xref: /openbmc/linux/arch/arc/include/asm/processor.h (revision 160b8e75)
1 /*
2  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * vineetg: March 2009
9  *  -Implemented task_pt_regs( )
10  *
11  * Amit Bhor, Sameer Dhavale, Ashwin Chaugule: Codito Technologies 2004
12  */
13 
14 #ifndef __ASM_ARC_PROCESSOR_H
15 #define __ASM_ARC_PROCESSOR_H
16 
17 #ifndef __ASSEMBLY__
18 
19 #include <asm/ptrace.h>
20 
21 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
22 /* These DPFP regs need to be saved/restored across ctx-sw */
23 struct arc_fpu {
24 	struct {
25 		unsigned int l, h;
26 	} aux_dpfp[2];
27 };
28 #endif
29 
30 #ifdef CONFIG_ARC_PLAT_EZNPS
31 struct eznps_dp {
32 	unsigned int eflags;
33 	unsigned int gpa1;
34 };
35 #endif
36 
37 /* Arch specific stuff which needs to be saved per task.
38  * However these items are not so important so as to earn a place in
39  * struct thread_info
40  */
41 struct thread_struct {
42 	unsigned long ksp;	/* kernel mode stack pointer */
43 	unsigned long callee_reg;	/* pointer to callee regs */
44 	unsigned long fault_address;	/* dbls as brkpt holder as well */
45 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
46 	struct arc_fpu fpu;
47 #endif
48 #ifdef CONFIG_ARC_PLAT_EZNPS
49 	struct eznps_dp dp;
50 #endif
51 };
52 
53 #define INIT_THREAD  {                          \
54 	.ksp = sizeof(init_stack) + (unsigned long) init_stack, \
55 }
56 
57 /* Forward declaration, a strange C thing */
58 struct task_struct;
59 
60 #define task_pt_regs(p) \
61 	((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
62 
63 /* Free all resources held by a thread */
64 #define release_thread(thread) do { } while (0)
65 
66 /*
67  * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
68  * get optimised away by gcc
69  */
70 #ifndef CONFIG_EZNPS_MTM_EXT
71 
72 #define cpu_relax()		barrier()
73 
74 #else
75 
76 #define cpu_relax()     \
77 	__asm__ __volatile__ (".word %0" : : "i"(CTOP_INST_SCHD_RW) : "memory")
78 
79 #endif
80 
81 #define KSTK_EIP(tsk)   (task_pt_regs(tsk)->ret)
82 #define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
83 
84 /*
85  * Where about of Task's sp, fp, blink when it was last seen in kernel mode.
86  * Look in process.c for details of kernel stack layout
87  */
88 #define TSK_K_ESP(tsk)		(tsk->thread.ksp)
89 
90 #define TSK_K_REG(tsk, off)	(*((unsigned long *)(TSK_K_ESP(tsk) + \
91 					sizeof(struct callee_regs) + off)))
92 
93 #define TSK_K_BLINK(tsk)	TSK_K_REG(tsk, 4)
94 #define TSK_K_FP(tsk)		TSK_K_REG(tsk, 0)
95 
96 extern void start_thread(struct pt_regs * regs, unsigned long pc,
97 			 unsigned long usp);
98 
99 extern unsigned int get_wchan(struct task_struct *p);
100 
101 /*
102  * Default implementation of macro that returns current
103  * instruction pointer ("program counter").
104  * Should the PC register be read instead ? This macro does not seem to
105  * be used in many places so this wont be all that bad.
106  */
107 #define current_text_addr() ({ __label__ _l; _l: &&_l; })
108 
109 #endif /* !__ASSEMBLY__ */
110 
111 /*
112  * Default System Memory Map on ARC
113  *
114  * ---------------------------- (lower 2G, Translated) -------------------------
115  * 0x0000_0000		0x5FFF_FFFF	(user vaddr: TASK_SIZE)
116  * 0x6000_0000		0x6FFF_FFFF	(reserved gutter between U/K)
117  * 0x7000_0000		0x7FFF_FFFF	(kvaddr: vmalloc/modules/pkmap..)
118  *
119  * PAGE_OFFSET ---------------- (Upper 2G, Untranslated) -----------------------
120  * 0x8000_0000		0xBFFF_FFFF	(kernel direct mapped)
121  * 0xC000_0000		0xFFFF_FFFF	(peripheral uncached space)
122  * -----------------------------------------------------------------------------
123  */
124 
125 #define TASK_SIZE	0x60000000
126 
127 #define VMALLOC_START	(PAGE_OFFSET - (CONFIG_ARC_KVADDR_SIZE << 20))
128 
129 /* 1 PGDIR_SIZE each for fixmap/pkmap, 2 PGDIR_SIZE gutter (see asm/highmem.h) */
130 #define VMALLOC_SIZE	((CONFIG_ARC_KVADDR_SIZE << 20) - PGDIR_SIZE * 4)
131 
132 #define VMALLOC_END	(VMALLOC_START + VMALLOC_SIZE)
133 
134 #define USER_KERNEL_GUTTER    (VMALLOC_START - TASK_SIZE)
135 
136 #ifdef CONFIG_ARC_PLAT_EZNPS
137 /* NPS architecture defines special window of 129M in user address space for
138  * special memory areas, when accessing this window the MMU do not use TLB.
139  * Instead MMU direct the access to:
140  * 0x57f00000:0x57ffffff -- 1M of closely coupled memory (aka CMEM)
141  * 0x58000000:0x5fffffff -- 16 huge pages, 8M each, with fixed map (aka FMTs)
142  *
143  * CMEM - is the fastest memory we got and its size is 16K.
144  * FMT  - is used to map either to internal/external memory.
145  * Internal memory is the second fast memory and its size is 16M
146  * External memory is the biggest memory (16G) and also the slowest.
147  *
148  * STACK_TOP need to be PMD align (21bit) that is why we supply 0x57e00000.
149  */
150 #define STACK_TOP       0x57e00000
151 #else
152 #define STACK_TOP       TASK_SIZE
153 #endif
154 
155 #define STACK_TOP_MAX   STACK_TOP
156 
157 /* This decides where the kernel will search for a free chunk of vm
158  * space during mmap's.
159  */
160 #define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
161 
162 #endif /* __ASM_ARC_PROCESSOR_H */
163