The patch titled
iommu sg merging: add device_dma_parameters structure
has been added to the -mm tree. Its filename is
iommu-sg-merging-add-device_dma_parameters-structure.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: iommu sg merging: add device_dma_parameters structure
From: FUJITA Tomonori <tomof@xxxxxxx>
IOMMUs merges scatter/gather segments without considering a low level
driver's restrictions. The problem is that IOMMUs can't access to the
limitations because they are in request_queue.
This patchset introduces a new structure, device_dma_parameters,
including dma information. A pointer to device_dma_parameters is added
to struct device. The bus specific structures (like pci_dev) includes
device_dma_parameters. Low level drivers can use dma_set_max_seg_size
to tell IOMMUs about the restrictions.
We can move more dma stuff in struct device (like dma_mask) to struct
device_dma_parameters later (needs some cleanups before that).
This includes patches for all the IOMMUs that could merge sg (x86_64,
ppc, IA64, alpha, sparc64, and parisc) though only the ppc patch was
tested. The patches for other IOMMUs are only compile tested.
This patch:
Add a new structure, device_dma_parameters, including dma information. A
pointer to device_dma_parameters is added to struct device.
- there are only max_segment_size and segment_boundary_mask there but we'll
move more dma stuff in struct device (like dma_mask) to struct
device_dma_parameters later. segment_boundary_mask is not supported yet.
- new accessors for the dma parameters are added. So we can easily change
where to place struct device_dma_parameters in the future.
- dma_get_max_seg_size returns 64K if dma_parms in struct device isn't set
up properly. 64K is the default max_segment_size in the block layer.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Acked-by: Jeff Garzik <jeff@xxxxxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxx>
Cc: Jens Axboe <jens.axboe@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/device.h | 11 +++++++++++
include/linux/dma-mapping.h | 15 +++++++++++++++
2 files changed, 26 insertions(+)
diff -puN include/linux/device.h~iommu-sg-merging-add-device_dma_parameters-structure include/linux/device.h
--- a/include/linux/device.h~iommu-sg-merging-add-device_dma_parameters-structure
+++ a/include/linux/device.h
@@ -392,6 +392,15 @@ extern int devres_release_group(struct d
extern void *devm_kzalloc(struct device *dev, size_t size, gfp_t gfp);
extern void devm_kfree(struct device *dev, void *p);
+struct device_dma_parameters {
+ /*
+ * a low level driver may set these to teach IOMMU code about
+ * sg limitations.
+ */
+ unsigned int max_segment_size;
+ unsigned long segment_boundary_mask;
+};
+
struct device {
struct klist klist_children;
struct klist_node knode_parent; /* node in sibling list */
@@ -427,6 +436,8 @@ struct device {
64 bit addresses for consistent
allocations such descriptors. */
+ struct device_dma_parameters *dma_parms;
+
struct list_head dma_pools; /* dma pools (if dma'ble) */
struct dma_coherent_mem *dma_mem; /* internal for coherent mem
diff -puN include/linux/dma-mapping.h~iommu-sg-merging-add-device_dma_parameters-structure include/linux/dma-mapping.h
--- a/include/linux/dma-mapping.h~iommu-sg-merging-add-device_dma_parameters-structure
+++ a/include/linux/dma-mapping.h
@@ -60,6 +60,21 @@ static inline int is_device_dma_capable(
extern u64 dma_get_required_mask(struct device *dev);
+static inline unsigned int dma_get_max_seg_size(struct device *dev)
+{
+ return dev->dma_parms ? dev->dma_parms->max_segment_size : 65536;
+}
+
+static inline unsigned int dma_set_max_seg_size(struct device *dev,
+ unsigned int size)
+{
+ if (dev->dma_parms) {
+ dev->dma_parms->max_segment_size = size;
+ return 0;
+ } else
+ return -EIO;
+}
+
/* flags for the coherent memory api */
#define DMA_MEMORY_MAP 0x01
#define DMA_MEMORY_IO 0x02
_
Patches currently in -mm which might be from tomof@xxxxxxx are
git-scsi-misc.patch
iommu-sg-merging-add-device_dma_parameters-structure.patch
iommu-sg-merging-pci-add-device_dma_parameters-support.patch
iommu-sg-merging-x86-make-pci-gart-iommu-respect-the-segment-size-limits.patch
iommu-sg-merging-ppc-make-iommu-respect-the-segment-size-limits.patch
iommu-sg-merging-ia64-make-sba_iommu-respect-the-segment-size-limits.patch
iommu-sg-merging-alpha-make-pci_iommu-respect-the-segment-size-limits.patch
iommu-sg-merging-sparc64-make-iommu-respect-the-segment-size-limits.patch
iommu-sg-merging-parisc-make-iommu-respect-the-segment-size-limits.patch
iommu-sg-merging-call-blk_queue_segment_boundary-in-__scsi_alloc_queue.patch
iommu-sg-merging-sata_inic162x-use-pci_set_dma_max_seg_size.patch
iommu-sg-merging-aacraid-use-pci_set_dma_max_seg_size.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
