omap4: l2x0: Set share override bit

Clearing bit 22 in the PL310 Auxiliary Control register (shared
attribute override enable) has the side effect of transforming Normal
Shared Non-cacheable reads into Cacheable no-allocate reads.

Coherent DMA buffers in Linux always have a Cacheable alias via the
kernel linear mapping and the processor can speculatively load cache
lines into the PL310 controller. With bit 22 cleared, Non-cacheable
reads would unexpectedly hit such cache lines leading to buffer
corruption

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This commit is contained in:
Santosh Shilimkar 2010-11-19 23:01:05 +05:30 committed by Tony Lindgren
parent 11e0264046
commit b0f20ff9d7
1 changed files with 1 additions and 0 deletions

View File

@ -80,6 +80,7 @@ static int __init omap_l2_cache_init(void)
aux_ctrl |= 0x2 << L2X0_AUX_CTRL_WAY_SIZE_SHIFT;
} else {
aux_ctrl |= ((0x3 << L2X0_AUX_CTRL_WAY_SIZE_SHIFT) |
(1 << L2X0_AUX_CTRL_SHARE_OVERRIDE_SHIFT) |
(1 << L2X0_AUX_CTRL_DATA_PREFETCH_SHIFT) |
(1 << L2X0_AUX_CTRL_INSTR_PREFETCH_SHIFT));
}