	141	unsigned long eshared_pfn = PFN_DOWN(__pa(&_eshared)) - 1;
d7441949 HC	142	unsigned long stext_pfn = PFN_DOWN(__pa(&_stext));
c48ff644	143
2573a575 HC	144	/* Always save lowcore pages (LC protection might be enabled). */
	145	if (pfn <= LC_PAGES)
	146	return 0;
c48ff644 HC	147	if (pfn >= nosave_begin_pfn && pfn < nosave_end_pfn)
c48ff644 HC	148	return 1;
2573a575	149	/* Skip memory holes and read-only pages (NSS, DCSS, ...). */
d7441949 HC	150	if (pfn >= stext_pfn && pfn <= eshared_pfn)
d7441949 HC	151	return ipl_info.type == IPL_TYPE_NSS ? 1 : 0;
2573a575	152	if (tprot(PFN_PHYS(pfn)))
c48ff644 HC	153	return 1;
	154	return 0;
	155	}
155af2f9	156
91c15a95 MH	157	/*
	158	* PM notifier callback for suspend
	159	*/
	160	static int suspend_pm_cb(struct notifier_block *nb, unsigned long action,
	161	void *ptr)
	162	{
	163	switch (action) {
	164	case PM_SUSPEND_PREPARE:
	165	case PM_HIBERNATION_PREPARE:
	166	suspend_zero_pages = __get_free_pages(GFP_KERNEL, LC_ORDER);
	167	if (!suspend_zero_pages)
	168	return NOTIFY_BAD;
	169	break;
	170	case PM_POST_SUSPEND:
	171	case PM_POST_HIBERNATION:
	172	free_pages(suspend_zero_pages, LC_ORDER);
	173	break;
	174	default:
	175	return NOTIFY_DONE;
	176	}
	177	return NOTIFY_OK;
	178	}
	179
	180	static int __init suspend_pm_init(void)
	181	{
	182	pm_notifier(suspend_pm_cb, 0);
	183	return 0;
	184	}
	185	arch_initcall(suspend_pm_init);
	186
155af2f9 HJP	187	void save_processor_state(void)
155af2f9 HJP	188	{
c63b196a HC	189	/* swsusp_arch_suspend() actually saves all cpu register contents.
	190	* Machine checks must be disabled since swsusp_arch_suspend() stores
	191	* register contents to their lowcore save areas. That's the same
	192	* place where register contents on machine checks would be saved.
	193	* To avoid register corruption disable machine checks.
	194	* We must also disable machine checks in the new psw mask for
	195	* program checks, since swsusp_arch_suspend() may generate program
	196	* checks. Disabling machine checks for all other new psw masks is
	197	* just paranoia.
155af2f9	198	*/
c63b196a HC	199	local_mcck_disable();
	200	/* Disable lowcore protection */
	201	__ctl_clear_bit(0,28);
	202	S390_lowcore.external_new_psw.mask &= ~PSW_MASK_MCHECK;
	203	S390_lowcore.svc_new_psw.mask &= ~PSW_MASK_MCHECK;
	204	S390_lowcore.io_new_psw.mask &= ~PSW_MASK_MCHECK;
	205	S390_lowcore.program_new_psw.mask &= ~PSW_MASK_MCHECK;
155af2f9 HJP	206	}
155af2f9 HJP	207
155af2f9 HJP	208	void restore_processor_state(void)
155af2f9 HJP	209	{
c63b196a HC	210	S390_lowcore.external_new_psw.mask \|= PSW_MASK_MCHECK;
	211	S390_lowcore.svc_new_psw.mask \|= PSW_MASK_MCHECK;
	212	S390_lowcore.io_new_psw.mask \|= PSW_MASK_MCHECK;
	213	S390_lowcore.program_new_psw.mask \|= PSW_MASK_MCHECK;
	214	/* Enable lowcore protection */
	215	__ctl_set_bit(0,28);
	216	local_mcck_enable();
155af2f9	217	}
77e844b9 SO	218
	219	/* Called at the end of swsusp_arch_resume */
	220	void s390_early_resume(void)
	221	{
	222	lgr_info_log();
	223	channel_subsystem_reinit();
57b5918c	224	zpci_rescan();
77e844b9	225	}