xref: /openbmc/linux/arch/arc/include/asm/processor.h (revision 002dff36)
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 #include <asm/dsp.h>
18 #include <asm/fpu.h>
19 
20 #ifdef CONFIG_ARC_PLAT_EZNPS
21 struct eznps_dp {
22 	unsigned int eflags;
23 	unsigned int gpa1;
24 };
25 #endif
26 
27 /* Arch specific stuff which needs to be saved per task.
28  * However these items are not so important so as to earn a place in
29  * struct thread_info
30  */
31 struct thread_struct {
32 	unsigned long ksp;	/* kernel mode stack pointer */
33 	unsigned long callee_reg;	/* pointer to callee regs */
34 	unsigned long fault_address;	/* dbls as brkpt holder as well */
35 #ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
36 	struct dsp_callee_regs dsp;
37 #endif
38 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
39 	struct arc_fpu fpu;
40 #endif
41 #ifdef CONFIG_ARC_PLAT_EZNPS
42 	struct eznps_dp dp;
43 #endif
44 };
45 
46 #define INIT_THREAD  {                          \
47 	.ksp = sizeof(init_stack) + (unsigned long) init_stack, \
48 }
49 
50 /* Forward declaration, a strange C thing */
51 struct task_struct;
52 
53 #define task_pt_regs(p) \
54 	((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
55 
56 /* Free all resources held by a thread */
57 #define release_thread(thread) do { } while (0)
58 
59 /*
60  * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
61  * get optimised away by gcc
62  */
63 #ifndef CONFIG_EZNPS_MTM_EXT
64 
65 #define cpu_relax()		barrier()
66 
67 #else
68 
69 #define cpu_relax()     \
70 	__asm__ __volatile__ (".word %0" : : "i"(CTOP_INST_SCHD_RW) : "memory")
71 
72 #endif
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 extern void start_thread(struct pt_regs * regs, unsigned long pc,
90 			 unsigned long usp);
91 
92 extern unsigned int get_wchan(struct task_struct *p);
93 
94 #endif /* !__ASSEMBLY__ */
95 
96 /*
97  * Default System Memory Map on ARC
98  *
99  * ---------------------------- (lower 2G, Translated) -------------------------
100  * 0x0000_0000		0x5FFF_FFFF	(user vaddr: TASK_SIZE)
101  * 0x6000_0000		0x6FFF_FFFF	(reserved gutter between U/K)
102  * 0x7000_0000		0x7FFF_FFFF	(kvaddr: vmalloc/modules/pkmap..)
103  *
104  * PAGE_OFFSET ---------------- (Upper 2G, Untranslated) -----------------------
105  * 0x8000_0000		0xBFFF_FFFF	(kernel direct mapped)
106  * 0xC000_0000		0xFFFF_FFFF	(peripheral uncached space)
107  * -----------------------------------------------------------------------------
108  */
109 
110 #define TASK_SIZE	0x60000000
111 
112 #define VMALLOC_START	(PAGE_OFFSET - (CONFIG_ARC_KVADDR_SIZE << 20))
113 
114 /* 1 PGDIR_SIZE each for fixmap/pkmap, 2 PGDIR_SIZE gutter (see asm/highmem.h) */
115 #define VMALLOC_SIZE	((CONFIG_ARC_KVADDR_SIZE << 20) - PGDIR_SIZE * 4)
116 
117 #define VMALLOC_END	(VMALLOC_START + VMALLOC_SIZE)
118 
119 #define USER_KERNEL_GUTTER    (VMALLOC_START - TASK_SIZE)
120 
121 #ifdef CONFIG_ARC_PLAT_EZNPS
122 /* NPS architecture defines special window of 129M in user address space for
123  * special memory areas, when accessing this window the MMU do not use TLB.
124  * Instead MMU direct the access to:
125  * 0x57f00000:0x57ffffff -- 1M of closely coupled memory (aka CMEM)
126  * 0x58000000:0x5fffffff -- 16 huge pages, 8M each, with fixed map (aka FMTs)
127  *
128  * CMEM - is the fastest memory we got and its size is 16K.
129  * FMT  - is used to map either to internal/external memory.
130  * Internal memory is the second fast memory and its size is 16M
131  * External memory is the biggest memory (16G) and also the slowest.
132  *
133  * STACK_TOP need to be PMD align (21bit) that is why we supply 0x57e00000.
134  */
135 #define STACK_TOP       0x57e00000
136 #else
137 #define STACK_TOP       TASK_SIZE
138 #endif
139 
140 #define STACK_TOP_MAX   STACK_TOP
141 
142 /* This decides where the kernel will search for a free chunk of vm
143  * space during mmap's.
144  */
145 #define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
146 
147 #endif /* __ASM_ARC_PROCESSOR_H */
148