s390_pci_mmio_write2
Transfer data to/from pci mmio memory page
Usage
#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).
Library
Standard C library (libc, -lc)
Overview
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.
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. |
Releases
6 releases since Debian 9 (Stretch); the text changed 5 times.