On 25/11/2024 12:31, Krzysztof Kozlowski wrote: > Google Juniper platforms have a very old bootloader which populates > /firmware node without proper address/size-cells leading to warnings: > > Missing '#address-cells' in /firmware > WARNING: CPU: 0 PID: 1 at drivers/of/base.c:106 of_bus_n_addr_cells+0x90/0xf0 > Modules linked in: > CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0 #1 933ab9971ff4d5dc58cb378a96f64c7f72e3454d > Hardware name: Google juniper sku16 board (DT) > ... > Missing '#size-cells' in /firmware > WARNING: CPU: 0 PID: 1 at drivers/of/base.c:133 of_bus_n_size_cells+0x90/0xf0 > Modules linked in: > CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.12.0 #1 933ab9971ff4d5dc58cb378a96f64c7f72e3454d > Tainted: [W]=WARN > Hardware name: Google juniper sku16 board (DT) > > The platform won't receive updated bootloader/firmware so add it to > excluded platform list to silence the warning. > > Reported-by: Sasha Levin <sashal@xxxxxxxxxx> > Closes: https://lore.kernel.org/all/Z0NUdoG17EwuCigT@sashalap/ > Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx> > Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx> > Cc: Chen-Yu Tsai <wenst@xxxxxxxxxxxx> > Cc: Conor Dooley <conor@xxxxxxxxxx> > Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> > --- > drivers/of/base.c | 26 ++++++++++++++++++++++++-- > 1 file changed, 24 insertions(+), 2 deletions(-) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index a8b0c42bdc8e..13f0b2877ee0 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -56,6 +56,16 @@ DEFINE_MUTEX(of_mutex); > */ > DEFINE_RAW_SPINLOCK(devtree_lock); > > +/* > + * List of machines running old firmware without explicit #address-cells and > + * #size-cells values for parent nodes, which are most likely not going get any > + * update. > + */ > +static const char * const excluded_default_cells_compats[] = { > + "google,juniper", > + NULL > +}; > + > bool of_node_name_eq(const struct device_node *np, const char *name) > { > const char *node_name; > @@ -91,6 +101,17 @@ static bool __of_node_is_type(const struct device_node *np, const char *type) > IS_ENABLED(CONFIG_SPARC) \ > ) > > +static bool excluded_default_cells_machines(void) > +{ > + /* Do not repeat the machine checks for every bus */ > + static int excluded_machine = -1; > + > + if (excluded_machine < 0) > + excluded_machine = of_machine_compatible_match(excluded_default_cells_compats); > + > + return !!excluded_machine; > +} > + > int of_bus_n_addr_cells(struct device_node *np) > { > u32 cells; > @@ -103,7 +124,7 @@ int of_bus_n_addr_cells(struct device_node *np) > * is deprecated. Any platforms which hit this warning should > * be added to the excluded list. > */ > - WARN_ONCE(!EXCLUDED_DEFAULT_CELLS_PLATFORMS, > + WARN_ONCE(!EXCLUDED_DEFAULT_CELLS_PLATFORMS && !excluded_default_cells_machines(), > "Missing '#address-cells' in %pOF\n", np); > } > return OF_ROOT_NODE_ADDR_CELLS_DEFAULT; > @@ -125,12 +146,13 @@ int of_bus_n_size_cells(struct device_node *np) > for (; np; np = np->parent) { > if (!of_property_read_u32(np, "#size-cells", &cells)) > return cells; > + This was not intentional, I'll fix it in v2. Obviously this code is not really SMP aware, but even with store tearing I don't think it will be issue. Worst case the of_machine_compatible_match() will be called more than one, which is not fatal and might not justify atomics or locks. Best regards, Krzysztof
