Thread (17 messages) 17 messages, 3 authors, 2018-01-12

[PATCH 2/9] iommu/rockchip: Fix error handling in attach

From: robin.murphy@arm.com (Robin Murphy)
Date: 2018-01-11 15:47:31
Also in: linux-iommu, linux-rockchip, lkml

On 11/01/18 08:22, Jeffy Chen wrote:
quoted hunk ↗ jump to hunk
From: Tomasz Figa <tfiga@chromium.org>

Currently if the driver encounters an error while attaching device, it
will leave the IOMMU in an inconsistent state. Even though it shouldn't
really happen in reality, let's just add proper error path to keep
things consistent.

Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Jeffy Chen <redacted>
---

  drivers/iommu/rockchip-iommu.c | 26 +++++++++++++++++---------
  1 file changed, 17 insertions(+), 9 deletions(-)
diff --git a/drivers/iommu/rockchip-iommu.c b/drivers/iommu/rockchip-iommu.c
index 9d991c2d8767..ee805e1dfba7 100644
--- a/drivers/iommu/rockchip-iommu.c
+++ b/drivers/iommu/rockchip-iommu.c
@@ -826,17 +826,10 @@ static int rk_iommu_attach_device(struct iommu_domain *domain,
  
  	ret = rk_iommu_force_reset(iommu);
  	if (ret)
-		return ret;
+		goto err_disable_stall;
  
  	iommu->domain = domain;
  
-	for (i = 0; i < iommu->num_irq; i++) {
-		ret = devm_request_irq(iommu->dev, iommu->irq[i], rk_iommu_irq,
-				       IRQF_SHARED, dev_name(dev), iommu);
-		if (ret)
-			return ret;
-	}
-
  	for (i = 0; i < iommu->num_mmu; i++) {
  		rk_iommu_write(iommu->bases[i], RK_MMU_DTE_ADDR,
  			       rk_domain->dt_dma);
@@ -844,9 +837,16 @@ static int rk_iommu_attach_device(struct iommu_domain *domain,
  		rk_iommu_write(iommu->bases[i], RK_MMU_INT_MASK, RK_MMU_IRQ_MASK);
  	}
  
+	for (i = 0; i < iommu->num_irq; i++) {
+		ret = devm_request_irq(iommu->dev, iommu->irq[i], rk_iommu_irq,
+				       IRQF_SHARED, dev_name(dev), iommu);
Why aren't we simply requesting the IRQ once in rk_iommu_probe()? Given 
that the hardware doesn't handle multiple translation contexts, there 
doesn't seem to be much point in being this dynamic about it.

Robin.
quoted hunk ↗ jump to hunk
+		if (ret)
+			goto err_free_irq;
+	}
+
  	ret = rk_iommu_enable_paging(iommu);
  	if (ret)
-		return ret;
+		goto err_free_irq;
  
  	spin_lock_irqsave(&rk_domain->iommus_lock, flags);
  	list_add_tail(&iommu->node, &rk_domain->iommus);
@@ -857,6 +857,14 @@ static int rk_iommu_attach_device(struct iommu_domain *domain,
  	rk_iommu_disable_stall(iommu);
  
  	return 0;
+
+err_free_irq:
+	while (i--)
+		devm_free_irq(iommu->dev, iommu->irq[i], iommu);
+err_disable_stall:
+	rk_iommu_disable_stall(iommu);
+
+	return ret;
  }
  
  static void rk_iommu_detach_device(struct iommu_domain *domain,
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