NAME

cxl_mmio_write32 - write a 32-bit word to the mapped AFU Problem State Area

SYNOPSIS

#include <libcxl.h>

int cxl_mmio_write32(struct cxl_afu_h *afu, uint64_t offset, uint32_t data);

DESCRIPTION

cxl_mmio_write32() writes the 32-bit word data at offset from the address of the mapped Problem State Area of afu. Bytes will be swapped if the AFU endianness declared by cxl_mmio_map() differs from the host endianness.

offset is a byte address that is aligned on a word (4 byte) boundary. It must be lower than the MMIO size returned by cxl_get_mmio_size(). The address of the mapped MMIO space is returned by cxl_mmio_ptr().

If the MMIO access fails due to an IO error, a SIGBUS may be sent to the application, which would ordinarily result in the process being terminated. libcxl provides an optional SIGBUS handler, which can be installed with cxl_mmio_install_sigbus_handler(). Installing this signal handler prior to using the MMIO accessor functions will cause them to return -1 and set errno to EIO in the event of an IO error.

RETURN VALUE

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

ERRORS

EINVAL

Invalid argument value, or unmapped MMIO space.

EIO

An unrecoverable error (cxl_mmio_install_sigbus_handler() must have been previously called)

SEE ALSO

cxl(3), cxl_get_mmio_size(3), cxl_mmio_install_sigbus_handler(3), cxl_mmio_map(3), cxl_mmio_ptr(3), cxl_mmio_read32(3), cxl_mmio_read64(3), cxl_mmio_unmap(3), cxl_mmio_write64(3)