Re: [PATCH] pnp: add PNP resource range checking function

[Bjorn Helgaas <bjorn.helgaas@hp.com>]

On Tuesday 14 April 2009 04:55:05 pm Jesse Barnes wrote:
> On Tue, 14 Apr 2009 16:53:11 -0600
> Bjorn Helgaas <bjorn.helgaas@hp.com> wrote:
> 
> > On Tuesday 14 April 2009 01:46:18 pm Jesse Barnes wrote:
> > > This patch adds a new export from the ACPI PNP core,
> > > is_acpi_pnp_reserved, which is intended for use by drivers to check
> > > whether a given range is already reserved (and therefore likely
> > > safe to use) or not (indicating that new resource space should
> > > probably be allocated).
> > 
> > This doesn't really need to be ACPI-specific, does it?  And can't
> > you use the pre-parsed resources in pnp_dev->resources?  And wouldn't
> > you just look at all resources for all PNP devices, not just the
> > PNP0C01/2 ones?
> > 
> > Sorry I don't have time to code up an example right now; maybe next
> > week, though, if you remind me :-)
> 
> Sure, that all sounds reasonable...  I'll try to remind you.  :)

Here's the sort of thing I was thinking (untested).

---
 drivers/pnp/resource.c |   17 +++++++++++++++++
 1 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/drivers/pnp/resource.c b/drivers/pnp/resource.c
index f604061..6665562 100644
--- a/drivers/pnp/resource.c
+++ b/drivers/pnp/resource.c
@@ -638,6 +638,23 @@ int pnp_possible_config(struct pnp_dev *dev, int type, resource_size_t start,
 }
 EXPORT_SYMBOL(pnp_possible_config);
 
+int pnp_range_reserved(resource_size_t start, resource_size_t end)
+{
+	struct pnp_dev *dev;
+	struct pnp_resource *pnp_res;
+	resource_size_t *dev_start, *dev_end;
+
+	pnp_for_each_dev(dev) {
+		list_for_each_entry(pnp_res, &dev->resources, list) {
+			dev_start = &pnp_res->res.start;
+			dev_end   = &pnp_res->res.end;
+			if (ranged_conflict(&start, &end, dev_start, dev_end))
+				return 1;
+		}
+	}
+	return 0;
+}
+
 /* format is: pnp_reserve_irq=irq1[,irq2] .... */
 static int __init pnp_setup_reserve_irq(char *str)
 {