NAME¶

cxl_mmio_map - map the per-process Problem State Area of an AFU to memory

SYNOPSIS¶

#include <libcxl.h>

int cxl_mmio_map(struct cxl_afu_h *afu, __u32 flag);

DESCRIPTION¶

cxl_mmio_map() maps the per-process Problem State Area of afu to the current process memory, and declares AFU endianness according to flag. The size and contents of this area are specific each AFU. The size can be discovered with cxl_get_mmio_size().

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.

The possible values of flag are:

CXL_MMIO_BIG_ENDIAN

AFU data is big-endian

CXL_MMIO_LITTLE_ENDIAN

AFU data is little-endian

CXL_MMIO_HOST_ENDIAN

AFU uses the same endianness as host.

Subsequent cxl_mmio_read32(), cxl_mmio_read64(), cxl_mmio_write32() and cxl_mmio_write64() will honor flag and swap bytes on behalf of the application when required. Only 32 and 64-bit accesses are supported by POWER8 and POWER9.

RETURN VALUE¶

On success, 0 is returned. On error, -1 is returned and errno is set appropriately.

ERRORS¶

EINVAL

Invalid argument value, or AFU does not support MMIO space.

EIO

AFU context is not attached.

ENODEV

AFU not opened, or missing flags.

ENOMEM

Insufficient memory.

FILES¶

/dev/cxl/afu<i>.<j>d

AFU device in dedicated process mode.

/dev/cxl/afu<i>.<j>m

AFU device in AFU directed mode, master context.

/dev/cxl/afu<i>.<j>s

AFU device in AFU directed mode, slave context.

SEE ALSO¶

cxl(3), cxl_afu_attach(3), cxl_afu_attach_full(3), cxl_afu_attach_work(3), cxl_get_mmio_size(3), cxl_mmio_ptr(3), cxl_mmio_read32(3), cxl_mmio_read64(3), cxl_mmio_unmap(3), cxl_mmio_write32(3), cxl_mmio_write64(3), mmap(3)