parisc: Use implicit space register selection for loading the coherence index of...

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>

diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c
index acba1f56af3e439647f6c3884a37ab78b233e1b3..d7649a70a0c45d757d3c5035bed077a4b6fb3853 100644 (file)
--- a/drivers/parisc/ccio-dma.c
+++ b/drivers/parisc/ccio-dma.c
@@ -565,8 +565,6 @@ ccio_io_pdir_entry(u64 *pdir_ptr, space_t sid, unsigned long vba,
        /* We currently only support kernel addresses */
        BUG_ON(sid != KERNEL_SPACE);
 
-       mtsp(sid,1);
-
        /*
        ** WORD 1 - low order word
        ** "hints" parm includes the VALID bit!
@@ -597,7 +595,7 @@ ccio_io_pdir_entry(u64 *pdir_ptr, space_t sid, unsigned long vba,
        ** Grab virtual index [0:11]
        ** Deposit virt_idx bits into I/O PDIR word
        */
-       asm volatile ("lci %%r0(%%sr1, %1), %0" : "=r" (ci) : "r" (vba));
+       asm volatile ("lci %%r0(%1), %0" : "=r" (ci) : "r" (vba));
        asm volatile ("extru %1,19,12,%0" : "+r" (ci) : "r" (ci));
        asm volatile ("depw  %1,15,12,%0" : "+r" (pa) : "r" (ci));
 

diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c
index 0a9c762a70fae5dae2187effec931df5bfd77550..5468490d2298b2503dc34bf6f5e0f1f1d6fb2c8d 100644 (file)
--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -575,8 +575,7 @@ sba_io_pdir_entry(u64 *pdir_ptr, space_t sid, unsigned long vba,
        pa = virt_to_phys(vba);
        pa &= IOVP_MASK;
 
-       mtsp(sid,1);
-       asm("lci 0(%%sr1, %1), %0" : "=r" (ci) : "r" (vba));
+       asm("lci 0(%1), %0" : "=r" (ci) : "r" (vba));
        pa |= (ci >> PAGE_SHIFT) & 0xff;  /* move CI (8 bits) into lowest byte */
 
        pa |= SBA_PDIR_VALID_BIT;       /* set "valid" bit */