[PATCH 01/24] m68k/PCI: Use pci_enable_resources() in pcibios_enable_device()
From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Date: 2025-08-22 14:56:26
Also in:
linux-m68k, linux-mips, linux-pci, lkml, sparclinux
Subsystem:
m68k architecture, the rest · Maintainers:
Geert Uytterhoeven, Linus Torvalds
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