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/arch/powerpc/kernel/paca.c

http://github.com/mirrors/linux
C | 325 lines | 211 code | 55 blank | 59 comment | 18 complexity | 3e09536bf070d5a759333e74f335c840 MD5 | raw file
  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
 26static 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
 59static 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 */
101static 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
114static 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 */
143static 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 */
176struct paca_struct **paca_ptrs __read_mostly;
177EXPORT_SYMBOL(paca_ptrs);
178
179void __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 */
208void __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
232static int __initdata paca_nr_cpu_ids;
233static int __initdata paca_ptrs_size;
234static int __initdata paca_struct_size;
235
236void __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
249void __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
280void __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
305void 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}