xref: /openbmc/linux/arch/powerpc/kernel/paca.c (revision b6dcefde)
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/threads.h>
11 #include <linux/module.h>
12 
13 #include <asm/lppaca.h>
14 #include <asm/paca.h>
15 #include <asm/sections.h>
16 #include <asm/pgtable.h>
17 
18 /* This symbol is provided by the linker - let it fill in the paca
19  * field correctly */
20 extern unsigned long __toc_start;
21 
22 #ifdef CONFIG_PPC_BOOK3S
23 
24 /*
25  * The structure which the hypervisor knows about - this structure
26  * should not cross a page boundary.  The vpa_init/register_vpa call
27  * is now known to fail if the lppaca structure crosses a page
28  * boundary.  The lppaca is also used on legacy iSeries and POWER5
29  * pSeries boxes.  The lppaca is 640 bytes long, and cannot readily
30  * change since the hypervisor knows its layout, so a 1kB alignment
31  * will suffice to ensure that it doesn't cross a page boundary.
32  */
33 struct lppaca lppaca[] = {
34 	[0 ... (NR_CPUS-1)] = {
35 		.desc = 0xd397d781,	/* "LpPa" */
36 		.size = sizeof(struct lppaca),
37 		.dyn_proc_status = 2,
38 		.decr_val = 0x00ff0000,
39 		.fpregs_in_use = 1,
40 		.end_of_quantum = 0xfffffffffffffffful,
41 		.slb_count = 64,
42 		.vmxregs_in_use = 0,
43 		.page_ins = 0,
44 	},
45 };
46 
47 #endif /* CONFIG_PPC_BOOK3S */
48 
49 #ifdef CONFIG_PPC_STD_MMU_64
50 
51 /*
52  * 3 persistent SLBs are registered here.  The buffer will be zero
53  * initially, hence will all be invaild until we actually write them.
54  */
55 struct slb_shadow slb_shadow[] __cacheline_aligned = {
56 	[0 ... (NR_CPUS-1)] = {
57 		.persistent = SLB_NUM_BOLTED,
58 		.buffer_length = sizeof(struct slb_shadow),
59 	},
60 };
61 
62 #endif /* CONFIG_PPC_STD_MMU_64 */
63 
64 /* The Paca is an array with one entry per processor.  Each contains an
65  * lppaca, which contains the information shared between the
66  * hypervisor and Linux.
67  * On systems with hardware multi-threading, there are two threads
68  * per processor.  The Paca array must contain an entry for each thread.
69  * The VPD Areas will give a max logical processors = 2 * max physical
70  * processors.  The processor VPD array needs one entry per physical
71  * processor (not thread).
72  */
73 struct paca_struct paca[NR_CPUS];
74 EXPORT_SYMBOL(paca);
75 
76 void __init initialise_pacas(void)
77 {
78 	int cpu;
79 
80 	/* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
81 	 * of the TOC can be addressed using a single machine instruction.
82 	 */
83 	unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL;
84 
85 	/* Can't use for_each_*_cpu, as they aren't functional yet */
86 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
87 		struct paca_struct *new_paca = &paca[cpu];
88 
89 #ifdef CONFIG_PPC_BOOK3S
90 		new_paca->lppaca_ptr = &lppaca[cpu];
91 #else
92 		new_paca->kernel_pgd = swapper_pg_dir;
93 #endif
94 		new_paca->lock_token = 0x8000;
95 		new_paca->paca_index = cpu;
96 		new_paca->kernel_toc = kernel_toc;
97 		new_paca->kernelbase = (unsigned long) _stext;
98 		new_paca->kernel_msr = MSR_KERNEL;
99 		new_paca->hw_cpu_id = 0xffff;
100 		new_paca->__current = &init_task;
101 #ifdef CONFIG_PPC_STD_MMU_64
102 		new_paca->slb_shadow_ptr = &slb_shadow[cpu];
103 #endif /* CONFIG_PPC_STD_MMU_64 */
104 
105 	}
106 }
107