From: Alexander Shishkin Date: Fri, 21 Jun 2019 16:19:29 +0000 (+0300) Subject: intel_th: msu: Fix single mode with disabled IOMMU X-Git-Tag: v5.1.20~12 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=298f90ab4a65fff39517c3f3353b98f1f582eec6;p=thirdparty%2Fkernel%2Fstable.git intel_th: msu: Fix single mode with disabled IOMMU commit 918b8646497b5dba6ae82d4a7325f01b258972b9 upstream. Commit 4e0eaf239fb3 ("intel_th: msu: Fix single mode with IOMMU") switched the single mode code to use dma mapping pages obtained from the page allocator, but with IOMMU disabled, that may lead to using SWIOTLB bounce buffers and without additional sync'ing, produces empty trace buffers. Fix this by using a DMA32 GFP flag to the page allocation in single mode, as the device supports full 32-bit DMA addressing. Signed-off-by: Alexander Shishkin Fixes: 4e0eaf239fb3 ("intel_th: msu: Fix single mode with IOMMU") Reviewed-by: Andy Shevchenko Reported-by: Ammy Yi Cc: stable Link: https://lore.kernel.org/r/20190621161930.60785-4-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c index 8ff326c0c406c..3cdf85b1ce4fe 100644 --- a/drivers/hwtracing/intel_th/msu.c +++ b/drivers/hwtracing/intel_th/msu.c @@ -632,7 +632,7 @@ static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size) goto err_out; ret = -ENOMEM; - page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order); + page = alloc_pages(GFP_KERNEL | __GFP_ZERO | GFP_DMA32, order); if (!page) goto err_free_sgt;