Re: [PATCH 6/9] swiotlb: refactor swiotlb_tbl_map_single
On Mon, Feb 22, 2021 at 02:29:37PM -0500, Konrad Rzeszutek Wilk wrote: > > 'max_slots' should be 'unsigned long' here. Breaks SWIOTLB on RPi4. Do you > > want > > me to send a fix or you prefer editing the patch? > > I can roll it in. Thx! Thanks to both of you! ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH 6/9] swiotlb: refactor swiotlb_tbl_map_single
> > +static int find_slots(struct device *dev, size_t alloc_size)
> > +{
> > + unsigned long boundary_mask = dma_get_seg_boundary(dev);
> > + dma_addr_t tbl_dma_addr =
> > + phys_to_dma_unencrypted(dev, io_tlb_start) & boundary_mask;
> > + unsigned int max_slots = get_max_slots(boundary_mask);
>
> 'max_slots' should be 'unsigned long' here. Breaks SWIOTLB on RPi4. Do you
> want
> me to send a fix or you prefer editing the patch?
I can roll it in. Thx!
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Re: [PATCH 6/9] swiotlb: refactor swiotlb_tbl_map_single
Hi Christoph,
On Sun, 2021-02-07 at 17:03 +0100, Christoph Hellwig wrote:
> Split out a bunch of a self-contained helpers to make the function easier
> to follow.
>
> Signed-off-by: Christoph Hellwig
> ---
> kernel/dma/swiotlb.c | 179 +--
> 1 file changed, 89 insertions(+), 90 deletions(-)
>
> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
> index b38b1553c4663a..381c24ef1ac1d0 100644
> --- a/kernel/dma/swiotlb.c
> +++ b/kernel/dma/swiotlb.c
> @@ -468,134 +468,133 @@ static void swiotlb_bounce(phys_addr_t orig_addr,
> phys_addr_t tlb_addr,
> }
> }
>
>
> -phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t
> orig_addr,
> - size_t mapping_size, size_t alloc_size,
> - enum dma_data_direction dir, unsigned long attrs)
> -{
> - dma_addr_t tbl_dma_addr = phys_to_dma_unencrypted(hwdev, io_tlb_start);
> - unsigned long flags;
> - phys_addr_t tlb_addr;
> - unsigned int nslots, stride, index, wrap;
> - int i;
> - unsigned long mask;
> - unsigned long offset_slots;
> - unsigned long max_slots;
> - unsigned long tmp_io_tlb_used;
> -
> - if (no_iotlb_memory)
> - panic("Can not allocate SWIOTLB buffer earlier and can't now
> provide you with the DMA bounce buffer");
> -
> - if (mem_encrypt_active())
> - pr_warn_once("Memory encryption is active and system is using
> DMA bounce buffers\n");
> +#define slot_addr(start, idx)((start) + ((idx) << IO_TLB_SHIFT))
>
>
> - if (mapping_size > alloc_size) {
> - dev_warn_once(hwdev, "Invalid sizes (mapping: %zd bytes, alloc:
> %zd bytes)",
> - mapping_size, alloc_size);
> - return (phys_addr_t)DMA_MAPPING_ERROR;
> - }
> -
> - mask = dma_get_seg_boundary(hwdev);
> +/*
> + * Carefully handle integer overflow which can occur when boundary_mask ==
> ~0UL.
> + */
> +static inline unsigned long get_max_slots(unsigned long boundary_mask)
> +{
> + if (boundary_mask == ~0UL)
> + return 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
> + return nr_slots(boundary_mask + 1);
> +}
>
>
> - tbl_dma_addr &= mask;
> +static unsigned int wrap_index(unsigned int index)
> +{
> + if (index >= io_tlb_nslabs)
> + return 0;
> + return index;
> +}
>
>
> - offset_slots = nr_slots(tbl_dma_addr);
> +/*
> + * Find a suitable number of IO TLB entries size that will fit this request
> and
> + * allocate a buffer from that IO TLB pool.
> + */
> +static int find_slots(struct device *dev, size_t alloc_size)
> +{
> + unsigned long boundary_mask = dma_get_seg_boundary(dev);
> + dma_addr_t tbl_dma_addr =
> + phys_to_dma_unencrypted(dev, io_tlb_start) & boundary_mask;
> + unsigned int max_slots = get_max_slots(boundary_mask);
'max_slots' should be 'unsigned long' here. Breaks SWIOTLB on RPi4. Do you want
me to send a fix or you prefer editing the patch?
Regards,
Nicolas
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[PATCH 6/9] swiotlb: refactor swiotlb_tbl_map_single
Split out a bunch of a self-contained helpers to make the function easier
to follow.
Signed-off-by: Christoph Hellwig
---
kernel/dma/swiotlb.c | 179 +--
1 file changed, 89 insertions(+), 90 deletions(-)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index b38b1553c4663a..381c24ef1ac1d0 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -468,134 +468,133 @@ static void swiotlb_bounce(phys_addr_t orig_addr,
phys_addr_t tlb_addr,
}
}
-phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr,
- size_t mapping_size, size_t alloc_size,
- enum dma_data_direction dir, unsigned long attrs)
-{
- dma_addr_t tbl_dma_addr = phys_to_dma_unencrypted(hwdev, io_tlb_start);
- unsigned long flags;
- phys_addr_t tlb_addr;
- unsigned int nslots, stride, index, wrap;
- int i;
- unsigned long mask;
- unsigned long offset_slots;
- unsigned long max_slots;
- unsigned long tmp_io_tlb_used;
-
- if (no_iotlb_memory)
- panic("Can not allocate SWIOTLB buffer earlier and can't now
provide you with the DMA bounce buffer");
-
- if (mem_encrypt_active())
- pr_warn_once("Memory encryption is active and system is using
DMA bounce buffers\n");
+#define slot_addr(start, idx) ((start) + ((idx) << IO_TLB_SHIFT))
- if (mapping_size > alloc_size) {
- dev_warn_once(hwdev, "Invalid sizes (mapping: %zd bytes, alloc:
%zd bytes)",
- mapping_size, alloc_size);
- return (phys_addr_t)DMA_MAPPING_ERROR;
- }
-
- mask = dma_get_seg_boundary(hwdev);
+/*
+ * Carefully handle integer overflow which can occur when boundary_mask ==
~0UL.
+ */
+static inline unsigned long get_max_slots(unsigned long boundary_mask)
+{
+ if (boundary_mask == ~0UL)
+ return 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
+ return nr_slots(boundary_mask + 1);
+}
- tbl_dma_addr &= mask;
+static unsigned int wrap_index(unsigned int index)
+{
+ if (index >= io_tlb_nslabs)
+ return 0;
+ return index;
+}
- offset_slots = nr_slots(tbl_dma_addr);
+/*
+ * Find a suitable number of IO TLB entries size that will fit this request and
+ * allocate a buffer from that IO TLB pool.
+ */
+static int find_slots(struct device *dev, size_t alloc_size)
+{
+ unsigned long boundary_mask = dma_get_seg_boundary(dev);
+ dma_addr_t tbl_dma_addr =
+ phys_to_dma_unencrypted(dev, io_tlb_start) & boundary_mask;
+ unsigned int max_slots = get_max_slots(boundary_mask);
+ unsigned int nslots = nr_slots(alloc_size), stride = 1;
+ unsigned int index, wrap, count = 0, i;
+ unsigned long flags;
- /*
-* Carefully handle integer overflow which can occur when mask == ~0UL.
-*/
- max_slots = mask + 1
- ? nr_slots(mask + 1)
- : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
+ BUG_ON(!nslots);
/*
* For mappings greater than or equal to a page, we limit the stride
* (and hence alignment) to a page size.
*/
- nslots = nr_slots(alloc_size);
if (alloc_size >= PAGE_SIZE)
- stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
- else
- stride = 1;
+ stride <<= (PAGE_SHIFT - IO_TLB_SHIFT);
- BUG_ON(!nslots);
-
- /*
-* Find suitable number of IO TLB entries size that will fit this
-* request and allocate a buffer from that IO TLB pool.
-*/
spin_lock_irqsave(&io_tlb_lock, flags);
-
if (unlikely(nslots > io_tlb_nslabs - io_tlb_used))
goto not_found;
- index = ALIGN(io_tlb_index, stride);
- if (index >= io_tlb_nslabs)
- index = 0;
- wrap = index;
-
+ index = wrap = wrap_index(ALIGN(io_tlb_index, stride));
do {
- while (iommu_is_span_boundary(index, nslots, offset_slots,
- max_slots)) {
- index += stride;
- if (index >= io_tlb_nslabs)
- index = 0;
- if (index == wrap)
- goto not_found;
- }
-
/*
* If we find a slot that indicates we have 'nslots' number of
* contiguous buffers, we allocate the buffers from that slot
* and mark the entries as '0' indicating unavailable.
*/
- if (io_tlb_list[index] >= nslots) {
- int count = 0;
-
- for (i = index; i < (int) (index + nslots); i++)
- io_tlb_list[i] = 0;
- for (i = index - 1;
-io_tlb_offset(i) != IO_TLB_SEGSIZ
