Linux 4.13.16
[linux/fpc-iii.git] / arch / x86 / xen / setup.c
blobc81046323ebca6df33ded3285affa1027c4482f4
1 /*
2 * Machine specific setup for xen
4 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
5 */
7 #include <linux/init.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 #include <linux/cpufreq.h>
15 #include <asm/elf.h>
16 #include <asm/vdso.h>
17 #include <asm/e820/api.h>
18 #include <asm/setup.h>
19 #include <asm/acpi.h>
20 #include <asm/numa.h>
21 #include <asm/xen/hypervisor.h>
22 #include <asm/xen/hypercall.h>
24 #include <xen/xen.h>
25 #include <xen/page.h>
26 #include <xen/interface/callback.h>
27 #include <xen/interface/memory.h>
28 #include <xen/interface/physdev.h>
29 #include <xen/features.h>
30 #include <xen/hvc-console.h>
31 #include "xen-ops.h"
32 #include "vdso.h"
33 #include "mmu.h"
35 #define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024)
37 /* Amount of extra memory space we add to the e820 ranges */
38 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
40 /* Number of pages released from the initial allocation. */
41 unsigned long xen_released_pages;
43 /* E820 map used during setting up memory. */
44 static struct e820_table xen_e820_table __initdata;
47 * Buffer used to remap identity mapped pages. We only need the virtual space.
48 * The physical page behind this address is remapped as needed to different
49 * buffer pages.
51 #define REMAP_SIZE (P2M_PER_PAGE - 3)
52 static struct {
53 unsigned long next_area_mfn;
54 unsigned long target_pfn;
55 unsigned long size;
56 unsigned long mfns[REMAP_SIZE];
57 } xen_remap_buf __initdata __aligned(PAGE_SIZE);
58 static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
60 /*
61 * The maximum amount of extra memory compared to the base size. The
62 * main scaling factor is the size of struct page. At extreme ratios
63 * of base:extra, all the base memory can be filled with page
64 * structures for the extra memory, leaving no space for anything
65 * else.
67 * 10x seems like a reasonable balance between scaling flexibility and
68 * leaving a practically usable system.
70 #define EXTRA_MEM_RATIO (10)
72 static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
74 static void __init xen_parse_512gb(void)
76 bool val = false;
77 char *arg;
79 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit");
80 if (!arg)
81 return;
83 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit=");
84 if (!arg)
85 val = true;
86 else if (strtobool(arg + strlen("xen_512gb_limit="), &val))
87 return;
89 xen_512gb_limit = val;
92 static void __init xen_add_extra_mem(unsigned long start_pfn,
93 unsigned long n_pfns)
95 int i;
98 * No need to check for zero size, should happen rarely and will only
99 * write a new entry regarded to be unused due to zero size.
101 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
102 /* Add new region. */
103 if (xen_extra_mem[i].n_pfns == 0) {
104 xen_extra_mem[i].start_pfn = start_pfn;
105 xen_extra_mem[i].n_pfns = n_pfns;
106 break;
108 /* Append to existing region. */
109 if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns ==
110 start_pfn) {
111 xen_extra_mem[i].n_pfns += n_pfns;
112 break;
115 if (i == XEN_EXTRA_MEM_MAX_REGIONS)
116 printk(KERN_WARNING "Warning: not enough extra memory regions\n");
118 memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
121 static void __init xen_del_extra_mem(unsigned long start_pfn,
122 unsigned long n_pfns)
124 int i;
125 unsigned long start_r, size_r;
127 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
128 start_r = xen_extra_mem[i].start_pfn;
129 size_r = xen_extra_mem[i].n_pfns;
131 /* Start of region. */
132 if (start_r == start_pfn) {
133 BUG_ON(n_pfns > size_r);
134 xen_extra_mem[i].start_pfn += n_pfns;
135 xen_extra_mem[i].n_pfns -= n_pfns;
136 break;
138 /* End of region. */
139 if (start_r + size_r == start_pfn + n_pfns) {
140 BUG_ON(n_pfns > size_r);
141 xen_extra_mem[i].n_pfns -= n_pfns;
142 break;
144 /* Mid of region. */
145 if (start_pfn > start_r && start_pfn < start_r + size_r) {
146 BUG_ON(start_pfn + n_pfns > start_r + size_r);
147 xen_extra_mem[i].n_pfns = start_pfn - start_r;
148 /* Calling memblock_reserve() again is okay. */
149 xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r -
150 (start_pfn + n_pfns));
151 break;
154 memblock_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
158 * Called during boot before the p2m list can take entries beyond the
159 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as
160 * invalid.
162 unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
164 int i;
166 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
167 if (pfn >= xen_extra_mem[i].start_pfn &&
168 pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns)
169 return INVALID_P2M_ENTRY;
172 return IDENTITY_FRAME(pfn);
176 * Mark all pfns of extra mem as invalid in p2m list.
178 void __init xen_inv_extra_mem(void)
180 unsigned long pfn, pfn_s, pfn_e;
181 int i;
183 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
184 if (!xen_extra_mem[i].n_pfns)
185 continue;
186 pfn_s = xen_extra_mem[i].start_pfn;
187 pfn_e = pfn_s + xen_extra_mem[i].n_pfns;
188 for (pfn = pfn_s; pfn < pfn_e; pfn++)
189 set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
194 * Finds the next RAM pfn available in the E820 map after min_pfn.
195 * This function updates min_pfn with the pfn found and returns
196 * the size of that range or zero if not found.
198 static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn)
200 const struct e820_entry *entry = xen_e820_table.entries;
201 unsigned int i;
202 unsigned long done = 0;
204 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
205 unsigned long s_pfn;
206 unsigned long e_pfn;
208 if (entry->type != E820_TYPE_RAM)
209 continue;
211 e_pfn = PFN_DOWN(entry->addr + entry->size);
213 /* We only care about E820 after this */
214 if (e_pfn <= *min_pfn)
215 continue;
217 s_pfn = PFN_UP(entry->addr);
219 /* If min_pfn falls within the E820 entry, we want to start
220 * at the min_pfn PFN.
222 if (s_pfn <= *min_pfn) {
223 done = e_pfn - *min_pfn;
224 } else {
225 done = e_pfn - s_pfn;
226 *min_pfn = s_pfn;
228 break;
231 return done;
234 static int __init xen_free_mfn(unsigned long mfn)
236 struct xen_memory_reservation reservation = {
237 .address_bits = 0,
238 .extent_order = 0,
239 .domid = DOMID_SELF
242 set_xen_guest_handle(reservation.extent_start, &mfn);
243 reservation.nr_extents = 1;
245 return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
249 * This releases a chunk of memory and then does the identity map. It's used
250 * as a fallback if the remapping fails.
252 static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
253 unsigned long end_pfn, unsigned long nr_pages)
255 unsigned long pfn, end;
256 int ret;
258 WARN_ON(start_pfn > end_pfn);
260 /* Release pages first. */
261 end = min(end_pfn, nr_pages);
262 for (pfn = start_pfn; pfn < end; pfn++) {
263 unsigned long mfn = pfn_to_mfn(pfn);
265 /* Make sure pfn exists to start with */
266 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
267 continue;
269 ret = xen_free_mfn(mfn);
270 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
272 if (ret == 1) {
273 xen_released_pages++;
274 if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
275 break;
276 } else
277 break;
280 set_phys_range_identity(start_pfn, end_pfn);
284 * Helper function to update the p2m and m2p tables and kernel mapping.
286 static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
288 struct mmu_update update = {
289 .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
290 .val = pfn
293 /* Update p2m */
294 if (!set_phys_to_machine(pfn, mfn)) {
295 WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n",
296 pfn, mfn);
297 BUG();
300 /* Update m2p */
301 if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) {
302 WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n",
303 mfn, pfn);
304 BUG();
307 /* Update kernel mapping, but not for highmem. */
308 if (pfn >= PFN_UP(__pa(high_memory - 1)))
309 return;
311 if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
312 mfn_pte(mfn, PAGE_KERNEL), 0)) {
313 WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n",
314 mfn, pfn);
315 BUG();
320 * This function updates the p2m and m2p tables with an identity map from
321 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the
322 * original allocation at remap_pfn. The information needed for remapping is
323 * saved in the memory itself to avoid the need for allocating buffers. The
324 * complete remap information is contained in a list of MFNs each containing
325 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap.
326 * This enables us to preserve the original mfn sequence while doing the
327 * remapping at a time when the memory management is capable of allocating
328 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and
329 * its callers.
331 static void __init xen_do_set_identity_and_remap_chunk(
332 unsigned long start_pfn, unsigned long size, unsigned long remap_pfn)
334 unsigned long buf = (unsigned long)&xen_remap_buf;
335 unsigned long mfn_save, mfn;
336 unsigned long ident_pfn_iter, remap_pfn_iter;
337 unsigned long ident_end_pfn = start_pfn + size;
338 unsigned long left = size;
339 unsigned int i, chunk;
341 WARN_ON(size == 0);
343 BUG_ON(xen_feature(XENFEAT_auto_translated_physmap));
345 mfn_save = virt_to_mfn(buf);
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;
352 /* Map first pfn to xen_remap_buf */
353 mfn = pfn_to_mfn(ident_pfn_iter);
354 set_pte_mfn(buf, mfn, PAGE_KERNEL);
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);
363 /* Put remap buf into list. */
364 xen_remap_mfn = mfn;
366 /* Set identity map */
367 set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
369 left -= chunk;
372 /* Restore old xen_remap_buf mapping */
373 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
377 * This function takes a contiguous pfn range that needs to be identity mapped
378 * and:
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.
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.
387 static 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)
391 unsigned long pfn;
392 unsigned long i = 0;
393 unsigned long n = end_pfn - start_pfn;
395 if (remap_pfn == 0)
396 remap_pfn = nr_pages;
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;
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;
410 if (cur_pfn + size > nr_pages)
411 size = nr_pages - cur_pfn;
413 remap_range_size = xen_find_pfn_range(&remap_pfn);
414 if (!remap_range_size) {
415 pr_warning("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;
420 /* Adjust size to fit in current e820 RAM region */
421 if (size > remap_range_size)
422 size = remap_range_size;
424 xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
426 /* Update variables to reflect new mappings. */
427 i += size;
428 remap_pfn += size;
432 * If the PFNs are currently mapped, the VA mapping also needs
433 * to be updated to be 1:1.
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);
440 return remap_pfn;
443 static 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)
447 if (start_pfn >= nr_pages)
448 return remap_pages;
450 return remap_pages + min(end_pfn, nr_pages) - start_pfn;
453 static 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))
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;
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.
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.
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);
479 if (entry->type == E820_TYPE_RAM)
480 end_pfn = PFN_UP(entry->addr);
482 if (start_pfn < end_pfn)
483 ret_val = func(start_pfn, end_pfn, nr_pages,
484 ret_val);
485 start = end;
489 return ret_val;
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 independant from the order.
499 void __init xen_remap_memory(void)
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;
508 mfn_save = virt_to_mfn(buf);
510 while (xen_remap_mfn != INVALID_P2M_ENTRY) {
511 /* Map the remap information */
512 set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL);
514 BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]);
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++;
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;
532 xen_remap_mfn = xen_remap_buf.next_area_mfn;
535 if (pfn_s != ~0UL && len)
536 xen_del_extra_mem(pfn_s, len);
538 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
540 pr_info("Remapped %ld page(s)\n", remapped);
543 static unsigned long __init xen_get_pages_limit(void)
545 unsigned long limit;
547 #ifdef CONFIG_X86_32
548 limit = GB(64) / PAGE_SIZE;
549 #else
550 limit = MAXMEM / PAGE_SIZE;
551 if (!xen_initial_domain() && xen_512gb_limit)
552 limit = GB(512) / PAGE_SIZE;
553 #endif
554 return limit;
557 static unsigned long __init xen_get_max_pages(void)
559 unsigned long max_pages, limit;
560 domid_t domid = DOMID_SELF;
561 long ret;
563 limit = xen_get_pages_limit();
564 max_pages = limit;
567 * For the initial domain we use the maximum reservation as
568 * the maximum page.
570 * For guest domains the current maximum reservation reflects
571 * the current maximum rather than the static maximum. In this
572 * case the e820 map provided to us will cover the static
573 * maximum region.
575 if (xen_initial_domain()) {
576 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
577 if (ret > 0)
578 max_pages = ret;
581 return min(max_pages, limit);
584 static void __init xen_align_and_add_e820_region(phys_addr_t start,
585 phys_addr_t size, int type)
587 phys_addr_t end = start + size;
589 /* Align RAM regions to page boundaries. */
590 if (type == E820_TYPE_RAM) {
591 start = PAGE_ALIGN(start);
592 end &= ~((phys_addr_t)PAGE_SIZE - 1);
595 e820__range_add(start, end - start, type);
598 static void __init xen_ignore_unusable(void)
600 struct e820_entry *entry = xen_e820_table.entries;
601 unsigned int i;
603 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
604 if (entry->type == E820_TYPE_UNUSABLE)
605 entry->type = E820_TYPE_RAM;
609 bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size)
611 struct e820_entry *entry;
612 unsigned mapcnt;
613 phys_addr_t end;
615 if (!size)
616 return false;
618 end = start + size;
619 entry = xen_e820_table.entries;
621 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
622 if (entry->type == E820_TYPE_RAM && entry->addr <= start &&
623 (entry->addr + entry->size) >= end)
624 return false;
626 entry++;
629 return true;
633 * Find a free area in physical memory not yet reserved and compliant with
634 * E820 map.
635 * Used to relocate pre-allocated areas like initrd or p2m list which are in
636 * conflict with the to be used E820 map.
637 * In case no area is found, return 0. Otherwise return the physical address
638 * of the area which is already reserved for convenience.
640 phys_addr_t __init xen_find_free_area(phys_addr_t size)
642 unsigned mapcnt;
643 phys_addr_t addr, start;
644 struct e820_entry *entry = xen_e820_table.entries;
646 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) {
647 if (entry->type != E820_TYPE_RAM || entry->size < size)
648 continue;
649 start = entry->addr;
650 for (addr = start; addr < start + size; addr += PAGE_SIZE) {
651 if (!memblock_is_reserved(addr))
652 continue;
653 start = addr + PAGE_SIZE;
654 if (start + size > entry->addr + entry->size)
655 break;
657 if (addr >= start + size) {
658 memblock_reserve(start, size);
659 return start;
663 return 0;
667 * Like memcpy, but with physical addresses for dest and src.
669 static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src,
670 phys_addr_t n)
672 phys_addr_t dest_off, src_off, dest_len, src_len, len;
673 void *from, *to;
675 while (n) {
676 dest_off = dest & ~PAGE_MASK;
677 src_off = src & ~PAGE_MASK;
678 dest_len = n;
679 if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off)
680 dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off;
681 src_len = n;
682 if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off)
683 src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off;
684 len = min(dest_len, src_len);
685 to = early_memremap(dest - dest_off, dest_len + dest_off);
686 from = early_memremap(src - src_off, src_len + src_off);
687 memcpy(to, from, len);
688 early_memunmap(to, dest_len + dest_off);
689 early_memunmap(from, src_len + src_off);
690 n -= len;
691 dest += len;
692 src += len;
697 * Reserve Xen mfn_list.
699 static void __init xen_reserve_xen_mfnlist(void)
701 phys_addr_t start, size;
703 if (xen_start_info->mfn_list >= __START_KERNEL_map) {
704 start = __pa(xen_start_info->mfn_list);
705 size = PFN_ALIGN(xen_start_info->nr_pages *
706 sizeof(unsigned long));
707 } else {
708 start = PFN_PHYS(xen_start_info->first_p2m_pfn);
709 size = PFN_PHYS(xen_start_info->nr_p2m_frames);
712 memblock_reserve(start, size);
713 if (!xen_is_e820_reserved(start, size))
714 return;
716 #ifdef CONFIG_X86_32
718 * Relocating the p2m on 32 bit system to an arbitrary virtual address
719 * is not supported, so just give up.
721 xen_raw_console_write("Xen hypervisor allocated p2m list conflicts with E820 map\n");
722 BUG();
723 #else
724 xen_relocate_p2m();
725 memblock_free(start, size);
726 #endif
730 * machine_specific_memory_setup - Hook for machine specific memory setup.
732 char * __init xen_memory_setup(void)
734 unsigned long max_pfn, pfn_s, n_pfns;
735 phys_addr_t mem_end, addr, size, chunk_size;
736 u32 type;
737 int rc;
738 struct xen_memory_map memmap;
739 unsigned long max_pages;
740 unsigned long extra_pages = 0;
741 int i;
742 int op;
744 xen_parse_512gb();
745 max_pfn = xen_get_pages_limit();
746 max_pfn = min(max_pfn, xen_start_info->nr_pages);
747 mem_end = PFN_PHYS(max_pfn);
749 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
750 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
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;
766 BUG_ON(rc);
767 BUG_ON(memmap.nr_entries == 0);
768 xen_e820_table.nr_entries = memmap.nr_entries;
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.
775 * UNUSABLE regions in domUs are not handled and will need
776 * a patch in the future.
778 if (xen_initial_domain())
779 xen_ignore_unusable();
781 /* Make sure the Xen-supplied memory map is well-ordered. */
782 e820__update_table(&xen_e820_table);
784 max_pages = xen_get_max_pages();
786 /* How many extra pages do we need due to remapping? */
787 max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages);
789 if (max_pages > max_pfn)
790 extra_pages += max_pages - max_pfn;
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.
799 * Make sure we have no memory above max_pages, as this area
800 * isn't handled by the p2m management.
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.
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;
814 chunk_size = size;
815 type = xen_e820_table.entries[i].type;
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;
831 if (!discard)
832 xen_align_and_add_e820_region(addr, chunk_size, type);
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;
846 * Set the rest as identity mapped, in case PCI BARs are
847 * located here.
849 set_phys_range_identity(addr / PAGE_SIZE, ~0ul);
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.
856 e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED);
858 e820__update_table(e820_table);
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.
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();
872 * Check for a conflict of the hypervisor supplied page tables with
873 * the target E820 map.
875 xen_pt_check_e820();
877 xen_reserve_xen_mfnlist();
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;
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();
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;
901 * Set identity map on non-RAM pages and prepare remapping the
902 * underlying RAM.
904 xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk);
906 pr_info("Released %ld page(s)\n", xen_released_pages);
908 return "Xen";
912 * Machine specific memory setup for auto-translated guests.
914 char * __init xen_auto_xlated_memory_setup(void)
916 struct xen_memory_map memmap;
917 int i;
918 int rc;
920 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
921 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
923 rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
924 if (rc < 0)
925 panic("No memory map (%d)\n", rc);
927 xen_e820_table.nr_entries = memmap.nr_entries;
929 e820__update_table(&xen_e820_table);
931 for (i = 0; i < xen_e820_table.nr_entries; i++)
932 e820__range_add(xen_e820_table.entries[i].addr, xen_e820_table.entries[i].size, xen_e820_table.entries[i].type);
934 /* Remove p2m info, it is not needed. */
935 xen_start_info->mfn_list = 0;
936 xen_start_info->first_p2m_pfn = 0;
937 xen_start_info->nr_p2m_frames = 0;
939 return "Xen";
943 * Set the bit indicating "nosegneg" library variants should be used.
944 * We only need to bother in pure 32-bit mode; compat 32-bit processes
945 * can have un-truncated segments, so wrapping around is allowed.
947 static void __init fiddle_vdso(void)
949 #ifdef CONFIG_X86_32
950 u32 *mask = vdso_image_32.data +
951 vdso_image_32.sym_VDSO32_NOTE_MASK;
952 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
953 #endif
956 static int register_callback(unsigned type, const void *func)
958 struct callback_register callback = {
959 .type = type,
960 .address = XEN_CALLBACK(__KERNEL_CS, func),
961 .flags = CALLBACKF_mask_events,
964 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
967 void xen_enable_sysenter(void)
969 int ret;
970 unsigned sysenter_feature;
972 #ifdef CONFIG_X86_32
973 sysenter_feature = X86_FEATURE_SEP;
974 #else
975 sysenter_feature = X86_FEATURE_SYSENTER32;
976 #endif
978 if (!boot_cpu_has(sysenter_feature))
979 return;
981 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
982 if(ret != 0)
983 setup_clear_cpu_cap(sysenter_feature);
986 void xen_enable_syscall(void)
988 #ifdef CONFIG_X86_64
989 int ret;
991 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
992 if (ret != 0) {
993 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
994 /* Pretty fatal; 64-bit userspace has no other
995 mechanism for syscalls. */
998 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
999 ret = register_callback(CALLBACKTYPE_syscall32,
1000 xen_syscall32_target);
1001 if (ret != 0)
1002 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
1004 #endif /* CONFIG_X86_64 */
1007 void __init xen_pvmmu_arch_setup(void)
1009 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
1010 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
1012 HYPERVISOR_vm_assist(VMASST_CMD_enable,
1013 VMASST_TYPE_pae_extended_cr3);
1015 if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
1016 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
1017 BUG();
1019 xen_enable_sysenter();
1020 xen_enable_syscall();
1023 /* This function is not called for HVM domains */
1024 void __init xen_arch_setup(void)
1026 xen_panic_handler_init();
1027 if (!xen_feature(XENFEAT_auto_translated_physmap))
1028 xen_pvmmu_arch_setup();
1030 #ifdef CONFIG_ACPI
1031 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
1032 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
1033 disable_acpi();
1035 #endif
1037 memcpy(boot_command_line, xen_start_info->cmd_line,
1038 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
1039 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
1041 /* Set up idle, making sure it calls safe_halt() pvop */
1042 disable_cpuidle();
1043 disable_cpufreq();
1044 WARN_ON(xen_set_default_idle());
1045 fiddle_vdso();
1046 #ifdef CONFIG_NUMA
1047 numa_off = 1;
1048 #endif