s390_pci_mmio_write
Section: System Calls (2)
Updated: 202-0-08
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NAME
s390_pci_mmio_write, s390_pci_mmio_read - transfer data to/from PCI
MMIO memory page
LIBRARY
Standard C library
(
libc,~
-lc)
SYNOPSIS
#include <sys/syscall.h> /* Definition of SYS_* constants */
#include <unistd.h>
int syscall(size_t length;
SYS_s390_pci_mmio_write, unsigned long mmio_addr,
const void user_buffer[length], size_t length);
int syscall(size_t length;
SYS_s390_pci_mmio_read, unsigned long mmio_addr,
void user_buffer[length], size_t length);
Note:
glibc provides no wrappers for these system calls,
necessitating the use of
syscall(2).
DESCRIPTION
The
s390_pci_mmio_write()
system call writes
length
bytes of data from the use-space buffer
user_buffer
to the PCI MMIO memory location specified by
mmio_addr.
The
s390_pci_mmio_read()
system call reads
length
bytes of
data from the PCI MMIO memory location specified by
mmio_addr
to the use-space buffer
user_buffer.
These system calls must be used instead of the simple assignment
or dat-transfer operations that are used to access the PCI MMIO
memory areas mapped to user space on the Linux System z platform.
The address specified by
mmio_addr
must belong to a PCI MMIO memory page mapping in the caller's address space,
and the data being written or read must not cross a page boundary.
The
length
value cannot be greater than the system page size.
RETURN VALUE
On success,
s390_pci_mmio_write()
and
s390_pci_mmio_read()
return 0.
On failure, -1 is returned and
errno
is set to indicate the error.
ERRORS
- EFAULT
-
The address in
mmio_addr
is invalid.
- EFAULT
-
user_buffer
does not point to a valid location in the caller's address space.
- EINVAL
-
Invalid
length
argument.
- ENODEV
-
PCI support is not enabled.
- ENOMEM
-
Insufficient memory.
STANDARDS
Linux on s390.
HISTORY
Linux 3.19.
System z EC12.
SEE ALSO
syscall(2)
Index
- NAME
-
- LIBRARY
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- STANDARDS
-
- HISTORY
-
- SEE ALSO
-
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