s390_pci_mmio_write(2) — Linux manual page


S390_PCI_MMIO_WRITE(2)     System Calls Manual    S390_PCI_MMIO_WRITE(2)

NAME         top

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

SYNOPSIS         top

       #include <sys/syscall.h>      /* Definition of SYS_* constants */
       #include <unistd.h>

       int syscall(SYS_s390_pci_mmio_write, unsigned long mmio_addr,
                              const void *user_buffer, size_t length);
       int syscall(SYS_s390_pci_mmio_read, unsigned long mmio_addr,
                              void *user_buffer, size_t length);

       Note: glibc provides no wrappers for these system calls,
       necessitating the use of syscall(2).

DESCRIPTION         top

       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         top

       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

ERRORS         top

       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.

VERSIONS         top

       These system calls are available since Linux 3.19.

CONFORMING TO         top

       This Linux-specific system call is available only on the s390
       architecture.  The required PCI support is available beginning
       with System z EC12.

SEE ALSO         top


COLOPHON         top

       This page is part of release 5.13 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

Linux Programmer's Manual      2021-03-22         S390_PCI_MMIO_WRITE(2)

Pages that refer to this page: syscalls(2)