Hi all,
I have a probably a dumb question that need some clarification. I was reading the kernel source code and I’m little bit confused with the three data type:
paddr_t, pptr_t, vptr_t and the following three data struct related to them.
typedef struct region {
pptr_t start;
pptr_t end;
} region_t;
typedef struct p_region {
paddr_t start;
paddr_t end;
} p_region_t;
typedef struct v_region {
vptr_t start;
vptr_t end;
} v_region_t;
Based on how those are being used I assume the paddr_t and p_region are data struct for physical address, vptr_t and v_region are for virtual address. According to the following functions seem that the translation between physical address to pptr_r is by adding/subtracting a offset. But I’m confused with the pptr_t and region I wonder what are those for? Tank you very much!
static inline void* CONST
ptrFromPAddr(paddr_t paddr)
{
return (void*)(paddr + physMappingOffset);
}
static inline paddr_t CONST
addrFromPPtr(void* pptr)
{
return (paddr_t)pptr - physMappingOffset;
}
static inline region_t CONST
paddr_to_pptr_reg(p_region_t p_reg)
{
return (region_t) {
p_reg.start + physMappingOffset, p_reg.end + physMappingOffset
};
}
static inline p_region_t CONST
pptr_to_paddr_reg(region_t reg)
{
return (p_region_t) {
reg.start - physMappingOffset, reg.end - physMappingOffset
};
}
Thanks
-Dan
