Commit Graph

4 Commits

Author SHA1 Message Date
James Hogan 9da3ee9aa8 metag: move usercopy.c exports out of metag_ksyms.c
It's less error prone to have function symbols exported immediately
after the function rather than in metag_ksyms.c. Move each EXPORT_SYMBOL
in metag_ksyms.c for symbols defined in usercopy.c into usercopy.c

Signed-off-by: James Hogan <james.hogan@imgtec.com>
2013-03-02 20:11:15 +00:00
James Hogan 5633004cc2 metag: Build infrastructure
Add metag build infrastructure.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
2013-03-02 20:09:54 +00:00
James Hogan 086e9dc0e2 metag: Optimised library functions
Add optimised library functions for metag.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
2013-03-02 20:09:52 +00:00
James Hogan 373cd784d0 metag: Memory handling
Meta has instructions for accessing:
 - bytes        - GETB (1 byte)
 - words        - GETW (2 bytes)
 - doublewords  - GETD (4 bytes)
 - longwords    - GETL (8 bytes)

All accesses must be aligned. Unaligned accesses can be detected and
made to fault on Meta2, however it isn't possible to fix up unaligned
writes so we don't bother fixing up reads either.

This patch adds metag memory handling code including:
 - I/O memory (io.h, ioremap.c): Actually any virtual memory can be
   accessed with these helpers. A part of the non-MMUable address space
   is used for memory mapped I/O. The ioremap() function is implemented
   one to one for non-MMUable addresses.
 - User memory (uaccess.h, usercopy.c): User memory is directly
   accessible from privileged code.
 - Kernel memory (maccess.c): probe_kernel_write() needs to be
   overwridden to use the I/O functions when doing a simple aligned
   write to non-writecombined memory, otherwise the write may be split
   by the generic version.

Note that due to the fact that a portion of the virtual address space is
non-MMUable, and therefore always maps directly to the physical address
space, metag specific I/O functions are made available (metag_in32,
metag_out32 etc). These cast the address argument to a pointer so that
they can be used with raw physical addresses. These accessors are only
to be used for accessing fixed core Meta architecture registers in the
non-MMU region, and not for any SoC/peripheral registers.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
2013-03-02 20:09:19 +00:00