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11#include <linux/uaccess.h>
12#include <linux/kernel.h>
13#include <linux/types.h>
14#include <linux/errno.h>
15#include <linux/gfp.h>
16#include <linux/cpu.h>
17#include <asm/ctl_reg.h>
18#include <asm/io.h>
19#include <asm/stacktrace.h>
20
21static notrace long s390_kernel_write_odd(void *dst, const void *src, size_t size)
22{
23 unsigned long aligned, offset, count;
24 char tmp[8];
25
26 aligned = (unsigned long) dst & ~7UL;
27 offset = (unsigned long) dst & 7UL;
28 size = min(8UL - offset, size);
29 count = size - 1;
30 asm volatile(
31 " bras 1,0f\n"
32 " mvc 0(1,%4),0(%5)\n"
33 "0: mvc 0(8,%3),0(%0)\n"
34 " ex %1,0(1)\n"
35 " lg %1,0(%3)\n"
36 " lra %0,0(%0)\n"
37 " sturg %1,%0\n"
38 : "+&a" (aligned), "+&a" (count), "=m" (tmp)
39 : "a" (&tmp), "a" (&tmp[offset]), "a" (src)
40 : "cc", "memory", "1");
41 return size;
42}
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54
55
56static DEFINE_SPINLOCK(s390_kernel_write_lock);
57
58void notrace s390_kernel_write(void *dst, const void *src, size_t size)
59{
60 unsigned long flags;
61 long copied;
62
63 spin_lock_irqsave(&s390_kernel_write_lock, flags);
64 while (size) {
65 copied = s390_kernel_write_odd(dst, src, size);
66 dst += copied;
67 src += copied;
68 size -= copied;
69 }
70 spin_unlock_irqrestore(&s390_kernel_write_lock, flags);
71}
72
73static int __memcpy_real(void *dest, void *src, size_t count)
74{
75 register unsigned long _dest asm("2") = (unsigned long) dest;
76 register unsigned long _len1 asm("3") = (unsigned long) count;
77 register unsigned long _src asm("4") = (unsigned long) src;
78 register unsigned long _len2 asm("5") = (unsigned long) count;
79 int rc = -EFAULT;
80
81 asm volatile (
82 "0: mvcle %1,%2,0x0\n"
83 "1: jo 0b\n"
84 " lhi %0,0x0\n"
85 "2:\n"
86 EX_TABLE(1b,2b)
87 : "+d" (rc), "+d" (_dest), "+d" (_src), "+d" (_len1),
88 "+d" (_len2), "=m" (*((long *) dest))
89 : "m" (*((long *) src))
90 : "cc", "memory");
91 return rc;
92}
93
94static unsigned long _memcpy_real(unsigned long dest, unsigned long src,
95 unsigned long count)
96{
97 int irqs_disabled, rc;
98 unsigned long flags;
99
100 if (!count)
101 return 0;
102 flags = __arch_local_irq_stnsm(0xf8UL);
103 irqs_disabled = arch_irqs_disabled_flags(flags);
104 if (!irqs_disabled)
105 trace_hardirqs_off();
106 rc = __memcpy_real((void *) dest, (void *) src, (size_t) count);
107 if (!irqs_disabled)
108 trace_hardirqs_on();
109 __arch_local_irq_ssm(flags);
110 return rc;
111}
112
113
114
115
116int memcpy_real(void *dest, void *src, size_t count)
117{
118 if (S390_lowcore.nodat_stack != 0)
119 return CALL_ON_STACK(_memcpy_real, S390_lowcore.nodat_stack,
120 3, dest, src, count);
121
122
123
124
125
126 return _memcpy_real((unsigned long) dest,(unsigned long) src,
127 (unsigned long) count);
128}
129
130
131
132
133void memcpy_absolute(void *dest, void *src, size_t count)
134{
135 unsigned long cr0, flags, prefix;
136
137 flags = arch_local_irq_save();
138 __ctl_store(cr0, 0, 0);
139 __ctl_clear_bit(0, 28);
140 prefix = store_prefix();
141 if (prefix) {
142 local_mcck_disable();
143 set_prefix(0);
144 memcpy(dest, src, count);
145 set_prefix(prefix);
146 local_mcck_enable();
147 } else {
148 memcpy(dest, src, count);
149 }
150 __ctl_load(cr0, 0, 0);
151 arch_local_irq_restore(flags);
152}
153
154
155
156
157int copy_to_user_real(void __user *dest, void *src, unsigned long count)
158{
159 int offs = 0, size, rc;
160 char *buf;
161
162 buf = (char *) __get_free_page(GFP_KERNEL);
163 if (!buf)
164 return -ENOMEM;
165 rc = -EFAULT;
166 while (offs < count) {
167 size = min(PAGE_SIZE, count - offs);
168 if (memcpy_real(buf, src + offs, size))
169 goto out;
170 if (copy_to_user(dest + offs, buf, size))
171 goto out;
172 offs += size;
173 }
174 rc = 0;
175out:
176 free_page((unsigned long) buf);
177 return rc;
178}
179
180
181
182
183static int is_swapped(unsigned long addr)
184{
185 unsigned long lc;
186 int cpu;
187
188 if (addr < sizeof(struct lowcore))
189 return 1;
190 for_each_online_cpu(cpu) {
191 lc = (unsigned long) lowcore_ptr[cpu];
192 if (addr > lc + sizeof(struct lowcore) - 1 || addr < lc)
193 continue;
194 return 1;
195 }
196 return 0;
197}
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204
205void *xlate_dev_mem_ptr(phys_addr_t addr)
206{
207 void *bounce = (void *) addr;
208 unsigned long size;
209
210 get_online_cpus();
211 preempt_disable();
212 if (is_swapped(addr)) {
213 size = PAGE_SIZE - (addr & ~PAGE_MASK);
214 bounce = (void *) __get_free_page(GFP_ATOMIC);
215 if (bounce)
216 memcpy_absolute(bounce, (void *) addr, size);
217 }
218 preempt_enable();
219 put_online_cpus();
220 return bounce;
221}
222
223
224
225
226void unxlate_dev_mem_ptr(phys_addr_t addr, void *buf)
227{
228 if ((void *) addr != buf)
229 free_page((unsigned long) buf);
230}
231