xref: /linux/arch/powerpc/kernel/paca.c (revision 165f2d2858013253042809df082b8df7e34e86d7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * c 2001 PPC 64 Team, IBM Corp
4  */
5 
6 #include <linux/smp.h>
7 #include <linux/export.h>
8 #include <linux/memblock.h>
9 #include <linux/sched/task.h>
10 #include <linux/numa.h>
11 
12 #include <asm/lppaca.h>
13 #include <asm/paca.h>
14 #include <asm/sections.h>
15 #include <asm/pgtable.h>
16 #include <asm/kexec.h>
17 #include <asm/svm.h>
18 #include <asm/ultravisor.h>
19 
20 #include "setup.h"
21 
22 #ifndef CONFIG_SMP
23 #define boot_cpuid 0
24 #endif
25 
26 static void *__init alloc_paca_data(unsigned long size, unsigned long align,
27 				unsigned long limit, int cpu)
28 {
29 	void *ptr;
30 	int nid;
31 
32 	/*
33 	 * boot_cpuid paca is allocated very early before cpu_to_node is up.
34 	 * Set bottom-up mode, because the boot CPU should be on node-0,
35 	 * which will put its paca in the right place.
36 	 */
37 	if (cpu == boot_cpuid) {
38 		nid = NUMA_NO_NODE;
39 		memblock_set_bottom_up(true);
40 	} else {
41 		nid = early_cpu_to_node(cpu);
42 	}
43 
44 	ptr = memblock_alloc_try_nid(size, align, MEMBLOCK_LOW_LIMIT,
45 				     limit, nid);
46 	if (!ptr)
47 		panic("cannot allocate paca data");
48 
49 	if (cpu == boot_cpuid)
50 		memblock_set_bottom_up(false);
51 
52 	return ptr;
53 }
54 
55 #ifdef CONFIG_PPC_PSERIES
56 
57 #define LPPACA_SIZE 0x400
58 
59 static void *__init alloc_shared_lppaca(unsigned long size, unsigned long align,
60 					unsigned long limit, int cpu)
61 {
62 	size_t shared_lppaca_total_size = PAGE_ALIGN(nr_cpu_ids * LPPACA_SIZE);
63 	static unsigned long shared_lppaca_size;
64 	static void *shared_lppaca;
65 	void *ptr;
66 
67 	if (!shared_lppaca) {
68 		memblock_set_bottom_up(true);
69 
70 		shared_lppaca =
71 			memblock_alloc_try_nid(shared_lppaca_total_size,
72 					       PAGE_SIZE, MEMBLOCK_LOW_LIMIT,
73 					       limit, NUMA_NO_NODE);
74 		if (!shared_lppaca)
75 			panic("cannot allocate shared data");
76 
77 		memblock_set_bottom_up(false);
78 		uv_share_page(PHYS_PFN(__pa(shared_lppaca)),
79 			      shared_lppaca_total_size >> PAGE_SHIFT);
80 	}
81 
82 	ptr = shared_lppaca + shared_lppaca_size;
83 	shared_lppaca_size += size;
84 
85 	/*
86 	 * This is very early in boot, so no harm done if the kernel crashes at
87 	 * this point.
88 	 */
89 	BUG_ON(shared_lppaca_size >= shared_lppaca_total_size);
90 
91 	return ptr;
92 }
93 
94 /*
95  * See asm/lppaca.h for more detail.
96  *
97  * lppaca structures must must be 1kB in size, L1 cache line aligned,
98  * and not cross 4kB boundary. A 1kB size and 1kB alignment will satisfy
99  * these requirements.
100  */
101 static inline void init_lppaca(struct lppaca *lppaca)
102 {
103 	BUILD_BUG_ON(sizeof(struct lppaca) != 640);
104 
105 	*lppaca = (struct lppaca) {
106 		.desc = cpu_to_be32(0xd397d781),	/* "LpPa" */
107 		.size = cpu_to_be16(LPPACA_SIZE),
108 		.fpregs_in_use = 1,
109 		.slb_count = cpu_to_be16(64),
110 		.vmxregs_in_use = 0,
111 		.page_ins = 0, };
112 };
113 
114 static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
115 {
116 	struct lppaca *lp;
117 
118 	BUILD_BUG_ON(sizeof(struct lppaca) > LPPACA_SIZE);
119 
120 	if (early_cpu_has_feature(CPU_FTR_HVMODE))
121 		return NULL;
122 
123 	if (is_secure_guest())
124 		lp = alloc_shared_lppaca(LPPACA_SIZE, 0x400, limit, cpu);
125 	else
126 		lp = alloc_paca_data(LPPACA_SIZE, 0x400, limit, cpu);
127 
128 	init_lppaca(lp);
129 
130 	return lp;
131 }
132 #endif /* CONFIG_PPC_PSERIES */
133 
134 #ifdef CONFIG_PPC_BOOK3S_64
135 
136 /*
137  * 3 persistent SLBs are allocated here.  The buffer will be zero
138  * initially, hence will all be invaild until we actually write them.
139  *
140  * If you make the number of persistent SLB entries dynamic, please also
141  * update PR KVM to flush and restore them accordingly.
142  */
143 static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
144 {
145 	struct slb_shadow *s;
146 
147 	if (cpu != boot_cpuid) {
148 		/*
149 		 * Boot CPU comes here before early_radix_enabled
150 		 * is parsed (e.g., for disable_radix). So allocate
151 		 * always and this will be fixed up in free_unused_pacas.
152 		 */
153 		if (early_radix_enabled())
154 			return NULL;
155 	}
156 
157 	s = alloc_paca_data(sizeof(*s), L1_CACHE_BYTES, limit, cpu);
158 
159 	s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
160 	s->buffer_length = cpu_to_be32(sizeof(*s));
161 
162 	return s;
163 }
164 
165 #endif /* CONFIG_PPC_BOOK3S_64 */
166 
167 /* The Paca is an array with one entry per processor.  Each contains an
168  * lppaca, which contains the information shared between the
169  * hypervisor and Linux.
170  * On systems with hardware multi-threading, there are two threads
171  * per processor.  The Paca array must contain an entry for each thread.
172  * The VPD Areas will give a max logical processors = 2 * max physical
173  * processors.  The processor VPD array needs one entry per physical
174  * processor (not thread).
175  */
176 struct paca_struct **paca_ptrs __read_mostly;
177 EXPORT_SYMBOL(paca_ptrs);
178 
179 void __init __nostackprotector initialise_paca(struct paca_struct *new_paca, int cpu)
180 {
181 #ifdef CONFIG_PPC_PSERIES
182 	new_paca->lppaca_ptr = NULL;
183 #endif
184 #ifdef CONFIG_PPC_BOOK3E
185 	new_paca->kernel_pgd = swapper_pg_dir;
186 #endif
187 	new_paca->lock_token = 0x8000;
188 	new_paca->paca_index = cpu;
189 	new_paca->kernel_toc = kernel_toc_addr();
190 	new_paca->kernelbase = (unsigned long) _stext;
191 	/* Only set MSR:IR/DR when MMU is initialized */
192 	new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
193 	new_paca->hw_cpu_id = 0xffff;
194 	new_paca->kexec_state = KEXEC_STATE_NONE;
195 	new_paca->__current = &init_task;
196 	new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
197 #ifdef CONFIG_PPC_BOOK3S_64
198 	new_paca->slb_shadow_ptr = NULL;
199 #endif
200 
201 #ifdef CONFIG_PPC_BOOK3E
202 	/* For now -- if we have threads this will be adjusted later */
203 	new_paca->tcd_ptr = &new_paca->tcd;
204 #endif
205 }
206 
207 /* Put the paca pointer into r13 and SPRG_PACA */
208 void __nostackprotector setup_paca(struct paca_struct *new_paca)
209 {
210 	/* Setup r13 */
211 	local_paca = new_paca;
212 
213 #ifdef CONFIG_PPC_BOOK3E
214 	/* On Book3E, initialize the TLB miss exception frames */
215 	mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
216 #else
217 	/*
218 	 * In HV mode, we setup both HPACA and PACA to avoid problems
219 	 * if we do a GET_PACA() before the feature fixups have been
220 	 * applied.
221 	 *
222 	 * Normally you should test against CPU_FTR_HVMODE, but CPU features
223 	 * are not yet set up when we first reach here.
224 	 */
225 	if (mfmsr() & MSR_HV)
226 		mtspr(SPRN_SPRG_HPACA, local_paca);
227 #endif
228 	mtspr(SPRN_SPRG_PACA, local_paca);
229 
230 }
231 
232 static int __initdata paca_nr_cpu_ids;
233 static int __initdata paca_ptrs_size;
234 static int __initdata paca_struct_size;
235 
236 void __init allocate_paca_ptrs(void)
237 {
238 	paca_nr_cpu_ids = nr_cpu_ids;
239 
240 	paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
241 	paca_ptrs = memblock_alloc_raw(paca_ptrs_size, SMP_CACHE_BYTES);
242 	if (!paca_ptrs)
243 		panic("Failed to allocate %d bytes for paca pointers\n",
244 		      paca_ptrs_size);
245 
246 	memset(paca_ptrs, 0x88, paca_ptrs_size);
247 }
248 
249 void __init allocate_paca(int cpu)
250 {
251 	u64 limit;
252 	struct paca_struct *paca;
253 
254 	BUG_ON(cpu >= paca_nr_cpu_ids);
255 
256 #ifdef CONFIG_PPC_BOOK3S_64
257 	/*
258 	 * We access pacas in real mode, and cannot take SLB faults
259 	 * on them when in virtual mode, so allocate them accordingly.
260 	 */
261 	limit = min(ppc64_bolted_size(), ppc64_rma_size);
262 #else
263 	limit = ppc64_rma_size;
264 #endif
265 
266 	paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
267 				limit, cpu);
268 	paca_ptrs[cpu] = paca;
269 
270 	initialise_paca(paca, cpu);
271 #ifdef CONFIG_PPC_PSERIES
272 	paca->lppaca_ptr = new_lppaca(cpu, limit);
273 #endif
274 #ifdef CONFIG_PPC_BOOK3S_64
275 	paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
276 #endif
277 	paca_struct_size += sizeof(struct paca_struct);
278 }
279 
280 void __init free_unused_pacas(void)
281 {
282 	int new_ptrs_size;
283 
284 	new_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
285 	if (new_ptrs_size < paca_ptrs_size)
286 		memblock_free(__pa(paca_ptrs) + new_ptrs_size,
287 					paca_ptrs_size - new_ptrs_size);
288 
289 	paca_nr_cpu_ids = nr_cpu_ids;
290 	paca_ptrs_size = new_ptrs_size;
291 
292 #ifdef CONFIG_PPC_BOOK3S_64
293 	if (early_radix_enabled()) {
294 		/* Ugly fixup, see new_slb_shadow() */
295 		memblock_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
296 				sizeof(struct slb_shadow));
297 		paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
298 	}
299 #endif
300 
301 	printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
302 			paca_ptrs_size + paca_struct_size, nr_cpu_ids);
303 }
304 
305 void copy_mm_to_paca(struct mm_struct *mm)
306 {
307 #ifdef CONFIG_PPC_BOOK3S
308 	mm_context_t *context = &mm->context;
309 
310 	get_paca()->mm_ctx_id = context->id;
311 #ifdef CONFIG_PPC_MM_SLICES
312 	VM_BUG_ON(!mm_ctx_slb_addr_limit(context));
313 	get_paca()->mm_ctx_slb_addr_limit = mm_ctx_slb_addr_limit(context);
314 	memcpy(&get_paca()->mm_ctx_low_slices_psize, mm_ctx_low_slices(context),
315 	       LOW_SLICE_ARRAY_SZ);
316 	memcpy(&get_paca()->mm_ctx_high_slices_psize, mm_ctx_high_slices(context),
317 	       TASK_SLICE_ARRAY_SZ(context));
318 #else /* CONFIG_PPC_MM_SLICES */
319 	get_paca()->mm_ctx_user_psize = context->user_psize;
320 	get_paca()->mm_ctx_sllp = context->sllp;
321 #endif
322 #else /* !CONFIG_PPC_BOOK3S */
323 	return;
324 #endif
325 }
326