Re: [PATCH 1/2] iommu: Fix iommu_unmap and iommu_unmap_fast return type
From: Robin Murphy
Date: Wed Jan 31 2018 - 13:02:57 EST
Hi Suravee,
On 31/01/18 01:48, Suravee Suthikulpanit wrote:
Currently, iommu_unmap and iommu_unmap_fast return unmapped
pages with size_t. However, the actual value returned could
be error codes (< 0), which can be misinterpreted as large
number of unmapped pages. Therefore, change the return type to ssize_t.
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
drivers/iommu/amd_iommu.c | 6 +++---
drivers/iommu/intel-iommu.c | 4 ++--
Er, there are a few more drivers than that implementing iommu_ops ;)
It seems like it might be more sensible to fix the single instance of a
driver returning -EINVAL (which appears to be a "should never happen if
used correctly" kinda thing anyway) and leave the API-internal callback
prototype as-is. I do agree the inconsistency of iommu_unmap() itself
wants sorting, though (particularly the !IOMMU_API stubs which are wrong
either way).
Robin.
drivers/iommu/iommu.c | 16 ++++++++--------
include/linux/iommu.h | 20 ++++++++++----------
4 files changed, 23 insertions(+), 23 deletions(-)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 7d5eb00..3609f51 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3030,11 +3030,11 @@ static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova,
return ret;
}
-static size_t amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova,
- size_t page_size)
+static ssize_t amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova,
+ size_t page_size)
{
struct protection_domain *domain = to_pdomain(dom);
- size_t unmap_size;
+ ssize_t unmap_size;
if (domain->mode == PAGE_MODE_NONE)
return -EINVAL;
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 4a2de34..15ba866 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5068,8 +5068,8 @@ static int intel_iommu_map(struct iommu_domain *domain,
return ret;
}
-static size_t intel_iommu_unmap(struct iommu_domain *domain,
- unsigned long iova, size_t size)
+static ssize_t intel_iommu_unmap(struct iommu_domain *domain,
+ unsigned long iova, size_t size)
{
struct dmar_domain *dmar_domain = to_dmar_domain(domain);
struct page *freelist = NULL;
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 3de5c0b..8f7da8a 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1557,12 +1557,12 @@ int iommu_map(struct iommu_domain *domain, unsigned long iova,
}
EXPORT_SYMBOL_GPL(iommu_map);
-static size_t __iommu_unmap(struct iommu_domain *domain,
- unsigned long iova, size_t size,
- bool sync)
+static ssize_t __iommu_unmap(struct iommu_domain *domain,
+ unsigned long iova, size_t size,
+ bool sync)
{
const struct iommu_ops *ops = domain->ops;
- size_t unmapped_page, unmapped = 0;
+ ssize_t unmapped_page, unmapped = 0;
unsigned long orig_iova = iova;
unsigned int min_pagesz;
@@ -1617,15 +1617,15 @@ static size_t __iommu_unmap(struct iommu_domain *domain,
return unmapped;
}
-size_t iommu_unmap(struct iommu_domain *domain,
- unsigned long iova, size_t size)
+ssize_t iommu_unmap(struct iommu_domain *domain,
+ unsigned long iova, size_t size)
{
return __iommu_unmap(domain, iova, size, true);
}
EXPORT_SYMBOL_GPL(iommu_unmap);
-size_t iommu_unmap_fast(struct iommu_domain *domain,
- unsigned long iova, size_t size)
+ssize_t iommu_unmap_fast(struct iommu_domain *domain,
+ unsigned long iova, size_t size)
{
return __iommu_unmap(domain, iova, size, false);
}
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 41b8c57..78df048 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -199,8 +199,8 @@ struct iommu_ops {
void (*detach_dev)(struct iommu_domain *domain, struct device *dev);
int (*map)(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot);
- size_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
- size_t size);
+ ssize_t (*unmap)(struct iommu_domain *domain, unsigned long iova,
+ size_t size);
size_t (*map_sg)(struct iommu_domain *domain, unsigned long iova,
struct scatterlist *sg, unsigned int nents, int prot);
void (*flush_iotlb_all)(struct iommu_domain *domain);
@@ -299,10 +299,10 @@ extern void iommu_detach_device(struct iommu_domain *domain,
extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev);
extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
phys_addr_t paddr, size_t size, int prot);
-extern size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
- size_t size);
-extern size_t iommu_unmap_fast(struct iommu_domain *domain,
- unsigned long iova, size_t size);
+extern ssize_t iommu_unmap(struct iommu_domain *domain, unsigned long iova,
+ size_t size);
+extern ssize_t iommu_unmap_fast(struct iommu_domain *domain,
+ unsigned long iova, size_t size);
extern size_t default_iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
struct scatterlist *sg,unsigned int nents,
int prot);
@@ -465,14 +465,14 @@ static inline int iommu_map(struct iommu_domain *domain, unsigned long iova,
return -ENODEV;
}
-static inline int iommu_unmap(struct iommu_domain *domain, unsigned long iova,
- size_t size)
+static inline ssize_t iommu_unmap(struct iommu_domain *domain,
+ unsigned long iova, size_t size)
{
return -ENODEV;
}
-static inline int iommu_unmap_fast(struct iommu_domain *domain, unsigned long iova,
- int gfp_order)
+static inline ssize_t iommu_unmap_fast(struct iommu_domain *domain,
+ unsigned long iova, int gfp_order)
{
return -ENODEV;
}