xen: clean up "extra" memory handling some more
[deliverable/linux.git] / arch / x86 / xen / setup.c
CommitLineData
5ead97c8
JF
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>
5ead97c8
JF
12
13#include <asm/elf.h>
6c3652ef 14#include <asm/vdso.h>
5ead97c8
JF
15#include <asm/e820.h>
16#include <asm/setup.h>
b792c755 17#include <asm/acpi.h>
5ead97c8
JF
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>
5ead97c8
JF
27#include <xen/features.h>
28
29#include "xen-ops.h"
d2eea68e 30#include "vdso.h"
5ead97c8
JF
31
32/* These are code, but not functions. Defined in entry.S */
33extern const char xen_hypervisor_callback[];
34extern const char xen_failsafe_callback[];
f63c2f24
T
35extern void xen_sysenter_target(void);
36extern void xen_syscall_target(void);
37extern void xen_syscall32_target(void);
5ead97c8 38
42ee1471
JF
39/* Amount of extra memory space we add to the e820 ranges */
40phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
41
698bb8d1
JF
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
42ee1471
JF
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;
42ee1471
JF
58
59 if (!pages)
60 return;
61
3654581e 62 e820_add_region(extra_start, size, E820_RAM);
42ee1471
JF
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");
42ee1471
JF
66
67 xen_extra_mem_size += size;
2f7acb20 68
3654581e 69 xen_max_p2m_pfn = PFN_DOWN(extra_start + size);
42ee1471
JF
70}
71
f89e048e
JF
72static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
73 phys_addr_t end_addr)
093d7b46
MR
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;
093d7b46
MR
82 unsigned long pfn;
83 int ret;
84
85 start = PFN_UP(start_addr);
f89e048e 86 end = PFN_DOWN(end_addr);
093d7b46
MR
87
88 if (end <= start)
89 return 0;
90
f89e048e
JF
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);
093d7b46
MR
113
114 return len;
115}
116
f89e048e
JF
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;
093d7b46
MR
122 unsigned long released = 0;
123 int i;
124
9ec23a7f 125 /* Free any unused memory above the low 1Mbyte. */
f89e048e
JF
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
9ec23a7f
IC
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);
093d7b46
MR
133 }
134
f89e048e
JF
135 if (last_end < max_addr)
136 released += xen_release_chunk(last_end, max_addr);
093d7b46
MR
137
138 printk(KERN_INFO "released %ld pages of unused memory\n", released);
139 return released;
140}
5ead97c8
JF
141
142/**
143 * machine_specific_memory_setup - Hook for machine specific memory setup.
144 **/
5ead97c8
JF
145char * __init xen_memory_setup(void)
146{
35ae11fd
IC
147 static struct e820entry map[E820MAX] __initdata;
148
5ead97c8 149 unsigned long max_pfn = xen_start_info->nr_pages;
35ae11fd
IC
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);
35ae11fd
IC
159 mem_end = PFN_PHYS(max_pfn);
160
161 memmap.nr_entries = E820MAX;
162 set_xen_guest_handle(memmap.buffer, map);
163
9e9a5fcb
IC
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());
35ae11fd
IC
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;
35ae11fd
IC
182 for (i = 0; i < memmap.nr_entries; i++) {
183 unsigned long long end = map[i].addr + map[i].size;
be5bf9fa 184
c2d08791
JF
185 if (map[i].type == E820_RAM && end > mem_end) {
186 /* RAM off the end - may be partially included */
187 u64 delta = min(map[i].size, end - mem_end);
42ee1471 188
c2d08791
JF
189 map[i].size -= delta;
190 end -= delta;
3654581e 191
c2d08791 192 extra_pages += PFN_DOWN(delta);
3654581e
JF
193 }
194
c2d08791 195 if (map[i].size > 0 && end > xen_extra_mem_start)
36bc251b 196 xen_extra_mem_start = end;
b5b43ced 197
c2d08791
JF
198 /* Add region if any remains */
199 if (map[i].size > 0)
35ae11fd
IC
200 e820_add_region(map[i].addr, map[i].size, map[i].type);
201 }
b792c755
JF
202
203 /*
9ec23a7f
IC
204 * In domU, the ISA region is normal, usable memory, but we
205 * reserve ISA memory anyway because too many things poke
b792c755 206 * about in there.
4ec5387c 207 *
9ec23a7f
IC
208 * In Dom0, the host E820 information can leave gaps in the
209 * ISA range, which would cause us to release those pages. To
210 * avoid this, we unconditionally reserve them here.
b792c755
JF
211 */
212 e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
213 E820_RESERVED);
5ead97c8 214
be5bf9fa
JF
215 /*
216 * Reserve Xen bits:
217 * - mfn_list
218 * - xen_start_info
219 * See comment above "struct start_info" in <xen/interface/xen.h>
220 */
a9ce6bc1 221 memblock_x86_reserve_range(__pa(xen_start_info->mfn_list),
6b2e8523
JF
222 __pa(xen_start_info->pt_base),
223 "XEN START INFO");
be5bf9fa
JF
224
225 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
226
42ee1471
JF
227 extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820);
228
698bb8d1
JF
229 /*
230 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
231 * factor the base size. On non-highmem systems, the base
232 * size is the full initial memory allocation; on highmem it
233 * is limited to the max size of lowmem, so that it doesn't
234 * get completely filled.
235 *
236 * In principle there could be a problem in lowmem systems if
237 * the initial memory is also very large with respect to
238 * lowmem, but we won't try to deal with that here.
239 */
240 extra_limit = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
241 max_pfn + extra_pages);
242
243 if (extra_limit >= max_pfn)
244 extra_pages = extra_limit - max_pfn;
245 else
246 extra_pages = 0;
247
d2a81713 248 xen_add_extra_mem(extra_pages);
093d7b46 249
5ead97c8
JF
250 return "Xen";
251}
252
253static void xen_idle(void)
254{
255 local_irq_disable();
256
257 if (need_resched())
258 local_irq_enable();
259 else {
260 current_thread_info()->status &= ~TS_POLLING;
261 smp_mb__after_clear_bit();
262 safe_halt();
263 current_thread_info()->status |= TS_POLLING;
264 }
265}
266
d2eea68e
RM
267/*
268 * Set the bit indicating "nosegneg" library variants should be used.
6a52e4b1
JF
269 * We only need to bother in pure 32-bit mode; compat 32-bit processes
270 * can have un-truncated segments, so wrapping around is allowed.
d2eea68e 271 */
08b6d290 272static void __init fiddle_vdso(void)
d2eea68e 273{
6a52e4b1
JF
274#ifdef CONFIG_X86_32
275 u32 *mask;
276 mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK);
277 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
278 mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK);
d2eea68e 279 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
6fcac6d3 280#endif
d2eea68e
RM
281}
282
88459d4c 283static __cpuinit int register_callback(unsigned type, const void *func)
e2a81baf 284{
88459d4c
JF
285 struct callback_register callback = {
286 .type = type,
287 .address = XEN_CALLBACK(__KERNEL_CS, func),
e2a81baf
JF
288 .flags = CALLBACKF_mask_events,
289 };
290
88459d4c
JF
291 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
292}
293
294void __cpuinit xen_enable_sysenter(void)
295{
6fcac6d3 296 int ret;
62541c37 297 unsigned sysenter_feature;
6fcac6d3
JF
298
299#ifdef CONFIG_X86_32
62541c37 300 sysenter_feature = X86_FEATURE_SEP;
6fcac6d3 301#else
62541c37 302 sysenter_feature = X86_FEATURE_SYSENTER32;
6fcac6d3 303#endif
88459d4c 304
62541c37
JF
305 if (!boot_cpu_has(sysenter_feature))
306 return;
307
6fcac6d3 308 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
62541c37
JF
309 if(ret != 0)
310 setup_clear_cpu_cap(sysenter_feature);
e2a81baf
JF
311}
312
6fcac6d3
JF
313void __cpuinit xen_enable_syscall(void)
314{
315#ifdef CONFIG_X86_64
6fcac6d3 316 int ret;
6fcac6d3
JF
317
318 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
319 if (ret != 0) {
d5303b81 320 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
62541c37
JF
321 /* Pretty fatal; 64-bit userspace has no other
322 mechanism for syscalls. */
323 }
324
325 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
6fcac6d3
JF
326 ret = register_callback(CALLBACKTYPE_syscall32,
327 xen_syscall32_target);
d5303b81 328 if (ret != 0)
62541c37 329 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
6fcac6d3
JF
330 }
331#endif /* CONFIG_X86_64 */
332}
333
5ead97c8
JF
334void __init xen_arch_setup(void)
335{
f09f6d19
DD
336 xen_panic_handler_init();
337
5ead97c8
JF
338 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
339 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
340
341 if (!xen_feature(XENFEAT_auto_translated_physmap))
f63c2f24
T
342 HYPERVISOR_vm_assist(VMASST_CMD_enable,
343 VMASST_TYPE_pae_extended_cr3);
5ead97c8 344
88459d4c
JF
345 if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
346 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
347 BUG();
5ead97c8 348
e2a81baf 349 xen_enable_sysenter();
6fcac6d3 350 xen_enable_syscall();
e2a81baf 351
5ead97c8
JF
352#ifdef CONFIG_ACPI
353 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
354 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
355 disable_acpi();
356 }
357#endif
358
359 memcpy(boot_command_line, xen_start_info->cmd_line,
360 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
361 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
362
363 pm_idle = xen_idle;
f87e4cac 364
d2eea68e 365 fiddle_vdso();
5ead97c8 366}
This page took 0.303144 seconds and 5 git commands to generate.