| blob | 6bc3a932fe457988214d665c677e5b960c4db134 |
1 /*
2 * Copyright 2011 Tilera Corporation. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
12 * more details.
13 *
14 * TILE startup code.
15 */
17 #include <linux/linkage.h>
18 #include <linux/init.h>
19 #include <asm/page.h>
20 #include <asm/pgtable.h>
21 #include <asm/thread_info.h>
22 #include <asm/processor.h>
23 #include <asm/asm-offsets.h>
24 #include <hv/hypervisor.h>
25 #include <arch/chip.h>
26 #include <arch/spr_def.h>
28 /*
29 * This module contains the entry code for kernel images. It performs the
30 * minimal setup needed to call the generic C routines.
31 */
33 __HEAD
34 ENTRY(_start)
35 /* Notify the hypervisor of what version of the API we want */
36 {
37 movei r1, TILE_CHIP
38 movei r2, TILE_CHIP_REV
39 }
40 {
41 moveli r0, _HV_VERSION
42 jal hv_init
43 }
44 /* Get a reasonable default ASID in r0 */
45 {
46 move r0, zero
47 jal hv_inquire_asid
48 }
50 /*
51 * Install the default page table. The relocation required to
52 * statically define the table is a bit too complex, so we have
53 * to plug in the pointer from the L0 to the L1 table by hand.
54 * We only do this on the first cpu to boot, though, since the
55 * other CPUs should see a properly-constructed page table.
56 */
57 {
58 v4int_l r2, zero, r0 /* ASID for hv_install_context */
59 moveli r4, hw1_last(swapper_pgprot - PAGE_OFFSET)
60 }
61 {
62 shl16insli r4, r4, hw0(swapper_pgprot - PAGE_OFFSET)
63 }
64 {
65 ld r1, r4 /* access_pte for hv_install_context */
66 }
67 {
68 moveli r0, hw1_last(.Lsv_data_pmd - PAGE_OFFSET)
69 moveli r6, hw1_last(temp_data_pmd - PAGE_OFFSET)
70 }
71 {
72 /* After initializing swapper_pgprot, HV_PTE_GLOBAL is set. */
73 bfextu r7, r1, HV_PTE_INDEX_GLOBAL, HV_PTE_INDEX_GLOBAL
74 inv r4
75 }
76 bnez r7, .Lno_write
77 {
78 shl16insli r0, r0, hw0(.Lsv_data_pmd - PAGE_OFFSET)
79 shl16insli r6, r6, hw0(temp_data_pmd - PAGE_OFFSET)
80 }
81 {
82 /* Cut off the low bits of the PT address. */
83 shrui r6, r6, HV_LOG2_PAGE_TABLE_ALIGN
84 /* Start with our access pte. */
85 move r5, r1
86 }
87 {
88 /* Stuff the address into the page table pointer slot of the PTE. */
89 bfins r5, r6, HV_PTE_INDEX_PTFN, \
90 HV_PTE_INDEX_PTFN + HV_PTE_PTFN_BITS - 1
91 }
92 {
93 /* Store the L0 data PTE. */
94 st r0, r5
95 addli r6, r6, (temp_code_pmd - temp_data_pmd) >> \
96 HV_LOG2_PAGE_TABLE_ALIGN
97 }
98 {
99 addli r0, r0, .Lsv_code_pmd - .Lsv_data_pmd
100 bfins r5, r6, HV_PTE_INDEX_PTFN, \
101 HV_PTE_INDEX_PTFN + HV_PTE_PTFN_BITS - 1
102 }
103 /* Store the L0 code PTE. */
104 st r0, r5
106 .Lno_write:
107 moveli lr, hw2_last(1f)
108 {
109 shl16insli lr, lr, hw1(1f)
110 moveli r0, hw1_last(swapper_pg_dir - PAGE_OFFSET)
111 }
112 {
113 shl16insli lr, lr, hw0(1f)
114 shl16insli r0, r0, hw0(swapper_pg_dir - PAGE_OFFSET)
115 }
116 {
117 move r3, zero
118 j hv_install_context
119 }
120 1:
122 /* Install the interrupt base. */
123 moveli r0, hw2_last(MEM_SV_START)
124 shl16insli r0, r0, hw1(MEM_SV_START)
125 shl16insli r0, r0, hw0(MEM_SV_START)
126 mtspr SPR_INTERRUPT_VECTOR_BASE_K, r0
128 /*
129 * Get our processor number and save it away in SAVE_K_0.
130 * Extract stuff from the topology structure: r4 = y, r6 = x,
131 * r5 = width. FIXME: consider whether we want to just make these
132 * 64-bit values (and if so fix smp_topology write below, too).
133 */
134 jal hv_inquire_topology
135 {
136 v4int_l r5, zero, r1 /* r5 = width */
137 shrui r4, r0, 32 /* r4 = y */
138 }
139 {
140 v4int_l r6, zero, r0 /* r6 = x */
141 mul_lu_lu r4, r4, r5
142 }
143 {
144 add r4, r4, r6 /* r4 == cpu == y*width + x */
145 }
147 #ifdef CONFIG_SMP
148 /*
149 * Load up our per-cpu offset. When the first (master) tile
150 * boots, this value is still zero, so we will load boot_pc
151 * with start_kernel, and boot_sp with init_stack + THREAD_SIZE.
152 * The master tile initializes the per-cpu offset array, so that
153 * when subsequent (secondary) tiles boot, they will instead load
154 * from their per-cpu versions of boot_sp and boot_pc.
155 */
156 moveli r5, hw2_last(__per_cpu_offset)
157 shl16insli r5, r5, hw1(__per_cpu_offset)
158 shl16insli r5, r5, hw0(__per_cpu_offset)
159 shl3add r5, r4, r5
160 ld r5, r5
161 bnez r5, 1f
163 /*
164 * Save the width and height to the smp_topology variable
165 * for later use.
166 */
167 moveli r0, hw2_last(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET)
168 shl16insli r0, r0, hw1(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET)
169 shl16insli r0, r0, hw0(smp_topology + HV_TOPOLOGY_WIDTH_OFFSET)
170 st r0, r1
171 1:
172 #else
173 move r5, zero
174 #endif
176 /* Load and go with the correct pc and sp. */
177 {
178 moveli r1, hw2_last(boot_sp)
179 moveli r0, hw2_last(boot_pc)
180 }
181 {
182 shl16insli r1, r1, hw1(boot_sp)
183 shl16insli r0, r0, hw1(boot_pc)
184 }
185 {
186 shl16insli r1, r1, hw0(boot_sp)
187 shl16insli r0, r0, hw0(boot_pc)
188 }
189 {
190 add r1, r1, r5
191 add r0, r0, r5
192 }
193 ld r0, r0
194 ld sp, r1
195 or r4, sp, r4
196 mtspr SPR_SYSTEM_SAVE_K_0, r4 /* save ksp0 + cpu */
197 addi sp, sp, -STACK_TOP_DELTA
198 {
199 move lr, zero /* stop backtraces in the called function */
200 jr r0
201 }
202 ENDPROC(_start)
204 __PAGE_ALIGNED_BSS
205 .align PAGE_SIZE
206 ENTRY(empty_zero_page)
207 .fill PAGE_SIZE,1,0
208 END(empty_zero_page)
210 .macro PTE cpa, bits1
211 .quad HV_PTE_PAGE | HV_PTE_DIRTY | HV_PTE_PRESENT | HV_PTE_ACCESSED |\
212 HV_PTE_GLOBAL | (HV_PTE_MODE_CACHE_NO_L3 << HV_PTE_INDEX_MODE) |\
213 (\bits1) | (HV_CPA_TO_PFN(\cpa) << HV_PTE_INDEX_PFN)
214 .endm
216 __PAGE_ALIGNED_DATA
217 .align PAGE_SIZE
218 ENTRY(swapper_pg_dir)
219 .org swapper_pg_dir + HV_L0_INDEX(PAGE_OFFSET) * HV_PTE_SIZE
220 .Lsv_data_pmd:
221 .quad 0 /* PTE temp_data_pmd - PAGE_OFFSET, 0 */
222 .org swapper_pg_dir + HV_L0_INDEX(MEM_SV_START) * HV_PTE_SIZE
223 .Lsv_code_pmd:
224 .quad 0 /* PTE temp_code_pmd - PAGE_OFFSET, 0 */
225 .org swapper_pg_dir + HV_L0_SIZE
226 END(swapper_pg_dir)
228 .align HV_PAGE_TABLE_ALIGN
229 ENTRY(temp_data_pmd)
230 /*
231 * We fill the PAGE_OFFSET pmd with huge pages with
232 * VA = PA + PAGE_OFFSET. We remap things with more precise access
233 * permissions later.
234 */
235 .set addr, 0
236 .rept HV_L1_ENTRIES
237 PTE addr, HV_PTE_READABLE | HV_PTE_WRITABLE
238 .set addr, addr + HV_PAGE_SIZE_LARGE
239 .endr
240 .org temp_data_pmd + HV_L1_SIZE
241 END(temp_data_pmd)
243 .align HV_PAGE_TABLE_ALIGN
244 ENTRY(temp_code_pmd)
245 /*
246 * We fill the MEM_SV_START pmd with huge pages with
247 * VA = PA + PAGE_OFFSET. We remap things with more precise access
248 * permissions later.
249 */
250 .set addr, 0
251 .rept HV_L1_ENTRIES
252 PTE addr, HV_PTE_READABLE | HV_PTE_EXECUTABLE
253 .set addr, addr + HV_PAGE_SIZE_LARGE
254 .endr
255 .org temp_code_pmd + HV_L1_SIZE
256 END(temp_code_pmd)
258 /*
259 * Isolate swapper_pgprot to its own cache line, since each cpu
260 * starting up will read it using VA-is-PA and local homing.
261 * This would otherwise likely conflict with other data on the cache
262 * line, once we have set its permanent home in the page tables.
263 */
264 __INITDATA
265 .align CHIP_L2_LINE_SIZE()
266 ENTRY(swapper_pgprot)
267 .quad HV_PTE_PRESENT | (HV_PTE_MODE_CACHE_NO_L3 << HV_PTE_INDEX_MODE)
268 .align CHIP_L2_LINE_SIZE()
269 END(swapper_pgprot)