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1 | /* |
2 | * include/asm-xtensa/processor.h | |
3 | * | |
4 | * This file is subject to the terms and conditions of the GNU General Public | |
5 | * License. See the file "COPYING" in the main directory of this archive | |
6 | * for more details. | |
7 | * | |
8 | * Copyright (C) 2001 - 2005 Tensilica Inc. | |
9 | */ | |
10 | ||
11 | #ifndef _XTENSA_PROCESSOR_H | |
12 | #define _XTENSA_PROCESSOR_H | |
13 | ||
367b8112 | 14 | #include <variant/core.h> |
e5083a63 | 15 | #include <platform/hardware.h> |
9a8fd558 | 16 | |
f6dc8c5b | 17 | #include <linux/compiler.h> |
9a8fd558 CZ |
18 | #include <asm/ptrace.h> |
19 | #include <asm/types.h> | |
173d6681 | 20 | #include <asm/regs.h> |
9a8fd558 CZ |
21 | |
22 | /* Assertions. */ | |
23 | ||
24 | #if (XCHAL_HAVE_WINDOWED != 1) | |
173d6681 | 25 | # error Linux requires the Xtensa Windowed Registers Option. |
9a8fd558 CZ |
26 | #endif |
27 | ||
a81cbd2d OS |
28 | #define ARCH_SLAB_MINALIGN XCHAL_DATA_WIDTH |
29 | ||
9a8fd558 CZ |
30 | /* |
31 | * User space process size: 1 GB. | |
32 | * Windowed call ABI requires caller and callee to be located within the same | |
33 | * 1 GB region. The C compiler places trampoline code on the stack for sources | |
34 | * that take the address of a nested C function (a feature used by glibc), so | |
35 | * the 1 GB requirement applies to the stack as well. | |
36 | */ | |
37 | ||
e5083a63 | 38 | #ifdef CONFIG_MMU |
24a9ab7f | 39 | #define TASK_SIZE __XTENSA_UL_CONST(0x40000000) |
e5083a63 JW |
40 | #else |
41 | #define TASK_SIZE (PLATFORM_DEFAULT_MEM_START + PLATFORM_DEFAULT_MEM_SIZE) | |
42 | #endif | |
43 | ||
922a70d3 DH |
44 | #define STACK_TOP TASK_SIZE |
45 | #define STACK_TOP_MAX STACK_TOP | |
9a8fd558 CZ |
46 | |
47 | /* | |
48 | * General exception cause assigned to debug exceptions. Debug exceptions go | |
49 | * to their own vector, rather than the general exception vectors (user, | |
50 | * kernel, double); and their specific causes are reported via DEBUGCAUSE | |
51 | * rather than EXCCAUSE. However it is sometimes convenient to redirect debug | |
52 | * exceptions to the general exception mechanism. To do this, an otherwise | |
53 | * unused EXCCAUSE value was assigned to debug exceptions for this purpose. | |
54 | */ | |
55 | ||
56 | #define EXCCAUSE_MAPPED_DEBUG 63 | |
57 | ||
58 | /* | |
59 | * We use DEPC also as a flag to distinguish between double and regular | |
60 | * exceptions. For performance reasons, DEPC might contain the value of | |
61 | * EXCCAUSE for regular exceptions, so we use this definition to mark a | |
62 | * valid double exception address. | |
63 | * (Note: We use it in bgeui, so it should be 64, 128, or 256) | |
64 | */ | |
65 | ||
66 | #define VALID_DOUBLE_EXCEPTION_ADDRESS 64 | |
67 | ||
68 | /* LOCKLEVEL defines the interrupt level that masks all | |
69 | * general-purpose interrupts. | |
70 | */ | |
71 | #define LOCKLEVEL 1 | |
72 | ||
73 | /* WSBITS and WBBITS are the width of the WINDOWSTART and WINDOWBASE | |
74 | * registers | |
75 | */ | |
76 | #define WSBITS (XCHAL_NUM_AREGS / 4) /* width of WINDOWSTART in bits */ | |
77 | #define WBBITS (XCHAL_NUM_AREGS_LOG2 - 2) /* width of WINDOWBASE in bits */ | |
78 | ||
79 | #ifndef __ASSEMBLY__ | |
80 | ||
81 | /* Build a valid return address for the specified call winsize. | |
82 | * winsize must be 1 (call4), 2 (call8), or 3 (call12) | |
83 | */ | |
84 | #define MAKE_RA_FOR_CALL(ra,ws) (((ra) & 0x3fffffff) | (ws) << 30) | |
85 | ||
86 | /* Convert return address to a valid pc | |
87 | * Note: We assume that the stack pointer is in the same 1GB ranges as the ra | |
88 | */ | |
89 | #define MAKE_PC_FROM_RA(ra,sp) (((ra) & 0x3fffffff) | ((sp) & 0xc0000000)) | |
90 | ||
91 | typedef struct { | |
92 | unsigned long seg; | |
93 | } mm_segment_t; | |
94 | ||
95 | struct thread_struct { | |
96 | ||
97 | /* kernel's return address and stack pointer for context switching */ | |
98 | unsigned long ra; /* kernel's a0: return address and window call size */ | |
99 | unsigned long sp; /* kernel's a1: stack pointer */ | |
100 | ||
101 | mm_segment_t current_ds; /* see uaccess.h for example uses */ | |
102 | ||
103 | /* struct xtensa_cpuinfo info; */ | |
104 | ||
105 | unsigned long bad_vaddr; /* last user fault */ | |
106 | unsigned long bad_uaddr; /* last kernel fault accessing user space */ | |
107 | unsigned long error_code; | |
108 | ||
109 | unsigned long ibreak[XCHAL_NUM_IBREAK]; | |
110 | unsigned long dbreaka[XCHAL_NUM_DBREAK]; | |
111 | unsigned long dbreakc[XCHAL_NUM_DBREAK]; | |
112 | ||
9a8fd558 CZ |
113 | /* Make structure 16 bytes aligned. */ |
114 | int align[0] __attribute__ ((aligned(16))); | |
115 | }; | |
116 | ||
117 | ||
118 | /* | |
119 | * Default implementation of macro that returns current | |
120 | * instruction pointer ("program counter"). | |
121 | */ | |
122 | #define current_text_addr() ({ __label__ _l; _l: &&_l;}) | |
123 | ||
124 | ||
125 | /* This decides where the kernel will search for a free chunk of vm | |
126 | * space during mmap's. | |
127 | */ | |
128 | #define TASK_UNMAPPED_BASE (TASK_SIZE / 2) | |
129 | ||
130 | #define INIT_THREAD \ | |
131 | { \ | |
132 | ra: 0, \ | |
133 | sp: sizeof(init_stack) + (long) &init_stack, \ | |
134 | current_ds: {0}, \ | |
135 | /*info: {0}, */ \ | |
136 | bad_vaddr: 0, \ | |
137 | bad_uaddr: 0, \ | |
138 | error_code: 0, \ | |
139 | } | |
140 | ||
141 | ||
142 | /* | |
143 | * Do necessary setup to start up a newly executed thread. | |
144 | * Note: We set-up ps as if we did a call4 to the new pc. | |
145 | * set_thread_state in signal.c depends on it. | |
146 | */ | |
173d6681 CZ |
147 | #define USER_PS_VALUE ((1 << PS_WOE_BIT) | \ |
148 | (1 << PS_CALLINC_SHIFT) | \ | |
149 | (USER_RING << PS_RING_SHIFT) | \ | |
150 | (1 << PS_UM_BIT) | \ | |
151 | (1 << PS_EXCM_BIT)) | |
9a8fd558 CZ |
152 | |
153 | /* Clearing a0 terminates the backtrace. */ | |
154 | #define start_thread(regs, new_pc, new_sp) \ | |
3306a726 | 155 | memset(regs, 0, sizeof(*regs)); \ |
9a8fd558 CZ |
156 | regs->pc = new_pc; \ |
157 | regs->ps = USER_PS_VALUE; \ | |
158 | regs->areg[1] = new_sp; \ | |
159 | regs->areg[0] = 0; \ | |
160 | regs->wmask = 1; \ | |
161 | regs->depc = 0; \ | |
162 | regs->windowbase = 0; \ | |
163 | regs->windowstart = 1; | |
164 | ||
165 | /* Forward declaration */ | |
166 | struct task_struct; | |
167 | struct mm_struct; | |
168 | ||
9a8fd558 CZ |
169 | /* Free all resources held by a thread. */ |
170 | #define release_thread(thread) do { } while(0) | |
171 | ||
9a8fd558 | 172 | /* Copy and release all segment info associated with a VM */ |
9a8fd558 CZ |
173 | #define copy_segments(p, mm) do { } while(0) |
174 | #define release_segments(mm) do { } while(0) | |
175 | #define forget_segments() do { } while (0) | |
176 | ||
04fe6faf | 177 | #define thread_saved_pc(tsk) (task_pt_regs(tsk)->pc) |
9a8fd558 CZ |
178 | |
179 | extern unsigned long get_wchan(struct task_struct *p); | |
180 | ||
04fe6faf AV |
181 | #define KSTK_EIP(tsk) (task_pt_regs(tsk)->pc) |
182 | #define KSTK_ESP(tsk) (task_pt_regs(tsk)->areg[1]) | |
9a8fd558 | 183 | |
f6dc8c5b | 184 | #define cpu_relax() barrier() |
9a8fd558 CZ |
185 | |
186 | /* Special register access. */ | |
187 | ||
188 | #define WSR(v,sr) __asm__ __volatile__ ("wsr %0,"__stringify(sr) :: "a"(v)); | |
189 | #define RSR(v,sr) __asm__ __volatile__ ("rsr %0,"__stringify(sr) : "=a"(v)); | |
190 | ||
191 | #define set_sr(x,sr) ({unsigned int v=(unsigned int)x; WSR(v,sr);}) | |
192 | #define get_sr(sr) ({unsigned int v; RSR(v,sr); v; }) | |
193 | ||
194 | #endif /* __ASSEMBLY__ */ | |
195 | #endif /* _XTENSA_PROCESSOR_H */ |