diff mbox series

[v3,2/4] iommu/dma-iommu: Handle deferred devices

Message ID 20190506185207.31069-3-tmurphy@arista.com (mailing list archive)
State New, archived
Headers show
Series iommu/amd: Convert the AMD iommu driver to the dma-iommu api | expand

Commit Message

Tom Murphy May 6, 2019, 6:52 p.m. UTC
Handle devices which defer their attach to the iommu in the dma-iommu api

Signed-off-by: Tom Murphy <tmurphy@arista.com>
---
 drivers/iommu/dma-iommu.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

Comments

Christoph Hellwig May 7, 2019, 6:40 a.m. UTC | #1
On Mon, May 06, 2019 at 07:52:04PM +0100, Tom Murphy wrote:
> +static int handle_deferred_device(struct device *dev)
> +{
> +	struct iommu_domain *domain;
> +	const struct iommu_ops *ops;
> +
> +	if (!is_kdump_kernel())
> +		return 0;
> +
> +	domain = iommu_get_domain_for_dev(dev);

> -	dma_handle =__iommu_dma_map(dev, phys, size,
> +	if (unlikely(handle_deferred_device(dev)))
> +		return DMA_MAPPING_ERROR;
> +
> +	dma_handle = __iommu_dma_map(dev, phys, size,

__iommu_dma_map already looks up the domain, and as far as I can
tell all callers need the handle_deferred_device call.  Should we
just move it to there and pass the domain from the caller?

Also shouldn't the iommu_attach_device call inside
handle_deferred_device also get an unlikely marker?
Tom Murphy May 15, 2019, 12:46 p.m. UTC | #2
like this?

In that case we need to add a call to iommu_dma_alloc_remap.

From 862aeebb601008cf863e3aff4ff8ed7cefebeefa Mon Sep 17 00:00:00 2001
From: Tom Murphy <tmurphy@tmurphy-419tom-0.sjc.aristanetworks.com>
Date: Wed, 15 May 2019 05:43:25 -0700
Subject: [PATCH] iommu/dma-iommu: Handle deferred devices

Handle devices which defer their attach to the iommu in the dma-iommu api

Signed-off-by: Tom Murphy <tmurphy@arista.com>
---
 drivers/iommu/dma-iommu.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 7f313cfa9..a48ae906d 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -22,6 +22,7 @@
 #include <linux/pci.h>
 #include <linux/scatterlist.h>
 #include <linux/vmalloc.h>
+#include <linux/crash_dump.h>

 struct iommu_dma_msi_page {
     struct list_head    list;
@@ -323,6 +324,21 @@ static int iommu_dma_init_domain(struct
iommu_domain *domain, dma_addr_t base,
     return iova_reserve_iommu_regions(dev, domain);
 }

+static int handle_deferred_device(struct device *dev,
+        struct iommu_domain *domain)
+{
+    const struct iommu_ops *ops = domain->ops;
+
+    if (!is_kdump_kernel())
+        return 0;
+
+    if (unlikely(ops->is_attach_deferred &&
+            ops->is_attach_deferred(domain, dev)))
+        return iommu_attach_device(domain, dev);
+
+    return 0;
+}
+
 /**
  * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API
  *                    page flags.
@@ -432,6 +448,9 @@ static dma_addr_t __iommu_dma_map(struct device
*dev, phys_addr_t phys,
     size_t iova_off = 0;
     dma_addr_t iova;

+    if (unlikely(handle_deferred_device(dev, domain)))
+        return DMA_MAPPING_ERROR;
+
     if (cookie->type == IOMMU_DMA_IOVA_COOKIE) {
         iova_off = iova_offset(&cookie->iovad, phys);
         size = iova_align(&cookie->iovad, size + iova_off);
@@ -609,6 +628,9 @@ static void *iommu_dma_alloc_remap(struct device
*dev, size_t size,
     dma_addr_t iova;
     void *vaddr;

+    if (unlikely(handle_deferred_device(dev, domain)))
+        return DMA_MAPPING_ERROR;
+
     *dma_handle = DMA_MAPPING_ERROR;

     min_size = alloc_sizes & -alloc_sizes;
@@ -836,7 +858,7 @@ static dma_addr_t iommu_dma_map_page(struct device
*dev, struct page *page,
     bool coherent = dev_is_dma_coherent(dev);
     dma_addr_t dma_handle;

-    dma_handle =__iommu_dma_map(dev, phys, size,
+    dma_handle = __iommu_dma_map(dev, phys, size,
             dma_info_to_prot(dir, coherent, attrs),
             iommu_get_dma_domain(dev));
     if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
@@ -954,6 +976,9 @@ static int iommu_dma_map_sg(struct device *dev,
struct scatterlist *sg,
     unsigned long mask = dma_get_seg_boundary(dev);
     int i;

+    if (unlikely(handle_deferred_device(dev, domain)))
+        return 0;
+
     if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
         iommu_dma_sync_sg_for_device(dev, sg, nents, dir);
diff mbox series

Patch

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 7a96c2c8f56b..b383498e2dc3 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -22,6 +22,7 @@ 
 #include <linux/pci.h>
 #include <linux/scatterlist.h>
 #include <linux/vmalloc.h>
+#include <linux/crash_dump.h>
 
 struct iommu_dma_msi_page {
 	struct list_head	list;
@@ -322,6 +323,22 @@  static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 	return iova_reserve_iommu_regions(dev, domain);
 }
 
+static int handle_deferred_device(struct device *dev)
+{
+	struct iommu_domain *domain;
+	const struct iommu_ops *ops;
+
+	if (!is_kdump_kernel())
+		return 0;
+
+	domain = iommu_get_domain_for_dev(dev);
+	ops = domain->ops;
+	if (ops->is_attach_deferred && ops->is_attach_deferred(domain, dev))
+		return iommu_attach_device(domain, dev);
+
+	return 0;
+}
+
 /**
  * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API
  *                    page flags.
@@ -835,7 +852,10 @@  static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
 	bool coherent = dev_is_dma_coherent(dev);
 	dma_addr_t dma_handle;
 
-	dma_handle =__iommu_dma_map(dev, phys, size,
+	if (unlikely(handle_deferred_device(dev)))
+		return DMA_MAPPING_ERROR;
+
+	dma_handle = __iommu_dma_map(dev, phys, size,
 			dma_info_to_prot(dir, coherent, attrs),
 			iommu_get_dma_domain(dev));
 	if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
@@ -953,6 +973,9 @@  static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
 	unsigned long mask = dma_get_seg_boundary(dev);
 	int i;
 
+	if (unlikely(handle_deferred_device(dev)))
+		return 0;
+
 	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		iommu_dma_sync_sg_for_device(dev, sg, nents, dir);
 
@@ -1056,6 +1079,9 @@  static void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
 static void *iommu_dma_alloc(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
+	if (unlikely(handle_deferred_device(dev)))
+		return NULL;
+
 	gfp |= __GFP_ZERO;
 
 #ifdef CONFIG_DMA_DIRECT_REMAP