Could /dev/mem mean all physical memory when I make a hole in ZONE_NORMAL

[Adam Jiang]

Hello, list

Could /dev/mem mean all physical memory when I make a hole in
ZONE_NORMAL. For example, if I create a memory hole by following code,

#define RAM_SIZE (256<<20)

zone_size[ZONE_DMA] = PFN_DOWN(16<<20);
zone_size[ZONE_NORMAL] = PFN_DOWN(RAM_SIZE) - zone_size[ZONE_DMA];
zholes_size[ZONE_NORMAL] = PFN_DOWN(RAM_SIZE) - PFN_DOWN(48<<20);

then I get a memory hole from 208M ~ 256M.
could I mmap() the reserved area into a process by

mmap(start, RAM_SIZE - 48, prot, flags, /dev/mem, 208M);

Best regards,
/Adam