xref: /openbmc/linux/arch/powerpc/kernel/paca.c (revision 7e1c4e27)
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 #include <linux/sched/task.h>
14 
15 #include <asm/lppaca.h>
16 #include <asm/paca.h>
17 #include <asm/sections.h>
18 #include <asm/pgtable.h>
19 #include <asm/kexec.h>
20 
21 #include "setup.h"
22 
23 #ifndef CONFIG_SMP
24 #define boot_cpuid 0
25 #endif
26 
27 static void *__init alloc_paca_data(unsigned long size, unsigned long align,
28 				unsigned long limit, int cpu)
29 {
30 	unsigned long pa;
31 	int nid;
32 
33 	/*
34 	 * boot_cpuid paca is allocated very early before cpu_to_node is up.
35 	 * Set bottom-up mode, because the boot CPU should be on node-0,
36 	 * which will put its paca in the right place.
37 	 */
38 	if (cpu == boot_cpuid) {
39 		nid = -1;
40 		memblock_set_bottom_up(true);
41 	} else {
42 		nid = early_cpu_to_node(cpu);
43 	}
44 
45 	pa = memblock_alloc_base_nid(size, align, limit, nid, MEMBLOCK_NONE);
46 	if (!pa) {
47 		pa = memblock_alloc_base(size, align, limit);
48 		if (!pa)
49 			panic("cannot allocate paca data");
50 	}
51 
52 	if (cpu == boot_cpuid)
53 		memblock_set_bottom_up(false);
54 
55 	return __va(pa);
56 }
57 
58 #ifdef CONFIG_PPC_PSERIES
59 
60 /*
61  * See asm/lppaca.h for more detail.
62  *
63  * lppaca structures must must be 1kB in size, L1 cache line aligned,
64  * and not cross 4kB boundary. A 1kB size and 1kB alignment will satisfy
65  * these requirements.
66  */
67 static inline void init_lppaca(struct lppaca *lppaca)
68 {
69 	BUILD_BUG_ON(sizeof(struct lppaca) != 640);
70 
71 	*lppaca = (struct lppaca) {
72 		.desc = cpu_to_be32(0xd397d781),	/* "LpPa" */
73 		.size = cpu_to_be16(0x400),
74 		.fpregs_in_use = 1,
75 		.slb_count = cpu_to_be16(64),
76 		.vmxregs_in_use = 0,
77 		.page_ins = 0, };
78 };
79 
80 static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
81 {
82 	struct lppaca *lp;
83 	size_t size = 0x400;
84 
85 	BUILD_BUG_ON(size < sizeof(struct lppaca));
86 
87 	if (early_cpu_has_feature(CPU_FTR_HVMODE))
88 		return NULL;
89 
90 	lp = alloc_paca_data(size, 0x400, limit, cpu);
91 	init_lppaca(lp);
92 
93 	return lp;
94 }
95 #endif /* CONFIG_PPC_BOOK3S */
96 
97 #ifdef CONFIG_PPC_BOOK3S_64
98 
99 /*
100  * 3 persistent SLBs are allocated here.  The buffer will be zero
101  * initially, hence will all be invaild until we actually write them.
102  *
103  * If you make the number of persistent SLB entries dynamic, please also
104  * update PR KVM to flush and restore them accordingly.
105  */
106 static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
107 {
108 	struct slb_shadow *s;
109 
110 	if (cpu != boot_cpuid) {
111 		/*
112 		 * Boot CPU comes here before early_radix_enabled
113 		 * is parsed (e.g., for disable_radix). So allocate
114 		 * always and this will be fixed up in free_unused_pacas.
115 		 */
116 		if (early_radix_enabled())
117 			return NULL;
118 	}
119 
120 	s = alloc_paca_data(sizeof(*s), L1_CACHE_BYTES, limit, cpu);
121 	memset(s, 0, sizeof(*s));
122 
123 	s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
124 	s->buffer_length = cpu_to_be32(sizeof(*s));
125 
126 	return s;
127 }
128 
129 #endif /* CONFIG_PPC_BOOK3S_64 */
130 
131 /* The Paca is an array with one entry per processor.  Each contains an
132  * lppaca, which contains the information shared between the
133  * hypervisor and Linux.
134  * On systems with hardware multi-threading, there are two threads
135  * per processor.  The Paca array must contain an entry for each thread.
136  * The VPD Areas will give a max logical processors = 2 * max physical
137  * processors.  The processor VPD array needs one entry per physical
138  * processor (not thread).
139  */
140 struct paca_struct **paca_ptrs __read_mostly;
141 EXPORT_SYMBOL(paca_ptrs);
142 
143 void __init initialise_paca(struct paca_struct *new_paca, int cpu)
144 {
145 #ifdef CONFIG_PPC_PSERIES
146 	new_paca->lppaca_ptr = NULL;
147 #endif
148 #ifdef CONFIG_PPC_BOOK3E
149 	new_paca->kernel_pgd = swapper_pg_dir;
150 #endif
151 	new_paca->lock_token = 0x8000;
152 	new_paca->paca_index = cpu;
153 	new_paca->kernel_toc = kernel_toc_addr();
154 	new_paca->kernelbase = (unsigned long) _stext;
155 	/* Only set MSR:IR/DR when MMU is initialized */
156 	new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
157 	new_paca->hw_cpu_id = 0xffff;
158 	new_paca->kexec_state = KEXEC_STATE_NONE;
159 	new_paca->__current = &init_task;
160 	new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
161 #ifdef CONFIG_PPC_BOOK3S_64
162 	new_paca->slb_shadow_ptr = NULL;
163 #endif
164 
165 #ifdef CONFIG_PPC_BOOK3E
166 	/* For now -- if we have threads this will be adjusted later */
167 	new_paca->tcd_ptr = &new_paca->tcd;
168 #endif
169 }
170 
171 /* Put the paca pointer into r13 and SPRG_PACA */
172 void setup_paca(struct paca_struct *new_paca)
173 {
174 	/* Setup r13 */
175 	local_paca = new_paca;
176 
177 #ifdef CONFIG_PPC_BOOK3E
178 	/* On Book3E, initialize the TLB miss exception frames */
179 	mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
180 #else
181 	/* In HV mode, we setup both HPACA and PACA to avoid problems
182 	 * if we do a GET_PACA() before the feature fixups have been
183 	 * applied
184 	 */
185 	if (early_cpu_has_feature(CPU_FTR_HVMODE))
186 		mtspr(SPRN_SPRG_HPACA, local_paca);
187 #endif
188 	mtspr(SPRN_SPRG_PACA, local_paca);
189 
190 }
191 
192 static int __initdata paca_nr_cpu_ids;
193 static int __initdata paca_ptrs_size;
194 static int __initdata paca_struct_size;
195 
196 void __init allocate_paca_ptrs(void)
197 {
198 	paca_nr_cpu_ids = nr_cpu_ids;
199 
200 	paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
201 	paca_ptrs = __va(memblock_phys_alloc(paca_ptrs_size, SMP_CACHE_BYTES));
202 	memset(paca_ptrs, 0x88, paca_ptrs_size);
203 }
204 
205 void __init allocate_paca(int cpu)
206 {
207 	u64 limit;
208 	struct paca_struct *paca;
209 
210 	BUG_ON(cpu >= paca_nr_cpu_ids);
211 
212 #ifdef CONFIG_PPC_BOOK3S_64
213 	/*
214 	 * We access pacas in real mode, and cannot take SLB faults
215 	 * on them when in virtual mode, so allocate them accordingly.
216 	 */
217 	limit = min(ppc64_bolted_size(), ppc64_rma_size);
218 #else
219 	limit = ppc64_rma_size;
220 #endif
221 
222 	paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
223 				limit, cpu);
224 	paca_ptrs[cpu] = paca;
225 	memset(paca, 0, sizeof(struct paca_struct));
226 
227 	initialise_paca(paca, cpu);
228 #ifdef CONFIG_PPC_PSERIES
229 	paca->lppaca_ptr = new_lppaca(cpu, limit);
230 #endif
231 #ifdef CONFIG_PPC_BOOK3S_64
232 	paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
233 #endif
234 	paca_struct_size += sizeof(struct paca_struct);
235 }
236 
237 void __init free_unused_pacas(void)
238 {
239 	int new_ptrs_size;
240 
241 	new_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
242 	if (new_ptrs_size < paca_ptrs_size)
243 		memblock_free(__pa(paca_ptrs) + new_ptrs_size,
244 					paca_ptrs_size - new_ptrs_size);
245 
246 	paca_nr_cpu_ids = nr_cpu_ids;
247 	paca_ptrs_size = new_ptrs_size;
248 
249 #ifdef CONFIG_PPC_BOOK3S_64
250 	if (early_radix_enabled()) {
251 		/* Ugly fixup, see new_slb_shadow() */
252 		memblock_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
253 				sizeof(struct slb_shadow));
254 		paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
255 	}
256 #endif
257 
258 	printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
259 			paca_ptrs_size + paca_struct_size, nr_cpu_ids);
260 }
261 
262 void copy_mm_to_paca(struct mm_struct *mm)
263 {
264 #ifdef CONFIG_PPC_BOOK3S
265 	mm_context_t *context = &mm->context;
266 
267 	get_paca()->mm_ctx_id = context->id;
268 #ifdef CONFIG_PPC_MM_SLICES
269 	VM_BUG_ON(!mm->context.slb_addr_limit);
270 	get_paca()->mm_ctx_slb_addr_limit = mm->context.slb_addr_limit;
271 	memcpy(&get_paca()->mm_ctx_low_slices_psize,
272 	       &context->low_slices_psize, sizeof(context->low_slices_psize));
273 	memcpy(&get_paca()->mm_ctx_high_slices_psize,
274 	       &context->high_slices_psize, TASK_SLICE_ARRAY_SZ(mm));
275 #else /* CONFIG_PPC_MM_SLICES */
276 	get_paca()->mm_ctx_user_psize = context->user_psize;
277 	get_paca()->mm_ctx_sllp = context->sllp;
278 #endif
279 #else /* !CONFIG_PPC_BOOK3S */
280 	return;
281 #endif
282 }
283