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v3.1
 
  1/*
  2 * Machine specific setup for xen
  3 *
  4 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
  5 */
  6
  7#include <linux/module.h>
  8#include <linux/sched.h>
  9#include <linux/mm.h>
 10#include <linux/pm.h>
 11#include <linux/memblock.h>
 12#include <linux/cpuidle.h>
 
 
 13
 14#include <asm/elf.h>
 15#include <asm/vdso.h>
 16#include <asm/e820.h>
 17#include <asm/setup.h>
 18#include <asm/acpi.h>
 
 
 19#include <asm/xen/hypervisor.h>
 20#include <asm/xen/hypercall.h>
 21
 22#include <xen/xen.h>
 23#include <xen/page.h>
 24#include <xen/interface/callback.h>
 25#include <xen/interface/memory.h>
 26#include <xen/interface/physdev.h>
 27#include <xen/features.h>
 28
 29#include "xen-ops.h"
 30#include "vdso.h"
 31
 32/* These are code, but not functions.  Defined in entry.S */
 33extern const char xen_hypervisor_callback[];
 34extern const char xen_failsafe_callback[];
 35extern void xen_sysenter_target(void);
 36extern void xen_syscall_target(void);
 37extern void xen_syscall32_target(void);
 38
 39/* Amount of extra memory space we add to the e820 ranges */
 40phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 41
 42/* 
 43 * The maximum amount of extra memory compared to the base size.  The
 44 * main scaling factor is the size of struct page.  At extreme ratios
 45 * of base:extra, all the base memory can be filled with page
 46 * structures for the extra memory, leaving no space for anything
 47 * else.
 48 * 
 49 * 10x seems like a reasonable balance between scaling flexibility and
 50 * leaving a practically usable system.
 51 */
 52#define EXTRA_MEM_RATIO		(10)
 53
 54static void __init xen_add_extra_mem(unsigned long pages)
 
 
 55{
 56	unsigned long pfn;
 
 57
 58	u64 size = (u64)pages * PAGE_SIZE;
 59	u64 extra_start = xen_extra_mem_start + xen_extra_mem_size;
 
 60
 61	if (!pages)
 
 
 
 62		return;
 63
 64	e820_add_region(extra_start, size, E820_RAM);
 65	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 66
 67	memblock_x86_reserve_range(extra_start, extra_start + size, "XEN EXTRA");
 
 
 
 
 68
 69	xen_extra_mem_size += size;
 
 70
 71	xen_max_p2m_pfn = PFN_DOWN(extra_start + size);
 
 
 
 
 
 
 72
 73	for (pfn = PFN_DOWN(extra_start); pfn <= xen_max_p2m_pfn; pfn++)
 74		__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
 
 
 
 
 
 
 75}
 76
 77static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
 78					      phys_addr_t end_addr)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 79{
 80	struct xen_memory_reservation reservation = {
 81		.address_bits = 0,
 82		.extent_order = 0,
 83		.domid        = DOMID_SELF
 84	};
 85	unsigned long start, end;
 86	unsigned long len = 0;
 87	unsigned long pfn;
 88	int ret;
 89
 90	start = PFN_UP(start_addr);
 91	end = PFN_DOWN(end_addr);
 92
 93	if (end <= start)
 94		return 0;
 
 
 
 
 
 
 
 
 
 
 95
 96	for(pfn = start; pfn < end; pfn++) {
 
 
 
 
 97		unsigned long mfn = pfn_to_mfn(pfn);
 98
 99		/* Make sure pfn exists to start with */
100		if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
101			continue;
102
103		set_xen_guest_handle(reservation.extent_start, &mfn);
104		reservation.nr_extents = 1;
105
106		ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
107					   &reservation);
108		WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
 
109		if (ret == 1) {
110			__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
111			len++;
112		}
 
 
113	}
114	printk(KERN_INFO "Freeing  %lx-%lx pfn range: %lu pages freed\n",
115	       start, end, len);
116
117	return len;
118}
119
120static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
121						     const struct e820map *e820)
 
 
122{
123	phys_addr_t max_addr = PFN_PHYS(max_pfn);
124	phys_addr_t last_end = ISA_END_ADDRESS;
125	unsigned long released = 0;
126	int i;
127
128	/* Free any unused memory above the low 1Mbyte. */
129	for (i = 0; i < e820->nr_map && last_end < max_addr; i++) {
130		phys_addr_t end = e820->map[i].addr;
131		end = min(max_addr, end);
 
 
132
133		if (last_end < end)
134			released += xen_release_chunk(last_end, end);
135		last_end = max(last_end, e820->map[i].addr + e820->map[i].size);
 
 
136	}
137
138	if (last_end < max_addr)
139		released += xen_release_chunk(last_end, max_addr);
 
140
141	printk(KERN_INFO "released %lu pages of unused memory\n", released);
142	return released;
 
 
 
 
143}
144
145static unsigned long __init xen_set_identity(const struct e820entry *list,
146					     ssize_t map_size)
 
 
 
 
 
 
 
 
 
 
 
 
147{
148	phys_addr_t last = xen_initial_domain() ? 0 : ISA_END_ADDRESS;
149	phys_addr_t start_pci = last;
150	const struct e820entry *entry;
151	unsigned long identity = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
152	int i;
153
154	for (i = 0, entry = list; i < map_size; i++, entry++) {
155		phys_addr_t start = entry->addr;
156		phys_addr_t end = start + entry->size;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
157
158		if (start < last)
159			start = last;
160
161		if (end <= start)
162			continue;
 
 
 
 
 
 
 
 
 
 
 
 
 
163
164		/* Skip over the 1MB region. */
165		if (last > end)
166			continue;
167
168		if ((entry->type == E820_RAM) || (entry->type == E820_UNUSABLE)) {
169			if (start > start_pci)
170				identity += set_phys_range_identity(
171						PFN_UP(start_pci), PFN_DOWN(start));
172
173			/* Without saving 'last' we would gooble RAM too
174			 * at the end of the loop. */
175			last = end;
176			start_pci = end;
177			continue;
 
 
 
 
 
 
 
 
 
 
 
178		}
179		start_pci = min(start, start_pci);
180		last = end;
181	}
182	if (last > start_pci)
183		identity += set_phys_range_identity(
184					PFN_UP(start_pci), PFN_DOWN(last));
185	return identity;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
186}
187
188static unsigned long __init xen_get_max_pages(void)
189{
190	unsigned long max_pages = MAX_DOMAIN_PAGES;
191	domid_t domid = DOMID_SELF;
192	int ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
193
194	ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
195	if (ret > 0)
196		max_pages = ret;
197	return min(max_pages, MAX_DOMAIN_PAGES);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
198}
199
200/**
201 * machine_specific_memory_setup - Hook for machine specific memory setup.
202 **/
203char * __init xen_memory_setup(void)
204{
205	static struct e820entry map[E820MAX] __initdata;
206	static struct e820entry map_raw[E820MAX] __initdata;
207
208	unsigned long max_pfn = xen_start_info->nr_pages;
209	unsigned long long mem_end;
210	int rc;
211	struct xen_memory_map memmap;
 
212	unsigned long extra_pages = 0;
213	unsigned long extra_limit;
214	unsigned long identity_pages = 0;
215	int i;
216	int op;
217
218	max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
 
 
219	mem_end = PFN_PHYS(max_pfn);
220
221	memmap.nr_entries = E820MAX;
222	set_xen_guest_handle(memmap.buffer, map);
 
 
 
 
223
224	op = xen_initial_domain() ?
225		XENMEM_machine_memory_map :
226		XENMEM_memory_map;
227	rc = HYPERVISOR_memory_op(op, &memmap);
228	if (rc == -ENOSYS) {
229		BUG_ON(xen_initial_domain());
230		memmap.nr_entries = 1;
231		map[0].addr = 0ULL;
232		map[0].size = mem_end;
233		/* 8MB slack (to balance backend allocations). */
234		map[0].size += 8ULL << 20;
235		map[0].type = E820_RAM;
236		rc = 0;
237	}
238	BUG_ON(rc);
239
240	memcpy(map_raw, map, sizeof(map));
241	e820.nr_map = 0;
242	xen_extra_mem_start = mem_end;
243	for (i = 0; i < memmap.nr_entries; i++) {
244		unsigned long long end;
245
246		/* Guard against non-page aligned E820 entries. */
247		if (map[i].type == E820_RAM)
248			map[i].size -= (map[i].size + map[i].addr) % PAGE_SIZE;
249
250		end = map[i].addr + map[i].size;
251		if (map[i].type == E820_RAM && end > mem_end) {
252			/* RAM off the end - may be partially included */
253			u64 delta = min(map[i].size, end - mem_end);
254
255			map[i].size -= delta;
256			end -= delta;
257
258			extra_pages += PFN_DOWN(delta);
259			/*
260			 * Set RAM below 4GB that is not for us to be unusable.
261			 * This prevents "System RAM" address space from being
262			 * used as potential resource for I/O address (happens
263			 * when 'allocate_resource' is called).
264			 */
265			if (delta &&
266				(xen_initial_domain() && end < 0x100000000ULL))
267				e820_add_region(end, delta, E820_UNUSABLE);
268		}
269
270		if (map[i].size > 0 && end > xen_extra_mem_start)
271			xen_extra_mem_start = end;
272
273		/* Add region if any remains */
274		if (map[i].size > 0)
275			e820_add_region(map[i].addr, map[i].size, map[i].type);
276	}
277	/* Align the balloon area so that max_low_pfn does not get set
278	 * to be at the _end_ of the PCI gap at the far end (fee01000).
279	 * Note that xen_extra_mem_start gets set in the loop above to be
280	 * past the last E820 region. */
281	if (xen_initial_domain() && (xen_extra_mem_start < (1ULL<<32)))
282		xen_extra_mem_start = (1ULL<<32);
283
284	/*
285	 * In domU, the ISA region is normal, usable memory, but we
286	 * reserve ISA memory anyway because too many things poke
287	 * about in there.
288	 *
289	 * In Dom0, the host E820 information can leave gaps in the
290	 * ISA range, which would cause us to release those pages.  To
291	 * avoid this, we unconditionally reserve them here.
292	 */
293	e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
294			E820_RESERVED);
295
296	/*
297	 * Reserve Xen bits:
298	 *  - mfn_list
299	 *  - xen_start_info
300	 * See comment above "struct start_info" in <xen/interface/xen.h>
301	 */
302	memblock_x86_reserve_range(__pa(xen_start_info->mfn_list),
303		      __pa(xen_start_info->pt_base),
304			"XEN START INFO");
305
306	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
307
308	extra_limit = xen_get_max_pages();
309	if (max_pfn + extra_pages > extra_limit) {
310		if (extra_limit > max_pfn)
311			extra_pages = extra_limit - max_pfn;
312		else
313			extra_pages = 0;
314	}
315
316	extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820);
 
317
318	/*
319	 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
320	 * factor the base size.  On non-highmem systems, the base
321	 * size is the full initial memory allocation; on highmem it
322	 * is limited to the max size of lowmem, so that it doesn't
323	 * get completely filled.
324	 *
 
 
 
325	 * In principle there could be a problem in lowmem systems if
326	 * the initial memory is also very large with respect to
327	 * lowmem, but we won't try to deal with that here.
328	 */
329	extra_limit = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
330			  max_pfn + extra_pages);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
331
332	if (extra_limit >= max_pfn)
333		extra_pages = extra_limit - max_pfn;
334	else
335		extra_pages = 0;
336
337	xen_add_extra_mem(extra_pages);
 
 
 
 
 
 
 
 
 
338
339	/*
340	 * Set P2M for all non-RAM pages and E820 gaps to be identity
341	 * type PFNs. We supply it with the non-sanitized version
342	 * of the E820.
343	 */
344	identity_pages = xen_set_identity(map_raw, memmap.nr_entries);
345	printk(KERN_INFO "Set %ld page(s) to 1-1 mapping.\n", identity_pages);
346	return "Xen";
347}
348
349/*
350 * Set the bit indicating "nosegneg" library variants should be used.
351 * We only need to bother in pure 32-bit mode; compat 32-bit processes
352 * can have un-truncated segments, so wrapping around is allowed.
353 */
354static void __init fiddle_vdso(void)
355{
356#ifdef CONFIG_X86_32
357	u32 *mask;
358	mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK);
359	*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
360	mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK);
361	*mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
362#endif
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
363}
364
365static int __cpuinit register_callback(unsigned type, const void *func)
366{
367	struct callback_register callback = {
368		.type = type,
369		.address = XEN_CALLBACK(__KERNEL_CS, func),
370		.flags = CALLBACKF_mask_events,
371	};
372
373	return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
374}
375
376void __cpuinit xen_enable_sysenter(void)
377{
378	int ret;
379	unsigned sysenter_feature;
380
381#ifdef CONFIG_X86_32
382	sysenter_feature = X86_FEATURE_SEP;
383#else
384	sysenter_feature = X86_FEATURE_SYSENTER32;
385#endif
386
387	if (!boot_cpu_has(sysenter_feature))
388		return;
389
390	ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
391	if(ret != 0)
392		setup_clear_cpu_cap(sysenter_feature);
393}
394
395void __cpuinit xen_enable_syscall(void)
396{
397#ifdef CONFIG_X86_64
398	int ret;
399
400	ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
401	if (ret != 0) {
402		printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
403		/* Pretty fatal; 64-bit userspace has no other
404		   mechanism for syscalls. */
405	}
406
407	if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
408		ret = register_callback(CALLBACKTYPE_syscall32,
409					xen_syscall32_target);
410		if (ret != 0)
411			setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
412	}
413#endif /* CONFIG_X86_64 */
414}
415
416void __init xen_arch_setup(void)
417{
418	xen_panic_handler_init();
419
420	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
421	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
422
423	if (!xen_feature(XENFEAT_auto_translated_physmap))
424		HYPERVISOR_vm_assist(VMASST_CMD_enable,
425				     VMASST_TYPE_pae_extended_cr3);
426
427	if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
 
428	    register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
429		BUG();
430
431	xen_enable_sysenter();
432	xen_enable_syscall();
 
 
 
 
 
 
 
433
434#ifdef CONFIG_ACPI
435	if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
436		printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
437		disable_acpi();
438	}
439#endif
440
441	memcpy(boot_command_line, xen_start_info->cmd_line,
442	       MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
443	       COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
444
445	/* Set up idle, making sure it calls safe_halt() pvop */
446#ifdef CONFIG_X86_32
447	boot_cpu_data.hlt_works_ok = 1;
448#endif
449	disable_cpuidle();
450	boot_option_idle_override = IDLE_HALT;
451
452	fiddle_vdso();
 
 
453}
v5.9
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Machine specific setup for xen
  4 *
  5 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
  6 */
  7
  8#include <linux/init.h>
  9#include <linux/sched.h>
 10#include <linux/mm.h>
 11#include <linux/pm.h>
 12#include <linux/memblock.h>
 13#include <linux/cpuidle.h>
 14#include <linux/cpufreq.h>
 15#include <linux/memory_hotplug.h>
 16
 17#include <asm/elf.h>
 18#include <asm/vdso.h>
 19#include <asm/e820/api.h>
 20#include <asm/setup.h>
 21#include <asm/acpi.h>
 22#include <asm/numa.h>
 23#include <asm/idtentry.h>
 24#include <asm/xen/hypervisor.h>
 25#include <asm/xen/hypercall.h>
 26
 27#include <xen/xen.h>
 28#include <xen/page.h>
 29#include <xen/interface/callback.h>
 30#include <xen/interface/memory.h>
 31#include <xen/interface/physdev.h>
 32#include <xen/features.h>
 33#include <xen/hvc-console.h>
 34#include "xen-ops.h"
 35#include "mmu.h"
 36
 37#define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024)
 
 
 
 
 
 38
 39/* Amount of extra memory space we add to the e820 ranges */
 40struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
 41
 42/* Number of pages released from the initial allocation. */
 43unsigned long xen_released_pages;
 44
 45/* E820 map used during setting up memory. */
 46static struct e820_table xen_e820_table __initdata;
 47
 48/*
 49 * Buffer used to remap identity mapped pages. We only need the virtual space.
 50 * The physical page behind this address is remapped as needed to different
 51 * buffer pages.
 52 */
 53#define REMAP_SIZE	(P2M_PER_PAGE - 3)
 54static struct {
 55	unsigned long	next_area_mfn;
 56	unsigned long	target_pfn;
 57	unsigned long	size;
 58	unsigned long	mfns[REMAP_SIZE];
 59} xen_remap_buf __initdata __aligned(PAGE_SIZE);
 60static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
 61
 62/* 
 63 * The maximum amount of extra memory compared to the base size.  The
 64 * main scaling factor is the size of struct page.  At extreme ratios
 65 * of base:extra, all the base memory can be filled with page
 66 * structures for the extra memory, leaving no space for anything
 67 * else.
 68 * 
 69 * 10x seems like a reasonable balance between scaling flexibility and
 70 * leaving a practically usable system.
 71 */
 72#define EXTRA_MEM_RATIO		(10)
 73
 74static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
 75
 76static void __init xen_parse_512gb(void)
 77{
 78	bool val = false;
 79	char *arg;
 80
 81	arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit");
 82	if (!arg)
 83		return;
 84
 85	arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit=");
 86	if (!arg)
 87		val = true;
 88	else if (strtobool(arg + strlen("xen_512gb_limit="), &val))
 89		return;
 90
 91	xen_512gb_limit = val;
 92}
 93
 94static void __init xen_add_extra_mem(unsigned long start_pfn,
 95				     unsigned long n_pfns)
 96{
 97	int i;
 98
 99	/*
100	 * No need to check for zero size, should happen rarely and will only
101	 * write a new entry regarded to be unused due to zero size.
102	 */
103	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
104		/* Add new region. */
105		if (xen_extra_mem[i].n_pfns == 0) {
106			xen_extra_mem[i].start_pfn = start_pfn;
107			xen_extra_mem[i].n_pfns = n_pfns;
108			break;
109		}
110		/* Append to existing region. */
111		if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns ==
112		    start_pfn) {
113			xen_extra_mem[i].n_pfns += n_pfns;
114			break;
115		}
116	}
117	if (i == XEN_EXTRA_MEM_MAX_REGIONS)
118		printk(KERN_WARNING "Warning: not enough extra memory regions\n");
119
120	memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
121}
122
123static void __init xen_del_extra_mem(unsigned long start_pfn,
124				     unsigned long n_pfns)
125{
126	int i;
127	unsigned long start_r, size_r;
128
129	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
130		start_r = xen_extra_mem[i].start_pfn;
131		size_r = xen_extra_mem[i].n_pfns;
132
133		/* Start of region. */
134		if (start_r == start_pfn) {
135			BUG_ON(n_pfns > size_r);
136			xen_extra_mem[i].start_pfn += n_pfns;
137			xen_extra_mem[i].n_pfns -= n_pfns;
138			break;
139		}
140		/* End of region. */
141		if (start_r + size_r == start_pfn + n_pfns) {
142			BUG_ON(n_pfns > size_r);
143			xen_extra_mem[i].n_pfns -= n_pfns;
144			break;
145		}
146		/* Mid of region. */
147		if (start_pfn > start_r && start_pfn < start_r + size_r) {
148			BUG_ON(start_pfn + n_pfns > start_r + size_r);
149			xen_extra_mem[i].n_pfns = start_pfn - start_r;
150			/* Calling memblock_reserve() again is okay. */
151			xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r -
152					  (start_pfn + n_pfns));
153			break;
154		}
155	}
156	memblock_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
157}
158
159/*
160 * Called during boot before the p2m list can take entries beyond the
161 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as
162 * invalid.
163 */
164unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
165{
166	int i;
167
168	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
169		if (pfn >= xen_extra_mem[i].start_pfn &&
170		    pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns)
171			return INVALID_P2M_ENTRY;
172	}
173
174	return IDENTITY_FRAME(pfn);
175}
176
177/*
178 * Mark all pfns of extra mem as invalid in p2m list.
179 */
180void __init xen_inv_extra_mem(void)
181{
182	unsigned long pfn, pfn_s, pfn_e;
183	int i;
184
185	for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
186		if (!xen_extra_mem[i].n_pfns)
187			continue;
188		pfn_s = xen_extra_mem[i].start_pfn;
189		pfn_e = pfn_s + xen_extra_mem[i].n_pfns;
190		for (pfn = pfn_s; pfn < pfn_e; pfn++)
191			set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
192	}
193}
194
195/*
196 * Finds the next RAM pfn available in the E820 map after min_pfn.
197 * This function updates min_pfn with the pfn found and returns
198 * the size of that range or zero if not found.
199 */
200static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn)
201{
202	const struct e820_entry *entry = xen_e820_table.entries;
203	unsigned int i;
204	unsigned long done = 0;
205
206	for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
207		unsigned long s_pfn;
208		unsigned long e_pfn;
209
210		if (entry->type != E820_TYPE_RAM)
211			continue;
212
213		e_pfn = PFN_DOWN(entry->addr + entry->size);
214
215		/* We only care about E820 after this */
216		if (e_pfn <= *min_pfn)
217			continue;
218
219		s_pfn = PFN_UP(entry->addr);
220
221		/* If min_pfn falls within the E820 entry, we want to start
222		 * at the min_pfn PFN.
223		 */
224		if (s_pfn <= *min_pfn) {
225			done = e_pfn - *min_pfn;
226		} else {
227			done = e_pfn - s_pfn;
228			*min_pfn = s_pfn;
229		}
230		break;
231	}
232
233	return done;
234}
235
236static int __init xen_free_mfn(unsigned long mfn)
237{
238	struct xen_memory_reservation reservation = {
239		.address_bits = 0,
240		.extent_order = 0,
241		.domid        = DOMID_SELF
242	};
 
 
 
 
243
244	set_xen_guest_handle(reservation.extent_start, &mfn);
245	reservation.nr_extents = 1;
246
247	return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
248}
249
250/*
251 * This releases a chunk of memory and then does the identity map. It's used
252 * as a fallback if the remapping fails.
253 */
254static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
255			unsigned long end_pfn, unsigned long nr_pages)
256{
257	unsigned long pfn, end;
258	int ret;
259
260	WARN_ON(start_pfn > end_pfn);
261
262	/* Release pages first. */
263	end = min(end_pfn, nr_pages);
264	for (pfn = start_pfn; pfn < end; pfn++) {
265		unsigned long mfn = pfn_to_mfn(pfn);
266
267		/* Make sure pfn exists to start with */
268		if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
269			continue;
270
271		ret = xen_free_mfn(mfn);
 
 
 
 
272		WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
273
274		if (ret == 1) {
275			xen_released_pages++;
276			if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
277				break;
278		} else
279			break;
280	}
 
 
281
282	set_phys_range_identity(start_pfn, end_pfn);
283}
284
285/*
286 * Helper function to update the p2m and m2p tables and kernel mapping.
287 */
288static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
289{
290	struct mmu_update update = {
291		.ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
292		.val = pfn
293	};
294
295	/* Update p2m */
296	if (!set_phys_to_machine(pfn, mfn)) {
297		WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n",
298		     pfn, mfn);
299		BUG();
300	}
301
302	/* Update m2p */
303	if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) {
304		WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n",
305		     mfn, pfn);
306		BUG();
307	}
308
309	/* Update kernel mapping, but not for highmem. */
310	if (pfn >= PFN_UP(__pa(high_memory - 1)))
311		return;
312
313	if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
314					 mfn_pte(mfn, PAGE_KERNEL), 0)) {
315		WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n",
316		      mfn, pfn);
317		BUG();
318	}
319}
320
321/*
322 * This function updates the p2m and m2p tables with an identity map from
323 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the
324 * original allocation at remap_pfn. The information needed for remapping is
325 * saved in the memory itself to avoid the need for allocating buffers. The
326 * complete remap information is contained in a list of MFNs each containing
327 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap.
328 * This enables us to preserve the original mfn sequence while doing the
329 * remapping at a time when the memory management is capable of allocating
330 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and
331 * its callers.
332 */
333static void __init xen_do_set_identity_and_remap_chunk(
334        unsigned long start_pfn, unsigned long size, unsigned long remap_pfn)
335{
336	unsigned long buf = (unsigned long)&xen_remap_buf;
337	unsigned long mfn_save, mfn;
338	unsigned long ident_pfn_iter, remap_pfn_iter;
339	unsigned long ident_end_pfn = start_pfn + size;
340	unsigned long left = size;
341	unsigned int i, chunk;
342
343	WARN_ON(size == 0);
344
345	mfn_save = virt_to_mfn(buf);
346
347	for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn;
348	     ident_pfn_iter < ident_end_pfn;
349	     ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) {
350		chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE;
351
352		/* Map first pfn to xen_remap_buf */
353		mfn = pfn_to_mfn(ident_pfn_iter);
354		set_pte_mfn(buf, mfn, PAGE_KERNEL);
355
356		/* Save mapping information in page */
357		xen_remap_buf.next_area_mfn = xen_remap_mfn;
358		xen_remap_buf.target_pfn = remap_pfn_iter;
359		xen_remap_buf.size = chunk;
360		for (i = 0; i < chunk; i++)
361			xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i);
362
363		/* Put remap buf into list. */
364		xen_remap_mfn = mfn;
365
366		/* Set identity map */
367		set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
368
369		left -= chunk;
370	}
371
372	/* Restore old xen_remap_buf mapping */
373	set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
374}
375
376/*
377 * This function takes a contiguous pfn range that needs to be identity mapped
378 * and:
379 *
380 *  1) Finds a new range of pfns to use to remap based on E820 and remap_pfn.
381 *  2) Calls the do_ function to actually do the mapping/remapping work.
382 *
383 * The goal is to not allocate additional memory but to remap the existing
384 * pages. In the case of an error the underlying memory is simply released back
385 * to Xen and not remapped.
386 */
387static unsigned long __init xen_set_identity_and_remap_chunk(
388	unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
389	unsigned long remap_pfn)
390{
391	unsigned long pfn;
392	unsigned long i = 0;
393	unsigned long n = end_pfn - start_pfn;
394
395	if (remap_pfn == 0)
396		remap_pfn = nr_pages;
397
398	while (i < n) {
399		unsigned long cur_pfn = start_pfn + i;
400		unsigned long left = n - i;
401		unsigned long size = left;
402		unsigned long remap_range_size;
403
404		/* Do not remap pages beyond the current allocation */
405		if (cur_pfn >= nr_pages) {
406			/* Identity map remaining pages */
407			set_phys_range_identity(cur_pfn, cur_pfn + size);
408			break;
409		}
410		if (cur_pfn + size > nr_pages)
411			size = nr_pages - cur_pfn;
412
413		remap_range_size = xen_find_pfn_range(&remap_pfn);
414		if (!remap_range_size) {
415			pr_warn("Unable to find available pfn range, not remapping identity pages\n");
416			xen_set_identity_and_release_chunk(cur_pfn,
417						cur_pfn + left, nr_pages);
418			break;
419		}
420		/* Adjust size to fit in current e820 RAM region */
421		if (size > remap_range_size)
422			size = remap_range_size;
423
424		xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
425
426		/* Update variables to reflect new mappings. */
427		i += size;
428		remap_pfn += size;
429	}
430
431	/*
432	 * If the PFNs are currently mapped, the VA mapping also needs
433	 * to be updated to be 1:1.
434	 */
435	for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
436		(void)HYPERVISOR_update_va_mapping(
437			(unsigned long)__va(pfn << PAGE_SHIFT),
438			mfn_pte(pfn, PAGE_KERNEL_IO), 0);
439
440	return remap_pfn;
441}
442
443static unsigned long __init xen_count_remap_pages(
444	unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
445	unsigned long remap_pages)
446{
447	if (start_pfn >= nr_pages)
448		return remap_pages;
449
450	return remap_pages + min(end_pfn, nr_pages) - start_pfn;
451}
452
453static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages,
454	unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn,
455			      unsigned long nr_pages, unsigned long last_val))
456{
457	phys_addr_t start = 0;
458	unsigned long ret_val = 0;
459	const struct e820_entry *entry = xen_e820_table.entries;
460	int i;
461
462	/*
463	 * Combine non-RAM regions and gaps until a RAM region (or the
464	 * end of the map) is reached, then call the provided function
465	 * to perform its duty on the non-RAM region.
466	 *
467	 * The combined non-RAM regions are rounded to a whole number
468	 * of pages so any partial pages are accessible via the 1:1
469	 * mapping.  This is needed for some BIOSes that put (for
470	 * example) the DMI tables in a reserved region that begins on
471	 * a non-page boundary.
472	 */
473	for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
474		phys_addr_t end = entry->addr + entry->size;
475		if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) {
476			unsigned long start_pfn = PFN_DOWN(start);
477			unsigned long end_pfn = PFN_UP(end);
478
479			if (entry->type == E820_TYPE_RAM)
480				end_pfn = PFN_UP(entry->addr);
481
482			if (start_pfn < end_pfn)
483				ret_val = func(start_pfn, end_pfn, nr_pages,
484					       ret_val);
485			start = end;
486		}
487	}
488
489	return ret_val;
490}
491
492/*
493 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk().
494 * The remap information (which mfn remap to which pfn) is contained in the
495 * to be remapped memory itself in a linked list anchored at xen_remap_mfn.
496 * This scheme allows to remap the different chunks in arbitrary order while
497 * the resulting mapping will be independent from the order.
498 */
499void __init xen_remap_memory(void)
500{
501	unsigned long buf = (unsigned long)&xen_remap_buf;
502	unsigned long mfn_save, pfn;
503	unsigned long remapped = 0;
504	unsigned int i;
505	unsigned long pfn_s = ~0UL;
506	unsigned long len = 0;
507
508	mfn_save = virt_to_mfn(buf);
 
 
509
510	while (xen_remap_mfn != INVALID_P2M_ENTRY) {
511		/* Map the remap information */
512		set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL);
513
514		BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]);
515
516		pfn = xen_remap_buf.target_pfn;
517		for (i = 0; i < xen_remap_buf.size; i++) {
518			xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]);
519			remapped++;
520			pfn++;
521		}
522		if (pfn_s == ~0UL || pfn == pfn_s) {
523			pfn_s = xen_remap_buf.target_pfn;
524			len += xen_remap_buf.size;
525		} else if (pfn_s + len == xen_remap_buf.target_pfn) {
526			len += xen_remap_buf.size;
527		} else {
528			xen_del_extra_mem(pfn_s, len);
529			pfn_s = xen_remap_buf.target_pfn;
530			len = xen_remap_buf.size;
531		}
532		xen_remap_mfn = xen_remap_buf.next_area_mfn;
 
533	}
534
535	if (pfn_s != ~0UL && len)
536		xen_del_extra_mem(pfn_s, len);
537
538	set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
539
540	pr_info("Remapped %ld page(s)\n", remapped);
541}
542
543static unsigned long __init xen_get_pages_limit(void)
544{
545	unsigned long limit;
546
547	limit = MAXMEM / PAGE_SIZE;
548	if (!xen_initial_domain() && xen_512gb_limit)
549		limit = GB(512) / PAGE_SIZE;
550
551	return limit;
552}
553
554static unsigned long __init xen_get_max_pages(void)
555{
556	unsigned long max_pages, limit;
557	domid_t domid = DOMID_SELF;
558	long ret;
559
560	limit = xen_get_pages_limit();
561	max_pages = limit;
562
563	/*
564	 * For the initial domain we use the maximum reservation as
565	 * the maximum page.
566	 *
567	 * For guest domains the current maximum reservation reflects
568	 * the current maximum rather than the static maximum. In this
569	 * case the e820 map provided to us will cover the static
570	 * maximum region.
571	 */
572	if (xen_initial_domain()) {
573		ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
574		if (ret > 0)
575			max_pages = ret;
576	}
577
578	return min(max_pages, limit);
579}
580
581static void __init xen_align_and_add_e820_region(phys_addr_t start,
582						 phys_addr_t size, int type)
583{
584	phys_addr_t end = start + size;
585
586	/* Align RAM regions to page boundaries. */
587	if (type == E820_TYPE_RAM) {
588		start = PAGE_ALIGN(start);
589		end &= ~((phys_addr_t)PAGE_SIZE - 1);
590#ifdef CONFIG_MEMORY_HOTPLUG
591		/*
592		 * Don't allow adding memory not in E820 map while booting the
593		 * system. Once the balloon driver is up it will remove that
594		 * restriction again.
595		 */
596		max_mem_size = end;
597#endif
598	}
599
600	e820__range_add(start, end - start, type);
601}
602
603static void __init xen_ignore_unusable(void)
604{
605	struct e820_entry *entry = xen_e820_table.entries;
606	unsigned int i;
607
608	for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
609		if (entry->type == E820_TYPE_UNUSABLE)
610			entry->type = E820_TYPE_RAM;
611	}
612}
613
614bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size)
615{
616	struct e820_entry *entry;
617	unsigned mapcnt;
618	phys_addr_t end;
619
620	if (!size)
621		return false;
622
623	end = start + size;
624	entry = xen_e820_table.entries;
625
626	for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
627		if (entry->type == E820_TYPE_RAM && entry->addr <= start &&
628		    (entry->addr + entry->size) >= end)
629			return false;
630
631		entry++;
632	}
633
634	return true;
635}
636
637/*
638 * Find a free area in physical memory not yet reserved and compliant with
639 * E820 map.
640 * Used to relocate pre-allocated areas like initrd or p2m list which are in
641 * conflict with the to be used E820 map.
642 * In case no area is found, return 0. Otherwise return the physical address
643 * of the area which is already reserved for convenience.
644 */
645phys_addr_t __init xen_find_free_area(phys_addr_t size)
646{
647	unsigned mapcnt;
648	phys_addr_t addr, start;
649	struct e820_entry *entry = xen_e820_table.entries;
650
651	for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) {
652		if (entry->type != E820_TYPE_RAM || entry->size < size)
653			continue;
654		start = entry->addr;
655		for (addr = start; addr < start + size; addr += PAGE_SIZE) {
656			if (!memblock_is_reserved(addr))
657				continue;
658			start = addr + PAGE_SIZE;
659			if (start + size > entry->addr + entry->size)
660				break;
661		}
662		if (addr >= start + size) {
663			memblock_reserve(start, size);
664			return start;
665		}
666	}
667
668	return 0;
669}
670
671/*
672 * Like memcpy, but with physical addresses for dest and src.
673 */
674static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src,
675				   phys_addr_t n)
676{
677	phys_addr_t dest_off, src_off, dest_len, src_len, len;
678	void *from, *to;
679
680	while (n) {
681		dest_off = dest & ~PAGE_MASK;
682		src_off = src & ~PAGE_MASK;
683		dest_len = n;
684		if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off)
685			dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off;
686		src_len = n;
687		if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off)
688			src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off;
689		len = min(dest_len, src_len);
690		to = early_memremap(dest - dest_off, dest_len + dest_off);
691		from = early_memremap(src - src_off, src_len + src_off);
692		memcpy(to, from, len);
693		early_memunmap(to, dest_len + dest_off);
694		early_memunmap(from, src_len + src_off);
695		n -= len;
696		dest += len;
697		src += len;
698	}
699}
700
701/*
702 * Reserve Xen mfn_list.
703 */
704static void __init xen_reserve_xen_mfnlist(void)
705{
706	phys_addr_t start, size;
707
708	if (xen_start_info->mfn_list >= __START_KERNEL_map) {
709		start = __pa(xen_start_info->mfn_list);
710		size = PFN_ALIGN(xen_start_info->nr_pages *
711				 sizeof(unsigned long));
712	} else {
713		start = PFN_PHYS(xen_start_info->first_p2m_pfn);
714		size = PFN_PHYS(xen_start_info->nr_p2m_frames);
715	}
716
717	memblock_reserve(start, size);
718	if (!xen_is_e820_reserved(start, size))
719		return;
720
721	xen_relocate_p2m();
722	memblock_free(start, size);
723}
724
725/**
726 * machine_specific_memory_setup - Hook for machine specific memory setup.
727 **/
728char * __init xen_memory_setup(void)
729{
730	unsigned long max_pfn, pfn_s, n_pfns;
731	phys_addr_t mem_end, addr, size, chunk_size;
732	u32 type;
 
 
733	int rc;
734	struct xen_memory_map memmap;
735	unsigned long max_pages;
736	unsigned long extra_pages = 0;
 
 
737	int i;
738	int op;
739
740	xen_parse_512gb();
741	max_pfn = xen_get_pages_limit();
742	max_pfn = min(max_pfn, xen_start_info->nr_pages);
743	mem_end = PFN_PHYS(max_pfn);
744
745	memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
746	set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
747
748#if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
749	xen_saved_max_mem_size = max_mem_size;
750#endif
751
752	op = xen_initial_domain() ?
753		XENMEM_machine_memory_map :
754		XENMEM_memory_map;
755	rc = HYPERVISOR_memory_op(op, &memmap);
756	if (rc == -ENOSYS) {
757		BUG_ON(xen_initial_domain());
758		memmap.nr_entries = 1;
759		xen_e820_table.entries[0].addr = 0ULL;
760		xen_e820_table.entries[0].size = mem_end;
761		/* 8MB slack (to balance backend allocations). */
762		xen_e820_table.entries[0].size += 8ULL << 20;
763		xen_e820_table.entries[0].type = E820_TYPE_RAM;
764		rc = 0;
765	}
766	BUG_ON(rc);
767	BUG_ON(memmap.nr_entries == 0);
768	xen_e820_table.nr_entries = memmap.nr_entries;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
769
770	/*
771	 * Xen won't allow a 1:1 mapping to be created to UNUSABLE
772	 * regions, so if we're using the machine memory map leave the
773	 * region as RAM as it is in the pseudo-physical map.
774	 *
775	 * UNUSABLE regions in domUs are not handled and will need
776	 * a patch in the future.
 
777	 */
778	if (xen_initial_domain())
779		xen_ignore_unusable();
780
781	/* Make sure the Xen-supplied memory map is well-ordered. */
782	e820__update_table(&xen_e820_table);
 
 
 
 
 
 
 
783
784	max_pages = xen_get_max_pages();
785
786	/* How many extra pages do we need due to remapping? */
787	max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages);
 
 
 
 
 
788
789	if (max_pages > max_pfn)
790		extra_pages += max_pages - max_pfn;
791
792	/*
793	 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
794	 * factor the base size.  On non-highmem systems, the base
795	 * size is the full initial memory allocation; on highmem it
796	 * is limited to the max size of lowmem, so that it doesn't
797	 * get completely filled.
798	 *
799	 * Make sure we have no memory above max_pages, as this area
800	 * isn't handled by the p2m management.
801	 *
802	 * In principle there could be a problem in lowmem systems if
803	 * the initial memory is also very large with respect to
804	 * lowmem, but we won't try to deal with that here.
805	 */
806	extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
807			   extra_pages, max_pages - max_pfn);
808	i = 0;
809	addr = xen_e820_table.entries[0].addr;
810	size = xen_e820_table.entries[0].size;
811	while (i < xen_e820_table.nr_entries) {
812		bool discard = false;
813
814		chunk_size = size;
815		type = xen_e820_table.entries[i].type;
816
817		if (type == E820_TYPE_RAM) {
818			if (addr < mem_end) {
819				chunk_size = min(size, mem_end - addr);
820			} else if (extra_pages) {
821				chunk_size = min(size, PFN_PHYS(extra_pages));
822				pfn_s = PFN_UP(addr);
823				n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
824				extra_pages -= n_pfns;
825				xen_add_extra_mem(pfn_s, n_pfns);
826				xen_max_p2m_pfn = pfn_s + n_pfns;
827			} else
828				discard = true;
829		}
830
831		if (!discard)
832			xen_align_and_add_e820_region(addr, chunk_size, type);
 
 
833
834		addr += chunk_size;
835		size -= chunk_size;
836		if (size == 0) {
837			i++;
838			if (i < xen_e820_table.nr_entries) {
839				addr = xen_e820_table.entries[i].addr;
840				size = xen_e820_table.entries[i].size;
841			}
842		}
843	}
844
845	/*
846	 * Set the rest as identity mapped, in case PCI BARs are
847	 * located here.
 
848	 */
849	set_phys_range_identity(addr / PAGE_SIZE, ~0ul);
 
 
 
850
851	/*
852	 * In domU, the ISA region is normal, usable memory, but we
853	 * reserve ISA memory anyway because too many things poke
854	 * about in there.
855	 */
856	e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED);
857
858	e820__update_table(e820_table);
859
860	/*
861	 * Check whether the kernel itself conflicts with the target E820 map.
862	 * Failing now is better than running into weird problems later due
863	 * to relocating (and even reusing) pages with kernel text or data.
864	 */
865	if (xen_is_e820_reserved(__pa_symbol(_text),
866			__pa_symbol(__bss_stop) - __pa_symbol(_text))) {
867		xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n");
868		BUG();
869	}
870
871	/*
872	 * Check for a conflict of the hypervisor supplied page tables with
873	 * the target E820 map.
874	 */
875	xen_pt_check_e820();
876
877	xen_reserve_xen_mfnlist();
878
879	/* Check for a conflict of the initrd with the target E820 map. */
880	if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image,
881				 boot_params.hdr.ramdisk_size)) {
882		phys_addr_t new_area, start, size;
883
884		new_area = xen_find_free_area(boot_params.hdr.ramdisk_size);
885		if (!new_area) {
886			xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n");
887			BUG();
888		}
889
890		start = boot_params.hdr.ramdisk_image;
891		size = boot_params.hdr.ramdisk_size;
892		xen_phys_memcpy(new_area, start, size);
893		pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n",
894			start, start + size, new_area, new_area + size);
895		memblock_free(start, size);
896		boot_params.hdr.ramdisk_image = new_area;
897		boot_params.ext_ramdisk_image = new_area >> 32;
898	}
899
900	/*
901	 * Set identity map on non-RAM pages and prepare remapping the
902	 * underlying RAM.
903	 */
904	xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk);
905
906	pr_info("Released %ld page(s)\n", xen_released_pages);
907
908	return "Xen";
909}
910
911static int register_callback(unsigned type, const void *func)
912{
913	struct callback_register callback = {
914		.type = type,
915		.address = XEN_CALLBACK(__KERNEL_CS, func),
916		.flags = CALLBACKF_mask_events,
917	};
918
919	return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
920}
921
922void xen_enable_sysenter(void)
923{
924	int ret;
925	unsigned sysenter_feature;
926
 
 
 
927	sysenter_feature = X86_FEATURE_SYSENTER32;
 
928
929	if (!boot_cpu_has(sysenter_feature))
930		return;
931
932	ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
933	if(ret != 0)
934		setup_clear_cpu_cap(sysenter_feature);
935}
936
937void xen_enable_syscall(void)
938{
 
939	int ret;
940
941	ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
942	if (ret != 0) {
943		printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
944		/* Pretty fatal; 64-bit userspace has no other
945		   mechanism for syscalls. */
946	}
947
948	if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
949		ret = register_callback(CALLBACKTYPE_syscall32,
950					xen_syscall32_target);
951		if (ret != 0)
952			setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
953	}
 
954}
955
956static void __init xen_pvmmu_arch_setup(void)
957{
 
 
958	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
959	HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
960
961	HYPERVISOR_vm_assist(VMASST_CMD_enable,
962			     VMASST_TYPE_pae_extended_cr3);
 
963
964	if (register_callback(CALLBACKTYPE_event,
965			      xen_asm_exc_xen_hypervisor_callback) ||
966	    register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
967		BUG();
968
969	xen_enable_sysenter();
970	xen_enable_syscall();
971}
972
973/* This function is not called for HVM domains */
974void __init xen_arch_setup(void)
975{
976	xen_panic_handler_init();
977	xen_pvmmu_arch_setup();
978
979#ifdef CONFIG_ACPI
980	if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
981		printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
982		disable_acpi();
983	}
984#endif
985
986	memcpy(boot_command_line, xen_start_info->cmd_line,
987	       MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
988	       COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
989
990	/* Set up idle, making sure it calls safe_halt() pvop */
 
 
 
991	disable_cpuidle();
992	disable_cpufreq();
993	WARN_ON(xen_set_default_idle());
994#ifdef CONFIG_NUMA
995	numa_off = 1;
996#endif
997}