Displaying 14 results from an estimated 14 matches for "kmap_to_pag".
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kmap_to_page
2012 Oct 19
5
[PATCH v2 1/3] mm: highmem: export kmap_to_page for modules
Some virtio device drivers (9p) need to translate high virtual addresses
to physical addresses, which are inserted into the virtqueue for
processing by userspace.
This patch exports the kmap_to_page symbol, so that the affected drivers
can be compiled as modules.
Signed-off-by: Will Deacon <will.deacon at arm.com>
---
mm/highmem.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/mm/highmem.c b/mm/highmem.c
index d517cd1..2a07f97 100644
--- a/mm/highmem.c
+++ b/...
2012 Oct 19
5
[PATCH v2 1/3] mm: highmem: export kmap_to_page for modules
Some virtio device drivers (9p) need to translate high virtual addresses
to physical addresses, which are inserted into the virtqueue for
processing by userspace.
This patch exports the kmap_to_page symbol, so that the affected drivers
can be compiled as modules.
Signed-off-by: Will Deacon <will.deacon at arm.com>
---
mm/highmem.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/mm/highmem.c b/mm/highmem.c
index d517cd1..2a07f97 100644
--- a/mm/highmem.c
+++ b/...
2020 Nov 03
0
[patch V3 22/37] highmem: High implementation details and document API
...ghmem.h>
+
+#ifndef ARCH_HAS_KMAP_FLUSH_TLB
+static inline void kmap_flush_tlb(unsigned long addr) { }
+#endif
+
+#ifndef kmap_prot
+#define kmap_prot PAGE_KERNEL
+#endif
+
+void *kmap_high(struct page *page);
+void kunmap_high(struct page *page);
+void __kmap_flush_unused(void);
+struct page *__kmap_to_page(void *addr);
+
+static inline void *kmap(struct page *page)
+{
+ void *addr;
+
+ might_sleep();
+ if (!PageHighMem(page))
+ addr = page_address(page);
+ else
+ addr = kmap_high(page);
+ kmap_flush_tlb((unsigned long)addr);
+ return addr;
+}
+
+static inline void kunmap(struct page *page)
+{
+ mi...
2012 Oct 18
1
[PATCH] virtio: 9p: correctly pass physical address to userspace for high pages
...indirect(struct vring_virtqueue *vq,
> /* Use a single buffer which doesn't continue */
> head = vq->free_head;
> vq->vring.desc[head].flags = VRING_DESC_F_INDIRECT;
> - vq->vring.desc[head].addr = virt_to_phys(desc);
> + vq->vring.desc[head].addr = page_to_phys(kmap_to_page(desc)) +
> + ((unsigned long)desc & ~PAGE_MASK);
> vq->vring.desc[head].len = i * sizeof(struct vring_desc);
Gah, virt_to_phys_harder()?
What's the performance effect? If it's negligible, why doesn't
virt_to_phys() just do this for us?
We do have an alternate...
2012 Oct 18
1
[PATCH] virtio: 9p: correctly pass physical address to userspace for high pages
...indirect(struct vring_virtqueue *vq,
> /* Use a single buffer which doesn't continue */
> head = vq->free_head;
> vq->vring.desc[head].flags = VRING_DESC_F_INDIRECT;
> - vq->vring.desc[head].addr = virt_to_phys(desc);
> + vq->vring.desc[head].addr = page_to_phys(kmap_to_page(desc)) +
> + ((unsigned long)desc & ~PAGE_MASK);
> vq->vring.desc[head].len = i * sizeof(struct vring_desc);
Gah, virt_to_phys_harder()?
What's the performance effect? If it's negligible, why doesn't
virt_to_phys() just do this for us?
We do have an alternate...
2013 Dec 04
3
[PATCH] 9p/trans_virtio.c: Fix broken zero-copy on vmalloc() buffers
.../trans_virtio.c b/net/9p/trans_virtio.c
index 9c5a1aa..5d1d04b 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -340,7 +340,10 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
int count = nr_pages;
while (nr_pages) {
s = rest_of_page(data);
- pages[index++] = kmap_to_page(data);
+ if (is_vmalloc_or_module_addr(data))
+ pages[index++] = vmalloc_to_page(data);
+ else
+ pages[index++] = kmap_to_page(data);
data += s;
nr_pages--;
}
--
1.8.3.2
2013 Dec 04
3
[PATCH] 9p/trans_virtio.c: Fix broken zero-copy on vmalloc() buffers
.../trans_virtio.c b/net/9p/trans_virtio.c
index 9c5a1aa..5d1d04b 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -340,7 +340,10 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
int count = nr_pages;
while (nr_pages) {
s = rest_of_page(data);
- pages[index++] = kmap_to_page(data);
+ if (is_vmalloc_or_module_addr(data))
+ pages[index++] = vmalloc_to_page(data);
+ else
+ pages[index++] = kmap_to_page(data);
data += s;
nr_pages--;
}
--
1.8.3.2
2013 Dec 06
1
[PATCH] 9p/trans_virtio.c: Fix broken zero-copy on vmalloc() buffers
...100644
>> --- a/net/9p/trans_virtio.c
>> +++ b/net/9p/trans_virtio.c
>> @@ -340,7 +340,10 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
>> int count = nr_pages;
>> while (nr_pages) {
>> s = rest_of_page(data);
>> - pages[index++] = kmap_to_page(data);
>> + if (is_vmalloc_or_module_addr(data))
>
> Can this really end up being a module address?
Yes. Here is the stacktrace to prove it:
[<ffffffff814878ce>] p9_virtio_zc_request+0x45e/0x510
[<ffffffff814814ed>] p9_client_zc_rpc.constprop.16+0xfd/0x4f0
[<fffffff...
2013 Dec 06
1
[PATCH] 9p/trans_virtio.c: Fix broken zero-copy on vmalloc() buffers
...100644
>> --- a/net/9p/trans_virtio.c
>> +++ b/net/9p/trans_virtio.c
>> @@ -340,7 +340,10 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
>> int count = nr_pages;
>> while (nr_pages) {
>> s = rest_of_page(data);
>> - pages[index++] = kmap_to_page(data);
>> + if (is_vmalloc_or_module_addr(data))
>
> Can this really end up being a module address?
Yes. Here is the stacktrace to prove it:
[<ffffffff814878ce>] p9_virtio_zc_request+0x45e/0x510
[<ffffffff814814ed>] p9_client_zc_rpc.constprop.16+0xfd/0x4f0
[<fffffff...
2013 Dec 06
0
[PATCH] 9p/trans_virtio.c: Fix broken zero-copy on vmalloc() buffers
...> index 9c5a1aa..5d1d04b 100644
> --- a/net/9p/trans_virtio.c
> +++ b/net/9p/trans_virtio.c
> @@ -340,7 +340,10 @@ static int p9_get_mapped_pages(struct virtio_chan *chan,
> int count = nr_pages;
> while (nr_pages) {
> s = rest_of_page(data);
> - pages[index++] = kmap_to_page(data);
> + if (is_vmalloc_or_module_addr(data))
Can this really end up being a module address?
Will
2020 Nov 03
0
[patch V3 25/37] mm/highmem: Provide kmap_local*
...c(__addr); \
} while (0)
+#define kunmap_local(__addr) \
+do { \
+ BUILD_BUG_ON(__same_type((__addr), struct page *)); \
+ __kunmap_local(__addr); \
+} while (0)
+
#endif
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -60,24 +60,22 @@ static inline struct page *kmap_to_page(
static inline void kmap_flush_unused(void);
/**
- * kmap_atomic - Atomically map a page for temporary usage
+ * kmap_local_page - Map a page for temporary usage
* @page: Pointer to the page to be mapped
*
* Returns: The virtual address of the mapping
*
- * Side effect: On return pagef...
2020 Nov 03
45
[patch V3 00/37] mm/highmem: Preemptible variant of kmap_atomic & friends
Following up to the discussion in:
https://lore.kernel.org/r/20200914204209.256266093 at linutronix.de
and the second version of this:
https://lore.kernel.org/r/20201029221806.189523375 at linutronix.de
this series provides a preemptible variant of kmap_atomic & related
interfaces.
This is achieved by:
- Removing the RT dependency from migrate_disable/enable()
- Consolidating all
2020 Nov 03
45
[patch V3 00/37] mm/highmem: Preemptible variant of kmap_atomic & friends
Following up to the discussion in:
https://lore.kernel.org/r/20200914204209.256266093 at linutronix.de
and the second version of this:
https://lore.kernel.org/r/20201029221806.189523375 at linutronix.de
this series provides a preemptible variant of kmap_atomic & related
interfaces.
This is achieved by:
- Removing the RT dependency from migrate_disable/enable()
- Consolidating all
2020 Nov 03
45
[patch V3 00/37] mm/highmem: Preemptible variant of kmap_atomic & friends
Following up to the discussion in:
https://lore.kernel.org/r/20200914204209.256266093 at linutronix.de
and the second version of this:
https://lore.kernel.org/r/20201029221806.189523375 at linutronix.de
this series provides a preemptible variant of kmap_atomic & related
interfaces.
This is achieved by:
- Removing the RT dependency from migrate_disable/enable()
- Consolidating all