arch/tile: support 4KB page size as well as 64KB
authorChris Metcalf <cmetcalf@tilera.com>
Mon, 28 Feb 2011 21:37:34 +0000 (16:37 -0500)
committerChris Metcalf <cmetcalf@tilera.com>
Thu, 10 Mar 2011 18:17:53 +0000 (13:17 -0500)
commit76c567fbba50c3da2f4d40e2e551bab26cfd4381
tree6e3c92a266d0ec255e1930adf5ba5268cd71dee9
parent09c17eab075ceeafb53935d858c575b6776394d1
arch/tile: support 4KB page size as well as 64KB

The Tilera architecture traditionally supports 64KB page sizes
to improve TLB utilization and improve performance when the
hardware is being used primarily to run a single application.

For more generic server scenarios, it can be beneficial to run
with 4KB page sizes, so this commit allows that to be specified
(by modifying the arch/tile/include/hv/pagesize.h header).

As part of this change, we also re-worked the PTE management
slightly so that PTE writes all go through a __set_pte() function
where we can do some additional validation.  The set_pte_order()
function was eliminated since the "order" argument wasn't being used.

One bug uncovered was in the PCI DMA code, which wasn't properly
flushing the specified range.  This was benign with 64KB pages,
but with 4KB pages we were getting some larger flushes wrong.

The per-cpu memory reservation code also needed updating to
conform with the newer percpu stuff; before it always chose 64KB,
and that was always correct, but with 4KB granularity we now have
to pay closer attention and reserve the amount of memory that will
be requested when the percpu code starts allocating.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
18 files changed:
arch/tile/Kconfig
arch/tile/include/asm/hugetlb.h
arch/tile/include/asm/page.h
arch/tile/include/asm/pgalloc.h
arch/tile/include/asm/pgtable.h
arch/tile/include/asm/pgtable_32.h
arch/tile/include/asm/stack.h
arch/tile/include/asm/thread_info.h
arch/tile/kernel/intvec_32.S
arch/tile/kernel/machine_kexec.c
arch/tile/kernel/pci-dma.c
arch/tile/kernel/process.c
arch/tile/kernel/setup.c
arch/tile/lib/memcpy_tile64.c
arch/tile/mm/homecache.c
arch/tile/mm/init.c
arch/tile/mm/migrate_32.S
arch/tile/mm/pgtable.c