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Commit Graph

3 Commits

Author SHA1 Message Date
Andres Salomon
54e5bc020c x86, olpc: Constify an olpc_ofw() arg
The arguments passed to OFW shouldn't be modified; update the 'args'
argument of olpc_ofw to reflect this.  This saves us some later
casting away of consts.

Signed-off-by: Andres Salomon <dilinger@queued.net>
LKML-Reference: <20100628220029.1555ac24@debian>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-07-30 18:02:21 -07:00
Andres Salomon
75a9cac430 x86, olpc: Add comment about implicit optimization barrier
Signed-off-by: Andres Salomon <dilinger@queued.net>
Cc: H. Peter Anvin <hpa@linux.intel.com>
LKML-Reference: <20100618174653.7755a39a@dev.queued.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-06-24 11:40:47 +02:00
Andres Salomon
fd699c7655 x86, olpc: Add support for calling into OpenFirmware
Add support for saving OFW's cif, and later calling into it to run OFW
commands.  OFW remains resident in memory, living within virtual range
0xff800000 - 0xffc00000.  A single page directory entry points to the
pgdir that OFW actually uses, so rather than saving the entire page
table, we grab and install that one entry permanently in the kernel's
page table.

This is currently only used by the OLPC XO.  Note that this particular
calling convention breaks PAE and PAT, and so cannot be used on newer
x86 hardware.

Signed-off-by: Andres Salomon <dilinger@queued.net>
LKML-Reference: <20100618174653.7755a39a@dev.queued.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-06-18 14:54:36 -07:00