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authorJohn David Anglin <dave.anglin@bell.net>2019-06-02 19:12:40 -0400
committerHelge Deller <deller@gmx.de>2019-06-06 14:12:22 +0200
commit116d753308cf032159c7b7aa87c9605bb5354784 (patch)
treef2642cc73c48384f7b7934d0c794d27121018ffd /drivers
parentec13c82d261b5a10e6f6e3273b60329d1146edbb (diff)
downloadlinux-116d753308cf032159c7b7aa87c9605bb5354784.tar.bz2
parisc: Use lpa instruction to load physical addresses in driver code
Most I/O in the kernel is done using the kernel offset mapping. However, there is one API that uses aliased kernel address ranges: > The final category of APIs is for I/O to deliberately aliased address > ranges inside the kernel. Such aliases are set up by use of the > vmap/vmalloc API. Since kernel I/O goes via physical pages, the I/O > subsystem assumes that the user mapping and kernel offset mapping are > the only aliases. This isn't true for vmap aliases, so anything in > the kernel trying to do I/O to vmap areas must manually manage > coherency. It must do this by flushing the vmap range before doing > I/O and invalidating it after the I/O returns. For this reason, we should use the hardware lpa instruction to load the physical address of kernel virtual addresses in the driver code. I believe we only use the vmap/vmalloc API with old PA 1.x processors which don't have a sba, so we don't hit this problem. Tested on c3750, c8000 and rp3440. Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/parisc/ccio-dma.c2
-rw-r--r--drivers/parisc/sba_iommu.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c
index 9b434644524c..8362517b98f9 100644
--- a/drivers/parisc/ccio-dma.c
+++ b/drivers/parisc/ccio-dma.c
@@ -570,7 +570,7 @@ ccio_io_pdir_entry(u64 *pdir_ptr, space_t sid, unsigned long vba,
** "hints" parm includes the VALID bit!
** "dep" clobbers the physical address offset bits as well.
*/
- pa = virt_to_phys(vba);
+ pa = lpa(vba);
asm volatile("depw %1,31,12,%0" : "+r" (pa) : "r" (hints));
((u32 *)pdir_ptr)[1] = (u32) pa;
diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c
index 78df92600203..aefb03ebeaf8 100644
--- a/drivers/parisc/sba_iommu.c
+++ b/drivers/parisc/sba_iommu.c
@@ -572,7 +572,7 @@ sba_io_pdir_entry(u64 *pdir_ptr, space_t sid, unsigned long vba,
u64 pa; /* physical address */
register unsigned ci; /* coherent index */
- pa = virt_to_phys(vba);
+ pa = lpa(vba);
pa &= IOVP_MASK;
asm("lci 0(%1), %0" : "=r" (ci) : "r" (vba));