xref: /openbmc/linux/arch/powerpc/kernel/paca.c (revision 545e4006)
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 
16 /* This symbol is provided by the linker - let it fill in the paca
17  * field correctly */
18 extern unsigned long __toc_start;
19 
20 /*
21  * The structure which the hypervisor knows about - this structure
22  * should not cross a page boundary.  The vpa_init/register_vpa call
23  * is now known to fail if the lppaca structure crosses a page
24  * boundary.  The lppaca is also used on legacy iSeries and POWER5
25  * pSeries boxes.  The lppaca is 640 bytes long, and cannot readily
26  * change since the hypervisor knows its layout, so a 1kB alignment
27  * will suffice to ensure that it doesn't cross a page boundary.
28  */
29 struct lppaca lppaca[] = {
30 	[0 ... (NR_CPUS-1)] = {
31 		.desc = 0xd397d781,	/* "LpPa" */
32 		.size = sizeof(struct lppaca),
33 		.dyn_proc_status = 2,
34 		.decr_val = 0x00ff0000,
35 		.fpregs_in_use = 1,
36 		.end_of_quantum = 0xfffffffffffffffful,
37 		.slb_count = 64,
38 		.vmxregs_in_use = 0,
39 	},
40 };
41 
42 /*
43  * 3 persistent SLBs are registered here.  The buffer will be zero
44  * initially, hence will all be invaild until we actually write them.
45  */
46 struct slb_shadow slb_shadow[] __cacheline_aligned = {
47 	[0 ... (NR_CPUS-1)] = {
48 		.persistent = SLB_NUM_BOLTED,
49 		.buffer_length = sizeof(struct slb_shadow),
50 	},
51 };
52 
53 /* The Paca is an array with one entry per processor.  Each contains an
54  * lppaca, which contains the information shared between the
55  * hypervisor and Linux.
56  * On systems with hardware multi-threading, there are two threads
57  * per processor.  The Paca array must contain an entry for each thread.
58  * The VPD Areas will give a max logical processors = 2 * max physical
59  * processors.  The processor VPD array needs one entry per physical
60  * processor (not thread).
61  */
62 struct paca_struct paca[NR_CPUS];
63 EXPORT_SYMBOL(paca);
64 
65 void __init initialise_pacas(void)
66 {
67 	int cpu;
68 
69 	/* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
70 	 * of the TOC can be addressed using a single machine instruction.
71 	 */
72 	unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL;
73 
74 	/* Can't use for_each_*_cpu, as they aren't functional yet */
75 	for (cpu = 0; cpu < NR_CPUS; cpu++) {
76 		struct paca_struct *new_paca = &paca[cpu];
77 
78 		new_paca->lppaca_ptr = &lppaca[cpu];
79 		new_paca->lock_token = 0x8000;
80 		new_paca->paca_index = cpu;
81 		new_paca->kernel_toc = kernel_toc;
82 		new_paca->hw_cpu_id = 0xffff;
83 		new_paca->slb_shadow_ptr = &slb_shadow[cpu];
84 		new_paca->__current = &init_task;
85 
86 	}
87 }
88