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 /* Arch specific stuff which needs to be saved per task.
21  * However these items are not so important so as to earn a place in
22  * struct thread_info
23  */
24 struct thread_struct {
25 	unsigned long callee_reg;	/* pointer to callee regs */
26 	unsigned long fault_address;	/* dbls as brkpt holder as well */
27 #ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
28 	struct dsp_callee_regs dsp;
29 #endif
30 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
31 	struct arc_fpu fpu;
32 #endif
33 };
34 
35 #define INIT_THREAD  { }
36 
37 /* Forward declaration, a strange C thing */
38 struct task_struct;
39 
40 #define task_pt_regs(p) \
41 	((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
42 
43 /*
44  * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
45  * get optimised away by gcc
46  */
47 #define cpu_relax()		barrier()
48 
49 #define KSTK_EIP(tsk)   (task_pt_regs(tsk)->ret)
50 #define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
51 
52 /*
53  * Where about of Task's sp, fp, blink when it was last seen in kernel mode.
54  * Look in process.c for details of kernel stack layout
55  */
56 #define TSK_K_ESP(tsk)		(task_thread_info(tsk)->ksp)
57 
58 #define TSK_K_REG(tsk, off)	(*((unsigned long *)(TSK_K_ESP(tsk) + \
59 					sizeof(struct callee_regs) + off)))
60 
61 #define TSK_K_BLINK(tsk)	TSK_K_REG(tsk, 4)
62 #define TSK_K_FP(tsk)		TSK_K_REG(tsk, 0)
63 
64 extern void start_thread(struct pt_regs * regs, unsigned long pc,
65 			 unsigned long usp);
66 
67 extern unsigned int __get_wchan(struct task_struct *p);
68 
69 #endif /* !__ASSEMBLY__ */
70 
71 /*
72  * Default System Memory Map on ARC
73  *
74  * ---------------------------- (lower 2G, Translated) -------------------------
75  * 0x0000_0000		0x5FFF_FFFF	(user vaddr: TASK_SIZE)
76  * 0x6000_0000		0x6FFF_FFFF	(reserved gutter between U/K)
77  * 0x7000_0000		0x7FFF_FFFF	(kvaddr: vmalloc/modules/pkmap..)
78  *
79  * PAGE_OFFSET ---------------- (Upper 2G, Untranslated) -----------------------
80  * 0x8000_0000		0xBFFF_FFFF	(kernel direct mapped)
81  * 0xC000_0000		0xFFFF_FFFF	(peripheral uncached space)
82  * -----------------------------------------------------------------------------
83  */
84 
85 #define TASK_SIZE	0x60000000
86 
87 #define VMALLOC_START	(PAGE_OFFSET - (CONFIG_ARC_KVADDR_SIZE << 20))
88 
89 /* 1 PGDIR_SIZE each for fixmap/pkmap, 2 PGDIR_SIZE gutter (see asm/highmem.h) */
90 #define VMALLOC_SIZE	((CONFIG_ARC_KVADDR_SIZE << 20) - PMD_SIZE * 4)
91 
92 #define VMALLOC_END	(VMALLOC_START + VMALLOC_SIZE)
93 
94 #define USER_KERNEL_GUTTER    (VMALLOC_START - TASK_SIZE)
95 
96 #define STACK_TOP       TASK_SIZE
97 #define STACK_TOP_MAX   STACK_TOP
98 
99 /* This decides where the kernel will search for a free chunk of vm
100  * space during mmap's.
101  */
102 #define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
103 
104 #endif /* __ASM_ARC_PROCESSOR_H */
105