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Commit 09abe5a6 authored by Alexander Shishkin's avatar Alexander Shishkin Committed by Greg Kroah-Hartman
Browse files

intel_th: msu: Fix single mode with IOMMU 



commit 4e0eaf239fb33ebc671303e2b736fa043462e2f4 upstream.

Currently, the pages that are allocated for the single mode of MSC are not
mapped into the device's dma space and the code is incorrectly using
*_to_phys() in place of a dma address. This fails with IOMMU enabled and
is otherwise bad practice.

Fix the single mode buffer allocation to map the pages into the device's
DMA space.

Signed-off-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: ba82664c ("intel_th: Add Memory Storage Unit driver")
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cd72ddca

drivers/hwtracing/intel_th/msu.c

+32 −3
Original line number Diff line number Diff line
@@ -90,6 +90,7 @@ struct msc_iter { 
 * @reg_base:		register window base address

 * @thdev:		intel_th_device pointer

 * @win_list:		list of windows in multiblock mode

 * @single_sgt:		single mode buffer

 * @nr_pages:		total number of pages allocated for this buffer

 * @single_sz:		amount of data in single mode

 * @single_wrap:	single mode wrap occurred
@@ -110,6 +111,7 @@ struct msc { 
	struct intel_th_device	*thdev;



	struct list_head	win_list;

	struct sg_table		single_sgt;

	unsigned long		nr_pages;

	unsigned long		single_sz;

	unsigned int		single_wrap : 1;
@@ -623,22 +625,45 @@ static void intel_th_msc_deactivate(struct intel_th_device *thdev) 
 */

static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size)

{

	unsigned long nr_pages = size >> PAGE_SHIFT;

	unsigned int order = get_order(size);

	struct page *page;

	int ret;



	if (!size)

		return 0;



	ret = sg_alloc_table(&msc->single_sgt, 1, GFP_KERNEL);

	if (ret)

		goto err_out;



	ret = -ENOMEM;

	page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);

	if (!page)

		return -ENOMEM;

		goto err_free_sgt;



	split_page(page, order);

	msc->nr_pages = size >> PAGE_SHIFT;

	sg_set_buf(msc->single_sgt.sgl, page_address(page), size);



	ret = dma_map_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl, 1,

			 DMA_FROM_DEVICE);

	if (ret < 0)

		goto err_free_pages;



	msc->nr_pages = nr_pages;

	msc->base = page_address(page);

	msc->base_addr = page_to_phys(page);

	msc->base_addr = sg_dma_address(msc->single_sgt.sgl);



	return 0;



err_free_pages:

	__free_pages(page, order);



err_free_sgt:

	sg_free_table(&msc->single_sgt);



err_out:

	return ret;

}



/**
@@ -649,6 +674,10 @@ static void msc_buffer_contig_free(struct msc *msc) 
{

	unsigned long off;



	dma_unmap_sg(msc_dev(msc)->parent->parent, msc->single_sgt.sgl,

		     1, DMA_FROM_DEVICE);

	sg_free_table(&msc->single_sgt);



	for (off = 0; off < msc->nr_pages << PAGE_SHIFT; off += PAGE_SIZE) {

		struct page *page = virt_to_page(msc->base + off);