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