[PATCH AUTOSEL 5.15 5/5] powerpc/prom_init: Fixup missing powermac #size-cells

Sasha Levin
2024-12-04T23:30:55Z

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit cf89c9434af122f28a3552e6f9cc5158c33ce50a ]

On some powermacs `escc` nodes are missing `#size-cells` properties,
which is deprecated and now triggers a warning at boot since commit
045b14ca5c36 ("of: WARN on deprecated #address-cells/#size-cells
handling").

For example:

Missing '#size-cells' in /pci@f2000000/mac-io@c/escc@13000
WARNING: CPU: 0 PID: 0 at drivers/of/base.c:133 of_bus_n_size_cells+0x98/0x108
Hardware name: PowerMac3,1 7400 0xc0209 PowerMac
...
Call Trace:
of_bus_n_size_cells+0x98/0x108 (unreliable)
of_bus_default_count_cells+0x40/0x60
__of_get_address+0xc8/0x21c
__of_address_to_resource+0x5c/0x228
pmz_init_port+0x5c/0x2ec
pmz_probe.isra.0+0x144/0x1e4
pmz_console_init+0x10/0x48
console_init+0xcc/0x138
start_kernel+0x5c4/0x694

As powermacs boot via prom_init it's possible to add the missing
properties to the device tree during boot, avoiding the warning. Note
that `escc-legacy` nodes are also missing `#size-cells` properties, but
they are skipped by the macio driver, so leave them alone.

Depends-on: 045b14ca5c36 ("of: WARN on deprecated #address-cells/#size-cells handling")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20241126025710.591683-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/kernel/prom_init.c | 29 +++++++++++++++++++++++++++--
1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index f845065c860e3..302c2acc8dcbf 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -2928,7 +2928,7 @@ static void __init fixup_device_tree_chrp(void)
#endif

#if defined(CONFIG_PPC64) && defined(CONFIG_PPC_PMAC)
-static void __init fixup_device_tree_pmac(void)
+static void __init fixup_device_tree_pmac64(void)
{
phandle u3, i2c, mpic;
u32 u3_rev;
@@ -2968,7 +2968,31 @@ static void __init fixup_device_tree_pmac(void)
&parent, sizeof(parent));
}
#else
-#define fixup_device_tree_pmac()
+#define fixup_device_tree_pmac64()
+#endif
+
+#ifdef CONFIG_PPC_PMAC
+static void __init fixup_device_tree_pmac(void)
+{
+ __be32 val = 1;
+ char type[8];
+ phandle node;
+
+ // Some pmacs are missing #size-cells on escc nodes
+ for (node = 0; prom_next_node(&node); ) {
+ type[0] = '\0';
+ prom_getprop(node, "device_type", type, sizeof(type));
+ if (prom_strcmp(type, "escc"))
+ continue;
+
+ if (prom_getproplen(node, "#size-cells") != PROM_ERROR)
+ continue;
+
+ prom_setprop(node, NULL, "#size-cells", &val, sizeof(val));
+ }
+}
+#else
+static inline void fixup_device_tree_pmac(void) { }
#endif

#ifdef CONFIG_PPC_EFIKA
@@ -3193,6 +3217,7 @@ static void __init fixup_device_tree(void)
fixup_device_tree_maple_memory_controller();
fixup_device_tree_chrp();
fixup_device_tree_pmac();
+ fixup_device_tree_pmac64();
fixup_device_tree_efika();
fixup_device_tree_pasemi();
}
--
2.43.0