x86, intel_txt: Factor out the code for S3 setup
[linux-2.6.git] / arch / x86 / kernel / tboot.c
1 /*
2  * tboot.c: main implementation of helper functions used by kernel for
3  *          runtime support of Intel(R) Trusted Execution Technology
4  *
5  * Copyright (c) 2006-2009, Intel Corporation
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19  *
20  */
21
22 #include <linux/dma_remapping.h>
23 #include <linux/init_task.h>
24 #include <linux/spinlock.h>
25 #include <linux/sched.h>
26 #include <linux/init.h>
27 #include <linux/dmar.h>
28 #include <linux/pfn.h>
29 #include <linux/mm.h>
30
31 #include <asm/trampoline.h>
32 #include <asm/processor.h>
33 #include <asm/bootparam.h>
34 #include <asm/pgtable.h>
35 #include <asm/pgalloc.h>
36 #include <asm/fixmap.h>
37 #include <asm/proto.h>
38 #include <asm/setup.h>
39 #include <asm/tboot.h>
40 #include <asm/e820.h>
41 #include <asm/io.h>
42
43 #include "acpi/realmode/wakeup.h"
44
45 /* Global pointer to shared data; NULL means no measured launch. */
46 struct tboot *tboot __read_mostly;
47
48 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */
49 #define AP_WAIT_TIMEOUT         1
50
51 #undef pr_fmt
52 #define pr_fmt(fmt)     "tboot: " fmt
53
54 static u8 tboot_uuid[16] __initdata = TBOOT_UUID;
55
56 void __init tboot_probe(void)
57 {
58         /* Look for valid page-aligned address for shared page. */
59         if (!boot_params.tboot_addr)
60                 return;
61         /*
62          * also verify that it is mapped as we expect it before calling
63          * set_fixmap(), to reduce chance of garbage value causing crash
64          */
65         if (!e820_any_mapped(boot_params.tboot_addr,
66                              boot_params.tboot_addr, E820_RESERVED)) {
67                 pr_warning("non-0 tboot_addr but it is not of type E820_RESERVED\n");
68                 return;
69         }
70
71         /* only a natively booted kernel should be using TXT */
72         if (paravirt_enabled()) {
73                 pr_warning("non-0 tboot_addr but pv_ops is enabled\n");
74                 return;
75         }
76
77         /* Map and check for tboot UUID. */
78         set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr);
79         tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE);
80         if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
81                 pr_warning("tboot at 0x%llx is invalid\n",
82                            boot_params.tboot_addr);
83                 tboot = NULL;
84                 return;
85         }
86         if (tboot->version < 5) {
87                 pr_warning("tboot version is invalid: %u\n", tboot->version);
88                 tboot = NULL;
89                 return;
90         }
91
92         pr_info("found shared page at phys addr 0x%llx:\n",
93                 boot_params.tboot_addr);
94         pr_debug("version: %d\n", tboot->version);
95         pr_debug("log_addr: 0x%08x\n", tboot->log_addr);
96         pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry);
97         pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base);
98         pr_debug("tboot_size: 0x%x\n", tboot->tboot_size);
99 }
100
101 static pgd_t *tboot_pg_dir;
102 static struct mm_struct tboot_mm = {
103         .mm_rb          = RB_ROOT,
104         .pgd            = swapper_pg_dir,
105         .mm_users       = ATOMIC_INIT(2),
106         .mm_count       = ATOMIC_INIT(1),
107         .mmap_sem       = __RWSEM_INITIALIZER(init_mm.mmap_sem),
108         .page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
109         .mmlist         = LIST_HEAD_INIT(init_mm.mmlist),
110         .cpu_vm_mask    = CPU_MASK_ALL,
111 };
112
113 static inline void switch_to_tboot_pt(void)
114 {
115         write_cr3(virt_to_phys(tboot_pg_dir));
116 }
117
118 static int map_tboot_page(unsigned long vaddr, unsigned long pfn,
119                           pgprot_t prot)
120 {
121         pgd_t *pgd;
122         pud_t *pud;
123         pmd_t *pmd;
124         pte_t *pte;
125
126         pgd = pgd_offset(&tboot_mm, vaddr);
127         pud = pud_alloc(&tboot_mm, pgd, vaddr);
128         if (!pud)
129                 return -1;
130         pmd = pmd_alloc(&tboot_mm, pud, vaddr);
131         if (!pmd)
132                 return -1;
133         pte = pte_alloc_map(&tboot_mm, pmd, vaddr);
134         if (!pte)
135                 return -1;
136         set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot));
137         pte_unmap(pte);
138         return 0;
139 }
140
141 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn,
142                            unsigned long nr)
143 {
144         /* Reuse the original kernel mapping */
145         tboot_pg_dir = pgd_alloc(&tboot_mm);
146         if (!tboot_pg_dir)
147                 return -1;
148
149         for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) {
150                 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC))
151                         return -1;
152         }
153
154         return 0;
155 }
156
157 void tboot_create_trampoline(void)
158 {
159         u32 map_base, map_size;
160
161         if (!tboot_enabled())
162                 return;
163
164         /* Create identity map for tboot shutdown code. */
165         map_base = PFN_DOWN(tboot->tboot_base);
166         map_size = PFN_UP(tboot->tboot_size);
167         if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size))
168                 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n",
169                       map_base, map_size);
170 }
171
172 #ifdef CONFIG_ACPI_SLEEP
173
174 static void add_mac_region(phys_addr_t start, unsigned long size)
175 {
176         struct tboot_mac_region *mr;
177         phys_addr_t end = start + size;
178
179         if (start && size) {
180                 mr = &tboot->mac_regions[tboot->num_mac_regions++];
181                 mr->start = round_down(start, PAGE_SIZE);
182                 mr->size  = round_up(end, PAGE_SIZE) - mr->start;
183         }
184 }
185
186 static int tboot_setup_sleep(void)
187 {
188         tboot->num_mac_regions = 0;
189
190         /* S3 resume code */
191         add_mac_region(acpi_wakeup_address, WAKEUP_SIZE);
192         /* AP trampoline code */
193         add_mac_region(virt_to_phys(trampoline_base), TRAMPOLINE_SIZE);
194         /* kernel code + data + bss */
195         add_mac_region(virt_to_phys(_text), _end - _text);
196
197         tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;
198
199         return 0;
200 }
201
202 #else /* no CONFIG_ACPI_SLEEP */
203
204 static int tboot_setup_sleep(void)
205 {
206         /* S3 shutdown requested, but S3 not supported by the kernel... */
207         BUG();
208         return -1;
209 }
210
211 #endif
212
213 void tboot_shutdown(u32 shutdown_type)
214 {
215         void (*shutdown)(void);
216
217         if (!tboot_enabled())
218                 return;
219
220         /*
221          * if we're being called before the 1:1 mapping is set up then just
222          * return and let the normal shutdown happen; this should only be
223          * due to very early panic()
224          */
225         if (!tboot_pg_dir)
226                 return;
227
228         /* if this is S3 then set regions to MAC */
229         if (shutdown_type == TB_SHUTDOWN_S3)
230                 if (tboot_setup_sleep())
231                         return;
232
233         tboot->shutdown_type = shutdown_type;
234
235         switch_to_tboot_pt();
236
237         shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry;
238         shutdown();
239
240         /* should not reach here */
241         while (1)
242                 halt();
243 }
244
245 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt)
246 {
247 #define TB_COPY_GAS(tbg, g)                     \
248         tbg.space_id     = g.space_id;          \
249         tbg.bit_width    = g.bit_width;         \
250         tbg.bit_offset   = g.bit_offset;        \
251         tbg.access_width = g.access_width;      \
252         tbg.address      = g.address;
253
254         TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block);
255         TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block);
256         TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block);
257         TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block);
258
259         /*
260          * We need phys addr of waking vector, but can't use virt_to_phys() on
261          * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys
262          * addr.
263          */
264         tboot->acpi_sinfo.wakeup_vector = fadt->facs +
265                 offsetof(struct acpi_table_facs, firmware_waking_vector);
266 }
267
268 void tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control)
269 {
270         static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = {
271                 /* S0,1,2: */ -1, -1, -1,
272                 /* S3: */ TB_SHUTDOWN_S3,
273                 /* S4: */ TB_SHUTDOWN_S4,
274                 /* S5: */ TB_SHUTDOWN_S5 };
275
276         if (!tboot_enabled())
277                 return;
278
279         tboot_copy_fadt(&acpi_gbl_FADT);
280         tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control;
281         tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control;
282         /* we always use the 32b wakeup vector */
283         tboot->acpi_sinfo.vector_width = 32;
284
285         if (sleep_state >= ACPI_S_STATE_COUNT ||
286             acpi_shutdown_map[sleep_state] == -1) {
287                 pr_warning("unsupported sleep state 0x%x\n", sleep_state);
288                 return;
289         }
290
291         tboot_shutdown(acpi_shutdown_map[sleep_state]);
292 }
293
294 int tboot_wait_for_aps(int num_aps)
295 {
296         unsigned long timeout;
297
298         if (!tboot_enabled())
299                 return 0;
300
301         timeout = jiffies + AP_WAIT_TIMEOUT*HZ;
302         while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps &&
303                time_before(jiffies, timeout))
304                 cpu_relax();
305
306         return time_before(jiffies, timeout) ? 0 : 1;
307 }
308
309 /*
310  * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE)
311  */
312
313 #define TXT_PUB_CONFIG_REGS_BASE       0xfed30000
314 #define TXT_PRIV_CONFIG_REGS_BASE      0xfed20000
315
316 /* # pages for each config regs space - used by fixmap */
317 #define NR_TXT_CONFIG_PAGES     ((TXT_PUB_CONFIG_REGS_BASE -                \
318                                   TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT)
319
320 /* offsets from pub/priv config space */
321 #define TXTCR_HEAP_BASE             0x0300
322 #define TXTCR_HEAP_SIZE             0x0308
323
324 #define SHA1_SIZE      20
325
326 struct sha1_hash {
327         u8 hash[SHA1_SIZE];
328 };
329
330 struct sinit_mle_data {
331         u32               version;             /* currently 6 */
332         struct sha1_hash  bios_acm_id;
333         u32               edx_senter_flags;
334         u64               mseg_valid;
335         struct sha1_hash  sinit_hash;
336         struct sha1_hash  mle_hash;
337         struct sha1_hash  stm_hash;
338         struct sha1_hash  lcp_policy_hash;
339         u32               lcp_policy_control;
340         u32               rlp_wakeup_addr;
341         u32               reserved;
342         u32               num_mdrs;
343         u32               mdrs_off;
344         u32               num_vtd_dmars;
345         u32               vtd_dmars_off;
346 } __packed;
347
348 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl)
349 {
350         void *heap_base, *heap_ptr, *config;
351
352         if (!tboot_enabled())
353                 return dmar_tbl;
354
355         /*
356          * ACPI tables may not be DMA protected by tboot, so use DMAR copy
357          * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
358          */
359
360         /* map config space in order to get heap addr */
361         config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES *
362                          PAGE_SIZE);
363         if (!config)
364                 return NULL;
365
366         /* now map TXT heap */
367         heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
368                             *(u64 *)(config + TXTCR_HEAP_SIZE));
369         iounmap(config);
370         if (!heap_base)
371                 return NULL;
372
373         /* walk heap to SinitMleData */
374         /* skip BiosData */
375         heap_ptr = heap_base + *(u64 *)heap_base;
376         /* skip OsMleData */
377         heap_ptr += *(u64 *)heap_ptr;
378         /* skip OsSinitData */
379         heap_ptr += *(u64 *)heap_ptr;
380         /* now points to SinitMleDataSize; set to SinitMleData */
381         heap_ptr += sizeof(u64);
382         /* get addr of DMAR table */
383         dmar_tbl = (struct acpi_table_header *)(heap_ptr +
384                    ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off -
385                    sizeof(u64));
386
387         /* don't unmap heap because dmar.c needs access to this */
388
389         return dmar_tbl;
390 }
391
392 int tboot_force_iommu(void)
393 {
394         if (!tboot_enabled())
395                 return 0;
396
397         if (no_iommu || swiotlb || dmar_disabled)
398                 pr_warning("Forcing Intel-IOMMU to enabled\n");
399
400         dmar_disabled = 0;
401 #ifdef CONFIG_SWIOTLB
402         swiotlb = 0;
403 #endif
404         no_iommu = 0;
405
406         return 1;
407 }