xref: /openbmc/linux/arch/arc/include/asm/processor.h (revision bc5aa3a0)
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 #define cpu_relax_lowlatency()	cpu_relax()
64 
65 #else
66 
67 #define cpu_relax()     \
68 	__asm__ __volatile__ (".word %0" : : "i"(CTOP_INST_SCHD_RW) : "memory")
69 
70 #define cpu_relax_lowlatency()	barrier()
71 
72 #endif
73 
74 #define copy_segments(tsk, mm)      do { } while (0)
75 #define release_segments(mm)        do { } while (0)
76 
77 #define KSTK_EIP(tsk)   (task_pt_regs(tsk)->ret)
78 #define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
79 
80 /*
81  * Where about of Task's sp, fp, blink when it was last seen in kernel mode.
82  * Look in process.c for details of kernel stack layout
83  */
84 #define TSK_K_ESP(tsk)		(tsk->thread.ksp)
85 
86 #define TSK_K_REG(tsk, off)	(*((unsigned long *)(TSK_K_ESP(tsk) + \
87 					sizeof(struct callee_regs) + off)))
88 
89 #define TSK_K_BLINK(tsk)	TSK_K_REG(tsk, 4)
90 #define TSK_K_FP(tsk)		TSK_K_REG(tsk, 0)
91 
92 #define thread_saved_pc(tsk)	TSK_K_BLINK(tsk)
93 
94 extern void start_thread(struct pt_regs * regs, unsigned long pc,
95 			 unsigned long usp);
96 
97 extern unsigned int get_wchan(struct task_struct *p);
98 
99 /*
100  * Default implementation of macro that returns current
101  * instruction pointer ("program counter").
102  * Should the PC register be read instead ? This macro does not seem to
103  * be used in many places so this wont be all that bad.
104  */
105 #define current_text_addr() ({ __label__ _l; _l: &&_l; })
106 
107 #endif /* !__ASSEMBLY__ */
108 
109 /*
110  * Default System Memory Map on ARC
111  *
112  * ---------------------------- (lower 2G, Translated) -------------------------
113  * 0x0000_0000		0x5FFF_FFFF	(user vaddr: TASK_SIZE)
114  * 0x6000_0000		0x6FFF_FFFF	(reserved gutter between U/K)
115  * 0x7000_0000		0x7FFF_FFFF	(kvaddr: vmalloc/modules/pkmap..)
116  *
117  * PAGE_OFFSET ---------------- (Upper 2G, Untranslated) -----------------------
118  * 0x8000_0000		0xBFFF_FFFF	(kernel direct mapped)
119  * 0xC000_0000		0xFFFF_FFFF	(peripheral uncached space)
120  * -----------------------------------------------------------------------------
121  */
122 
123 #define TASK_SIZE	0x60000000
124 
125 #define VMALLOC_START	(PAGE_OFFSET - (CONFIG_ARC_KVADDR_SIZE << 20))
126 
127 /* 1 PGDIR_SIZE each for fixmap/pkmap, 2 PGDIR_SIZE gutter (see asm/highmem.h) */
128 #define VMALLOC_SIZE	((CONFIG_ARC_KVADDR_SIZE << 20) - PGDIR_SIZE * 4)
129 
130 #define VMALLOC_END	(VMALLOC_START + VMALLOC_SIZE)
131 
132 #define USER_KERNEL_GUTTER    (VMALLOC_START - TASK_SIZE)
133 
134 #ifdef CONFIG_ARC_PLAT_EZNPS
135 /* NPS architecture defines special window of 129M in user address space for
136  * special memory areas, when accessing this window the MMU do not use TLB.
137  * Instead MMU direct the access to:
138  * 0x57f00000:0x57ffffff -- 1M of closely coupled memory (aka CMEM)
139  * 0x58000000:0x5fffffff -- 16 huge pages, 8M each, with fixed map (aka FMTs)
140  *
141  * CMEM - is the fastest memory we got and its size is 16K.
142  * FMT  - is used to map either to internal/external memory.
143  * Internal memory is the second fast memory and its size is 16M
144  * External memory is the biggest memory (16G) and also the slowest.
145  *
146  * STACK_TOP need to be PMD align (21bit) that is why we supply 0x57e00000.
147  */
148 #define STACK_TOP       0x57e00000
149 #else
150 #define STACK_TOP       TASK_SIZE
151 #endif
152 
153 #define STACK_TOP_MAX   STACK_TOP
154 
155 /* This decides where the kernel will search for a free chunk of vm
156  * space during mmap's.
157  */
158 #define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
159 
160 #endif /* __ASM_ARC_PROCESSOR_H */
161