NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | VERSIONS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

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 <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);

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 error, -1 is returned and errno is set to one of the error codes
       listed below.

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.

NOTES         top

       Glibc does not provide a wrapper for this system call, use syscall(2)
       to call it.

SEE ALSO         top

       syscall(2)

COLOPHON         top

       This page is part of release 4.10 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/.

Linux Programmer's Manual        2015-01-15           S390_PCI_MMIO_WRITE(2)