93 lines
2.7 KiB
Diff
93 lines
2.7 KiB
Diff
From 69abbee01268780b8ccb952555ce8362ad8a8b5e Mon Sep 17 00:00:00 2001
|
|
From: Pavel Golikov <Paullo612@ya.ru>
|
|
Date: Mon, 6 Jun 2022 17:57:53 +0300
|
|
Subject: [PATCH 1/2] ARM/dma-mapping: implement ->alloc_noncontiguous
|
|
|
|
Implement support for allocating a non-contiguous DMA region.
|
|
Implementation is based on one in ma-iommu driver.
|
|
|
|
Signed-off-by: Pavel Golikov <Paullo612@ya.ru>
|
|
---
|
|
arch/arm/mm/dma-mapping.c | 59 +++++++++++++++++++++++++++++++++++++++
|
|
1 file changed, 59 insertions(+)
|
|
|
|
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
|
|
index 4b61541853ea..bbccfba968fc 100644
|
|
--- a/arch/arm/mm/dma-mapping.c
|
|
+++ b/arch/arm/mm/dma-mapping.c
|
|
@@ -1757,6 +1757,63 @@ static void arm_iommu_unmap_sg(struct device *dev,
|
|
__iommu_unmap_sg(dev, sg, nents, dir, attrs, false);
|
|
}
|
|
|
|
+static struct sg_table *arm_iommu_alloc_noncontiguous(struct device *dev,
|
|
+ size_t size, enum dma_data_direction dir, gfp_t gfp,
|
|
+ unsigned long attrs)
|
|
+{
|
|
+ struct dma_sgt_handle *sh;
|
|
+ int count;
|
|
+
|
|
+ sh = kmalloc(sizeof(*sh), gfp);
|
|
+ if (!sh)
|
|
+ return NULL;
|
|
+
|
|
+ size = PAGE_ALIGN(size);
|
|
+ count = size >> PAGE_SHIFT;
|
|
+
|
|
+ /*
|
|
+ * Following is a work-around (a.k.a. hack) to prevent pages
|
|
+ * with __GFP_COMP being passed to split_page() which cannot
|
|
+ * handle them. The real problem is that this flag probably
|
|
+ * should be 0 on ARM as it is not supported on this
|
|
+ * platform; see CONFIG_HUGETLBFS.
|
|
+ */
|
|
+ gfp &= ~(__GFP_COMP);
|
|
+
|
|
+ sh->pages = __iommu_alloc_buffer(dev, size, gfp, attrs, false);
|
|
+ if (!sh->pages)
|
|
+ goto err_sh;
|
|
+
|
|
+ if (sg_alloc_table_from_pages(&sh->sgt, sh->pages, count, 0, size,
|
|
+ GFP_KERNEL))
|
|
+ goto err_buffer;
|
|
+
|
|
+ if (__iommu_map_sg(dev, sh->sgt.sgl, sh->sgt.orig_nents, dir, attrs,
|
|
+ false) < 1)
|
|
+ goto err_free_sg;
|
|
+
|
|
+ return &sh->sgt;
|
|
+
|
|
+err_free_sg:
|
|
+ sg_free_table(&sh->sgt);
|
|
+err_buffer:
|
|
+ __iommu_free_buffer(dev, sh->pages, size, attrs);
|
|
+err_sh:
|
|
+ kfree(sh);
|
|
+ return NULL;
|
|
+}
|
|
+
|
|
+static void arm_iommu_free_noncontiguous(struct device *dev, size_t size,
|
|
+ struct sg_table *sgt, enum dma_data_direction dir)
|
|
+{
|
|
+ struct dma_sgt_handle *sh = sgt_handle(sgt);
|
|
+
|
|
+ __iommu_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir, 0, false);
|
|
+ __iommu_free_buffer(dev, sh->pages, PAGE_ALIGN(size), 0);
|
|
+ sg_free_table(&sh->sgt);
|
|
+ kfree(sh);
|
|
+}
|
|
+
|
|
/**
|
|
* arm_iommu_sync_sg_for_cpu
|
|
* @dev: valid struct device pointer
|
|
@@ -1994,6 +2051,8 @@ static const struct dma_map_ops iommu_ops = {
|
|
|
|
.map_page = arm_iommu_map_page,
|
|
.unmap_page = arm_iommu_unmap_page,
|
|
+ .alloc_noncontiguous = arm_iommu_alloc_noncontiguous,
|
|
+ .free_noncontiguous = arm_iommu_free_noncontiguous,
|
|
.sync_single_for_cpu = arm_iommu_sync_single_for_cpu,
|
|
.sync_single_for_device = arm_iommu_sync_single_for_device,
|
|
|
|
--
|
|
2.25.1
|
|
|