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From:   Stefano Stabellini <sstabellini@kernel.org>
To:     jgross@suse.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com
Cc:     sstabellini@kernel.org, xen-devel@lists.xenproject.org,
        linux-kernel@vger.kernel.org,
        Stefano Stabellini <stefano.stabellini@xilinx.com>
Subject: [PATCH 09/10] xen/arm: introduce phys/dma translations in xen_dma_sync_for_*
Date:   Wed, 20 May 2020 16:45:19 -0700
Message-Id: <20200520234520.22563-9-sstabellini@kernel.org>
In-Reply-To: <alpine.DEB.2.21.2005201628330.27502@sstabellini-ThinkPad-T480s>
References: <alpine.DEB.2.21.2005201628330.27502@sstabellini-ThinkPad-T480s>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Stefano Stabellini <stefano.stabellini@xilinx.com>

Add phys_to_dma/dma_to_phys calls to
xen_dma_sync_for_cpu, xen_dma_sync_for_device, and
xen_arch_need_swiotlb.

In xen_arch_need_swiotlb, take the opportunity to switch to the simpler
pfn_valid check we use everywhere else.

dma_cache_maint is fixed by the next patch.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
---
 arch/arm/xen/mm.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index f2414ea40a79..7639251bcc79 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 #include <linux/cpu.h>
+#include <linux/dma-direct.h>
 #include <linux/dma-noncoherent.h>
 #include <linux/gfp.h>
 #include <linux/highmem.h>
@@ -75,7 +76,7 @@ void xen_dma_sync_for_cpu(struct device *dev, dma_addr_t handle,
 			  phys_addr_t paddr, size_t size,
 			  enum dma_data_direction dir)
 {
-	if (pfn_valid(PFN_DOWN(handle)))
+	if (pfn_valid(PFN_DOWN(dma_to_phys(dev, handle))))
 		arch_sync_dma_for_cpu(paddr, size, dir);
 	else if (dir != DMA_TO_DEVICE)
 		dma_cache_maint(handle, size, GNTTAB_CACHE_INVAL);
@@ -85,7 +86,7 @@ void xen_dma_sync_for_device(struct device *dev, dma_addr_t handle,
 			     phys_addr_t paddr, size_t size,
 			     enum dma_data_direction dir)
 {
-	if (pfn_valid(PFN_DOWN(handle)))
+	if (pfn_valid(PFN_DOWN(dma_to_phys(dev, handle))))
 		arch_sync_dma_for_device(paddr, size, dir);
 	else if (dir == DMA_FROM_DEVICE)
 		dma_cache_maint(handle, size, GNTTAB_CACHE_INVAL);
@@ -97,8 +98,7 @@ bool xen_arch_need_swiotlb(struct device *dev,
 			   phys_addr_t phys,
 			   dma_addr_t dev_addr)
 {
-	unsigned int xen_pfn = XEN_PFN_DOWN(phys);
-	unsigned int bfn = XEN_PFN_DOWN(dev_addr);
+	unsigned int bfn = XEN_PFN_DOWN(dma_to_phys(dev, dev_addr));
 
 	/*
 	 * The swiotlb buffer should be used if
@@ -115,7 +115,7 @@ bool xen_arch_need_swiotlb(struct device *dev,
 	 * require a bounce buffer because the device doesn't support coherent
 	 * memory and we are not able to flush the cache.
 	 */
-	return (!hypercall_cflush && (xen_pfn != bfn) &&
+	return (!hypercall_cflush && !pfn_valid(bfn) &&
 		!dev_is_dma_coherent(dev));
 }
 
-- 
2.17.1