On 07/08/2019 17:08, Julien Grall wrote:
Hi Stefano,
On 06/08/2019 22:49, Stefano Stabellini wrote:
Add new parameters to device_tree_for_each_node: node, depth,
address_cells, size_cells.
address_cells (resp. size_cells) are named address_cells_p (resp. size_cells_p)
in the code.
But I am not convinced you need them. Per the DT spec (v0.2 section 2.3.5), the
parent should either contain the #address-cells and #size-cells or default
values (resp. 2 and 1) will be used. It is clearly stated that values are not
inherited from the ancestors.
So technically the implementation of device_tree_for_each_node() is incorrect.
If you follow the spec here, then the address_cells_p and size_cells_p would
become unnecessary.
Node is the parent node to start the search from;
depth is the min depth of the search (the depth of the parent node);
Actually, on the previous version [1] you agreed that this should be the
children depth node and not the parent node. Why hasn't it been changed?
address_cells and size_cells are the respective parameters at the parent
node. Passing 0, 0, 0, 0 triggers the old behavior.
We need this change because in follow-up patches we want to be able to
use reuse device_tree_for_each_node to call a function for each children
nodes of a provided node.
Signed-off-by: Stefano Stabellini <stefa...@xilinx.com>
---
Changes in v4:
- add address_cells and size_cells parameters
Changes in v3:
- improve commit message
- improve in-code comments
- improve code style
Changes in v2:
- new
---
xen/arch/arm/acpi/boot.c | 2 +-
xen/arch/arm/bootfdt.c | 21 +++++++++++++++------
xen/include/xen/device_tree.h | 6 ++++--
3 files changed, 20 insertions(+), 9 deletions(-)
diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c
index 9b29769a10..d275f8c535 100644
--- a/xen/arch/arm/acpi/boot.c
+++ b/xen/arch/arm/acpi/boot.c
@@ -248,7 +248,7 @@ int __init acpi_boot_table_init(void)
*/
if ( param_acpi_off || ( !param_acpi_force
&&
device_tree_for_each_node(device_tree_flattened,
- dt_scan_depth1_nodes,
NULL)))
+ 0, 0, 0, 0, dt_scan_depth1_nodes, NULL)))
NIT: Can we split the if?
Cheers,
[1] <alpine.DEB.2.21.1908061206000.2451@sstabellini-ThinkPad-T480s>
--
Julien Grall
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