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devmap_devmem_setup() and devmap_umem_setup() are used in the devmap(9E) entry point to pass mapping parameters from the driver to the system.
dhp is a device mapping handle that the system uses to store all mapping parameters of a physical contiguous memory. The system copies the data pointed to by callbackops to a system private memory. This allows the driver to free the data after
returning from either devmap_devmem_setup() or devmap_umem_setup(). The driver is notified of user events on the mappings via the entry points defined by devmap_callback_ctl(9S). The driver is notified of the following user events:
- Mapping Setup
- User has called mmap(2) to create a mapping to the device memory.
- Access
- User has accessed an address in the mapping that has no translations.
- Duplication
- User has duplicated the mapping. Mappings are duplicated when the process calls fork(2).
- Unmapping
- User has called munmap(2) on the mapping or is exiting, exit(2).
See devmap_map(9E), devmap_access(9E), devmap_dup(9E), and devmap_unmap(9E) for details on these entry points.
By specifying a valid callbackops to the system, device drivers can manage events on a device mapping. For example, the devmap_access(9E)
entry point allows the drivers to perform context switching by unloading the mappings of other processes and to load the mapping of the calling process. Device drivers may specify NULL to callbackops which means the drivers do not want to be notified
by the system.
The maximum protection allowed for the mapping is specified in maxprot. accattrp defines the device access attributes. See ddi_device_acc_attr(9S) for more details.
devmap_devmem_setup() is used for device memory to map in the register set given by rnumber and the offset into the register address space given by roff. The system uses rnumber and roff to go up the device tree to get the physical address that corresponds to roff. The range to be affected is defined by len and roff. The range from roff to roff + len must be a physical contiguous memory and page aligned.
Drivers use devmap_umem_setup() for kernel memory to map in the kernel memory described by cookie and the offset into the kernel memory space given by koff. cookie is a kernel memory pointer obtained
from ddi_umem_alloc(9F). If cookie is NULL, devmap_umem_setup() returns -1. The range to be affected is defined by len and koff. The range from koff to koff + len must be within the limits of the kernel
memory described by koff + len and must be page aligned.
Drivers use devmap_umem_setup() to export the kernel memory allocated by ddi_umem_alloc(9F) to user space. The system selects a user virtual address that is
aligned with the kernel virtual address being mapped to avoid cache incoherence if the mapping is not MAP_FIXED.
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