parisc: Use implicit space register selection for loading the coherence index of...
commit91f4595129915406ad2ecbc6bd2591cdf0ce5f8b
authorJohn David Anglin <dave.anglin@bell.net>
Tue, 28 May 2019 00:15:14 +0000 (27 20:15 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 11 Jun 2019 10:21:47 +0000 (11 12:21 +0200)
tree49956ce7e4b60f89acab02294eb532e7a06eff81
parentcfa2e34ffb62d018172a614a2dea69e4bc89d32e
parisc: Use implicit space register selection for loading the coherence index of I/O pdirs

commit 63923d2c3800919774f5c651d503d1dd2adaddd5 upstream.

We only support I/O to kernel space. Using %sr1 to load the coherence
index may be racy unless interrupts are disabled. This patch changes the
code used to load the coherence index to use implicit space register
selection. This saves one instruction and eliminates the race.

Tested on rp3440, c8000 and c3750.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/parisc/ccio-dma.c
drivers/parisc/sba_iommu.c