From: Joerg Roedel <joro@8bytes.org>
To: "Michael S . Tsirkin" <mst@redhat.com>,
Jason Wang <jasowang@redhat.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>,
virtualization@lists.linux-foundation.org,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
iommu@lists.linux-foundation.org, jfehlig@suse.com,
jon.grimm@amd.com, brijesh.singh@amd.com, joro@8bytes.org,
jroedel@suse.de, Thomas.Lendacky@amd.com
Subject: [PATCH v7 2/5] swiotlb: Add is_swiotlb_active() function
Date: Thu, 7 Feb 2019 12:59:14 +0100 [thread overview]
Message-ID: <20190207115917.20535-3-joro@8bytes.org> (raw)
In-Reply-To: <20190207115917.20535-1-joro@8bytes.org>
From: Joerg Roedel <jroedel@suse.de>
This function will be used from dma_direct code to determine
the maximum segment size of a dma mapping.
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
include/linux/swiotlb.h | 6 ++++++
kernel/dma/swiotlb.c | 9 +++++++++
2 files changed, 15 insertions(+)
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index d3980aeed4a0..29bc3a203283 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -77,6 +77,7 @@ bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr,
void __init swiotlb_exit(void);
unsigned int swiotlb_max_segment(void);
size_t swiotlb_max_mapping_size(struct device *dev);
+bool is_swiotlb_active(void);
#else
#define swiotlb_force SWIOTLB_NO_FORCE
static inline bool is_swiotlb_buffer(phys_addr_t paddr)
@@ -100,6 +101,11 @@ static inline size_t swiotlb_max_mapping_size(struct device *dev)
{
return SIZE_MAX;
}
+
+static inline bool is_swiotlb_active(void)
+{
+ return false;
+}
#endif /* CONFIG_SWIOTLB */
extern void swiotlb_print_info(void);
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 9cb21259cb0b..c873f9cc2146 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -667,3 +667,12 @@ size_t swiotlb_max_mapping_size(struct device *dev)
{
return ((size_t)1 << IO_TLB_SHIFT) * IO_TLB_SEGSIZE;
}
+
+bool is_swiotlb_active(void)
+{
+ /*
+ * When SWIOTLB is initialized, even if io_tlb_start points to physical
+ * address zero, io_tlb_end surely doesn't.
+ */
+ return io_tlb_end != 0;
+}
--
2.17.1
next prev parent reply other threads:[~2019-02-07 11:59 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-07 11:59 [PATCH v7 0/5] Fix virtio-blk issue with SWIOTLB Joerg Roedel
2019-02-07 11:59 ` [PATCH v7 1/5] swiotlb: Introduce swiotlb_max_mapping_size() Joerg Roedel
2019-02-07 11:59 ` Joerg Roedel [this message]
2019-02-07 11:59 ` [PATCH v7 3/5] dma: Introduce dma_max_mapping_size() Joerg Roedel
2019-02-07 11:59 ` [PATCH v7 4/5] virtio: Introduce virtio_max_dma_size() Joerg Roedel
2019-02-07 11:59 ` [PATCH v7 5/5] virtio-blk: Consider virtio_max_dma_size() for maximum segment size Joerg Roedel
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