[dpdk-dev] [PATCH 4/7] bus/pci: avoid call to DMA mask check

Alejandro Lucero alejandro.lucero at netronome.com
Wed Oct 31 18:29:28 CET 2018


Calling rte_mem_check_dma_mask when memory has not been initialized
yet is wrong. This patch use rte_mem_set_dma_mask instead.

Once memory initialization is done, the dma mask set will be used
for checking memory mapped is within the specified mask.

Fixes: fe822eb8c565 ("bus/pci: use IOVA DMA mask check when setting IOVA mode")

Signed-off-by: Alejandro Lucero <alejandro.lucero at netronome.com>
---
 drivers/bus/pci/linux/pci.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
index 0a81e063b..d87384c72 100644
--- a/drivers/bus/pci/linux/pci.c
+++ b/drivers/bus/pci/linux/pci.c
@@ -590,7 +590,16 @@ pci_one_device_iommu_support_va(struct rte_pci_device *dev)
 
 	mgaw = ((vtd_cap_reg & VTD_CAP_MGAW_MASK) >> VTD_CAP_MGAW_SHIFT) + 1;
 
-	return rte_mem_check_dma_mask(mgaw) == 0 ? true : false;
+	/*
+	 * Assuming there is no limitation by now. We can not know at this point
+	 * because the memory has not been initialized yet. Setting the dma mask
+	 * will force a check once memory initialization is done. We can not do
+	 * a fallback to IOVA PA now, but if the dma check fails, the error
+	 * message should advice for using '--iova-mode pa' if IOVA VA is the
+	 * current mode.
+	 */
+	rte_mem_set_dma_mask(mgaw);
+	return true;
 }
 #elif defined(RTE_ARCH_PPC_64)
 static bool
-- 
2.17.1



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