linux-stable.git/drivers/of/address.c, branch linux-5.6.y

of: Add OF_DMA_DEFAULT_COHERENT & select it on powerpc

2020-01-28T14:26:20+00:00

There's an OF helper called of_dma_is_coherent(), which checks if a
device has a "dma-coherent" property to see if the device is coherent
for DMA.

But on some platforms devices are coherent by default, and on some
platforms it's not possible to update existing device trees to add the
"dma-coherent" property.

So add a Kconfig symbol to allow arch code to tell
of_dma_is_coherent() that devices are coherent by default, regardless
of the presence of the property.

Select that symbol on powerpc when NOT_COHERENT_CACHE is not set, ie.
when the system has a coherent cache.

Fixes: 92ea637edea3 ("of: introduce of_dma_is_coherent() helper")
Cc: stable@vger.kernel.org # v3.16+
Reported-by: Christian Zigotzky 
Tested-by: Christian Zigotzky 
Signed-off-by: Michael Ellerman 
Reviewed-by: Ulf Hansson 
Signed-off-by: Rob Herring

of: Make of_dma_get_range() work on bus nodes

2019-10-09T17:30:09+00:00

Since the "dma-ranges" property is only valid for a node representing a
bus, of_dma_get_range() currently assumes the node passed in is a leaf
representing a device, and starts the walk from its parent. In cases
like PCI host controllers on typical FDT systems, however, where the PCI
endpoints are probed dynamically the initial leaf node represents the
'bus' itself, and this logic means we fail to consider any "dma-ranges"
describing the host bridge itself. Rework the logic such that
of_dma_get_range() also works correctly starting from a bus node
containing "dma-ranges".

While this does mean "dma-ranges" could incorrectly be in a device leaf
node, there isn't really any way in this function to ensure that a leaf
node is or isn't a bus node.

Signed-off-by: Robin Murphy 
[robh: Allow for the bus child node to still be passed in]
Signed-off-by: Rob Herring 
Reviewed-by: Robin Murphy 
Reviewed-by: Nicolas Saenz Julienne 
Tested-by: Nicolas Saenz Julienne

of/address: Fix of_pci_range_parser_one translation of DMA addresses

2019-10-08T18:55:26+00:00

of_pci_range_parser_one() has a bug when parsing dma-ranges. When it
translates the parent address (aka cpu address in the code), 'ranges' is
always being used. This happens to work because most users are just 1:1
translation.

Cc: Robin Murphy 
Tested-by: Nicolas Saenz Julienne 
Reviewed-by: Nicolas Saenz Julienne 
Signed-off-by: Rob Herring

of/address: Translate 'dma-ranges' for parent nodes missing 'dma-ranges'

2019-10-08T18:55:26+00:00

'dma-ranges' frequently exists without parent nodes having 'dma-ranges'.
While this is an error for 'ranges', this is fine because DMA capable
devices always have a translatable DMA address. Also, with no
'dma-ranges' at all, the assumption is that DMA addresses are 1:1 with
no restrictions unless perhaps the device itself has implicit
restrictions.

Cc: Robin Murphy 
Tested-by: Nicolas Saenz Julienne 
Reviewed-by: Nicolas Saenz Julienne 
Signed-off-by: Rob Herring

of: Factor out #{addr,size}-cells parsing

2019-10-08T18:50:22+00:00

In some cases such as PCI host controllers, we may have a "parent bus"
which is an OF leaf node, but still need to correctly parse ranges from
the point of view of that bus. For that, factor out variants of the
"#addr-cells" and "#size-cells" parsers which do not assume they have a
device node and thus immediately traverse upwards before reading the
relevant property.

Signed-off-by: Robin Murphy 
[robh: don't make of_bus_n_{addr,size}_cells() public]
Reviewed-by: Geert Uytterhoeven 
Tested-by: Nicolas Saenz Julienne 
Reviewed-by: Nicolas Saenz Julienne 
Signed-off-by: Rob Herring

of: address: Follow DMA parent for "dma-coherent"

2019-10-08T18:50:22+00:00

Much like for address translation, when checking for DMA coherence we
should be sure to walk up the DMA hierarchy, rather than the MMIO one,
now that we can accommodate them being different.

Signed-off-by: Robin Murphy 
Tested-by: Nicolas Saenz Julienne 
Reviewed-by: Nicolas Saenz Julienne 
Signed-off-by: Rob Herring

of/address: Introduce of_get_next_dma_parent() helper

2019-10-08T18:50:22+00:00

Add of_get_next_dma_parent() helper which is similar to
__of_get_dma_parent(), but can be used in iterators and decrements the
ref count on the prior parent.

Signed-off-by: Robin Murphy 
Reviewed-by: Geert Uytterhoeven 
Tested-by: Nicolas Saenz Julienne 
Reviewed-by: Nicolas Saenz Julienne 
Signed-off-by: Rob Herring

of: address: Report of_dma_get_range() errors meaningfully

2019-10-08T18:50:22+00:00

If we failed to translate a DMA address, at least show the offending
address rather than the uninitialised contents of the destination
argument.

Signed-off-by: Robin Murphy 
Reviewed-by: Geert Uytterhoeven 
Tested-by: Nicolas Saenz Julienne 
Reviewed-by: Nicolas Saenz Julienne 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Rob Herring

of: Make of_dma_get_range() private

2019-10-08T18:50:22+00:00

of_dma_get_range() is only used within the DT core code, so remove the
export and move the header declaration to the private header.

Cc: Robin Murphy 
Reviewed-by: Geert Uytterhoeven 
Tested-by: Nicolas Saenz Julienne 
Reviewed-by: Nicolas Saenz Julienne 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Rob Herring

of: Remove unused of_find_matching_node_by_address()

2019-10-08T18:50:22+00:00

of_find_matching_node_by_address() is unused, so remove it.

Cc: Robin Murphy 
Reviewed-by: Geert Uytterhoeven 
Reviewed-by: Christoph Hellwig 
Tested-by: Nicolas Saenz Julienne 
Reviewed-by: Nicolas Saenz Julienne 
Signed-off-by: Rob Herring