1S390_PCI_MMIO_WRITE(2)        System Calls Manual       S390_PCI_MMIO_WRITE(2)
2
3
4

NAME

6       s390_pci_mmio_write,  s390_pci_mmio_read  -  transfer  data to/from PCI
7       MMIO memory page
8

SYNOPSIS

10       #include <asm/unistd.h>
11
12       int s390_pci_mmio_write(unsigned long mmio_addr,
13                               void *user_buffer, size_t length);
14       int s390_pci_mmio_read(unsigned long mmio_addr,
15                               void *user_buffer, size_t length);
16

DESCRIPTION

18       The s390_pci_mmio_write() system call writes length bytes of data  from
19       the user-space buffer user_buffer to the PCI MMIO memory location spec‐
20       ified by mmio_addr.  The s390_pci_mmio_read() system call reads  length
21       bytes  of data from the PCI MMIO memory location specified by mmio_addr
22       to the user-space buffer user_buffer.
23
24       These system calls must be used instead of  the  simple  assignment  or
25       data-transfer  operations  that  are used to access the PCI MMIO memory
26       areas mapped to user space on the Linux System z platform.  The address
27       specified by mmio_addr must belong to a PCI MMIO memory page mapping in
28       the caller's address space, and the data being written or read must not
29       cross  a  page  boundary.   The length value cannot be greater than the
30       system page size.
31

RETURN VALUE

33       On success, s390_pci_mmio_write() and  s390_pci_mmio_read()  return  0.
34       On  error,  -1  is  returned and errno is set to one of the error codes
35       listed below.
36

ERRORS

38       EFAULT The address in mmio_addr is invalid.
39
40       EFAULT user_buffer does not point to a valid location in  the  caller's
41              address space.
42
43       EINVAL Invalid length argument.
44
45       ENODEV PCI support is not enabled.
46
47       ENOMEM Insufficient memory.
48

VERSIONS

50       These system calls are available since Linux 3.19.
51

CONFORMING TO

53       This Linux-specific system call is available only on the s390 architec‐
54       ture.  The required PCI support is available beginning  with  System  z
55       EC12.
56

NOTES

58       Glibc  does  not provide a wrapper for this system call, use syscall(2)
59       to call it.
60

SEE ALSO

62       syscall(2)
63

COLOPHON

65       This page is part of release 5.10 of the Linux  man-pages  project.   A
66       description  of  the project, information about reporting bugs, and the
67       latest    version    of    this    page,    can     be     found     at
68       https://www.kernel.org/doc/man-pages/.
69
70
71
72Linux Programmer's Manual         2017-09-15            S390_PCI_MMIO_WRITE(2)
Impressum