xref: /openbmc/linux/arch/arc/include/asm/processor.h (revision b8b350af)
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 ksp;	/* kernel mode stack pointer */
26 	unsigned long callee_reg;	/* pointer to callee regs */
27 	unsigned long fault_address;	/* dbls as brkpt holder as well */
28 #ifdef CONFIG_ARC_DSP_SAVE_RESTORE_REGS
29 	struct dsp_callee_regs dsp;
30 #endif
31 #ifdef CONFIG_ARC_FPU_SAVE_RESTORE
32 	struct arc_fpu fpu;
33 #endif
34 };
35 
36 #define INIT_THREAD  {                          \
37 	.ksp = sizeof(init_stack) + (unsigned long) init_stack, \
38 }
39 
40 /* Forward declaration, a strange C thing */
41 struct task_struct;
42 
43 #define task_pt_regs(p) \
44 	((struct pt_regs *)(THREAD_SIZE + (void *)task_stack_page(p)) - 1)
45 
46 /* Free all resources held by a thread */
47 #define release_thread(thread) do { } while (0)
48 
49 /*
50  * A lot of busy-wait loops in SMP are based off of non-volatile data otherwise
51  * get optimised away by gcc
52  */
53 #define cpu_relax()		barrier()
54 
55 #define KSTK_EIP(tsk)   (task_pt_regs(tsk)->ret)
56 #define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
57 
58 /*
59  * Where about of Task's sp, fp, blink when it was last seen in kernel mode.
60  * Look in process.c for details of kernel stack layout
61  */
62 #define TSK_K_ESP(tsk)		(tsk->thread.ksp)
63 
64 #define TSK_K_REG(tsk, off)	(*((unsigned long *)(TSK_K_ESP(tsk) + \
65 					sizeof(struct callee_regs) + off)))
66 
67 #define TSK_K_BLINK(tsk)	TSK_K_REG(tsk, 4)
68 #define TSK_K_FP(tsk)		TSK_K_REG(tsk, 0)
69 
70 extern void start_thread(struct pt_regs * regs, unsigned long pc,
71 			 unsigned long usp);
72 
73 extern unsigned int get_wchan(struct task_struct *p);
74 
75 #endif /* !__ASSEMBLY__ */
76 
77 /*
78  * Default System Memory Map on ARC
79  *
80  * ---------------------------- (lower 2G, Translated) -------------------------
81  * 0x0000_0000		0x5FFF_FFFF	(user vaddr: TASK_SIZE)
82  * 0x6000_0000		0x6FFF_FFFF	(reserved gutter between U/K)
83  * 0x7000_0000		0x7FFF_FFFF	(kvaddr: vmalloc/modules/pkmap..)
84  *
85  * PAGE_OFFSET ---------------- (Upper 2G, Untranslated) -----------------------
86  * 0x8000_0000		0xBFFF_FFFF	(kernel direct mapped)
87  * 0xC000_0000		0xFFFF_FFFF	(peripheral uncached space)
88  * -----------------------------------------------------------------------------
89  */
90 
91 #define TASK_SIZE	0x60000000
92 
93 #define VMALLOC_START	(PAGE_OFFSET - (CONFIG_ARC_KVADDR_SIZE << 20))
94 
95 /* 1 PGDIR_SIZE each for fixmap/pkmap, 2 PGDIR_SIZE gutter (see asm/highmem.h) */
96 #define VMALLOC_SIZE	((CONFIG_ARC_KVADDR_SIZE << 20) - PMD_SIZE * 4)
97 
98 #define VMALLOC_END	(VMALLOC_START + VMALLOC_SIZE)
99 
100 #define USER_KERNEL_GUTTER    (VMALLOC_START - TASK_SIZE)
101 
102 #define STACK_TOP       TASK_SIZE
103 #define STACK_TOP_MAX   STACK_TOP
104 
105 /* This decides where the kernel will search for a free chunk of vm
106  * space during mmap's.
107  */
108 #define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
109 
110 #endif /* __ASM_ARC_PROCESSOR_H */
111