xref: /linux/arch/powerpc/kernel/paca.c (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
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  #include <linux/pgtable.h>
12  
13  #include <asm/lppaca.h>
14  #include <asm/paca.h>
15  #include <asm/sections.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  
alloc_paca_data(unsigned long size,unsigned long align,unsigned long limit,int cpu)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  
alloc_shared_lppaca(unsigned long size,unsigned long limit,int cpu)59  static void *__init alloc_shared_lppaca(unsigned long size, unsigned long limit,
60  					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  		/*
71  		 * See Documentation/arch/powerpc/ultravisor.rst for more details.
72  		 *
73  		 * UV/HV data sharing is in PAGE_SIZE granularity. In order to
74  		 * minimize the number of pages shared, align the allocation to
75  		 * PAGE_SIZE.
76  		 */
77  		shared_lppaca =
78  			memblock_alloc_try_nid(shared_lppaca_total_size,
79  					       PAGE_SIZE, MEMBLOCK_LOW_LIMIT,
80  					       limit, NUMA_NO_NODE);
81  		if (!shared_lppaca)
82  			panic("cannot allocate shared data");
83  
84  		memblock_set_bottom_up(false);
85  		uv_share_page(PHYS_PFN(__pa(shared_lppaca)),
86  			      shared_lppaca_total_size >> PAGE_SHIFT);
87  	}
88  
89  	ptr = shared_lppaca + shared_lppaca_size;
90  	shared_lppaca_size += size;
91  
92  	/*
93  	 * This is very early in boot, so no harm done if the kernel crashes at
94  	 * this point.
95  	 */
96  	BUG_ON(shared_lppaca_size > shared_lppaca_total_size);
97  
98  	return ptr;
99  }
100  
101  /*
102   * See asm/lppaca.h for more detail.
103   *
104   * lppaca structures must must be 1kB in size, L1 cache line aligned,
105   * and not cross 4kB boundary. A 1kB size and 1kB alignment will satisfy
106   * these requirements.
107   */
init_lppaca(struct lppaca * lppaca)108  static inline void init_lppaca(struct lppaca *lppaca)
109  {
110  	BUILD_BUG_ON(sizeof(struct lppaca) != 640);
111  
112  	*lppaca = (struct lppaca) {
113  		.desc = cpu_to_be32(0xd397d781),	/* "LpPa" */
114  		.size = cpu_to_be16(LPPACA_SIZE),
115  		.fpregs_in_use = 1,
116  		.slb_count = cpu_to_be16(64),
117  		.vmxregs_in_use = 0,
118  		.page_ins = 0, };
119  };
120  
new_lppaca(int cpu,unsigned long limit)121  static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
122  {
123  	struct lppaca *lp;
124  
125  	BUILD_BUG_ON(sizeof(struct lppaca) > LPPACA_SIZE);
126  
127  	if (early_cpu_has_feature(CPU_FTR_HVMODE))
128  		return NULL;
129  
130  	if (is_secure_guest())
131  		lp = alloc_shared_lppaca(LPPACA_SIZE, limit, cpu);
132  	else
133  		lp = alloc_paca_data(LPPACA_SIZE, 0x400, limit, cpu);
134  
135  	init_lppaca(lp);
136  
137  	return lp;
138  }
139  #endif /* CONFIG_PPC_PSERIES */
140  
141  #ifdef CONFIG_PPC_64S_HASH_MMU
142  /*
143   * 3 persistent SLBs are allocated here.  The buffer will be zero
144   * initially, hence will all be invaild until we actually write them.
145   *
146   * If you make the number of persistent SLB entries dynamic, please also
147   * update PR KVM to flush and restore them accordingly.
148   */
new_slb_shadow(int cpu,unsigned long limit)149  static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
150  {
151  	struct slb_shadow *s;
152  
153  	if (cpu != boot_cpuid) {
154  		/*
155  		 * Boot CPU comes here before early_radix_enabled
156  		 * is parsed (e.g., for disable_radix). So allocate
157  		 * always and this will be fixed up in free_unused_pacas.
158  		 */
159  		if (early_radix_enabled())
160  			return NULL;
161  	}
162  
163  	s = alloc_paca_data(sizeof(*s), L1_CACHE_BYTES, limit, cpu);
164  
165  	s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
166  	s->buffer_length = cpu_to_be32(sizeof(*s));
167  
168  	return s;
169  }
170  #endif /* CONFIG_PPC_64S_HASH_MMU */
171  
172  /* The Paca is an array with one entry per processor.  Each contains an
173   * lppaca, which contains the information shared between the
174   * hypervisor and Linux.
175   * On systems with hardware multi-threading, there are two threads
176   * per processor.  The Paca array must contain an entry for each thread.
177   * The VPD Areas will give a max logical processors = 2 * max physical
178   * processors.  The processor VPD array needs one entry per physical
179   * processor (not thread).
180   */
181  struct paca_struct **paca_ptrs __read_mostly;
182  EXPORT_SYMBOL(paca_ptrs);
183  
initialise_paca(struct paca_struct * new_paca,int cpu)184  void __init initialise_paca(struct paca_struct *new_paca, int cpu)
185  {
186  #ifdef CONFIG_PPC_PSERIES
187  	new_paca->lppaca_ptr = NULL;
188  #endif
189  #ifdef CONFIG_PPC_BOOK3E_64
190  	new_paca->kernel_pgd = swapper_pg_dir;
191  #endif
192  	new_paca->lock_token = 0x8000;
193  	new_paca->paca_index = cpu;
194  #ifndef CONFIG_PPC_KERNEL_PCREL
195  	new_paca->kernel_toc = kernel_toc_addr();
196  #endif
197  	new_paca->kernelbase = (unsigned long) _stext;
198  	/* Only set MSR:IR/DR when MMU is initialized */
199  	new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
200  	new_paca->hw_cpu_id = 0xffff;
201  	new_paca->kexec_state = KEXEC_STATE_NONE;
202  	new_paca->__current = &init_task;
203  	new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
204  #ifdef CONFIG_PPC_64S_HASH_MMU
205  	new_paca->slb_shadow_ptr = NULL;
206  #endif
207  
208  #ifdef CONFIG_PPC_BOOK3E_64
209  	/* For now -- if we have threads this will be adjusted later */
210  	new_paca->tcd_ptr = &new_paca->tcd;
211  #endif
212  }
213  
214  /* Put the paca pointer into r13 and SPRG_PACA */
setup_paca(struct paca_struct * new_paca)215  void setup_paca(struct paca_struct *new_paca)
216  {
217  	/* Setup r13 */
218  	local_paca = new_paca;
219  
220  #ifdef CONFIG_PPC_BOOK3E_64
221  	/* On Book3E, initialize the TLB miss exception frames */
222  	mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
223  #else
224  	/*
225  	 * In HV mode, we setup both HPACA and PACA to avoid problems
226  	 * if we do a GET_PACA() before the feature fixups have been
227  	 * applied.
228  	 *
229  	 * Normally you should test against CPU_FTR_HVMODE, but CPU features
230  	 * are not yet set up when we first reach here.
231  	 */
232  	if (mfmsr() & MSR_HV)
233  		mtspr(SPRN_SPRG_HPACA, local_paca);
234  #endif
235  	mtspr(SPRN_SPRG_PACA, local_paca);
236  
237  }
238  
239  static int __initdata paca_nr_cpu_ids;
240  static int __initdata paca_ptrs_size;
241  static int __initdata paca_struct_size;
242  
allocate_paca_ptrs(void)243  void __init allocate_paca_ptrs(void)
244  {
245  	paca_nr_cpu_ids = nr_cpu_ids;
246  
247  	paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
248  	paca_ptrs = memblock_alloc_raw(paca_ptrs_size, SMP_CACHE_BYTES);
249  	if (!paca_ptrs)
250  		panic("Failed to allocate %d bytes for paca pointers\n",
251  		      paca_ptrs_size);
252  
253  	memset(paca_ptrs, 0x88, paca_ptrs_size);
254  }
255  
allocate_paca(int cpu)256  void __init allocate_paca(int cpu)
257  {
258  	u64 limit;
259  	struct paca_struct *paca;
260  
261  	BUG_ON(cpu >= paca_nr_cpu_ids);
262  
263  #ifdef CONFIG_PPC_BOOK3S_64
264  	/*
265  	 * We access pacas in real mode, and cannot take SLB faults
266  	 * on them when in virtual mode, so allocate them accordingly.
267  	 */
268  	limit = min(ppc64_bolted_size(), ppc64_rma_size);
269  #else
270  	limit = ppc64_rma_size;
271  #endif
272  
273  	paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
274  				limit, cpu);
275  	paca_ptrs[cpu] = paca;
276  
277  	initialise_paca(paca, cpu);
278  #ifdef CONFIG_PPC_PSERIES
279  	paca->lppaca_ptr = new_lppaca(cpu, limit);
280  #endif
281  #ifdef CONFIG_PPC_64S_HASH_MMU
282  	paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
283  #endif
284  	paca_struct_size += sizeof(struct paca_struct);
285  }
286  
free_unused_pacas(void)287  void __init free_unused_pacas(void)
288  {
289  	int new_ptrs_size;
290  
291  	new_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
292  	if (new_ptrs_size < paca_ptrs_size)
293  		memblock_phys_free(__pa(paca_ptrs) + new_ptrs_size,
294  				   paca_ptrs_size - new_ptrs_size);
295  
296  	paca_nr_cpu_ids = nr_cpu_ids;
297  	paca_ptrs_size = new_ptrs_size;
298  
299  #ifdef CONFIG_PPC_64S_HASH_MMU
300  	if (early_radix_enabled()) {
301  		/* Ugly fixup, see new_slb_shadow() */
302  		memblock_phys_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
303  				   sizeof(struct slb_shadow));
304  		paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
305  	}
306  #endif
307  
308  	printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
309  			paca_ptrs_size + paca_struct_size, nr_cpu_ids);
310  }
311  
312  #ifdef CONFIG_PPC_64S_HASH_MMU
copy_mm_to_paca(struct mm_struct * mm)313  void copy_mm_to_paca(struct mm_struct *mm)
314  {
315  	mm_context_t *context = &mm->context;
316  
317  	VM_BUG_ON(!mm_ctx_slb_addr_limit(context));
318  	memcpy(&get_paca()->mm_ctx_low_slices_psize, mm_ctx_low_slices(context),
319  	       LOW_SLICE_ARRAY_SZ);
320  	memcpy(&get_paca()->mm_ctx_high_slices_psize, mm_ctx_high_slices(context),
321  	       TASK_SLICE_ARRAY_SZ(context));
322  }
323  #endif /* CONFIG_PPC_64S_HASH_MMU */
324