From: Christoph Hellwig <hch@lst.de>
To: jxgao@google.com, gregkh@linuxfoundation.org
Cc: saravanak@google.com, konrad.wilk@oracle.com, marcorr@google.com,
linux-nvme@lists.infradead.org, kbusch@kernel.org,
iommu@lists.linux-foundation.org, robin.murphy@arm.com
Subject: [PATCH 4/9] swiotlb: factor out a nr_slots helper
Date: Sun, 7 Feb 2021 17:03:22 +0100 [thread overview]
Message-ID: <20210207160327.2955490-5-hch@lst.de> (raw)
In-Reply-To: <20210207160327.2955490-1-hch@lst.de>
Factor out a helper to find the number of slots for a given size.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
kernel/dma/swiotlb.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 7705821dcdbd27..9492219b0743ae 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -194,6 +194,11 @@ static inline unsigned long io_tlb_offset(unsigned long val)
return val & (IO_TLB_SEGSIZE - 1);
}
+static inline unsigned long nr_slots(u64 val)
+{
+ return DIV_ROUND_UP(val, IO_TLB_SIZE);
+}
+
/*
* Early SWIOTLB allocation may be too early to allow an architecture to
* perform the desired operations. This function allows the architecture to
@@ -493,20 +498,20 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr,
tbl_dma_addr &= mask;
- offset_slots = ALIGN(tbl_dma_addr, IO_TLB_SIZE) >> IO_TLB_SHIFT;
+ offset_slots = nr_slots(tbl_dma_addr);
/*
* Carefully handle integer overflow which can occur when mask == ~0UL.
*/
max_slots = mask + 1
- ? ALIGN(mask + 1, IO_TLB_SIZE) >> IO_TLB_SHIFT
+ ? nr_slots(mask + 1)
: 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
/*
* For mappings greater than or equal to a page, we limit the stride
* (and hence alignment) to a page size.
*/
- nslots = ALIGN(alloc_size, IO_TLB_SIZE) >> IO_TLB_SHIFT;
+ nslots = nr_slots(alloc_size);
if (alloc_size >= PAGE_SIZE)
stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
else
@@ -602,7 +607,7 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,
enum dma_data_direction dir, unsigned long attrs)
{
unsigned long flags;
- int i, count, nslots = ALIGN(alloc_size, IO_TLB_SIZE) >> IO_TLB_SHIFT;
+ int i, count, nslots = nr_slots(alloc_size);
int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT;
phys_addr_t orig_addr = io_tlb_orig_addr[index];
--
2.29.2
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next prev parent reply other threads:[~2021-02-07 16:03 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-07 16:03 preserve DMA offsets when using swiotlb v2 Christoph Hellwig
2021-02-07 16:03 ` [PATCH 1/9] driver core: add a min_align_mask field to struct device_dma_parameters Christoph Hellwig
2021-02-07 16:03 ` [PATCH 2/9] swiotlb: add a IO_TLB_SIZE define Christoph Hellwig
2021-02-07 16:03 ` [PATCH 3/9] swiotlb: factor out an io_tlb_offset helper Christoph Hellwig
2021-02-07 16:03 ` Christoph Hellwig [this message]
2021-02-07 16:03 ` [PATCH 5/9] swiotlb: clean up swiotlb_tbl_unmap_single Christoph Hellwig
2021-02-07 16:03 ` [PATCH 6/9] swiotlb: refactor swiotlb_tbl_map_single Christoph Hellwig
2021-02-22 19:05 ` Nicolas Saenz Julienne
2021-02-22 19:29 ` Konrad Rzeszutek Wilk
2021-02-23 7:25 ` Christoph Hellwig
2021-02-07 16:03 ` [PATCH 7/9] swiotlb: don't modify orig_addr in swiotlb_tbl_sync_single Christoph Hellwig
2021-02-07 16:03 ` [PATCH 8/9] swiotlb: respect min_align_mask Christoph Hellwig
2021-02-07 16:03 ` [PATCH 9/9] nvme-pci: set min_align_mask Christoph Hellwig
[not found] ` <20210209084156.GA32320@lst.de>
2021-02-09 8:46 ` preserve DMA offsets when using swiotlb v2 Greg KH
2021-02-09 19:49 ` Jianxiong Gao via iommu
2021-02-19 18:13 ` Konrad Rzeszutek Wilk
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