Re: [PATCH 02/24] sparc/PCI: Remove pcibios_enable_device() as they do nothing extra

["Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>]

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On Thu, 6 Nov 2025, John Paul Adrian Glaubitz wrote:

> Hello Ilpo,
> 
> On Fri, 2025-08-22 at 17:55 +0300, Ilpo Järvinen wrote:
> > Under arch/sparc/ there are multiple copies of pcibios_enable_device()
> > but none of those seem to do anything extra beyond what
> > pci_enable_resources() is supposed to do. These functions 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.
> > 
> > Remove all pcibios_enable_device() from arch/sparc/ so that PCI core
> > can simply call into pci_enable_resources() instead using it's __weak
> > version of pcibios_enable_device().
> > 
> > Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> > ---
> >  arch/sparc/kernel/leon_pci.c | 27 ---------------------------
> >  arch/sparc/kernel/pci.c      | 27 ---------------------------
> >  arch/sparc/kernel/pcic.c     | 27 ---------------------------
> >  3 files changed, 81 deletions(-)
> > 
> > diff --git a/arch/sparc/kernel/leon_pci.c b/arch/sparc/kernel/leon_pci.c
> > index 8de6646e9ce8..10934dfa987a 100644
> > --- a/arch/sparc/kernel/leon_pci.c
> > +++ b/arch/sparc/kernel/leon_pci.c
> > @@ -60,30 +60,3 @@ void leon_pci_init(struct platform_device *ofdev, struct leon_pci_info *info)
> >  	pci_assign_unassigned_resources();
> >  	pci_bus_add_devices(root_bus);
> >  }
> > -
> > -int pcibios_enable_device(struct pci_dev *dev, int mask)
> > -{
> > -	struct resource *res;
> > -	u16 cmd, oldcmd;
> > -	int i;
> > -
> > -	pci_read_config_word(dev, PCI_COMMAND, &cmd);
> > -	oldcmd = cmd;
> > -
> > -	pci_dev_for_each_resource(dev, res, i) {
> > -		/* Only set up the requested stuff */
> > -		if (!(mask & (1<<i)))
> > -			continue;
> > -
> > -		if (res->flags & IORESOURCE_IO)
> > -			cmd |= PCI_COMMAND_IO;
> > -		if (res->flags & IORESOURCE_MEM)
> > -			cmd |= PCI_COMMAND_MEMORY;
> > -	}
> > -
> > -	if (cmd != oldcmd) {
> > -		pci_info(dev, "enabling device (%04x -> %04x)\n", oldcmd, cmd);
> > -		pci_write_config_word(dev, PCI_COMMAND, cmd);
> > -	}
> > -	return 0;
> > -}
> > diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
> > index ddac216a2aff..a9448088e762 100644
> > --- a/arch/sparc/kernel/pci.c
> > +++ b/arch/sparc/kernel/pci.c
> > @@ -722,33 +722,6 @@ struct pci_bus *pci_scan_one_pbm(struct pci_pbm_info *pbm,
> >  	return bus;
> >  }
> >  
> > -int pcibios_enable_device(struct pci_dev *dev, int mask)
> > -{
> > -	struct resource *res;
> > -	u16 cmd, oldcmd;
> > -	int i;
> > -
> > -	pci_read_config_word(dev, PCI_COMMAND, &cmd);
> > -	oldcmd = cmd;
> > -
> > -	pci_dev_for_each_resource(dev, res, i) {
> > -		/* Only set up the requested stuff */
> > -		if (!(mask & (1<<i)))
> > -			continue;
> > -
> > -		if (res->flags & IORESOURCE_IO)
> > -			cmd |= PCI_COMMAND_IO;
> > -		if (res->flags & IORESOURCE_MEM)
> > -			cmd |= PCI_COMMAND_MEMORY;
> > -	}
> > -
> > -	if (cmd != oldcmd) {
> > -		pci_info(dev, "enabling device (%04x -> %04x)\n", oldcmd, cmd);
> > -		pci_write_config_word(dev, PCI_COMMAND, cmd);
> > -	}
> > -	return 0;
> > -}
> > -
> >  /* Platform support for /proc/bus/pci/X/Y mmap()s. */
> >  int pci_iobar_pfn(struct pci_dev *pdev, int bar, struct vm_area_struct *vma)
> >  {
> > diff --git a/arch/sparc/kernel/pcic.c b/arch/sparc/kernel/pcic.c
> > index 25fe0a061732..3d54ad5656a4 100644
> > --- a/arch/sparc/kernel/pcic.c
> > +++ b/arch/sparc/kernel/pcic.c
> > @@ -641,33 +641,6 @@ void pcibios_fixup_bus(struct pci_bus *bus)
> >  	}
> >  }
> >  
> > -int pcibios_enable_device(struct pci_dev *dev, int mask)
> > -{
> > -	struct resource *res;
> > -	u16 cmd, oldcmd;
> > -	int i;
> > -
> > -	pci_read_config_word(dev, PCI_COMMAND, &cmd);
> > -	oldcmd = cmd;
> > -
> > -	pci_dev_for_each_resource(dev, res, i) {
> > -		/* Only set up the requested stuff */
> > -		if (!(mask & (1<<i)))
> > -			continue;
> > -
> > -		if (res->flags & IORESOURCE_IO)
> > -			cmd |= PCI_COMMAND_IO;
> > -		if (res->flags & IORESOURCE_MEM)
> > -			cmd |= PCI_COMMAND_MEMORY;
> > -	}
> > -
> > -	if (cmd != oldcmd) {
> > -		pci_info(dev, "enabling device (%04x -> %04x)\n", oldcmd, cmd);
> > -		pci_write_config_word(dev, PCI_COMMAND, cmd);
> > -	}
> > -	return 0;
> > -}
> > -
> >  /* Makes compiler happy */
> >  static volatile int pcic_timer_dummy;
> 
> This change actually broke driver initialization on SPARC, see:
> 
> https://github.com/sparclinux/issues/issues/22

Does the attached patch help?

--
 i.

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From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Subject: [PATCH] SPARC/PCI: Correct 64-bit non-pref -> pref

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

---
 arch/sparc/kernel/of_device_64.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/sparc/kernel/of_device_64.c b/arch/sparc/kernel/of_device_64.c
index f53092b07b9e..ea21d90e3f94 100644
--- a/arch/sparc/kernel/of_device_64.c
+++ b/arch/sparc/kernel/of_device_64.c
@@ -311,6 +311,23 @@ static int __init use_1to1_mapping(struct device_node *pp)
 	return 1;
 }
 
+static void of_fixup_pci_pref(struct device_node *dp, int index,
+			      struct device_node *pp, struct resource *res)
+{
+	if (!resource_size(res))
+		return;
+	if (res->end <= ~((u32)0))
+		return;
+
+	if (!of_node_is_type(pp, "pci") && !of_node_is_type(pp, "pciex"))
+		return;
+
+	if (!(res->flags & IORESOURCE_PREFETCH)) {
+		res->flags |= IORESOURCE_PREFETCH;
+		printk("%pOF reg[%d] fixup: pref corrected\n", dp, index);
+	}
+}
+
 static int of_resource_verbose;
 
 static void __init build_device_resources(struct platform_device *op,
@@ -412,6 +429,7 @@ static void __init build_device_resources(struct platform_device *op,
 			r->start = result;
 			r->end = result + size - 1;
 			r->flags = flags;
+			of_fixup_pci_pref(dp, index, pp, r);
 		}
 		r->name = op->dev.of_node->full_name;
 	}

-- 
tg: (3a8660878839..) sparc/dt-fixup-pref (depends on: main)