From: Leonardo Bras <leobras.c@gmail.com>
To: Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Leonardo Bras <leobras.c@gmail.com>,
Alexey Kardashevskiy <aik@ozlabs.ru>,
Thiago Jung Bauermann <bauerman@linux.ibm.com>,
Ram Pai <linuxram@us.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 6/6] powerpc/pseries/iommu: Avoid errors when DDW starts at 0x00
Date: Wed, 24 Jun 2020 03:24:11 -0300 [thread overview]
Message-ID: <20200624062411.367796-7-leobras.c@gmail.com> (raw)
In-Reply-To: <20200624062411.367796-1-leobras.c@gmail.com>
As of today, enable_ddw() will return a non-null DMA address if the
created DDW maps the whole partition. If the address is valid,
iommu_bypass_supported_pSeriesLP() will consider iommu bypass enabled.
This can cause some trouble if the DDW happens to start at 0x00.
Instead if checking if the address is non-null, check directly if
the DDW maps the whole partition, so it can bypass iommu.
Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
---
arch/powerpc/platforms/pseries/iommu.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 2d217cda4075..967634a379b0 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1078,7 +1078,8 @@ static void reset_dma_window(struct pci_dev *dev, struct device_node *par_dn)
*
* returns the dma offset for use by the direct mapped DMA code.
*/
-static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
+static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn,
+ bool *maps_partition)
{
int len, ret;
struct ddw_query_response query;
@@ -1237,9 +1238,9 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
list_add(&window->list, &direct_window_list);
spin_unlock(&direct_window_list_lock);
- /* Only returns the dma_addr if DDW maps the whole partition */
if (len == order_base_2(max_addr))
- dma_addr = be64_to_cpu(ddwprop->dma_base);
+ *maps_partition = true;
+ dma_addr = be64_to_cpu(ddwprop->dma_base);
goto out_unlock;
out_free_window:
@@ -1324,6 +1325,7 @@ static bool iommu_bypass_supported_pSeriesLP(struct pci_dev *pdev, u64 dma_mask)
{
struct device_node *dn = pci_device_to_OF_node(pdev), *pdn;
const __be32 *dma_window = NULL;
+ bool ret = false;
/* only attempt to use a new window if 64-bit DMA is requested */
if (dma_mask < DMA_BIT_MASK(64))
@@ -1344,13 +1346,10 @@ static bool iommu_bypass_supported_pSeriesLP(struct pci_dev *pdev, u64 dma_mask)
break;
}
- if (pdn && PCI_DN(pdn)) {
- pdev->dev.archdata.dma_offset = enable_ddw(pdev, pdn);
- if (pdev->dev.archdata.dma_offset)
- return true;
- }
+ if (pdn && PCI_DN(pdn))
+ pdev->dev.archdata.dma_offset = enable_ddw(pdev, pdn, &ret);
- return false;
+ return ret;
}
static int iommu_mem_notifier(struct notifier_block *nb, unsigned long action,
--
2.25.4
next prev parent reply other threads:[~2020-06-24 6:24 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-24 6:24 [PATCH v2 0/6] Remove default DMA window before creating DDW Leonardo Bras
2020-06-24 6:24 ` [PATCH v2 1/6] powerpc/pseries/iommu: Create defines for operations in ibm,ddw-applicable Leonardo Bras
2020-07-01 8:16 ` Alexey Kardashevskiy
2020-07-01 13:28 ` Leonardo Bras
2020-07-02 0:21 ` Alexey Kardashevskiy
2020-07-02 0:36 ` Leonardo Bras
2020-07-02 0:43 ` Alexey Kardashevskiy
2020-07-02 0:46 ` Leonardo Bras
2020-06-24 6:24 ` [PATCH v2 2/6] powerpc/pseries/iommu: Update call to ibm,query-pe-dma-windows Leonardo Bras
2020-07-01 8:17 ` Alexey Kardashevskiy
2020-07-01 14:04 ` Leonardo Bras
2020-07-02 0:18 ` Alexey Kardashevskiy
2020-07-02 0:28 ` Leonardo Bras
2020-06-24 6:24 ` [PATCH v2 3/6] powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window Leonardo Bras
2020-06-24 6:24 ` [PATCH v2 4/6] powerpc/pseries/iommu: Remove default DMA window before creating DDW Leonardo Bras
2020-07-01 8:17 ` Alexey Kardashevskiy
2020-07-01 19:48 ` Leonardo Bras
2020-07-02 0:25 ` Alexey Kardashevskiy
2020-06-24 6:24 ` [PATCH v2 5/6] powerpc/pseries/iommu: Make use of DDW even if it does not map the partition Leonardo Bras
2020-06-26 15:23 ` Leonardo Bras
2020-06-26 17:55 ` Leonardo Bras
2020-07-01 8:16 ` Alexey Kardashevskiy
2020-07-01 19:57 ` Leonardo Bras
2020-07-01 23:48 ` Leonardo Bras
2020-07-02 0:31 ` Alexey Kardashevskiy
2020-07-02 0:54 ` Leonardo Bras
2020-07-03 6:27 ` Leonardo Bras
2020-06-24 6:24 ` Leonardo Bras [this message]
2020-06-26 17:46 ` [PATCH v2 6/6] powerpc/pseries/iommu: Avoid errors when DDW starts at 0x00 Leonardo Bras
2020-07-01 8:04 ` Alexey Kardashevskiy
2020-07-01 19:59 ` Leonardo Bras
2020-06-24 15:54 ` [PATCH v2 0/6] Remove default DMA window before creating DDW Leonardo Bras
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