linux-kernel - [PATCH v2 2/8] NTB: Setup the DMA mask globally for all drivers

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Message-Id: <20180720180034.3964-3-logang@deltatee.com>
Date:   Fri, 20 Jul 2018 12:00:28 -0600
From:   Logan Gunthorpe <logang@...tatee.com>
To:     linux-kernel@...r.kernel.org, linux-ntb@...glegroups.com,
        Jon Mason <jdmason@...zu.us>
Cc:     Allen Hubbe <allenbh@...il.com>,
        Serge Semin <fancer.lancer@...il.com>,
        Shyam Sundar S K <Shyam-sundar.S-k@....com>,
        Shuah Khan <shuah@...nel.org>, Doug Meyer <dmeyer@...aio.com>,
        Logan Gunthorpe <logang@...tatee.com>
Subject: [PATCH v2 2/8] NTB: Setup the DMA mask globally for all drivers

Commit  417cf39cfea9 ("NTB: Set dma mask and dma coherent mask to NTB
devices") added code to set the DMA mask for the NTB device
to each driver individually. However, it neglected to set it for the
Switchtec driver. So when the monolithic commit 7f46c8b3a552 ("NTB:
ntb_tool: Add full multi-port NTB API support") started allocating
DMA memory against the NTB device it broke the Switchtec driver.

Seeing this is setting up a property of the NTB device, it should be
done by the common NTB code (inside ntb_register_device()) so we can be
sure it's done properly for all drivers. This avoids each driver needing
to duplicate the code and helps prevent us from inadvertently breaking
one of the drivers in the future if we have to make changes in this area.

Additionally, all existing drivers are setting a property of the
struct device before calling device_initialize() which works fine now,
but may not be the safest choice if someone decides to change
something such that the propery is overridden by the initialization.

Fixes: 7f46c8b3a552 ("NTB: ntb_tool: Add full multi-port NTB API support")
Signed-off-by: Logan Gunthorpe <logang@...tatee.com>
Acked-by: Dave Jiang <dave.jiang@...el.com>
---
 drivers/ntb/hw/amd/ntb_hw_amd.c    |  4 ----
 drivers/ntb/hw/idt/ntb_hw_idt.c    |  6 ------
 drivers/ntb/hw/intel/ntb_hw_gen1.c |  4 ----
 drivers/ntb/ntb.c                  | 13 ++++++++++++-
 4 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.c b/drivers/ntb/hw/amd/ntb_hw_amd.c
index efb214fc545a..16c10dfe0919 100644
--- a/drivers/ntb/hw/amd/ntb_hw_amd.c
+++ b/drivers/ntb/hw/amd/ntb_hw_amd.c
@@ -1020,10 +1020,6 @@ static int amd_ntb_init_pci(struct amd_ntb_dev *ndev,
 			goto err_dma_mask;
 		dev_warn(&pdev->dev, "Cannot DMA consistent highmem\n");
 	}
-	rc = dma_coerce_mask_and_coherent(&ndev->ntb.dev,
-					  dma_get_mask(&pdev->dev));
-	if (rc)
-		goto err_dma_mask;
 
 	ndev->self_mmio = pci_iomap(pdev, 0, 0);
 	if (!ndev->self_mmio) {
diff --git a/drivers/ntb/hw/idt/ntb_hw_idt.c b/drivers/ntb/hw/idt/ntb_hw_idt.c
index dbe72f116017..576a2a986085 100644
--- a/drivers/ntb/hw/idt/ntb_hw_idt.c
+++ b/drivers/ntb/hw/idt/ntb_hw_idt.c
@@ -2447,12 +2447,6 @@ static int idt_init_pci(struct idt_ntb_dev *ndev)
 		dev_warn(&pdev->dev,
 			"Cannot set consistent DMA highmem bit mask\n");
 	}
-	ret = dma_coerce_mask_and_coherent(&ndev->ntb.dev,
-					   dma_get_mask(&pdev->dev));
-	if (ret != 0) {
-		dev_err(&pdev->dev, "Failed to set NTB device DMA bit mask\n");
-		return ret;
-	}
 
 	/*
 	 * Enable the device advanced error reporting. It's not critical to
diff --git a/drivers/ntb/hw/intel/ntb_hw_gen1.c b/drivers/ntb/hw/intel/ntb_hw_gen1.c
index 6aa573227279..805845fa614b 100644
--- a/drivers/ntb/hw/intel/ntb_hw_gen1.c
+++ b/drivers/ntb/hw/intel/ntb_hw_gen1.c
@@ -1770,10 +1770,6 @@ static int intel_ntb_init_pci(struct intel_ntb_dev *ndev, struct pci_dev *pdev)
 			goto err_dma_mask;
 		dev_warn(&pdev->dev, "Cannot DMA consistent highmem\n");
 	}
-	rc = dma_coerce_mask_and_coherent(&ndev->ntb.dev,
-					  dma_get_mask(&pdev->dev));
-	if (rc)
-		goto err_dma_mask;
 
 	ndev->self_mmio = pci_iomap(pdev, 0, 0);
 	if (!ndev->self_mmio) {
diff --git a/drivers/ntb/ntb.c b/drivers/ntb/ntb.c
index 2581ab724c34..93f24440d11d 100644
--- a/drivers/ntb/ntb.c
+++ b/drivers/ntb/ntb.c
@@ -100,6 +100,8 @@ EXPORT_SYMBOL(ntb_unregister_client);
 
 int ntb_register_device(struct ntb_dev *ntb)
 {
+	int ret;
+
 	if (!ntb)
 		return -EINVAL;
 	if (!ntb->pdev)
@@ -120,7 +122,16 @@ int ntb_register_device(struct ntb_dev *ntb)
 	ntb->ctx_ops = NULL;
 	spin_lock_init(&ntb->ctx_lock);
 
-	return device_register(&ntb->dev);
+	device_initialize(&ntb->dev);
+
+	ret = dma_coerce_mask_and_coherent(&ntb->dev,
+					   dma_get_mask(&ntb->pdev->dev));
+	if (ret != 0) {
+		dev_err(&ntb->dev, "Failed to set NTB device DMA bit mask\n");
+		return ret;
+	}
+
+	return device_add(&ntb->dev);
 }
 EXPORT_SYMBOL(ntb_register_device);
 
-- 
2.11.0