1 /*
2 * c 2001 PPC 64 Team, IBM Corp
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; either version
7 * 2 of the License, or (at your option) any later version.
8 */
9
10 #include <linux/smp.h>
11 #include <linux/export.h>
12 #include <linux/memblock.h>
13
14 #include <asm/lppaca.h>
15 #include <asm/paca.h>
16 #include <asm/sections.h>
17 #include <asm/pgtable.h>
18 #include <asm/kexec.h>
19
20 /* This symbol is provided by the linker - let it fill in the paca
21 * field correctly */
22 extern unsigned long __toc_start;
23
24 #ifdef CONFIG_PPC_BOOK3S
25
26 /*
27 * The structure which the hypervisor knows about - this structure
28 * should not cross a page boundary. The vpa_init/register_vpa call
29 * is now known to fail if the lppaca structure crosses a page
30 * boundary. The lppaca is also used on POWER5 pSeries boxes.
31 * The lppaca is 640 bytes long, and cannot readily
32 * change since the hypervisor knows its layout, so a 1kB alignment
33 * will suffice to ensure that it doesn't cross a page boundary.
34 */
35 struct lppaca lppaca[] = {
36 [0 ... (NR_LPPACAS-1)] = {
37 .desc = 0xd397d781, /* "LpPa" */
38 .size = sizeof(struct lppaca),
39 .dyn_proc_status = 2,
40 .decr_val = 0x00ff0000,
41 .fpregs_in_use = 1,
42 .end_of_quantum = 0xfffffffffffffffful,
43 .slb_count = 64,
44 .vmxregs_in_use = 0,
45 .page_ins = 0,
46 },
47 };
48
49 static struct lppaca *extra_lppacas;
50 static long __initdata lppaca_size;
51
allocate_lppacas(int nr_cpus,unsigned long limit)52 static void allocate_lppacas(int nr_cpus, unsigned long limit)
53 {
54 if (nr_cpus <= NR_LPPACAS)
55 return;
56
57 lppaca_size = PAGE_ALIGN(sizeof(struct lppaca) *
58 (nr_cpus - NR_LPPACAS));
59 extra_lppacas = __va(memblock_alloc_base(lppaca_size,
60 PAGE_SIZE, limit));
61 }
62
new_lppaca(int cpu)63 static struct lppaca *new_lppaca(int cpu)
64 {
65 struct lppaca *lp;
66
67 if (cpu < NR_LPPACAS)
68 return &lppaca[cpu];
69
70 lp = extra_lppacas + (cpu - NR_LPPACAS);
71 *lp = lppaca[0];
72
73 return lp;
74 }
75
free_lppacas(void)76 static void free_lppacas(void)
77 {
78 long new_size = 0, nr;
79
80 if (!lppaca_size)
81 return;
82 nr = num_possible_cpus() - NR_LPPACAS;
83 if (nr > 0)
84 new_size = PAGE_ALIGN(nr * sizeof(struct lppaca));
85 if (new_size >= lppaca_size)
86 return;
87
88 memblock_free(__pa(extra_lppacas) + new_size, lppaca_size - new_size);
89 lppaca_size = new_size;
90 }
91
92 #else
93
allocate_lppacas(int nr_cpus,unsigned long limit)94 static inline void allocate_lppacas(int nr_cpus, unsigned long limit) { }
free_lppacas(void)95 static inline void free_lppacas(void) { }
96
97 #endif /* CONFIG_PPC_BOOK3S */
98
99 #ifdef CONFIG_PPC_STD_MMU_64
100
101 /*
102 * 3 persistent SLBs are registered here. The buffer will be zero
103 * initially, hence will all be invaild until we actually write them.
104 */
105 struct slb_shadow slb_shadow[] __cacheline_aligned = {
106 [0 ... (NR_CPUS-1)] = {
107 .persistent = SLB_NUM_BOLTED,
108 .buffer_length = sizeof(struct slb_shadow),
109 },
110 };
111
112 #endif /* CONFIG_PPC_STD_MMU_64 */
113
114 /* The Paca is an array with one entry per processor. Each contains an
115 * lppaca, which contains the information shared between the
116 * hypervisor and Linux.
117 * On systems with hardware multi-threading, there are two threads
118 * per processor. The Paca array must contain an entry for each thread.
119 * The VPD Areas will give a max logical processors = 2 * max physical
120 * processors. The processor VPD array needs one entry per physical
121 * processor (not thread).
122 */
123 struct paca_struct *paca;
124 EXPORT_SYMBOL(paca);
125
126 struct paca_struct boot_paca;
127
initialise_paca(struct paca_struct * new_paca,int cpu)128 void __init initialise_paca(struct paca_struct *new_paca, int cpu)
129 {
130 /* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
131 * of the TOC can be addressed using a single machine instruction.
132 */
133 unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL;
134
135 #ifdef CONFIG_PPC_BOOK3S
136 new_paca->lppaca_ptr = new_lppaca(cpu);
137 #else
138 new_paca->kernel_pgd = swapper_pg_dir;
139 #endif
140 new_paca->lock_token = 0x8000;
141 new_paca->paca_index = cpu;
142 new_paca->kernel_toc = kernel_toc;
143 new_paca->kernelbase = (unsigned long) _stext;
144 new_paca->kernel_msr = MSR_KERNEL;
145 new_paca->hw_cpu_id = 0xffff;
146 new_paca->kexec_state = KEXEC_STATE_NONE;
147 new_paca->__current = &init_task;
148 #ifdef CONFIG_PPC_STD_MMU_64
149 new_paca->slb_shadow_ptr = &slb_shadow[cpu];
150 #endif /* CONFIG_PPC_STD_MMU_64 */
151 }
152
153 /* Put the paca pointer into r13 and SPRG_PACA */
setup_paca(struct paca_struct * new_paca)154 void setup_paca(struct paca_struct *new_paca)
155 {
156 /* Setup r13 */
157 local_paca = new_paca;
158
159 #ifdef CONFIG_PPC_BOOK3E
160 /* On Book3E, initialize the TLB miss exception frames */
161 mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
162 #else
163 /* In HV mode, we setup both HPACA and PACA to avoid problems
164 * if we do a GET_PACA() before the feature fixups have been
165 * applied
166 */
167 if (cpu_has_feature(CPU_FTR_HVMODE))
168 mtspr(SPRN_SPRG_HPACA, local_paca);
169 #endif
170 mtspr(SPRN_SPRG_PACA, local_paca);
171
172 }
173
174 static int __initdata paca_size;
175
allocate_pacas(void)176 void __init allocate_pacas(void)
177 {
178 int cpu, limit;
179
180 /*
181 * We can't take SLB misses on the paca, and we want to access them
182 * in real mode, so allocate them within the RMA and also within
183 * the first segment.
184 */
185 limit = min(0x10000000ULL, ppc64_rma_size);
186
187 paca_size = PAGE_ALIGN(sizeof(struct paca_struct) * nr_cpu_ids);
188
189 paca = __va(memblock_alloc_base(paca_size, PAGE_SIZE, limit));
190 memset(paca, 0, paca_size);
191
192 printk(KERN_DEBUG "Allocated %u bytes for %d pacas at %p\n",
193 paca_size, nr_cpu_ids, paca);
194
195 allocate_lppacas(nr_cpu_ids, limit);
196
197 /* Can't use for_each_*_cpu, as they aren't functional yet */
198 for (cpu = 0; cpu < nr_cpu_ids; cpu++)
199 initialise_paca(&paca[cpu], cpu);
200 }
201
free_unused_pacas(void)202 void __init free_unused_pacas(void)
203 {
204 int new_size;
205
206 new_size = PAGE_ALIGN(sizeof(struct paca_struct) * nr_cpu_ids);
207
208 if (new_size >= paca_size)
209 return;
210
211 memblock_free(__pa(paca) + new_size, paca_size - new_size);
212
213 printk(KERN_DEBUG "Freed %u bytes for unused pacas\n",
214 paca_size - new_size);
215
216 paca_size = new_size;
217
218 free_lppacas();
219 }
220