ia64/xen-unstable

view linux-2.6-xen-sparse/arch/ia64/kernel/patch.c @ 10703:8d501f39286c

[IA64] vDSO paravirtualization: paravirtualize vDSO

paravirtualize vdso areabased on Kevin's pointout and Dan's Idea.
introduce hyperprivop HYPERPRIVOP_RSM_BE and HYPERPRIVOP_GET_PSR.
and paravirtualize vdso area using them.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
author awilliam@xenbuild.aw
date Mon Jul 24 13:43:35 2006 -0600 (2006-07-24)
parents f8ab23b4f704
children 99ff540b0efe 4fad820a2233
line source
1 /*
2 * Instruction-patching support.
3 *
4 * Copyright (C) 2003 Hewlett-Packard Co
5 * David Mosberger-Tang <davidm@hpl.hp.com>
6 */
7 #include <linux/init.h>
8 #include <linux/string.h>
10 #include <asm/patch.h>
11 #include <asm/processor.h>
12 #include <asm/sections.h>
13 #include <asm/system.h>
14 #include <asm/unistd.h>
16 /*
17 * This was adapted from code written by Tony Luck:
18 *
19 * The 64-bit value in a "movl reg=value" is scattered between the two words of the bundle
20 * like this:
21 *
22 * 6 6 5 4 3 2 1
23 * 3210987654321098765432109876543210987654321098765432109876543210
24 * ABBBBBBBBBBBBBBBBBBBBBBBCCCCCCCCCCCCCCCCCCDEEEEEFFFFFFFFFGGGGGGG
25 *
26 * CCCCCCCCCCCCCCCCCCxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
27 * xxxxAFFFFFFFFFEEEEEDxGGGGGGGxxxxxxxxxxxxxBBBBBBBBBBBBBBBBBBBBBBB
28 */
29 static u64
30 get_imm64 (u64 insn_addr)
31 {
32 u64 *p = (u64 *) (insn_addr & -16); /* mask out slot number */
34 return ( (p[1] & 0x0800000000000000UL) << 4) | /*A*/
35 ((p[1] & 0x00000000007fffffUL) << 40) | /*B*/
36 ((p[0] & 0xffffc00000000000UL) >> 24) | /*C*/
37 ((p[1] & 0x0000100000000000UL) >> 23) | /*D*/
38 ((p[1] & 0x0003e00000000000UL) >> 29) | /*E*/
39 ((p[1] & 0x07fc000000000000UL) >> 43) | /*F*/
40 ((p[1] & 0x000007f000000000UL) >> 36); /*G*/
41 }
43 /* Patch instruction with "val" where "mask" has 1 bits. */
44 void
45 ia64_patch (u64 insn_addr, u64 mask, u64 val)
46 {
47 u64 m0, m1, v0, v1, b0, b1, *b = (u64 *) (insn_addr & -16);
48 # define insn_mask ((1UL << 41) - 1)
49 unsigned long shift;
51 b0 = b[0]; b1 = b[1];
52 shift = 5 + 41 * (insn_addr % 16); /* 5 bits of template, then 3 x 41-bit instructions */
53 if (shift >= 64) {
54 m1 = mask << (shift - 64);
55 v1 = val << (shift - 64);
56 } else {
57 m0 = mask << shift; m1 = mask >> (64 - shift);
58 v0 = val << shift; v1 = val >> (64 - shift);
59 b[0] = (b0 & ~m0) | (v0 & m0);
60 }
61 b[1] = (b1 & ~m1) | (v1 & m1);
62 }
64 void
65 ia64_patch_imm64 (u64 insn_addr, u64 val)
66 {
67 /* The assembler may generate offset pointing to either slot 1
68 or slot 2 for a long (2-slot) instruction, occupying slots 1
69 and 2. */
70 insn_addr &= -16UL;
71 ia64_patch(insn_addr + 2,
72 0x01fffefe000UL, ( ((val & 0x8000000000000000UL) >> 27) /* bit 63 -> 36 */
73 | ((val & 0x0000000000200000UL) << 0) /* bit 21 -> 21 */
74 | ((val & 0x00000000001f0000UL) << 6) /* bit 16 -> 22 */
75 | ((val & 0x000000000000ff80UL) << 20) /* bit 7 -> 27 */
76 | ((val & 0x000000000000007fUL) << 13) /* bit 0 -> 13 */));
77 ia64_patch(insn_addr + 1, 0x1ffffffffffUL, val >> 22);
78 }
80 void
81 ia64_patch_imm60 (u64 insn_addr, u64 val)
82 {
83 /* The assembler may generate offset pointing to either slot 1
84 or slot 2 for a long (2-slot) instruction, occupying slots 1
85 and 2. */
86 insn_addr &= -16UL;
87 ia64_patch(insn_addr + 2,
88 0x011ffffe000UL, ( ((val & 0x0800000000000000UL) >> 23) /* bit 59 -> 36 */
89 | ((val & 0x00000000000fffffUL) << 13) /* bit 0 -> 13 */));
90 ia64_patch(insn_addr + 1, 0x1fffffffffcUL, val >> 18);
91 }
93 /*
94 * We need sometimes to load the physical address of a kernel
95 * object. Often we can convert the virtual address to physical
96 * at execution time, but sometimes (either for performance reasons
97 * or during error recovery) we cannot to this. Patch the marked
98 * bundles to load the physical address.
99 */
100 void __init
101 ia64_patch_vtop (unsigned long start, unsigned long end)
102 {
103 s32 *offp = (s32 *) start;
104 u64 ip;
106 while (offp < (s32 *) end) {
107 ip = (u64) offp + *offp;
109 /* replace virtual address with corresponding physical address: */
110 ia64_patch_imm64(ip, ia64_tpa(get_imm64(ip)));
111 ia64_fc((void *) ip);
112 ++offp;
113 }
114 ia64_sync_i();
115 ia64_srlz_i();
116 }
118 void
119 ia64_patch_mckinley_e9 (unsigned long start, unsigned long end)
120 {
121 static int first_time = 1;
122 int need_workaround;
123 s32 *offp = (s32 *) start;
124 u64 *wp;
126 need_workaround = (local_cpu_data->family == 0x1f && local_cpu_data->model == 0);
128 if (first_time) {
129 first_time = 0;
130 if (need_workaround)
131 printk(KERN_INFO "Leaving McKinley Errata 9 workaround enabled\n");
132 else
133 printk(KERN_INFO "McKinley Errata 9 workaround not needed; "
134 "disabling it\n");
135 }
136 if (need_workaround)
137 return;
139 while (offp < (s32 *) end) {
140 wp = (u64 *) ia64_imva((char *) offp + *offp);
141 wp[0] = 0x0000000100000000UL; /* nop.m 0; nop.i 0; nop.i 0 */
142 wp[1] = 0x0004000000000200UL;
143 wp[2] = 0x0000000100000011UL; /* nop.m 0; nop.i 0; br.ret.sptk.many b6 */
144 wp[3] = 0x0084006880000200UL;
145 ia64_fc(wp); ia64_fc(wp + 2);
146 ++offp;
147 }
148 ia64_sync_i();
149 ia64_srlz_i();
150 }
152 static void
153 patch_fsyscall_table (unsigned long start, unsigned long end)
154 {
155 extern unsigned long fsyscall_table[NR_syscalls];
156 s32 *offp = (s32 *) start;
157 u64 ip;
159 while (offp < (s32 *) end) {
160 ip = (u64) ia64_imva((char *) offp + *offp);
161 ia64_patch_imm64(ip, (u64) fsyscall_table);
162 ia64_fc((void *) ip);
163 ++offp;
164 }
165 ia64_sync_i();
166 ia64_srlz_i();
167 }
169 static void
170 patch_brl_fsys_bubble_down (unsigned long start, unsigned long end)
171 {
172 extern char fsys_bubble_down[];
173 s32 *offp = (s32 *) start;
174 u64 ip;
176 while (offp < (s32 *) end) {
177 ip = (u64) offp + *offp;
178 ia64_patch_imm60((u64) ia64_imva((void *) ip),
179 (u64) (fsys_bubble_down - (ip & -16)) / 16);
180 ia64_fc((void *) ip);
181 ++offp;
182 }
183 ia64_sync_i();
184 ia64_srlz_i();
185 }
187 #ifdef CONFIG_XEN_IA64_VDSO_PARAVIRT
188 extern char __start_gate_running_on_xen_patchlist[];
189 extern char __end_gate_running_on_xen_patchlist[];
191 void
192 patch_running_on_xen(unsigned long start, unsigned long end)
193 {
194 extern int running_on_xen;
195 s32 *offp = (s32 *)start;
196 u64 ip;
198 while (offp < (s32 *)end) {
199 ip = (u64)ia64_imva((char *)offp + *offp);
200 ia64_patch_imm64(ip, (u64)&running_on_xen);
201 ia64_fc((void *)ip);
202 ++offp;
203 }
204 ia64_sync_i();
205 ia64_srlz_i();
206 }
208 static void
209 patch_brl_symaddr(unsigned long start, unsigned long end,
210 unsigned long symaddr)
211 {
212 s32 *offp = (s32 *)start;
213 u64 ip;
215 while (offp < (s32 *)end) {
216 ip = (u64)offp + *offp;
217 ia64_patch_imm60((u64)ia64_imva((void *)ip),
218 (u64)(symaddr - (ip & -16)) / 16);
219 ia64_fc((void *)ip);
220 ++offp;
221 }
222 ia64_sync_i();
223 ia64_srlz_i();
224 }
226 #define EXTERN_PATCHLIST(name) \
227 extern char __start_gate_brl_##name##_patchlist[]; \
228 extern char __end_gate_brl_##name##_patchlist[]; \
229 extern char name[]
231 #define PATCH_BRL_SYMADDR(name) \
232 patch_brl_symaddr((unsigned long)__start_gate_brl_##name##_patchlist, \
233 (unsigned long)__end_gate_brl_##name##_patchlist, \
234 (unsigned long)name)
236 static void
237 patch_brl_in_vdso(void)
238 {
239 EXTERN_PATCHLIST(xen_rsm_be_i);
240 EXTERN_PATCHLIST(xen_get_psr);
241 EXTERN_PATCHLIST(xen_ssm_i_0);
242 EXTERN_PATCHLIST(xen_ssm_i_1);
244 PATCH_BRL_SYMADDR(xen_rsm_be_i);
245 PATCH_BRL_SYMADDR(xen_get_psr);
246 PATCH_BRL_SYMADDR(xen_ssm_i_0);
247 PATCH_BRL_SYMADDR(xen_ssm_i_1);
248 }
249 #else
250 #define patch_running_on_xen(start, end) do { } while (0)
251 #define patch_brl_in_vdso() do { } while (0)
252 #endif
254 void
255 ia64_patch_gate (void)
256 {
257 # define START(name) ((unsigned long) __start_gate_##name##_patchlist)
258 # define END(name) ((unsigned long)__end_gate_##name##_patchlist)
260 patch_fsyscall_table(START(fsyscall), END(fsyscall));
261 patch_brl_fsys_bubble_down(START(brl_fsys_bubble_down), END(brl_fsys_bubble_down));
262 #ifdef CONFIG_XEN
263 patch_running_on_xen(START(running_on_xen), END(running_on_xen));
264 patch_brl_in_vdso();
265 #endif
266 ia64_patch_vtop(START(vtop), END(vtop));
267 ia64_patch_mckinley_e9(START(mckinley_e9), END(mckinley_e9));
268 }