Support DMA mapping of all kernel "unmapped" virtual address segments
to the corresponding physical addresses for 32- and 64-bit architectures.
Signed-off-by: David VomLehn <firstname.lastname@example.org>
The current virt_to_phys function does not map KSEG1 address to the correct
physical address, nor will it map most of the XKPHYS addresses correctly. This
patch addresses this problem.
Unfortunately, I don't have access to a 64-bit system, so I need to ask for
someone to perform additional verification. Any volunteers?
addrspace.h | 18 +++++++++++-------
io.h | 2 +-
2 files changed, 12 insertions(+), 8 deletions(-)
@@ -75,6 +75,12 @@
#define CKSEG2ADDR(a) (CPHYSADDR(a) | CKSEG2)
#define CKSEG3ADDR(a) (CPHYSADDR(a) | CKSEG3)
+ * The ultimate limited of the 64-bit MIPS architecture: 2 bits for selecting
+ * the region, 3 bits for the CCA mode. This leaves 59 bits of which the
+ * R8000 implements most with its 48-bit physical address space.
+#define TO_PHYS_MASK _CONST64_(0x07ffffffffffffff) /* 2^59 - 1 */
#define CKSEG0ADDR(a) (CPHYSADDR(a) | KSEG0)
@@ -106,6 +112,11 @@
#define CKSEG2 0xc0000000
#define CKSEG3 0xe0000000
+ * The ultimate limit of the 32-bit MIPS architecture. 3 bits for selecting
+ * the region, leaving 29 bits for the physical address spaces
+#define TO_PHYS_MASK 0x1fffffffl /* 2^29 - 1 */
@@ -129,13 +140,6 @@
#define PHYS_TO_XKPHYS(cm, a) (_CONST64_(0x8000000000000000) | \
((cm)<<59) | (a))
- * The ultimate limited of the 64-bit MIPS architecture: 2 bits for selecting
- * the region, 3 bits for the CCA mode. This leaves 59 bits of which the
- * R8000 implements most with its 48-bit physical address space.
-#define TO_PHYS_MASK _CONST64_(0x07ffffffffffffff) /* 2^^59 - 1 */
@@ -118,7 +118,7 @@ static inline void set_io_port_base(unsi
static inline unsigned long virt_to_phys(volatile const void *address)
- return (unsigned long)address - PAGE_OFFSET + PHYS_OFFSET;
+ return (unsigned long)address & TO_PHYS_MASK;
- - - - - Cisco - - - - -
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