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1 #ifndef __PARISC_SYSTEM_H
2 #define __PARISC_SYSTEM_H
3 
4 #include <asm/psw.h>
5 
6 /* The program status word as bitfields.  */
7 struct pa_psw {
8 	unsigned int y:1;
9 	unsigned int z:1;
10 	unsigned int rv:2;
11 	unsigned int w:1;
12 	unsigned int e:1;
13 	unsigned int s:1;
14 	unsigned int t:1;
15 
16 	unsigned int h:1;
17 	unsigned int l:1;
18 	unsigned int n:1;
19 	unsigned int x:1;
20 	unsigned int b:1;
21 	unsigned int c:1;
22 	unsigned int v:1;
23 	unsigned int m:1;
24 
25 	unsigned int cb:8;
26 
27 	unsigned int o:1;
28 	unsigned int g:1;
29 	unsigned int f:1;
30 	unsigned int r:1;
31 	unsigned int q:1;
32 	unsigned int p:1;
33 	unsigned int d:1;
34 	unsigned int i:1;
35 };
36 
37 #ifdef CONFIG_64BIT
38 #define pa_psw(task) ((struct pa_psw *) ((char *) (task) + TASK_PT_PSW + 4))
39 #else
40 #define pa_psw(task) ((struct pa_psw *) ((char *) (task) + TASK_PT_PSW))
41 #endif
42 
43 struct task_struct;
44 
45 extern struct task_struct *_switch_to(struct task_struct *, struct task_struct *);
46 
47 #define switch_to(prev, next, last) do {			\
48 	(last) = _switch_to(prev, next);			\
49 } while(0)
50 
51 /* interrupt control */
52 #define local_save_flags(x)	__asm__ __volatile__("ssm 0, %0" : "=r" (x) : : "memory")
53 #define local_irq_disable()	__asm__ __volatile__("rsm %0,%%r0\n" : : "i" (PSW_I) : "memory" )
54 #define local_irq_enable()	__asm__ __volatile__("ssm %0,%%r0\n" : : "i" (PSW_I) : "memory" )
55 
56 #define local_irq_save(x) \
57 	__asm__ __volatile__("rsm %1,%0" : "=r" (x) :"i" (PSW_I) : "memory" )
58 #define local_irq_restore(x) \
59 	__asm__ __volatile__("mtsm %0" : : "r" (x) : "memory" )
60 
61 #define irqs_disabled()			\
62 ({					\
63 	unsigned long flags;		\
64 	local_save_flags(flags);	\
65 	(flags & PSW_I) == 0;		\
66 })
67 
68 #define mfctl(reg)	({		\
69 	unsigned long cr;		\
70 	__asm__ __volatile__(		\
71 		"mfctl " #reg ",%0" :	\
72 		 "=r" (cr)		\
73 	);				\
74 	cr;				\
75 })
76 
77 #define mtctl(gr, cr) \
78 	__asm__ __volatile__("mtctl %0,%1" \
79 		: /* no outputs */ \
80 		: "r" (gr), "i" (cr) : "memory")
81 
82 /* these are here to de-mystefy the calling code, and to provide hooks */
83 /* which I needed for debugging EIEM problems -PB */
84 #define get_eiem() mfctl(15)
set_eiem(unsigned long val)85 static inline void set_eiem(unsigned long val)
86 {
87 	mtctl(val, 15);
88 }
89 
90 #define mfsp(reg)	({		\
91 	unsigned long cr;		\
92 	__asm__ __volatile__(		\
93 		"mfsp " #reg ",%0" :	\
94 		 "=r" (cr)		\
95 	);				\
96 	cr;				\
97 })
98 
99 #define mtsp(gr, cr) \
100 	__asm__ __volatile__("mtsp %0,%1" \
101 		: /* no outputs */ \
102 		: "r" (gr), "i" (cr) : "memory")
103 
104 
105 /*
106 ** This is simply the barrier() macro from linux/kernel.h but when serial.c
107 ** uses tqueue.h uses smp_mb() defined using barrier(), linux/kernel.h
108 ** hasn't yet been included yet so it fails, thus repeating the macro here.
109 **
110 ** PA-RISC architecture allows for weakly ordered memory accesses although
111 ** none of the processors use it. There is a strong ordered bit that is
112 ** set in the O-bit of the page directory entry. Operating systems that
113 ** can not tolerate out of order accesses should set this bit when mapping
114 ** pages. The O-bit of the PSW should also be set to 1 (I don't believe any
115 ** of the processor implemented the PSW O-bit). The PCX-W ERS states that
116 ** the TLB O-bit is not implemented so the page directory does not need to
117 ** have the O-bit set when mapping pages (section 3.1). This section also
118 ** states that the PSW Y, Z, G, and O bits are not implemented.
119 ** So it looks like nothing needs to be done for parisc-linux (yet).
120 ** (thanks to chada for the above comment -ggg)
121 **
122 ** The __asm__ op below simple prevents gcc/ld from reordering
123 ** instructions across the mb() "call".
124 */
125 #define mb()		__asm__ __volatile__("":::"memory")	/* barrier() */
126 #define rmb()		mb()
127 #define wmb()		mb()
128 #define smp_mb()	mb()
129 #define smp_rmb()	mb()
130 #define smp_wmb()	mb()
131 #define smp_read_barrier_depends()	do { } while(0)
132 #define read_barrier_depends()		do { } while(0)
133 
134 #define set_mb(var, value)		do { var = value; mb(); } while (0)
135 
136 #ifndef CONFIG_PA20
137 /* Because kmalloc only guarantees 8-byte alignment for kmalloc'd data,
138    and GCC only guarantees 8-byte alignment for stack locals, we can't
139    be assured of 16-byte alignment for atomic lock data even if we
140    specify "__attribute ((aligned(16)))" in the type declaration.  So,
141    we use a struct containing an array of four ints for the atomic lock
142    type and dynamically select the 16-byte aligned int from the array
143    for the semaphore.  */
144 
145 #define __PA_LDCW_ALIGNMENT	16
146 #define __ldcw_align(a) ({					\
147 	unsigned long __ret = (unsigned long) &(a)->lock[0];	\
148 	__ret = (__ret + __PA_LDCW_ALIGNMENT - 1)		\
149 		& ~(__PA_LDCW_ALIGNMENT - 1);			\
150 	(volatile unsigned int *) __ret;			\
151 })
152 #define __LDCW	"ldcw"
153 
154 #else /*CONFIG_PA20*/
155 /* From: "Jim Hull" <jim.hull of hp.com>
156    I've attached a summary of the change, but basically, for PA 2.0, as
157    long as the ",CO" (coherent operation) completer is specified, then the
158    16-byte alignment requirement for ldcw and ldcd is relaxed, and instead
159    they only require "natural" alignment (4-byte for ldcw, 8-byte for
160    ldcd). */
161 
162 #define __PA_LDCW_ALIGNMENT	4
163 #define __ldcw_align(a) ((volatile unsigned int *)a)
164 #define __LDCW	"ldcw,co"
165 
166 #endif /*!CONFIG_PA20*/
167 
168 /* LDCW, the only atomic read-write operation PA-RISC has. *sigh*.  */
169 #define __ldcw(a) ({						\
170 	unsigned __ret;						\
171 	__asm__ __volatile__(__LDCW " 0(%1),%0"			\
172 		: "=r" (__ret) : "r" (a));			\
173 	__ret;							\
174 })
175 
176 #ifdef CONFIG_SMP
177 # define __lock_aligned __attribute__((__section__(".data.lock_aligned")))
178 #endif
179 
180 #define arch_align_stack(x) (x)
181 
182 #endif
183