From cf30c19534676189ba7aa84fe78780a1030d78ca Mon Sep 17 00:00:00 2001 From: John David Anglin Date: Mon, 27 May 2019 20:15:14 -0400 Subject: [PATCH] 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 Cc: stable@vger.kernel.org Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman --- drivers/parisc/ccio-dma.c | 4 +--- drivers/parisc/sba_iommu.c | 3 +-- 2 files changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c index 34f1d6b41fb90..cc3708ea8084a 100644 --- a/drivers/parisc/ccio-dma.c +++ b/drivers/parisc/ccio-dma.c @@ -563,8 +563,6 @@ 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! @@ -595,7 +593,7 @@ 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 d6326144ce01e..f3b9746157f81 100644 --- a/drivers/parisc/sba_iommu.c +++ b/drivers/parisc/sba_iommu.c @@ -573,8 +573,7 @@ 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 */