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4eafad7f AI |
1 | /* |
2 | * Access to PCI I/O memory from user space programs. | |
3 | * | |
4 | * Copyright IBM Corp. 2014 | |
5 | * Author(s): Alexey Ishchuk <aishchuk@linux.vnet.ibm.com> | |
6 | */ | |
7 | #include <linux/kernel.h> | |
8 | #include <linux/syscalls.h> | |
9 | #include <linux/init.h> | |
10 | #include <linux/mm.h> | |
11 | #include <linux/errno.h> | |
12 | #include <linux/pci.h> | |
13 | ||
14 | static long get_pfn(unsigned long user_addr, unsigned long access, | |
15 | unsigned long *pfn) | |
16 | { | |
17 | struct vm_area_struct *vma; | |
18 | long ret; | |
19 | ||
20 | down_read(¤t->mm->mmap_sem); | |
21 | ret = -EINVAL; | |
22 | vma = find_vma(current->mm, user_addr); | |
23 | if (!vma) | |
24 | goto out; | |
25 | ret = -EACCES; | |
26 | if (!(vma->vm_flags & access)) | |
27 | goto out; | |
28 | ret = follow_pfn(vma, user_addr, pfn); | |
29 | out: | |
30 | up_read(¤t->mm->mmap_sem); | |
31 | return ret; | |
32 | } | |
33 | ||
34 | SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr, | |
35 | const void __user *, user_buffer, size_t, length) | |
36 | { | |
37 | u8 local_buf[64]; | |
38 | void __iomem *io_addr; | |
39 | void *buf; | |
40 | unsigned long pfn; | |
41 | long ret; | |
42 | ||
43 | if (!zpci_is_enabled()) | |
44 | return -ENODEV; | |
45 | ||
46 | if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length) | |
47 | return -EINVAL; | |
48 | if (length > 64) { | |
49 | buf = kmalloc(length, GFP_KERNEL); | |
50 | if (!buf) | |
51 | return -ENOMEM; | |
52 | } else | |
53 | buf = local_buf; | |
54 | ||
55 | ret = get_pfn(mmio_addr, VM_WRITE, &pfn); | |
56 | if (ret) | |
57 | goto out; | |
eba84525 | 58 | io_addr = (void __iomem *)((pfn << PAGE_SHIFT) | (mmio_addr & ~PAGE_MASK)); |
4eafad7f AI |
59 | |
60 | ret = -EFAULT; | |
61 | if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE) | |
62 | goto out; | |
63 | ||
64 | if (copy_from_user(buf, user_buffer, length)) | |
65 | goto out; | |
66 | ||
67 | memcpy_toio(io_addr, buf, length); | |
68 | ret = 0; | |
69 | out: | |
70 | if (buf != local_buf) | |
71 | kfree(buf); | |
72 | return ret; | |
73 | } | |
74 | ||
75 | SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr, | |
76 | void __user *, user_buffer, size_t, length) | |
77 | { | |
78 | u8 local_buf[64]; | |
79 | void __iomem *io_addr; | |
80 | void *buf; | |
81 | unsigned long pfn; | |
82 | long ret; | |
83 | ||
84 | if (!zpci_is_enabled()) | |
85 | return -ENODEV; | |
86 | ||
87 | if (length <= 0 || PAGE_SIZE - (mmio_addr & ~PAGE_MASK) < length) | |
88 | return -EINVAL; | |
89 | if (length > 64) { | |
90 | buf = kmalloc(length, GFP_KERNEL); | |
91 | if (!buf) | |
92 | return -ENOMEM; | |
93 | } else | |
94 | buf = local_buf; | |
95 | ||
96 | ret = get_pfn(mmio_addr, VM_READ, &pfn); | |
97 | if (ret) | |
98 | goto out; | |
eba84525 | 99 | io_addr = (void __iomem *)((pfn << PAGE_SHIFT) | (mmio_addr & ~PAGE_MASK)); |
4eafad7f AI |
100 | |
101 | ret = -EFAULT; | |
102 | if ((unsigned long) io_addr < ZPCI_IOMAP_ADDR_BASE) | |
103 | goto out; | |
104 | ||
105 | memcpy_fromio(buf, io_addr, length); | |
106 | ||
107 | if (copy_to_user(user_buffer, buf, length)) | |
108 | goto out; | |
109 | ||
110 | ret = 0; | |
111 | out: | |
112 | if (buf != local_buf) | |
113 | kfree(buf); | |
114 | return ret; | |
115 | } |