s390_pci_mmio_write(2) — Linux manual page

s390_pci_mmio_write(2)     System Calls Manual    s390_pci_mmio_write(2)

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(SYS_s390_pci_mmio_write, unsigned long mmio_addr,
                              const void user_buffer[.length], size_t length);
       int syscall(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 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.

STANDARDS

       Linux on s390.

HISTORY

       Linux 3.19.  System z EC12.

SEE ALSO

       syscall(2)

COLOPHON

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Linux man-pages 6.9.1          2024-05-02         s390_pci_mmio_write(2)

Pages that refer to this page: syscalls(2)

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