On Wed, Mar 22, 2023 at 02:28:04PM -0500, Bjorn Helgaas wrote:

On Mon, Mar 20, 2023 at 03:16:30PM +0200, Andy Shevchenko wrote:

...

quoted

+	pci_dev_for_each_resource_p(dev, r) {
 		/* zap the 2nd function of the winbond chip */
-		if (dev->resource[i].flags & IORESOURCE_IO
-		    && dev->bus->number == 0 && dev->devfn == 0x81)
-			dev->resource[i].flags &= ~IORESOURCE_IO;
-		if (dev->resource[i].start == 0 && dev->resource[i].end) {
-			dev->resource[i].flags = 0;
-			dev->resource[i].end = 0;
+		if (dev->bus->number == 0 && dev->devfn == 0x81 &&
+		    r->flags & IORESOURCE_IO)

This is a nice literal conversion, but it's kind of lame to test
bus->number and devfn *inside* the loop here, since they can't change
inside the loop.

Hmm... why are you asking me, even if I may agree on that? It's
in the original code and out of scope of this series.

quoted

+			r->flags &= ~IORESOURCE_IO;
+		if (r->start == 0 && r->end) {
+			r->flags = 0;
+			r->end = 0;
 		}
 	}

...

quoted

 #define pci_resource_len(dev,bar) \
 	((pci_resource_end((dev), (bar)) == 0) ? 0 :	\
 							\
-	 (pci_resource_end((dev), (bar)) -		\
-	  pci_resource_start((dev), (bar)) + 1))
+	 resource_size(pci_resource_n((dev), (bar))))

I like this change, but it's unrelated to pci_dev_for_each_resource()
and unmentioned in the commit log.

And as you rightfully noticed this either. I can split it to a separate one.

...

quoted

+#define __pci_dev_for_each_resource(dev, res, __i, vartype)		\
+	for (vartype __i = 0;						\
+	     res = pci_resource_n(dev, __i), __i < PCI_NUM_RESOURCES;	\
+	     __i++)
+
+#define pci_dev_for_each_resource(dev, res, i)				\
+       __pci_dev_for_each_resource(dev, res, i, )
+
+#define pci_dev_for_each_resource_p(dev, res)				\
+	__pci_dev_for_each_resource(dev, res, __i, unsigned int)

This series converts many cases to drop the iterator variable ("i"),
which is fantastic.

Several of the remaining places need the iterator variable only to
call pci_claim_resource(), which could be converted to take a "struct
resource *" directly without much trouble.

We don't have to do that pci_claim_resource() conversion now,

Exactly, it's definitely should be separate change.

but
since we're converging on the "(dev, res)" style, I think we should
reverse the names so we have something like:

  pci_dev_for_each_resource(dev, res)
  pci_dev_for_each_resource_idx(dev, res, i)

Wouldn't it be more churn, including pci_bus_for_each_resource() correction?

...

Not sure __pci_dev_for_each_resource() is worthwhile since it only
avoids repeating that single "for" statement, and passing in "vartype"
(sometimes empty to implicitly avoid the declaration) is a little
complicated to read.  I think it'd be easier to read like this:

No objections here.

  #define pci_dev_for_each_resource(dev, res)                      \
    for (unsigned int __i = 0;                                     \
         res = pci_resource_n(dev, __i), __i < PCI_NUM_RESOURCES;  \
         __i++)

  #define pci_dev_for_each_resource_idx(dev, res, idx)             \
    for (idx = 0;                                                  \
         res = pci_resource_n(dev, idx), idx < PCI_NUM_RESOURCES;  \
         idx++)

-- 
With Best Regards,
Andy Shevchenko



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