.\" Copyright 2015-2017 IBM Corp.
.\"
.TH CXL_MMIO_MAP 3 2017-05-24 "LIBCXL 1.5" "CXL Programmer's Manual"
.SH NAME
cxl_mmio_map \- map the per-process Problem State Area of an AFU to memory
.SH SYNOPSIS
.B #include <libcxl.h>
.PP
.B "int cxl_mmio_map(struct cxl_afu_h"
.BI * afu ", __u32 " flag );
.SH DESCRIPTION
.BR cxl_mmio_map ()
maps the per-process Problem State Area of
.I afu
to the current process memory, and declares AFU endianness according to
.IR flag .
The size and contents of this area are specific each AFU.
The size can be discovered with
.BR cxl_get_mmio_size ().
.PP
In AFU directed mode, master contexts are allowed to map all of
the MMIO space and slave contexts are allowed to only map the per
process MMIO space associated with the context.
In dedicated process mode the entire MMIO space can always be mapped.
.PP
The possible values of
.I flag
are:
.TP
.B CXL_MMIO_BIG_ENDIAN
AFU data is big-endian
.TP
.B CXL_MMIO_LITTLE_ENDIAN
AFU data is little-endian
.TP
.B CXL_MMIO_HOST_ENDIAN
AFU uses the same endianness as host.
.PP
Subsequent
.BR cxl_mmio_read32 (),
.BR cxl_mmio_read64 (),
.BR cxl_mmio_write32 ()
and
.BR cxl_mmio_write64 ()
will honor
.I flag
and swap bytes on behalf of the application when required.
Only 32 and 64-bit accesses are supported by POWER8 and POWER9.
.SH RETURN VALUE
On success, 0 is returned.
On error, \-1 is returned and
.I errno
is set appropriately.
.SH ERRORS
.TP
.B EINVAL
Invalid argument value, or AFU does not support MMIO space.
.TP
.B EIO
AFU context is not attached.
.TP
.B ENODEV
AFU not opened, or missing flags.
.TP
.B ENOMEM
Insufficient memory.
.SH FILES
.TP
.BI /dev/cxl/afu <i> . <j> d
AFU device in dedicated process mode.
.TP
.BI /dev/cxl/afu <i> . <j> m
AFU device in AFU directed mode, master context.
.TP
.BI /dev/cxl/afu <i> . <j> s
AFU device in AFU directed mode, slave context.
.SH SEE ALSO
.BR cxl (3),
.BR cxl_afu_attach (3),
.BR cxl_afu_attach_full (3),
.BR cxl_afu_attach_work (3),
.BR cxl_get_mmio_size (3),
.BR cxl_mmio_ptr (3),
.BR cxl_mmio_read32 (3),
.BR cxl_mmio_read64 (3),
.BR cxl_mmio_unmap (3),
.BR cxl_mmio_write32 (3),
.BR cxl_mmio_write64 (3),
.BR mmap (3)