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/threads.h>
11 #include <linux/module.h>
12 #include <linux/memblock.h>
13
14 #include <asm/firmware.h>
15 #include <asm/lppaca.h>
16 #include <asm/paca.h>
17 #include <asm/sections.h>
18 #include <asm/pgtable.h>
19 #include <asm/iseries/lpar_map.h>
20 #include <asm/iseries/hv_types.h>
21 #include <asm/kexec.h>
22
23 /* This symbol is provided by the linker - let it fill in the paca
24 * field correctly */
25 extern unsigned long __toc_start;
26
27 #ifdef CONFIG_PPC_BOOK3S
28
29 /*
30 * The structure which the hypervisor knows about - this structure
31 * should not cross a page boundary. The vpa_init/register_vpa call
32 * is now known to fail if the lppaca structure crosses a page
33 * boundary. The lppaca is also used on legacy iSeries and POWER5
34 * pSeries boxes. The lppaca is 640 bytes long, and cannot readily
35 * change since the hypervisor knows its layout, so a 1kB alignment
36 * will suffice to ensure that it doesn't cross a page boundary.
37 */
38 struct lppaca lppaca[] = {
39 [0 ... (NR_LPPACAS-1)] = {
40 .desc = 0xd397d781, /* "LpPa" */
41 .size = sizeof(struct lppaca),
42 .dyn_proc_status = 2,
43 .decr_val = 0x00ff0000,
44 .fpregs_in_use = 1,
45 .end_of_quantum = 0xfffffffffffffffful,
46 .slb_count = 64,
47 .vmxregs_in_use = 0,
48 .page_ins = 0,
49 },
50 };
51
52 static struct lppaca *extra_lppacas;
53 static long __initdata lppaca_size;
54
allocate_lppacas(int nr_cpus,unsigned long limit)55 static void allocate_lppacas(int nr_cpus, unsigned long limit)
56 {
57 if (nr_cpus <= NR_LPPACAS)
58 return;
59
60 lppaca_size = PAGE_ALIGN(sizeof(struct lppaca) *
61 (nr_cpus - NR_LPPACAS));
62 extra_lppacas = __va(memblock_alloc_base(lppaca_size,
63 PAGE_SIZE, limit));
64 }
65
new_lppaca(int cpu)66 static struct lppaca *new_lppaca(int cpu)
67 {
68 struct lppaca *lp;
69
70 if (cpu < NR_LPPACAS)
71 return &lppaca[cpu];
72
73 lp = extra_lppacas + (cpu - NR_LPPACAS);
74 *lp = lppaca[0];
75
76 return lp;
77 }
78
free_lppacas(void)79 static void free_lppacas(void)
80 {
81 long new_size = 0, nr;
82
83 if (!lppaca_size)
84 return;
85 nr = num_possible_cpus() - NR_LPPACAS;
86 if (nr > 0)
87 new_size = PAGE_ALIGN(nr * sizeof(struct lppaca));
88 if (new_size >= lppaca_size)
89 return;
90
91 memblock_free(__pa(extra_lppacas) + new_size, lppaca_size - new_size);
92 lppaca_size = new_size;
93 }
94
95 #else
96
allocate_lppacas(int nr_cpus,unsigned long limit)97 static inline void allocate_lppacas(int nr_cpus, unsigned long limit) { }
free_lppacas(void)98 static inline void free_lppacas(void) { }
99
100 #endif /* CONFIG_PPC_BOOK3S */
101
102 #ifdef CONFIG_PPC_STD_MMU_64
103
104 /*
105 * 3 persistent SLBs are registered here. The buffer will be zero
106 * initially, hence will all be invaild until we actually write them.
107 */
108 struct slb_shadow slb_shadow[] __cacheline_aligned = {
109 [0 ... (NR_CPUS-1)] = {
110 .persistent = SLB_NUM_BOLTED,
111 .buffer_length = sizeof(struct slb_shadow),
112 },
113 };
114
115 #endif /* CONFIG_PPC_STD_MMU_64 */
116
117 /* The Paca is an array with one entry per processor. Each contains an
118 * lppaca, which contains the information shared between the
119 * hypervisor and Linux.
120 * On systems with hardware multi-threading, there are two threads
121 * per processor. The Paca array must contain an entry for each thread.
122 * The VPD Areas will give a max logical processors = 2 * max physical
123 * processors. The processor VPD array needs one entry per physical
124 * processor (not thread).
125 */
126 struct paca_struct *paca;
127 EXPORT_SYMBOL(paca);
128
129 struct paca_struct boot_paca;
130
initialise_paca(struct paca_struct * new_paca,int cpu)131 void __init initialise_paca(struct paca_struct *new_paca, int cpu)
132 {
133 /* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
134 * of the TOC can be addressed using a single machine instruction.
135 */
136 unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL;
137
138 #ifdef CONFIG_PPC_BOOK3S
139 new_paca->lppaca_ptr = new_lppaca(cpu);
140 #else
141 new_paca->kernel_pgd = swapper_pg_dir;
142 #endif
143 new_paca->lock_token = 0x8000;
144 new_paca->paca_index = cpu;
145 new_paca->kernel_toc = kernel_toc;
146 new_paca->kernelbase = (unsigned long) _stext;
147 new_paca->kernel_msr = MSR_KERNEL;
148 new_paca->hw_cpu_id = 0xffff;
149 new_paca->kexec_state = KEXEC_STATE_NONE;
150 new_paca->__current = &init_task;
151 #ifdef CONFIG_PPC_STD_MMU_64
152 new_paca->slb_shadow_ptr = &slb_shadow[cpu];
153 #endif /* CONFIG_PPC_STD_MMU_64 */
154 }
155
156 /* Put the paca pointer into r13 and SPRG_PACA */
setup_paca(struct paca_struct * new_paca)157 void setup_paca(struct paca_struct *new_paca)
158 {
159 local_paca = new_paca;
160 mtspr(SPRN_SPRG_PACA, local_paca);
161 #ifdef CONFIG_PPC_BOOK3E
162 mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
163 #endif
164 }
165
166 static int __initdata paca_size;
167
allocate_pacas(void)168 void __init allocate_pacas(void)
169 {
170 int nr_cpus, cpu, limit;
171
172 /*
173 * We can't take SLB misses on the paca, and we want to access them
174 * in real mode, so allocate them within the RMA and also within
175 * the first segment. On iSeries they must be within the area mapped
176 * by the HV, which is HvPagesToMap * HVPAGESIZE bytes.
177 */
178 limit = min(0x10000000ULL, ppc64_rma_size);
179 if (firmware_has_feature(FW_FEATURE_ISERIES))
180 limit = min(limit, HvPagesToMap * HVPAGESIZE);
181
182 nr_cpus = NR_CPUS;
183 /* On iSeries we know we can never have more than 64 cpus */
184 if (firmware_has_feature(FW_FEATURE_ISERIES))
185 nr_cpus = min(64, nr_cpus);
186
187 paca_size = PAGE_ALIGN(sizeof(struct paca_struct) * nr_cpus);
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_cpus, paca);
194
195 allocate_lppacas(nr_cpus, limit);
196
197 /* Can't use for_each_*_cpu, as they aren't functional yet */
198 for (cpu = 0; cpu < nr_cpus; 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