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

[Ilpo Järvinen]

On Mon, 10 Nov 2025, Ilpo Järvinen wrote:

> 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@xxxxxxxxxxxxxxx>
> > > ---
> > >  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?

Second fixup patch attached.

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

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>

---
 arch/sparc/kernel/pci.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
index a9448088e762..3b8575891006 100644
--- a/arch/sparc/kernel/pci.c
+++ b/arch/sparc/kernel/pci.c
@@ -181,6 +181,24 @@ static int __init ofpci_debug(char *str)
 
 __setup("ofpci_debug=", ofpci_debug);
 
+static void of_fixup_pci_pref(struct pci_dev *dev, int index,
+			      struct resource *res)
+{
+	if (!(res->flags & IORESOURCE_MEM_64))
+		return;
+
+	if (!resource_size(res))
+		return;
+	if (res->end <= ~((u32)0))
+		return;
+
+	if (!(res->flags & IORESOURCE_PREFETCH)) {
+		res->flags |= IORESOURCE_PREFETCH;
+		pci_info(dev, "reg 0x%x: fixup: pref added to 64-bit resource\n",
+			 index);
+	}
+}
+
 static unsigned long pci_parse_of_flags(u32 addr0)
 {
 	unsigned long flags = 0;
@@ -244,6 +262,7 @@ static void pci_parse_of_addrs(struct platform_device *op,
 		res->end = op_res->end;
 		res->flags = flags;
 		res->name = pci_name(dev);
+		of_fixup_pci_pref(dev, i, res);
 
 		pci_info(dev, "reg 0x%x: %pR\n", i, res);
 	}

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