s390_pci_mmio_write, s390_pci_mmio_read - transfer data to/from PCI MMIO memory page
#include <asm/unistd.h>
int s390_pci_mmio_write(unsigned long mmio_addr,
void *user_buffer, size_t length);
int s390_pci_mmio_read(unsigned long mmio_addr,
void *user_buffer, size_t length);
The s390_pci_mmio_write() system call writes
length
bytes of data from the user-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 user-space buffer
user_buffer
.
These system calls must be used instead of the simple assignment or
data-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.
On success, s390_pci_mmio_write() and
s390_pci_mmio_read() return 0. On error, -1 is returned
and errno
is set to one of the error codes listed below.
The address in mmio_addr
is invalid.
user_buffer
does not point to a valid location in the
caller's address space.
Invalid length
argument.
PCI support is not enabled.
Insufficient memory.
These system calls are available since Linux 3.19.
This Linux-specific system call is available only on the s390 architecture. The required PCI support is available beginning with System z EC12.
Glibc does not provide a wrapper for this system call, use syscall(2) to call it.
syscall(2)
This page is part of release 5.10 of the Linux man-pages
project. A description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.