[PATCH v2 01/24] m68k/PCI: Use pci_enable_resources() in pcibios_enable_device()

Ilpo Järvinen
2025-08-29T13:11:31Z

m68k has a resource enable (check) loop in its pcibios_enable_device()
which for some reason differs from pci_enable_resources(). This could lead
to inconsistencies in behavior, especially now as pci_enable_resources()
and the bridge window resource flags behavior are going to be altered by
upcoming changes.

The check for !r->start && r->end is already covered by the more generic
checks done in pci_enable_resources().

The entire pcibios_enable_device() suspiciously looks copy-paste from some
other arch as also indicated by the preceding comment. However, it also
enables PCI_COMMAND_IO | PCI_COMMAND_MEMORY always for bridges. It is not
clear why that is being done as the commit e93a6bbeb5a5 ("m68k: common PCI
support definitions and code") introducing this code states "Nothing
specific to any PCI implementation in any m68k class CPU hardware yet".

Replace the resource enable loop with a call to pci_enable_resources() and
adjust the Command Register afterwards as it's unclear if that is necessary
or not so keep it for now.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
arch/m68k/kernel/pcibios.c | 39 +++++++++++---------------------------
1 file changed, 11 insertions(+), 28 deletions(-)

diff --git a/arch/m68k/kernel/pcibios.c b/arch/m68k/kernel/pcibios.c
index 9504eb19d73a..e6ab3f9ff5d8 100644
--- a/arch/m68k/kernel/pcibios.c
+++ b/arch/m68k/kernel/pcibios.c
@@ -44,41 +44,24 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
*/
int pcibios_enable_device(struct pci_dev *dev, int mask)
{
- struct resource *r;
u16 cmd, newcmd;
- int idx;
+ int ret;

- pci_read_config_word(dev, PCI_COMMAND, &cmd);
- newcmd = cmd;
-
- for (idx = 0; idx < 6; idx++) {
- /* Only set up the requested stuff */
- if (!(mask & (1 << idx)))
- continue;
-
- r = dev->resource + idx;
- if (!r->start && r->end) {
- pr_err("PCI: Device %s not available because of resource collisions\n",
- pci_name(dev));
- return -EINVAL;
- }
- if (r->flags & IORESOURCE_IO)
- newcmd |= PCI_COMMAND_IO;
- if (r->flags & IORESOURCE_MEM)
- newcmd |= PCI_COMMAND_MEMORY;
- }
+ ret = pci_enable_resources(dev, mask);
+ if (ret < 0)
+ return ret;

/*
* Bridges (eg, cardbus bridges) need to be fully enabled
*/
- if ((dev->class >> 16) == PCI_BASE_CLASS_BRIDGE)
+ if ((dev->class >> 16) == PCI_BASE_CLASS_BRIDGE) {
+ pci_read_config_word(dev, PCI_COMMAND, &cmd);
newcmd |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
-
-
- if (newcmd != cmd) {
- pr_info("PCI: enabling device %s (0x%04x -> 0x%04x)\n",
- pci_name(dev), cmd, newcmd);
- pci_write_config_word(dev, PCI_COMMAND, newcmd);
+ if (newcmd != cmd) {
+ pr_info("PCI: enabling bridge %s (0x%04x -> 0x%04x)\n",
+ pci_name(dev), cmd, newcmd);
+ pci_write_config_word(dev, PCI_COMMAND, newcmd);
+ }
}
return 0;
}
--
2.39.5