Linux 2.6.38-rc2
[linux-block.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>
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25#include <xen/interface/physdev.h>
26#include <xen/features.h>
27
28#include "xen-ops.h"
d2eea68e 29#include "vdso.h"
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30
31/* These are code, but not functions. Defined in entry.S */
32extern const char xen_hypervisor_callback[];
33extern const char xen_failsafe_callback[];
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34extern void xen_sysenter_target(void);
35extern void xen_syscall_target(void);
36extern void xen_syscall32_target(void);
5ead97c8 37
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38/* Amount of extra memory space we add to the e820 ranges */
39phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
40
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41/*
42 * The maximum amount of extra memory compared to the base size. The
43 * main scaling factor is the size of struct page. At extreme ratios
44 * of base:extra, all the base memory can be filled with page
45 * structures for the extra memory, leaving no space for anything
46 * else.
47 *
48 * 10x seems like a reasonable balance between scaling flexibility and
49 * leaving a practically usable system.
50 */
51#define EXTRA_MEM_RATIO (10)
52
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53static __init void xen_add_extra_mem(unsigned long pages)
54{
55 u64 size = (u64)pages * PAGE_SIZE;
3654581e 56 u64 extra_start = xen_extra_mem_start + xen_extra_mem_size;
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57
58 if (!pages)
59 return;
60
3654581e 61 e820_add_region(extra_start, size, E820_RAM);
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62 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
63
520045db 64 memblock_x86_reserve_range(extra_start, extra_start + size, "XEN EXTRA");
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65
66 xen_extra_mem_size += size;
2f7acb20 67
3654581e 68 xen_max_p2m_pfn = PFN_DOWN(extra_start + size);
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69}
70
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71static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
72 phys_addr_t end_addr)
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73{
74 struct xen_memory_reservation reservation = {
75 .address_bits = 0,
76 .extent_order = 0,
77 .domid = DOMID_SELF
78 };
093d7b46 79 unsigned long start, end;
f89e048e 80 unsigned long len = 0;
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81 unsigned long pfn;
82 int ret;
83
84 start = PFN_UP(start_addr);
f89e048e 85 end = PFN_DOWN(end_addr);
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86
87 if (end <= start)
88 return 0;
89
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90 printk(KERN_INFO "xen_release_chunk: looking at area pfn %lx-%lx: ",
91 start, end);
92 for(pfn = start; pfn < end; pfn++) {
93 unsigned long mfn = pfn_to_mfn(pfn);
94
95 /* Make sure pfn exists to start with */
96 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
97 continue;
98
99 set_xen_guest_handle(reservation.extent_start, &mfn);
100 reservation.nr_extents = 1;
101
102 ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
103 &reservation);
104 WARN(ret != 1, "Failed to release memory %lx-%lx err=%d\n",
105 start, end, ret);
106 if (ret == 1) {
107 set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
108 len++;
109 }
110 }
111 printk(KERN_CONT "%ld pages freed\n", len);
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112
113 return len;
114}
115
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116static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
117 const struct e820map *e820)
093d7b46 118{
f89e048e 119 phys_addr_t max_addr = PFN_PHYS(max_pfn);
9ec23a7f 120 phys_addr_t last_end = ISA_END_ADDRESS;
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121 unsigned long released = 0;
122 int i;
123
9ec23a7f 124 /* Free any unused memory above the low 1Mbyte. */
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125 for (i = 0; i < e820->nr_map && last_end < max_addr; i++) {
126 phys_addr_t end = e820->map[i].addr;
127 end = min(max_addr, end);
128
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129 if (last_end < end)
130 released += xen_release_chunk(last_end, end);
131 last_end = max(last_end, e820->map[i].addr + e820->map[i].size);
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132 }
133
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134 if (last_end < max_addr)
135 released += xen_release_chunk(last_end, max_addr);
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136
137 printk(KERN_INFO "released %ld pages of unused memory\n", released);
138 return released;
139}
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140
141/**
142 * machine_specific_memory_setup - Hook for machine specific memory setup.
143 **/
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144char * __init xen_memory_setup(void)
145{
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146 static struct e820entry map[E820MAX] __initdata;
147
5ead97c8 148 unsigned long max_pfn = xen_start_info->nr_pages;
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149 unsigned long long mem_end;
150 int rc;
151 struct xen_memory_map memmap;
42ee1471 152 unsigned long extra_pages = 0;
698bb8d1 153 unsigned long extra_limit;
35ae11fd 154 int i;
9e9a5fcb 155 int op;
5ead97c8 156
8006ec3e 157 max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
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158 mem_end = PFN_PHYS(max_pfn);
159
160 memmap.nr_entries = E820MAX;
161 set_xen_guest_handle(memmap.buffer, map);
162
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163 op = xen_initial_domain() ?
164 XENMEM_machine_memory_map :
165 XENMEM_memory_map;
166 rc = HYPERVISOR_memory_op(op, &memmap);
35ae11fd 167 if (rc == -ENOSYS) {
9ec23a7f 168 BUG_ON(xen_initial_domain());
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169 memmap.nr_entries = 1;
170 map[0].addr = 0ULL;
171 map[0].size = mem_end;
172 /* 8MB slack (to balance backend allocations). */
173 map[0].size += 8ULL << 20;
174 map[0].type = E820_RAM;
175 rc = 0;
176 }
177 BUG_ON(rc);
8006ec3e 178
5ead97c8 179 e820.nr_map = 0;
42ee1471 180 xen_extra_mem_start = mem_end;
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181 for (i = 0; i < memmap.nr_entries; i++) {
182 unsigned long long end = map[i].addr + map[i].size;
be5bf9fa 183
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184 if (map[i].type == E820_RAM && end > mem_end) {
185 /* RAM off the end - may be partially included */
186 u64 delta = min(map[i].size, end - mem_end);
42ee1471 187
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188 map[i].size -= delta;
189 end -= delta;
3654581e 190
c2d08791 191 extra_pages += PFN_DOWN(delta);
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192 }
193
c2d08791 194 if (map[i].size > 0 && end > xen_extra_mem_start)
36bc251b 195 xen_extra_mem_start = end;
b5b43ced 196
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197 /* Add region if any remains */
198 if (map[i].size > 0)
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199 e820_add_region(map[i].addr, map[i].size, map[i].type);
200 }
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201
202 /*
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203 * In domU, the ISA region is normal, usable memory, but we
204 * reserve ISA memory anyway because too many things poke
b792c755 205 * about in there.
4ec5387c 206 *
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207 * In Dom0, the host E820 information can leave gaps in the
208 * ISA range, which would cause us to release those pages. To
209 * avoid this, we unconditionally reserve them here.
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210 */
211 e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
212 E820_RESERVED);
5ead97c8 213
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214 /*
215 * Reserve Xen bits:
216 * - mfn_list
217 * - xen_start_info
218 * See comment above "struct start_info" in <xen/interface/xen.h>
219 */
a9ce6bc1 220 memblock_x86_reserve_range(__pa(xen_start_info->mfn_list),
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221 __pa(xen_start_info->pt_base),
222 "XEN START INFO");
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223
224 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
225
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226 extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820);
227
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228 /*
229 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
230 * factor the base size. On non-highmem systems, the base
231 * size is the full initial memory allocation; on highmem it
232 * is limited to the max size of lowmem, so that it doesn't
233 * get completely filled.
234 *
235 * In principle there could be a problem in lowmem systems if
236 * the initial memory is also very large with respect to
237 * lowmem, but we won't try to deal with that here.
238 */
239 extra_limit = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
240 max_pfn + extra_pages);
241
242 if (extra_limit >= max_pfn)
243 extra_pages = extra_limit - max_pfn;
244 else
245 extra_pages = 0;
246
d2a81713 247 xen_add_extra_mem(extra_pages);
093d7b46 248
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249 return "Xen";
250}
251
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252/*
253 * Set the bit indicating "nosegneg" library variants should be used.
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254 * We only need to bother in pure 32-bit mode; compat 32-bit processes
255 * can have un-truncated segments, so wrapping around is allowed.
d2eea68e 256 */
08b6d290 257static void __init fiddle_vdso(void)
d2eea68e 258{
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259#ifdef CONFIG_X86_32
260 u32 *mask;
261 mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK);
262 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
263 mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK);
d2eea68e 264 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
6fcac6d3 265#endif
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266}
267
88459d4c 268static __cpuinit int register_callback(unsigned type, const void *func)
e2a81baf 269{
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270 struct callback_register callback = {
271 .type = type,
272 .address = XEN_CALLBACK(__KERNEL_CS, func),
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273 .flags = CALLBACKF_mask_events,
274 };
275
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276 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
277}
278
279void __cpuinit xen_enable_sysenter(void)
280{
6fcac6d3 281 int ret;
62541c37 282 unsigned sysenter_feature;
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283
284#ifdef CONFIG_X86_32
62541c37 285 sysenter_feature = X86_FEATURE_SEP;
6fcac6d3 286#else
62541c37 287 sysenter_feature = X86_FEATURE_SYSENTER32;
6fcac6d3 288#endif
88459d4c 289
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290 if (!boot_cpu_has(sysenter_feature))
291 return;
292
6fcac6d3 293 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
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294 if(ret != 0)
295 setup_clear_cpu_cap(sysenter_feature);
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296}
297
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298void __cpuinit xen_enable_syscall(void)
299{
300#ifdef CONFIG_X86_64
6fcac6d3 301 int ret;
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302
303 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
304 if (ret != 0) {
d5303b81 305 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
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306 /* Pretty fatal; 64-bit userspace has no other
307 mechanism for syscalls. */
308 }
309
310 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
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311 ret = register_callback(CALLBACKTYPE_syscall32,
312 xen_syscall32_target);
d5303b81 313 if (ret != 0)
62541c37 314 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
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315 }
316#endif /* CONFIG_X86_64 */
317}
318
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319void __init xen_arch_setup(void)
320{
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321 xen_panic_handler_init();
322
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323 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
324 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
325
326 if (!xen_feature(XENFEAT_auto_translated_physmap))
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327 HYPERVISOR_vm_assist(VMASST_CMD_enable,
328 VMASST_TYPE_pae_extended_cr3);
5ead97c8 329
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330 if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
331 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
332 BUG();
5ead97c8 333
e2a81baf 334 xen_enable_sysenter();
6fcac6d3 335 xen_enable_syscall();
e2a81baf 336
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337#ifdef CONFIG_ACPI
338 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
339 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
340 disable_acpi();
341 }
342#endif
343
344 memcpy(boot_command_line, xen_start_info->cmd_line,
345 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
346 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
347
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348 /* Set up idle, making sure it calls safe_halt() pvop */
349#ifdef CONFIG_X86_32
350 boot_cpu_data.hlt_works_ok = 1;
351#endif
352 pm_idle = default_idle;
f87e4cac 353
d2eea68e 354 fiddle_vdso();
5ead97c8 355}