DCA: Add Direct Cache Access driver

Direct Cache Access (DCA) is a method for warming the CPU cache before data
is used, with the intent of lessening the impact of cache misses.  This
patch adds a manager and interface for matching up client requests for DCA
services with devices that offer DCA services.

In order to use DCA, a module must do bus writes with the appropriate tag
bits set to trigger a cache read for a specific CPU.  However, different
CPUs and chipsets can require different sets of tag bits, and the methods
for determining the correct bits may be simple hardcoding or may be a
hardware specific magic incantation.  This interface is a way for DCA
clients to find the correct tag bits for the targeted CPU without needing
to know the specifics.

    [Dave Miller] use DEFINE_SPINLOCK()

Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/Makefile b/drivers/Makefile
index a168eacdcd9..174c27eb443 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -85,6 +85,7 @@ obj-$(CONFIG_CRYPTO)		+= crypto/
 obj-$(CONFIG_SUPERH)            += sh/
 obj-$(CONFIG_GENERIC_TIME)      += clocksource/
 obj-$(CONFIG_DMA_ENGINE)        += dma/
+obj-$(CONFIG_DCA)               += dca/
 obj-$(CONFIG_HID)               += hid/
 obj-$(CONFIG_PPC_PS3)           += ps3/
 obj-$(CONFIG_OF)                += of/