xref: /openbmc/linux/arch/arc/include/asm/processor.h (revision 1c2dd16a)
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 /* Arch specific stuff which needs to be saved per task.
31  * However these items are not so important so as to earn a place in
32  * struct thread_info
33  */
34 struct thread_struct {
35 	unsigned long ksp;	/* kernel mode stack pointer */
36 	unsigned long callee_reg;	/* pointer to callee regs */
37 	unsigned long fault_address;	/* dbls as brkpt holder as well */
38 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
39 	struct arc_fpu fpu;
40 #endif
41 };
42 
43 #define INIT_THREAD  {                          \
44 	.ksp = sizeof(init_stack) + (unsigned long) init_stack, \
45 }
46 
47 /* Forward declaration, a strange C thing */
48 struct task_struct;
49 
50 #define task_pt_regs(p) \
51 	((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
52 
53 /* Free all resources held by a thread */
54 #define release_thread(thread) do { } while (0)
55 
56 /*
57  * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
58  * get optimised away by gcc
59  */
60 #ifndef CONFIG_EZNPS_MTM_EXT
61 
62 #define cpu_relax()		barrier()
63 
64 #else
65 
66 #define cpu_relax()     \
67 	__asm__ __volatile__ (".word %0" : : "i"(CTOP_INST_SCHD_RW) : "memory")
68 
69 #endif
70 
71 #define copy_segments(tsk, mm)      do { } while (0)
72 #define release_segments(mm)        do { } while (0)
73 
74 #define KSTK_EIP(tsk)   (task_pt_regs(tsk)->ret)
75 #define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
76 
77 /*
78  * Where about of Task's sp, fp, blink when it was last seen in kernel mode.
79  * Look in process.c for details of kernel stack layout
80  */
81 #define TSK_K_ESP(tsk)		(tsk->thread.ksp)
82 
83 #define TSK_K_REG(tsk, off)	(*((unsigned long *)(TSK_K_ESP(tsk) + \
84 					sizeof(struct callee_regs) + off)))
85 
86 #define TSK_K_BLINK(tsk)	TSK_K_REG(tsk, 4)
87 #define TSK_K_FP(tsk)		TSK_K_REG(tsk, 0)
88 
89 #define thread_saved_pc(tsk)	TSK_K_BLINK(tsk)
90 
91 extern void start_thread(struct pt_regs * regs, unsigned long pc,
92 			 unsigned long usp);
93 
94 extern unsigned int get_wchan(struct task_struct *p);
95 
96 /*
97  * Default implementation of macro that returns current
98  * instruction pointer ("program counter").
99  * Should the PC register be read instead ? This macro does not seem to
100  * be used in many places so this wont be all that bad.
101  */
102 #define current_text_addr() ({ __label__ _l; _l: &&_l; })
103 
104 #endif /* !__ASSEMBLY__ */
105 
106 /*
107  * Default System Memory Map on ARC
108  *
109  * ---------------------------- (lower 2G, Translated) -------------------------
110  * 0x0000_0000		0x5FFF_FFFF	(user vaddr: TASK_SIZE)
111  * 0x6000_0000		0x6FFF_FFFF	(reserved gutter between U/K)
112  * 0x7000_0000		0x7FFF_FFFF	(kvaddr: vmalloc/modules/pkmap..)
113  *
114  * PAGE_OFFSET ---------------- (Upper 2G, Untranslated) -----------------------
115  * 0x8000_0000		0xBFFF_FFFF	(kernel direct mapped)
116  * 0xC000_0000		0xFFFF_FFFF	(peripheral uncached space)
117  * -----------------------------------------------------------------------------
118  */
119 
120 #define TASK_SIZE	0x60000000
121 
122 #define VMALLOC_START	(PAGE_OFFSET - (CONFIG_ARC_KVADDR_SIZE << 20))
123 
124 /* 1 PGDIR_SIZE each for fixmap/pkmap, 2 PGDIR_SIZE gutter (see asm/highmem.h) */
125 #define VMALLOC_SIZE	((CONFIG_ARC_KVADDR_SIZE << 20) - PGDIR_SIZE * 4)
126 
127 #define VMALLOC_END	(VMALLOC_START + VMALLOC_SIZE)
128 
129 #define USER_KERNEL_GUTTER    (VMALLOC_START - TASK_SIZE)
130 
131 #ifdef CONFIG_ARC_PLAT_EZNPS
132 /* NPS architecture defines special window of 129M in user address space for
133  * special memory areas, when accessing this window the MMU do not use TLB.
134  * Instead MMU direct the access to:
135  * 0x57f00000:0x57ffffff -- 1M of closely coupled memory (aka CMEM)
136  * 0x58000000:0x5fffffff -- 16 huge pages, 8M each, with fixed map (aka FMTs)
137  *
138  * CMEM - is the fastest memory we got and its size is 16K.
139  * FMT  - is used to map either to internal/external memory.
140  * Internal memory is the second fast memory and its size is 16M
141  * External memory is the biggest memory (16G) and also the slowest.
142  *
143  * STACK_TOP need to be PMD align (21bit) that is why we supply 0x57e00000.
144  */
145 #define STACK_TOP       0x57e00000
146 #else
147 #define STACK_TOP       TASK_SIZE
148 #endif
149 
150 #define STACK_TOP_MAX   STACK_TOP
151 
152 /* This decides where the kernel will search for a free chunk of vm
153  * space during mmap's.
154  */
155 #define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
156 
157 #endif /* __ASM_ARC_PROCESSOR_H */
158