From: Marek Szyprowski <m.szyprow...@samsung.com>
Zero is a valid DMA and IOVA address on many architectures, so adjust the
IOVA management code to properly handle it. A new value IOVA_BAD_ADDR
(~0UL) is introduced as a generic value for the error case. Adjust all
callers of the alloc_iova_fast() function for the new return value.
Signed-off-by: Marek Szyprowski <m.szyprow...@samsung.com>
Signed-off-by: Ajay Kumar <ajaykumar...@samsung.com>
---
drivers/iommu/dma-iommu.c | 16 +++++++++-------
drivers/iommu/iova.c | 13 +++++++++----
include/linux/iova.h | 1 +
3 files changed, 19 insertions(+), 11 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 1ca85d37eeab..16218d6a0703 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -605,7 +605,7 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain
*domain,
{
struct iommu_dma_cookie *cookie = domain->iova_cookie;
struct iova_domain *iovad = &cookie->iovad;
- unsigned long shift, iova_len, iova = 0;
+ unsigned long shift, iova_len, iova = IOVA_BAD_ADDR;
if (cookie->type == IOMMU_DMA_MSI_COOKIE) {
cookie->msi_iova += size;
@@ -625,11 +625,13 @@ static dma_addr_t iommu_dma_alloc_iova(struct
iommu_domain *domain,
iova = alloc_iova_fast(iovad, iova_len,
DMA_BIT_MASK(32) >> shift, false);
- if (!iova)
+ if (iova == IOVA_BAD_ADDR)
iova = alloc_iova_fast(iovad, iova_len, dma_limit >> shift,
true);
- return (dma_addr_t)iova << shift;
+ if (iova != IOVA_BAD_ADDR)
+ return (dma_addr_t)iova << shift;
+ return DMA_MAPPING_ERROR;
}
static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
@@ -688,7 +690,7 @@ static dma_addr_t __iommu_dma_map(struct device *dev,
phys_addr_t phys,
size = iova_align(iovad, size + iova_off);
iova = iommu_dma_alloc_iova(domain, size, dma_mask, dev);
- if (!iova)
+ if (iova == DMA_MAPPING_ERROR)
return DMA_MAPPING_ERROR;
if (iommu_map_atomic(domain, iova, phys - iova_off, size, prot)) {
@@ -799,7 +801,7 @@ static struct page **__iommu_dma_alloc_noncontiguous(struct
device *dev,
size = iova_align(iovad, size);
iova = iommu_dma_alloc_iova(domain, size, dev->coherent_dma_mask, dev);
- if (!iova)
+ if (iova == DMA_MAPPING_ERROR)
goto out_free_pages;
if (sg_alloc_table_from_pages(sgt, pages, count, 0, size, GFP_KERNEL))
@@ -1204,7 +1206,7 @@ static int iommu_dma_map_sg(struct device *dev, struct
scatterlist *sg,
}
iova = iommu_dma_alloc_iova(domain, iova_len, dma_get_mask(dev), dev);
- if (!iova) {
+ if (iova == DMA_MAPPING_ERROR) {
ret = -ENOMEM;
goto out_restore_sg;
}
@@ -1516,7 +1518,7 @@ static struct iommu_dma_msi_page
*iommu_dma_get_msi_page(struct device *dev,
return NULL;
iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
- if (!iova)
+ if (iova == DMA_MAPPING_ERROR)
goto out_free_page;
if (iommu_map(domain, iova, msi_addr, size, prot))
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index db77aa675145..ae0fe0a6714e 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -429,6 +429,8 @@ EXPORT_SYMBOL_GPL(free_iova);
* This function tries to satisfy an iova allocation from the rcache,
* and falls back to regular allocation on failure. If regular allocation
* fails too and the flush_rcache flag is set then the rcache will be flushed.
+ * Returns a pfn the allocated iova starts at or IOVA_BAD_ADDR in the case
+ * of a failure.
*/
unsigned long
alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
@@ -447,7 +449,7 @@ alloc_iova_fast(struct iova_domain *iovad, unsigned long
size,
size = roundup_pow_of_two(size);
iova_pfn = iova_rcache_get(iovad, size, limit_pfn + 1);
- if (iova_pfn)
+ if (iova_pfn != IOVA_BAD_ADDR)
return iova_pfn;
retry:
@@ -456,7 +458,7 @@ alloc_iova_fast(struct iova_domain *iovad, unsigned long
size,
unsigned int cpu;
if (!flush_rcache)
- return 0;
+ return IOVA_BAD_ADDR;
/* Try replenishing IOVAs by flushing rcache. */
flush_rcache = false;
@@ -831,7 +833,7 @@ static unsigned long __iova_rcache_get(struct iova_rcache
*rcache,
unsigned long limit_pfn)
{
struct iova_cpu_rcache *cpu_rcache;
- unsigned long iova_pfn = 0;
+ unsigned long iova_pfn = IOVA_BAD_ADDR;
bool has_pfn = false;
unsigned long flags;
@@ -858,6 +860,9 @@ static unsigned long __iova_rcache_get(struct iova_rcache
*rcache,
spin_unlock_irqrestore(&cpu_rcache->lock, flags);
+ if (!iova_pfn)
+ return IOVA_BAD_ADDR;
+
return iova_pfn;
}
@@ -873,7 +878,7 @@ static unsigned long iova_rcache_get(struct iova_domain
*iovad,
unsigned int log_size = order_base_2(size);
if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE || !iovad->rcaches)
- return 0;
+ return IOVA_BAD_ADDR;
return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn - size);
}
diff --git a/include/linux/iova.h b/include/linux/iova.h
index 320a70e40233..46b5b10c532b 100644
--- a/include/linux/iova.h
+++ b/include/linux/iova.h
@@ -21,6 +21,7 @@ struct iova {
unsigned long pfn_lo; /* Lowest allocated pfn */
};
+#define IOVA_BAD_ADDR (~0UL)
struct iova_rcache;
--
2.17.1
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