xref: /openbmc/linux/arch/arc/include/asm/processor.h (revision ecd25094)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4  *
5  * vineetg: March 2009
6  *  -Implemented task_pt_regs( )
7  *
8  * Amit Bhor, Sameer Dhavale, Ashwin Chaugule: Codito Technologies 2004
9  */
10 
11 #ifndef __ASM_ARC_PROCESSOR_H
12 #define __ASM_ARC_PROCESSOR_H
13 
14 #ifndef __ASSEMBLY__
15 
16 #include <asm/ptrace.h>
17 
18 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
19 /* These DPFP regs need to be saved/restored across ctx-sw */
20 struct arc_fpu {
21 	struct {
22 		unsigned int l, h;
23 	} aux_dpfp[2];
24 };
25 #endif
26 
27 #ifdef CONFIG_ARC_PLAT_EZNPS
28 struct eznps_dp {
29 	unsigned int eflags;
30 	unsigned int gpa1;
31 };
32 #endif
33 
34 /* Arch specific stuff which needs to be saved per task.
35  * However these items are not so important so as to earn a place in
36  * struct thread_info
37  */
38 struct thread_struct {
39 	unsigned long ksp;	/* kernel mode stack pointer */
40 	unsigned long callee_reg;	/* pointer to callee regs */
41 	unsigned long fault_address;	/* dbls as brkpt holder as well */
42 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
43 	struct arc_fpu fpu;
44 #endif
45 #ifdef CONFIG_ARC_PLAT_EZNPS
46 	struct eznps_dp dp;
47 #endif
48 };
49 
50 #define INIT_THREAD  {                          \
51 	.ksp = sizeof(init_stack) + (unsigned long) init_stack, \
52 }
53 
54 /* Forward declaration, a strange C thing */
55 struct task_struct;
56 
57 #define task_pt_regs(p) \
58 	((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
59 
60 /* Free all resources held by a thread */
61 #define release_thread(thread) do { } while (0)
62 
63 /*
64  * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
65  * get optimised away by gcc
66  */
67 #ifndef CONFIG_EZNPS_MTM_EXT
68 
69 #define cpu_relax()		barrier()
70 
71 #else
72 
73 #define cpu_relax()     \
74 	__asm__ __volatile__ (".word %0" : : "i"(CTOP_INST_SCHD_RW) : "memory")
75 
76 #endif
77 
78 #define KSTK_EIP(tsk)   (task_pt_regs(tsk)->ret)
79 #define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
80 
81 /*
82  * Where about of Task's sp, fp, blink when it was last seen in kernel mode.
83  * Look in process.c for details of kernel stack layout
84  */
85 #define TSK_K_ESP(tsk)		(tsk->thread.ksp)
86 
87 #define TSK_K_REG(tsk, off)	(*((unsigned long *)(TSK_K_ESP(tsk) + \
88 					sizeof(struct callee_regs) + off)))
89 
90 #define TSK_K_BLINK(tsk)	TSK_K_REG(tsk, 4)
91 #define TSK_K_FP(tsk)		TSK_K_REG(tsk, 0)
92 
93 extern void start_thread(struct pt_regs * regs, unsigned long pc,
94 			 unsigned long usp);
95 
96 extern unsigned int get_wchan(struct task_struct *p);
97 
98 #endif /* !__ASSEMBLY__ */
99 
100 /*
101  * Default System Memory Map on ARC
102  *
103  * ---------------------------- (lower 2G, Translated) -------------------------
104  * 0x0000_0000		0x5FFF_FFFF	(user vaddr: TASK_SIZE)
105  * 0x6000_0000		0x6FFF_FFFF	(reserved gutter between U/K)
106  * 0x7000_0000		0x7FFF_FFFF	(kvaddr: vmalloc/modules/pkmap..)
107  *
108  * PAGE_OFFSET ---------------- (Upper 2G, Untranslated) -----------------------
109  * 0x8000_0000		0xBFFF_FFFF	(kernel direct mapped)
110  * 0xC000_0000		0xFFFF_FFFF	(peripheral uncached space)
111  * -----------------------------------------------------------------------------
112  */
113 
114 #define TASK_SIZE	0x60000000
115 
116 #define VMALLOC_START	(PAGE_OFFSET - (CONFIG_ARC_KVADDR_SIZE << 20))
117 
118 /* 1 PGDIR_SIZE each for fixmap/pkmap, 2 PGDIR_SIZE gutter (see asm/highmem.h) */
119 #define VMALLOC_SIZE	((CONFIG_ARC_KVADDR_SIZE << 20) - PGDIR_SIZE * 4)
120 
121 #define VMALLOC_END	(VMALLOC_START + VMALLOC_SIZE)
122 
123 #define USER_KERNEL_GUTTER    (VMALLOC_START - TASK_SIZE)
124 
125 #ifdef CONFIG_ARC_PLAT_EZNPS
126 /* NPS architecture defines special window of 129M in user address space for
127  * special memory areas, when accessing this window the MMU do not use TLB.
128  * Instead MMU direct the access to:
129  * 0x57f00000:0x57ffffff -- 1M of closely coupled memory (aka CMEM)
130  * 0x58000000:0x5fffffff -- 16 huge pages, 8M each, with fixed map (aka FMTs)
131  *
132  * CMEM - is the fastest memory we got and its size is 16K.
133  * FMT  - is used to map either to internal/external memory.
134  * Internal memory is the second fast memory and its size is 16M
135  * External memory is the biggest memory (16G) and also the slowest.
136  *
137  * STACK_TOP need to be PMD align (21bit) that is why we supply 0x57e00000.
138  */
139 #define STACK_TOP       0x57e00000
140 #else
141 #define STACK_TOP       TASK_SIZE
142 #endif
143 
144 #define STACK_TOP_MAX   STACK_TOP
145 
146 /* This decides where the kernel will search for a free chunk of vm
147  * space during mmap's.
148  */
149 #define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
150 
151 #endif /* __ASM_ARC_PROCESSOR_H */
152