On 6/28/22 05:45, lizhe.67@xxxxxxxxxxxxx wrote: > From: Li Zhe <lizhe.67@xxxxxxxxxxxxx> > > In current kernel we can use memmap=nn[KMG]$ss[KMG] to reserve an > area of memory for userspace usage through /dev/mem. We have to > determine the start addr and length. In our scenario, we need > reserve or alloc large continuous physical memory at least 256M in > 512G's machine, and need reserve more memory in larger machine, at > just boot phase for a userspace program. And these memories will not > be freed to system before system reboot. The userspace program can > use the memory through /dev/mem to store some data. Besides, a > hardware will need the data stored by the userspace program to do > it's job. Why we need continuous memory is that the hardware can > only access memory without mmu. That's still a rather anemic description. I don't think we want this code in the kernel with that description, sorry. If you'd like to come back with an actual description, naming the exact hardware that you have *AND* explaining sane reasons for why the hardware doesn't have a normal kernel driver (or interface) like every other piece of hardware, then we can talk. But, otherwise, this isn't something that can go upstream.
