lkml.org 
[lkml]   [2019]   [Jan]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/3] swiotlb: Export maximum allocation size
Date
From: Joerg Roedel <jroedel@suse.de>

The SWIOTLB implementation has a maximum size it can
allocate dma-handles for. This needs to be exported so that
device drivers don't try to allocate larger chunks.

This is especially important for block device drivers like
virtio-blk, that might do DMA through SWIOTLB.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
include/linux/swiotlb.h | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 7c007ed7505f..0bcc80a97036 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -72,6 +72,11 @@ static inline bool is_swiotlb_buffer(phys_addr_t paddr)
return paddr >= io_tlb_start && paddr < io_tlb_end;
}

+static inline size_t swiotlb_max_alloc_size(void)
+{
+ return ((1UL << IO_TLB_SHIFT) * IO_TLB_SEGSIZE);
+}
+
bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr,
size_t size, enum dma_data_direction dir, unsigned long attrs);
void __init swiotlb_exit(void);
@@ -95,6 +100,13 @@ static inline unsigned int swiotlb_max_segment(void)
{
return 0;
}
+
+static inline size_t swiotlb_max_alloc_size(void)
+{
+ /* There is no limit when SWIOTLB isn't used */
+ return ~0UL;
+}
+
#endif /* CONFIG_SWIOTLB */

extern void swiotlb_print_info(void);
--
2.17.1
\
 
 \ /
  Last update: 2019-01-10 14:44    [W:0.074 / U:0.040 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site