xref: /openbmc/linux/arch/powerpc/kernel/paca.c (revision 95777591)
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 #include <linux/numa.h>
15 
16 #include <asm/lppaca.h>
17 #include <asm/paca.h>
18 #include <asm/sections.h>
19 #include <asm/pgtable.h>
20 #include <asm/kexec.h>
21 
22 #include "setup.h"
23 
24 #ifndef CONFIG_SMP
25 #define boot_cpuid 0
26 #endif
27 
28 static void *__init alloc_paca_data(unsigned long size, unsigned long align,
29 				unsigned long limit, int cpu)
30 {
31 	unsigned long pa;
32 	int nid;
33 
34 	/*
35 	 * boot_cpuid paca is allocated very early before cpu_to_node is up.
36 	 * Set bottom-up mode, because the boot CPU should be on node-0,
37 	 * which will put its paca in the right place.
38 	 */
39 	if (cpu == boot_cpuid) {
40 		nid = NUMA_NO_NODE;
41 		memblock_set_bottom_up(true);
42 	} else {
43 		nid = early_cpu_to_node(cpu);
44 	}
45 
46 	pa = memblock_alloc_base_nid(size, align, limit, nid, MEMBLOCK_NONE);
47 	if (!pa) {
48 		pa = memblock_alloc_base(size, align, limit);
49 		if (!pa)
50 			panic("cannot allocate paca data");
51 	}
52 
53 	if (cpu == boot_cpuid)
54 		memblock_set_bottom_up(false);
55 
56 	return __va(pa);
57 }
58 
59 #ifdef CONFIG_PPC_PSERIES
60 
61 /*
62  * See asm/lppaca.h for more detail.
63  *
64  * lppaca structures must must be 1kB in size, L1 cache line aligned,
65  * and not cross 4kB boundary. A 1kB size and 1kB alignment will satisfy
66  * these requirements.
67  */
68 static inline void init_lppaca(struct lppaca *lppaca)
69 {
70 	BUILD_BUG_ON(sizeof(struct lppaca) != 640);
71 
72 	*lppaca = (struct lppaca) {
73 		.desc = cpu_to_be32(0xd397d781),	/* "LpPa" */
74 		.size = cpu_to_be16(0x400),
75 		.fpregs_in_use = 1,
76 		.slb_count = cpu_to_be16(64),
77 		.vmxregs_in_use = 0,
78 		.page_ins = 0, };
79 };
80 
81 static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
82 {
83 	struct lppaca *lp;
84 	size_t size = 0x400;
85 
86 	BUILD_BUG_ON(size < sizeof(struct lppaca));
87 
88 	if (early_cpu_has_feature(CPU_FTR_HVMODE))
89 		return NULL;
90 
91 	lp = alloc_paca_data(size, 0x400, limit, cpu);
92 	init_lppaca(lp);
93 
94 	return lp;
95 }
96 #endif /* CONFIG_PPC_BOOK3S */
97 
98 #ifdef CONFIG_PPC_BOOK3S_64
99 
100 /*
101  * 3 persistent SLBs are allocated here.  The buffer will be zero
102  * initially, hence will all be invaild until we actually write them.
103  *
104  * If you make the number of persistent SLB entries dynamic, please also
105  * update PR KVM to flush and restore them accordingly.
106  */
107 static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
108 {
109 	struct slb_shadow *s;
110 
111 	if (cpu != boot_cpuid) {
112 		/*
113 		 * Boot CPU comes here before early_radix_enabled
114 		 * is parsed (e.g., for disable_radix). So allocate
115 		 * always and this will be fixed up in free_unused_pacas.
116 		 */
117 		if (early_radix_enabled())
118 			return NULL;
119 	}
120 
121 	s = alloc_paca_data(sizeof(*s), L1_CACHE_BYTES, limit, cpu);
122 	memset(s, 0, sizeof(*s));
123 
124 	s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
125 	s->buffer_length = cpu_to_be32(sizeof(*s));
126 
127 	return s;
128 }
129 
130 #endif /* CONFIG_PPC_BOOK3S_64 */
131 
132 /* The Paca is an array with one entry per processor.  Each contains an
133  * lppaca, which contains the information shared between the
134  * hypervisor and Linux.
135  * On systems with hardware multi-threading, there are two threads
136  * per processor.  The Paca array must contain an entry for each thread.
137  * The VPD Areas will give a max logical processors = 2 * max physical
138  * processors.  The processor VPD array needs one entry per physical
139  * processor (not thread).
140  */
141 struct paca_struct **paca_ptrs __read_mostly;
142 EXPORT_SYMBOL(paca_ptrs);
143 
144 void __init initialise_paca(struct paca_struct *new_paca, int cpu)
145 {
146 #ifdef CONFIG_PPC_PSERIES
147 	new_paca->lppaca_ptr = NULL;
148 #endif
149 #ifdef CONFIG_PPC_BOOK3E
150 	new_paca->kernel_pgd = swapper_pg_dir;
151 #endif
152 	new_paca->lock_token = 0x8000;
153 	new_paca->paca_index = cpu;
154 	new_paca->kernel_toc = kernel_toc_addr();
155 	new_paca->kernelbase = (unsigned long) _stext;
156 	/* Only set MSR:IR/DR when MMU is initialized */
157 	new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
158 	new_paca->hw_cpu_id = 0xffff;
159 	new_paca->kexec_state = KEXEC_STATE_NONE;
160 	new_paca->__current = &init_task;
161 	new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
162 #ifdef CONFIG_PPC_BOOK3S_64
163 	new_paca->slb_shadow_ptr = NULL;
164 #endif
165 
166 #ifdef CONFIG_PPC_BOOK3E
167 	/* For now -- if we have threads this will be adjusted later */
168 	new_paca->tcd_ptr = &new_paca->tcd;
169 #endif
170 }
171 
172 /* Put the paca pointer into r13 and SPRG_PACA */
173 void setup_paca(struct paca_struct *new_paca)
174 {
175 	/* Setup r13 */
176 	local_paca = new_paca;
177 
178 #ifdef CONFIG_PPC_BOOK3E
179 	/* On Book3E, initialize the TLB miss exception frames */
180 	mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
181 #else
182 	/* In HV mode, we setup both HPACA and PACA to avoid problems
183 	 * if we do a GET_PACA() before the feature fixups have been
184 	 * applied
185 	 */
186 	if (early_cpu_has_feature(CPU_FTR_HVMODE))
187 		mtspr(SPRN_SPRG_HPACA, local_paca);
188 #endif
189 	mtspr(SPRN_SPRG_PACA, local_paca);
190 
191 }
192 
193 static int __initdata paca_nr_cpu_ids;
194 static int __initdata paca_ptrs_size;
195 static int __initdata paca_struct_size;
196 
197 void __init allocate_paca_ptrs(void)
198 {
199 	paca_nr_cpu_ids = nr_cpu_ids;
200 
201 	paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
202 	paca_ptrs = __va(memblock_phys_alloc(paca_ptrs_size, SMP_CACHE_BYTES));
203 	memset(paca_ptrs, 0x88, paca_ptrs_size);
204 }
205 
206 void __init allocate_paca(int cpu)
207 {
208 	u64 limit;
209 	struct paca_struct *paca;
210 
211 	BUG_ON(cpu >= paca_nr_cpu_ids);
212 
213 #ifdef CONFIG_PPC_BOOK3S_64
214 	/*
215 	 * We access pacas in real mode, and cannot take SLB faults
216 	 * on them when in virtual mode, so allocate them accordingly.
217 	 */
218 	limit = min(ppc64_bolted_size(), ppc64_rma_size);
219 #else
220 	limit = ppc64_rma_size;
221 #endif
222 
223 	paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
224 				limit, cpu);
225 	paca_ptrs[cpu] = paca;
226 	memset(paca, 0, sizeof(struct paca_struct));
227 
228 	initialise_paca(paca, cpu);
229 #ifdef CONFIG_PPC_PSERIES
230 	paca->lppaca_ptr = new_lppaca(cpu, limit);
231 #endif
232 #ifdef CONFIG_PPC_BOOK3S_64
233 	paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
234 #endif
235 	paca_struct_size += sizeof(struct paca_struct);
236 }
237 
238 void __init free_unused_pacas(void)
239 {
240 	int new_ptrs_size;
241 
242 	new_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
243 	if (new_ptrs_size < paca_ptrs_size)
244 		memblock_free(__pa(paca_ptrs) + new_ptrs_size,
245 					paca_ptrs_size - new_ptrs_size);
246 
247 	paca_nr_cpu_ids = nr_cpu_ids;
248 	paca_ptrs_size = new_ptrs_size;
249 
250 #ifdef CONFIG_PPC_BOOK3S_64
251 	if (early_radix_enabled()) {
252 		/* Ugly fixup, see new_slb_shadow() */
253 		memblock_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
254 				sizeof(struct slb_shadow));
255 		paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
256 	}
257 #endif
258 
259 	printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
260 			paca_ptrs_size + paca_struct_size, nr_cpu_ids);
261 }
262 
263 void copy_mm_to_paca(struct mm_struct *mm)
264 {
265 #ifdef CONFIG_PPC_BOOK3S
266 	mm_context_t *context = &mm->context;
267 
268 	get_paca()->mm_ctx_id = context->id;
269 #ifdef CONFIG_PPC_MM_SLICES
270 	VM_BUG_ON(!mm->context.slb_addr_limit);
271 	get_paca()->mm_ctx_slb_addr_limit = mm->context.slb_addr_limit;
272 	memcpy(&get_paca()->mm_ctx_low_slices_psize,
273 	       &context->low_slices_psize, sizeof(context->low_slices_psize));
274 	memcpy(&get_paca()->mm_ctx_high_slices_psize,
275 	       &context->high_slices_psize, TASK_SLICE_ARRAY_SZ(mm));
276 #else /* CONFIG_PPC_MM_SLICES */
277 	get_paca()->mm_ctx_user_psize = context->user_psize;
278 	get_paca()->mm_ctx_sllp = context->sllp;
279 #endif
280 #else /* !CONFIG_PPC_BOOK3S */
281 	return;
282 #endif
283 }
284