tce_buildmulti_pSeriesLP uses a per cpu page to communicate with the hypervisor. We currently rely on the IOMMU table spinlock but subsequent patches will be removing that so disable interrupts around all accesses of tce_page.
Signed-off-by: Anton Blanchard <an...@samba.org> --- Index: linux-build/arch/powerpc/platforms/pseries/iommu.c =================================================================== --- linux-build.orig/arch/powerpc/platforms/pseries/iommu.c 2012-06-04 10:25:34.420492862 +1000 +++ linux-build/arch/powerpc/platforms/pseries/iommu.c 2012-06-04 10:25:39.300597880 +1000 @@ -192,12 +192,15 @@ static int tce_buildmulti_pSeriesLP(stru long l, limit; long tcenum_start = tcenum, npages_start = npages; int ret = 0; + unsigned long flags; if (npages == 1) { return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr, direction, attrs); } + local_irq_save(flags); /* to protect tcep and the page behind it */ + tcep = __get_cpu_var(tce_page); /* This is safe to do since interrupts are off when we're called @@ -207,6 +210,7 @@ static int tce_buildmulti_pSeriesLP(stru tcep = (u64 *)__get_free_page(GFP_ATOMIC); /* If allocation fails, fall back to the loop implementation */ if (!tcep) { + local_irq_restore(flags); return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr, direction, attrs); } @@ -240,6 +244,8 @@ static int tce_buildmulti_pSeriesLP(stru tcenum += limit; } while (npages > 0 && !rc); + local_irq_restore(flags); + if (unlikely(rc == H_NOT_ENOUGH_RESOURCES)) { ret = (int)rc; tce_freemulti_pSeriesLP(tbl, tcenum_start, _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev