It can be surprising to the user if DMA functions are only traced on
success. On failure, it can be unclear what the source of the problem
is. Fix this by tracing all functions even when they fail. Cases where
we BUG/WARN are skipped, since those should be sufficiently noisy
already.
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
In some cases, we use trace_dma_map to trace dma_alloc* functions. This
generally follows dma_debug. However, this does not record all of the
relevant information for allocations, such as GFP flags. Create new
dma_alloc tracepoints for these functions. Note that while
dma_alloc_noncontiguous may allocate discontiguous pages (from the CPU's
point of view), the device will only see one contiguous mapping.
Therefore, we just need to trace dma_addr and size.
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
In preparation for using these tracepoints in a few more places, trace
the DMA direction as well. For coherent allocations this is always
bidirectional.
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Commit b5c58b2fdc ("dma-mapping: direct calls for dma-iommu") switched
to use direct calls to dma-iommu, but missed the dma_vmap_noncontiguous,
dma_vunmap_noncontiguous and dma_mmap_noncontiguous behavior keyed off the
presence of the alloc_noncontiguous method.
Fix this by removing the now unused alloc_noncontiguous and
free_noncontiguous methods and moving the vmapping and mmaping of the
noncontiguous allocations into the iommu code, as it is the only provider
of actually noncontiguous allocations.
Fixes: b5c58b2fdc ("dma-mapping: direct calls for dma-iommu")
Reported-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Leon Romanovsky <leon@kernel.org>
Tested-by: Xi Ruoyao <xry111@xry111.site>
dma_supported has become too much spaghetti for my taste. Reflow it to
remove the duplicate use_dma_iommu condition and make the main path more
obvious.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Leon Romanovsky <leon@kernel.org>
When debugging drivers, it can often be useful to trace when memory gets
(un)mapped for DMA (and can be accessed by the device). Add some
tracepoints for this purpose.
Use u64 instead of phys_addr_t and dma_addr_t (and similarly %llx instead
of %pa) because libtraceevent can't handle typedefs in all cases.
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Directly call into dma-iommu just like we have been doing for dma-direct
for a while. This avoids the indirect call overhead for IOMMU ops and
removes the need to have DMA ops entirely for many common configurations.
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Almost all instances of the dma_map_ops ->map_page()/map_sg() methods
implement ->unmap_page()/unmap_sg() too. The once instance which doesn't
dma_dummy_ops which is used to fail the DMA mapping and thus there won't
be any calls to ->unmap_page()/unmap_sg().
Remove the checks for ->unmap_page()/unmap_sg() and call them directly to
create an interface that is symmetrical to ->map_page()/map_sg().
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
dmam_free_coherent() frees a DMA allocation, which makes the
freed vaddr available for reuse, then calls devres_destroy()
to remove and free the data structure used to track the DMA
allocation. Between the two calls, it is possible for a
concurrent task to make an allocation with the same vaddr
and add it to the devres list.
If this happens, there will be two entries in the devres list
with the same vaddr and devres_destroy() can free the wrong
entry, triggering the WARN_ON() in dmam_match.
Fix by destroying the devres entry before freeing the DMA
allocation.
Tested:
kokonut //net/encryption
http://sponge2/b9145fe6-0f72-4325-ac2f-a84d81075b03
Fixes: 9ac7849e35 ("devres: device resource management")
Signed-off-by: Lance Richardson <rlance@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Pull dma-mapping updates from Christoph Hellwig:
- optimize DMA sync calls when they are no-ops (Alexander Lobakin)
- fix swiotlb padding for untrusted devices (Michael Kelley)
- add documentation for swiotb (Michael Kelley)
* tag 'dma-mapping-6.10-2024-05-20' of git://git.infradead.org/users/hch/dma-mapping:
dma: fix DMA sync for drivers not calling dma_set_mask*()
xsk: use generic DMA sync shortcut instead of a custom one
page_pool: check for DMA sync shortcut earlier
page_pool: don't use driver-set flags field directly
page_pool: make sure frag API fields don't span between cachelines
iommu/dma: avoid expensive indirect calls for sync operations
dma: avoid redundant calls for sync operations
dma: compile-out DMA sync op calls when not used
iommu/dma: fix zeroing of bounce buffer padding used by untrusted devices
swiotlb: remove alloc_size argument to swiotlb_tbl_map_single()
Documentation/core-api: add swiotlb documentation
Quite often, devices do not need dma_sync operations on x86_64 at least.
Indeed, when dev_is_dma_coherent(dev) is true and
dev_use_swiotlb(dev) is false, iommu_dma_sync_single_for_cpu()
and friends do nothing.
However, indirectly calling them when CONFIG_RETPOLINE=y consumes about
10% of cycles on a cpu receiving packets from softirq at ~100Gbit rate.
Even if/when CONFIG_RETPOLINE is not set, there is a cost of about 3%.
Add dev->need_dma_sync boolean and turn it off during the device
initialization (dma_set_mask()) depending on the setup:
dev_is_dma_coherent() for the direct DMA, !(sync_single_for_device ||
sync_single_for_cpu) or the new dma_map_ops flag, %DMA_F_CAN_SKIP_SYNC,
advertised for non-NULL DMA ops.
Then later, if/when swiotlb is used for the first time, the flag
is reset back to on, from swiotlb_tbl_map_single().
On iavf, the UDP trafficgen with XDP_DROP in skb mode test shows
+3-5% increase for direct DMA.
Suggested-by: Christoph Hellwig <hch@lst.de> # direct DMA shortcut
Co-developed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Some platforms do have DMA, but DMA there is always direct and coherent.
Currently, even on such platforms DMA sync operations are compiled and
called.
Add a new hidden Kconfig symbol, DMA_NEED_SYNC, and set it only when
either sync operations are needed or there is DMA ops or swiotlb
or DMA debug is enabled. Compile global dma_sync_*() and dma_need_sync()
only when it's set, otherwise provide empty inline stubs.
The change allows for future optimizations of DMA sync calls depending
on runtime conditions.
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
There is an unusual case that the range map covers right up to the top
of system RAM, but leaves a hole somewhere lower down. Then it prevents
the nvme device dma mapping in the checking path of phys_to_dma() and
causes the hangs at boot.
E.g. On an Armv8 Ampere server, the dsdt ACPI table is:
Method (_DMA, 0, Serialized) // _DMA: Direct Memory Access
{
Name (RBUF, ResourceTemplate ()
{
QWordMemory (ResourceConsumer, PosDecode, MinFixed,
MaxFixed, Cacheable, ReadWrite,
0x0000000000000000, // Granularity
0x0000000000000000, // Range Minimum
0x00000000FFFFFFFF, // Range Maximum
0x0000000000000000, // Translation Offset
0x0000000100000000, // Length
,, , AddressRangeMemory, TypeStatic)
QWordMemory (ResourceConsumer, PosDecode, MinFixed,
MaxFixed, Cacheable, ReadWrite,
0x0000000000000000, // Granularity
0x0000006010200000, // Range Minimum
0x000000602FFFFFFF, // Range Maximum
0x0000000000000000, // Translation Offset
0x000000001FE00000, // Length
,, , AddressRangeMemory, TypeStatic)
QWordMemory (ResourceConsumer, PosDecode, MinFixed,
MaxFixed, Cacheable, ReadWrite,
0x0000000000000000, // Granularity
0x00000060F0000000, // Range Minimum
0x00000060FFFFFFFF, // Range Maximum
0x0000000000000000, // Translation Offset
0x0000000010000000, // Length
,, , AddressRangeMemory, TypeStatic)
QWordMemory (ResourceConsumer, PosDecode, MinFixed,
MaxFixed, Cacheable, ReadWrite,
0x0000000000000000, // Granularity
0x0000007000000000, // Range Minimum
0x000003FFFFFFFFFF, // Range Maximum
0x0000000000000000, // Translation Offset
0x0000039000000000, // Length
,, , AddressRangeMemory, TypeStatic)
})
But the System RAM ranges are:
cat /proc/iomem |grep -i ram
90000000-91ffffff : System RAM
92900000-fffbffff : System RAM
880000000-fffffffff : System RAM
8800000000-bff5990fff : System RAM
bff59d0000-bff5a4ffff : System RAM
bff8000000-bfffffffff : System RAM
So some RAM ranges are out of dma_range_map.
Fix it by checking whether each of the system RAM resources can be
properly encompassed within the dma_range_map.
Signed-off-by: Jia He <justin.he@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This patch moves dma_addressing_limited() out of line, serving as a
preliminary step to prevent the introduction of a new publicly accessible
low-level helper when validating whether all system RAM is mapped within
the DMA mapping range.
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jia He <justin.he@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This function has a __weak definition and an override that is only used on
freescale powerpc chips. The powerpc definition however does not see the
declaration that is in a .c file:
arch/powerpc/kernel/dma-mask.c:7:6: error: no previous prototype for 'arch_dma_set_mask' [-Werror=missing-prototypes]
Move it into the linux/dma-map-ops.h header where the other arch_dma_* functions
are declared.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Provide a kconfig option to allow arches to manipulate default
value of dma_default_coherent in Kconfig.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
dma_default_coherent was decleared unconditionally at kernel/dma/mapping.c
but only decleared when any of non-coherent options is enabled in
dma-map-ops.h.
Guard the declaration in mapping.c with non-coherent options and provide
a fallback definition.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
While not quite as bogus as for the dma-coherent allocations that were
fixed earlier, GFP_COMP for these allocations has no benefits for
the dma-direct case, and can't be supported at all by dma dma-iommu
backend which splits up allocations into smaller orders. Due to an
oversight in ffcb754584 that flag stopped being cleared for all
dma allocations, but only got rejected for coherent ones, so fix up
these callers to not allow __GFP_COMP as well after the sound code
has been fixed to not ask for it.
Fixes: ffcb754584 ("dma-mapping: reject __GFP_COMP in dma_alloc_attrs")
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Reported-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Tested-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
DMA allocations can never be turned back into a page pointer, so
requesting compound pages doesn't make sense and it can't even be
supported at all by various backends.
Reject __GFP_COMP with a warning in dma_alloc_attrs, and stop clearing
the flag in the arm dma ops and dma-iommu.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
