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>,
Alexey Kardashevskiy <aik@ozlabs.ru>,
Leonardo Bras <leobras.c@gmail.com>,
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 4/4] powerpc/pseries/iommu: Remove default DMA window before creating DDW
Date: Fri, 19 Jun 2020 02:06:20 -0300 [thread overview]
Message-ID: <20200619050619.266888-5-leobras.c@gmail.com> (raw)
In-Reply-To: <20200619050619.266888-1-leobras.c@gmail.com>
On LoPAR "DMA Window Manipulation Calls", it's recommended to remove the
default DMA window for the device, before attempting to configure a DDW,
in order to make the maximum resources available for the next DDW to be
created.
This is a requirement for some devices to use DDW, given they only
allow one DMA window.
If setting up a new DDW fails anywhere after the removal of this
default DMA window, restore it using reset_dma_window.
Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
---
arch/powerpc/platforms/pseries/iommu.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index de633f6ae093..68d1ea957ac7 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1074,8 +1074,9 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
u64 dma_addr, max_addr;
struct device_node *dn;
u32 ddw_avail[3];
+
struct direct_window *window;
- struct property *win64;
+ struct property *win64, *dfl_win;
struct dynamic_dma_window_prop *ddwprop;
struct failed_ddw_pdn *fpdn;
@@ -1110,8 +1111,19 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
if (ret)
goto out_failed;
- /*
- * Query if there is a second window of size to map the
+ /*
+ * First step of setting up DDW is removing the default DMA window,
+ * if it's present. It will make all the resources available to the
+ * new DDW window.
+ * If anything fails after this, we need to restore it.
+ */
+
+ dfl_win = of_find_property(pdn, "ibm,dma-window", NULL);
+ if (dfl_win)
+ remove_dma_window(pdn, ddw_avail, dfl_win);
+
+ /*
+ * Query if there is a window of size to map the
* whole partition. Query returns number of windows, largest
* block assigned to PE (partition endpoint), and two bitmasks
* of page sizes: supported and supported for migrate-dma.
@@ -1219,6 +1231,8 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
kfree(win64);
out_failed:
+ if (dfl_win)
+ reset_dma_window(dev, pdn);
fpdn = kzalloc(sizeof(*fpdn), GFP_KERNEL);
if (!fpdn)
--
2.25.4
next prev parent reply other threads:[~2020-06-19 5:07 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-19 5:06 [PATCH 0/4] Remove default DMA window before creating DDW Leonardo Bras
2020-06-19 5:06 ` [PATCH 1/4] powerpc/pseries/iommu: Update call to ibm,query-pe-dma-windows Leonardo Bras
2020-06-22 10:02 ` Alexey Kardashevskiy
2020-06-22 18:58 ` Leonardo Bras
2020-06-23 1:12 ` Alexey Kardashevskiy
2020-06-23 2:14 ` Leonardo Bras
2020-06-23 2:29 ` Alexey Kardashevskiy
2020-06-19 5:06 ` [PATCH 2/4] powerpc/pseries/iommu: Implement ibm,reset-pe-dma-windows rtas call Leonardo Bras
2020-06-22 10:02 ` Alexey Kardashevskiy
2020-06-22 18:58 ` Leonardo Bras
2020-06-23 1:11 ` Alexey Kardashevskiy
2020-06-23 2:20 ` Leonardo Bras
2020-06-19 5:06 ` [PATCH 3/4] powerpc/pseries/iommu: Move window-removing part of remove_ddw into remove_dma_window Leonardo Bras
2020-06-22 10:02 ` Alexey Kardashevskiy
2020-06-22 18:59 ` Leonardo Bras
2020-06-23 1:12 ` Alexey Kardashevskiy
2020-06-23 1:33 ` Oliver O'Halloran
2020-06-23 2:26 ` Leonardo Bras
2020-06-23 2:22 ` Leonardo Bras
2020-06-19 5:06 ` Leonardo Bras [this message]
2020-06-20 6:13 ` [PATCH 4/4] powerpc/pseries/iommu: Remove default DMA window before creating DDW kernel test robot
2020-06-22 10:02 ` Alexey Kardashevskiy
2020-06-22 18:59 ` Leonardo Bras
2020-06-23 1:11 ` Alexey Kardashevskiy
2020-06-23 2:31 ` Leonardo Bras
2020-06-23 2:35 ` Alexey Kardashevskiy
2020-06-23 2:43 ` Leonardo Bras
2020-06-23 3:52 ` Alexey Kardashevskiy
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