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
14#include <asm/lppaca.h>
15#include <asm/paca.h>
16#include <asm/sections.h>
17#include <asm/pgtable.h>
18#include <asm/kexec.h>
19
20/* This symbol is provided by the linker - let it fill in the paca
21 * field correctly */
22extern unsigned long __toc_start;
23
24#ifdef CONFIG_PPC_BOOK3S
25
26/*
27 * The structure which the hypervisor knows about - this structure
28 * should not cross a page boundary.  The vpa_init/register_vpa call
29 * is now known to fail if the lppaca structure crosses a page
30 * boundary.  The lppaca is also used on POWER5 pSeries boxes.
31 * The lppaca is 640 bytes long, and cannot readily
32 * change since the hypervisor knows its layout, so a 1kB alignment
33 * will suffice to ensure that it doesn't cross a page boundary.
34 */
35struct lppaca lppaca[] = {
36	[0 ... (NR_LPPACAS-1)] = {
37		.desc = cpu_to_be32(0xd397d781),	/* "LpPa" */
38		.size = cpu_to_be16(sizeof(struct lppaca)),
39		.fpregs_in_use = 1,
40		.slb_count = cpu_to_be16(64),
41		.vmxregs_in_use = 0,
42		.page_ins = 0,
43	},
44};
45
46static struct lppaca *extra_lppacas;
47static long __initdata lppaca_size;
48
49static void __init allocate_lppacas(int nr_cpus, unsigned long limit)
50{
51	if (nr_cpus <= NR_LPPACAS)
52		return;
53
54	lppaca_size = PAGE_ALIGN(sizeof(struct lppaca) *
55				 (nr_cpus - NR_LPPACAS));
56	extra_lppacas = __va(memblock_alloc_base(lppaca_size,
57						 PAGE_SIZE, limit));
58}
59
60static struct lppaca * __init new_lppaca(int cpu)
61{
62	struct lppaca *lp;
63
64	if (cpu < NR_LPPACAS)
65		return &lppaca[cpu];
66
67	lp = extra_lppacas + (cpu - NR_LPPACAS);
68	*lp = lppaca[0];
69
70	return lp;
71}
72
73static void __init free_lppacas(void)
74{
75	long new_size = 0, nr;
76
77	if (!lppaca_size)
78		return;
79	nr = num_possible_cpus() - NR_LPPACAS;
80	if (nr > 0)
81		new_size = PAGE_ALIGN(nr * sizeof(struct lppaca));
82	if (new_size >= lppaca_size)
83		return;
84
85	memblock_free(__pa(extra_lppacas) + new_size, lppaca_size - new_size);
86	lppaca_size = new_size;
87}
88
89#else
90
91static inline void allocate_lppacas(int nr_cpus, unsigned long limit) { }
92static inline void free_lppacas(void) { }
93
94#endif /* CONFIG_PPC_BOOK3S */
95
96#ifdef CONFIG_PPC_STD_MMU_64
97
98/*
99 * 3 persistent SLBs are registered here.  The buffer will be zero
100 * initially, hence will all be invaild until we actually write them.
101 *
102 * If you make the number of persistent SLB entries dynamic, please also
103 * update PR KVM to flush and restore them accordingly.
104 */
105static struct slb_shadow *slb_shadow;
106
107static void __init allocate_slb_shadows(int nr_cpus, int limit)
108{
109	int size = PAGE_ALIGN(sizeof(struct slb_shadow) * nr_cpus);
110	slb_shadow = __va(memblock_alloc_base(size, PAGE_SIZE, limit));
111	memset(slb_shadow, 0, size);
112}
113
114static struct slb_shadow * __init init_slb_shadow(int cpu)
115{
116	struct slb_shadow *s = &slb_shadow[cpu];
117
118	/*
119	 * When we come through here to initialise boot_paca, the slb_shadow
120	 * buffers are not allocated yet. That's OK, we'll get one later in
121	 * boot, but make sure we don't corrupt memory at 0.
122	 */
123	if (!slb_shadow)
124		return NULL;
125
126	s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
127	s->buffer_length = cpu_to_be32(sizeof(*s));
128
129	return s;
130}
131
132#else /* CONFIG_PPC_STD_MMU_64 */
133
134static void __init allocate_slb_shadows(int nr_cpus, int limit) { }
135
136#endif /* CONFIG_PPC_STD_MMU_64 */
137
138/* The Paca is an array with one entry per processor.  Each contains an
139 * lppaca, which contains the information shared between the
140 * hypervisor and Linux.
141 * On systems with hardware multi-threading, there are two threads
142 * per processor.  The Paca array must contain an entry for each thread.
143 * The VPD Areas will give a max logical processors = 2 * max physical
144 * processors.  The processor VPD array needs one entry per physical
145 * processor (not thread).
146 */
147struct paca_struct *paca;
148EXPORT_SYMBOL(paca);
149
150void __init initialise_paca(struct paca_struct *new_paca, int cpu)
151{
152       /* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
153	* of the TOC can be addressed using a single machine instruction.
154	*/
155	unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL;
156
157#ifdef CONFIG_PPC_BOOK3S
158	new_paca->lppaca_ptr = new_lppaca(cpu);
159#else
160	new_paca->kernel_pgd = swapper_pg_dir;
161#endif
162	new_paca->lock_token = 0x8000;
163	new_paca->paca_index = cpu;
164	new_paca->kernel_toc = kernel_toc;
165	new_paca->kernelbase = (unsigned long) _stext;
166	/* Only set MSR:IR/DR when MMU is initialized */
167	new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
168	new_paca->hw_cpu_id = 0xffff;
169	new_paca->kexec_state = KEXEC_STATE_NONE;
170	new_paca->__current = &init_task;
171	new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
172#ifdef CONFIG_PPC_STD_MMU_64
173	new_paca->slb_shadow_ptr = init_slb_shadow(cpu);
174#endif /* CONFIG_PPC_STD_MMU_64 */
175
176#ifdef CONFIG_PPC_BOOK3E
177	/* For now -- if we have threads this will be adjusted later */
178	new_paca->tcd_ptr = &new_paca->tcd;
179#endif
180}
181
182/* Put the paca pointer into r13 and SPRG_PACA */
183void setup_paca(struct paca_struct *new_paca)
184{
185	/* Setup r13 */
186	local_paca = new_paca;
187
188#ifdef CONFIG_PPC_BOOK3E
189	/* On Book3E, initialize the TLB miss exception frames */
190	mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
191#else
192	/* In HV mode, we setup both HPACA and PACA to avoid problems
193	 * if we do a GET_PACA() before the feature fixups have been
194	 * applied
195	 */
196	if (cpu_has_feature(CPU_FTR_HVMODE))
197		mtspr(SPRN_SPRG_HPACA, local_paca);
198#endif
199	mtspr(SPRN_SPRG_PACA, local_paca);
200
201}
202
203static int __initdata paca_size;
204
205void __init allocate_pacas(void)
206{
207	u64 limit;
208	int cpu;
209
210	limit = ppc64_rma_size;
211
212#ifdef CONFIG_PPC_BOOK3S_64
213	/*
214	 * We can't take SLB misses on the paca, and we want to access them
215	 * in real mode, so allocate them within the RMA and also within
216	 * the first segment.
217	 */
218	limit = min(0x10000000ULL, limit);
219#endif
220
221	paca_size = PAGE_ALIGN(sizeof(struct paca_struct) * nr_cpu_ids);
222
223	paca = __va(memblock_alloc_base(paca_size, PAGE_SIZE, limit));
224	memset(paca, 0, paca_size);
225
226	printk(KERN_DEBUG "Allocated %u bytes for %d pacas at %p\n",
227		paca_size, nr_cpu_ids, paca);
228
229	allocate_lppacas(nr_cpu_ids, limit);
230
231	allocate_slb_shadows(nr_cpu_ids, limit);
232
233	/* Can't use for_each_*_cpu, as they aren't functional yet */
234	for (cpu = 0; cpu < nr_cpu_ids; cpu++)
235		initialise_paca(&paca[cpu], cpu);
236}
237
238void __init free_unused_pacas(void)
239{
240	int new_size;
241
242	new_size = PAGE_ALIGN(sizeof(struct paca_struct) * nr_cpu_ids);
243
244	if (new_size >= paca_size)
245		return;
246
247	memblock_free(__pa(paca) + new_size, paca_size - new_size);
248
249	printk(KERN_DEBUG "Freed %u bytes for unused pacas\n",
250		paca_size - new_size);
251
252	paca_size = new_size;
253
254	free_lppacas();
255}
256