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Merge branch 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
[net-next-2.6.git] / arch / x86 / xen / setup.c
CommitLineData
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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>
a9ce6bc1 11#include <linux/memblock.h>
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12
13#include <asm/elf.h>
6c3652ef 14#include <asm/vdso.h>
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15#include <asm/e820.h>
16#include <asm/setup.h>
b792c755 17#include <asm/acpi.h>
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18#include <asm/xen/hypervisor.h>
19#include <asm/xen/hypercall.h>
20
45263cb0 21#include <xen/xen.h>
8006ec3e 22#include <xen/page.h>
e2a81baf 23#include <xen/interface/callback.h>
35ae11fd 24#include <xen/interface/memory.h>
5ead97c8 25#include <xen/interface/physdev.h>
093d7b46 26#include <xen/interface/memory.h>
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27#include <xen/features.h>
28
29#include "xen-ops.h"
d2eea68e 30#include "vdso.h"
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31
32/* These are code, but not functions. Defined in entry.S */
33extern const char xen_hypervisor_callback[];
34extern const char xen_failsafe_callback[];
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35extern void xen_sysenter_target(void);
36extern void xen_syscall_target(void);
37extern void xen_syscall32_target(void);
5ead97c8 38
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39/* Amount of extra memory space we add to the e820 ranges */
40phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
41
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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
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54static __init void xen_add_extra_mem(unsigned long pages)
55{
56 u64 size = (u64)pages * PAGE_SIZE;
3654581e 57 u64 extra_start = xen_extra_mem_start + xen_extra_mem_size;
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58
59 if (!pages)
60 return;
61
3654581e 62 e820_add_region(extra_start, size, E820_RAM);
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63 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
64
520045db 65 memblock_x86_reserve_range(extra_start, extra_start + size, "XEN EXTRA");
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66
67 xen_extra_mem_size += size;
2f7acb20 68
3654581e 69 xen_max_p2m_pfn = PFN_DOWN(extra_start + size);
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70}
71
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72static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
73 phys_addr_t end_addr)
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74{
75 struct xen_memory_reservation reservation = {
76 .address_bits = 0,
77 .extent_order = 0,
78 .domid = DOMID_SELF
79 };
093d7b46 80 unsigned long start, end;
f89e048e 81 unsigned long len = 0;
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82 unsigned long pfn;
83 int ret;
84
85 start = PFN_UP(start_addr);
f89e048e 86 end = PFN_DOWN(end_addr);
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87
88 if (end <= start)
89 return 0;
90
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91 printk(KERN_INFO "xen_release_chunk: looking at area pfn %lx-%lx: ",
92 start, end);
93 for(pfn = start; pfn < end; pfn++) {
94 unsigned long mfn = pfn_to_mfn(pfn);
95
96 /* Make sure pfn exists to start with */
97 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
98 continue;
99
100 set_xen_guest_handle(reservation.extent_start, &mfn);
101 reservation.nr_extents = 1;
102
103 ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
104 &reservation);
105 WARN(ret != 1, "Failed to release memory %lx-%lx err=%d\n",
106 start, end, ret);
107 if (ret == 1) {
108 set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
109 len++;
110 }
111 }
112 printk(KERN_CONT "%ld pages freed\n", len);
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113
114 return len;
115}
116
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117static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
118 const struct e820map *e820)
093d7b46 119{
f89e048e 120 phys_addr_t max_addr = PFN_PHYS(max_pfn);
9ec23a7f 121 phys_addr_t last_end = ISA_END_ADDRESS;
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122 unsigned long released = 0;
123 int i;
124
9ec23a7f 125 /* Free any unused memory above the low 1Mbyte. */
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126 for (i = 0; i < e820->nr_map && last_end < max_addr; i++) {
127 phys_addr_t end = e820->map[i].addr;
128 end = min(max_addr, end);
129
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130 if (last_end < end)
131 released += xen_release_chunk(last_end, end);
132 last_end = max(last_end, e820->map[i].addr + e820->map[i].size);
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133 }
134
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135 if (last_end < max_addr)
136 released += xen_release_chunk(last_end, max_addr);
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137
138 printk(KERN_INFO "released %ld pages of unused memory\n", released);
139 return released;
140}
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141
142/**
143 * machine_specific_memory_setup - Hook for machine specific memory setup.
144 **/
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145char * __init xen_memory_setup(void)
146{
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147 static struct e820entry map[E820MAX] __initdata;
148
5ead97c8 149 unsigned long max_pfn = xen_start_info->nr_pages;
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150 unsigned long long mem_end;
151 int rc;
152 struct xen_memory_map memmap;
42ee1471 153 unsigned long extra_pages = 0;
698bb8d1 154 unsigned long extra_limit;
35ae11fd 155 int i;
9e9a5fcb 156 int op;
5ead97c8 157
8006ec3e 158 max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
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159 mem_end = PFN_PHYS(max_pfn);
160
161 memmap.nr_entries = E820MAX;
162 set_xen_guest_handle(memmap.buffer, map);
163
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164 op = xen_initial_domain() ?
165 XENMEM_machine_memory_map :
166 XENMEM_memory_map;
167 rc = HYPERVISOR_memory_op(op, &memmap);
35ae11fd 168 if (rc == -ENOSYS) {
9ec23a7f 169 BUG_ON(xen_initial_domain());
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170 memmap.nr_entries = 1;
171 map[0].addr = 0ULL;
172 map[0].size = mem_end;
173 /* 8MB slack (to balance backend allocations). */
174 map[0].size += 8ULL << 20;
175 map[0].type = E820_RAM;
176 rc = 0;
177 }
178 BUG_ON(rc);
8006ec3e 179
5ead97c8 180 e820.nr_map = 0;
42ee1471 181 xen_extra_mem_start = mem_end;
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182 for (i = 0; i < memmap.nr_entries; i++) {
183 unsigned long long end = map[i].addr + map[i].size;
be5bf9fa 184
35ae11fd 185 if (map[i].type == E820_RAM) {
3654581e 186 if (map[i].addr < mem_end && end > mem_end) {
35ae11fd 187 /* Truncate region to max_mem. */
3654581e 188 u64 delta = end - mem_end;
42ee1471 189
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190 map[i].size -= delta;
191 extra_pages += PFN_DOWN(delta);
192
193 end = mem_end;
35ae11fd 194 }
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195 }
196
197 if (end > xen_extra_mem_start)
36bc251b 198 xen_extra_mem_start = end;
b5b43ced 199
3654581e 200 /* If region is non-RAM or below mem_end, add what remains */
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201 if ((map[i].type != E820_RAM || map[i].addr < mem_end) &&
202 map[i].size > 0)
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203 e820_add_region(map[i].addr, map[i].size, map[i].type);
204 }
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205
206 /*
9ec23a7f
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207 * In domU, the ISA region is normal, usable memory, but we
208 * reserve ISA memory anyway because too many things poke
b792c755 209 * about in there.
4ec5387c 210 *
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211 * In Dom0, the host E820 information can leave gaps in the
212 * ISA range, which would cause us to release those pages. To
213 * avoid this, we unconditionally reserve them here.
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214 */
215 e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
216 E820_RESERVED);
5ead97c8 217
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218 /*
219 * Reserve Xen bits:
220 * - mfn_list
221 * - xen_start_info
222 * See comment above "struct start_info" in <xen/interface/xen.h>
223 */
a9ce6bc1 224 memblock_x86_reserve_range(__pa(xen_start_info->mfn_list),
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225 __pa(xen_start_info->pt_base),
226 "XEN START INFO");
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227
228 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
229
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230 extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820);
231
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232 /*
233 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
234 * factor the base size. On non-highmem systems, the base
235 * size is the full initial memory allocation; on highmem it
236 * is limited to the max size of lowmem, so that it doesn't
237 * get completely filled.
238 *
239 * In principle there could be a problem in lowmem systems if
240 * the initial memory is also very large with respect to
241 * lowmem, but we won't try to deal with that here.
242 */
243 extra_limit = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
244 max_pfn + extra_pages);
245
246 if (extra_limit >= max_pfn)
247 extra_pages = extra_limit - max_pfn;
248 else
249 extra_pages = 0;
250
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251 if (!xen_initial_domain())
252 xen_add_extra_mem(extra_pages);
093d7b46 253
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254 return "Xen";
255}
256
257static void xen_idle(void)
258{
259 local_irq_disable();
260
261 if (need_resched())
262 local_irq_enable();
263 else {
264 current_thread_info()->status &= ~TS_POLLING;
265 smp_mb__after_clear_bit();
266 safe_halt();
267 current_thread_info()->status |= TS_POLLING;
268 }
269}
270
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271/*
272 * Set the bit indicating "nosegneg" library variants should be used.
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273 * We only need to bother in pure 32-bit mode; compat 32-bit processes
274 * can have un-truncated segments, so wrapping around is allowed.
d2eea68e 275 */
08b6d290 276static void __init fiddle_vdso(void)
d2eea68e 277{
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278#ifdef CONFIG_X86_32
279 u32 *mask;
280 mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK);
281 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
282 mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK);
d2eea68e 283 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
6fcac6d3 284#endif
d2eea68e
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285}
286
88459d4c 287static __cpuinit int register_callback(unsigned type, const void *func)
e2a81baf 288{
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289 struct callback_register callback = {
290 .type = type,
291 .address = XEN_CALLBACK(__KERNEL_CS, func),
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292 .flags = CALLBACKF_mask_events,
293 };
294
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295 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
296}
297
298void __cpuinit xen_enable_sysenter(void)
299{
6fcac6d3 300 int ret;
62541c37 301 unsigned sysenter_feature;
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302
303#ifdef CONFIG_X86_32
62541c37 304 sysenter_feature = X86_FEATURE_SEP;
6fcac6d3 305#else
62541c37 306 sysenter_feature = X86_FEATURE_SYSENTER32;
6fcac6d3 307#endif
88459d4c 308
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309 if (!boot_cpu_has(sysenter_feature))
310 return;
311
6fcac6d3 312 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
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313 if(ret != 0)
314 setup_clear_cpu_cap(sysenter_feature);
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315}
316
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317void __cpuinit xen_enable_syscall(void)
318{
319#ifdef CONFIG_X86_64
6fcac6d3 320 int ret;
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321
322 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
323 if (ret != 0) {
d5303b81 324 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
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325 /* Pretty fatal; 64-bit userspace has no other
326 mechanism for syscalls. */
327 }
328
329 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
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330 ret = register_callback(CALLBACKTYPE_syscall32,
331 xen_syscall32_target);
d5303b81 332 if (ret != 0)
62541c37 333 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
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334 }
335#endif /* CONFIG_X86_64 */
336}
337
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338void __init xen_arch_setup(void)
339{
340 struct physdev_set_iopl set_iopl;
341 int rc;
342
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343 xen_panic_handler_init();
344
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345 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
346 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
347
348 if (!xen_feature(XENFEAT_auto_translated_physmap))
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349 HYPERVISOR_vm_assist(VMASST_CMD_enable,
350 VMASST_TYPE_pae_extended_cr3);
5ead97c8 351
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352 if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
353 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
354 BUG();
5ead97c8 355
e2a81baf 356 xen_enable_sysenter();
6fcac6d3 357 xen_enable_syscall();
e2a81baf 358
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359 set_iopl.iopl = 1;
360 rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
361 if (rc != 0)
362 printk(KERN_INFO "physdev_op failed %d\n", rc);
363
364#ifdef CONFIG_ACPI
365 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
366 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
367 disable_acpi();
368 }
369#endif
370
371 memcpy(boot_command_line, xen_start_info->cmd_line,
372 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
373 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
374
375 pm_idle = xen_idle;
f87e4cac 376
d2eea68e 377 fiddle_vdso();
5ead97c8 378}