Commit 6ca45a24 authored by Grant Grundler's avatar Grant Grundler Committed by Kyle McMartin
Browse files

[PARISC] Truncate overlapping PAT PDC reported ranges 



Deal with overlapping LBA MMIO resources,

rp3440 PDC BUG: PDC reports lmmio range for the last rope that overlaps
with the CPU HPA. Console output was:

...
Found devices:
1. Storm Peak Fast at 0xfffffffffe798000 [152] { 0, 0x0, 0x889, 0x00004 }
2. Storm Peak Fast at 0xfffffffffe799000 [153] { 0, 0x0, 0x889, 0x00004 }
...
FAILED: lba_fixup_bus() request for lmmio_space
[fffffffff0000000/fffffffffecffffe]

Output is now:

LBA: Truncating lmmio_space [fffffffff0000000/fffffffffecffffe] to
[fffffffff0000000,fffffffffe797fff]

My only concern with this patch is how C8000 (PAT PDC) will report
elmmio ranges when a gfx card is installed. I'll have to test this
another day.

Signed-off-by: default avatarGrant Grundler <grundler@parisc-linux.org>
Signed-off-by: default avatarJames Bottomley <jejb@parisc-linux.org>
Signed-off-by: default avatarMatthew Wilcox <willy@parisc-linux.org>
Signed-off-by: default avatarKyle McMartin <kyle@parisc-linux.org>
parent 110957f0

drivers/parisc/lba_pci.c

+90 −23
Original line number Diff line number Diff line
@@ -695,11 +695,71 @@ lba_claim_dev_resources(struct pci_dev *dev) 
		}

	}

}





/*

 * truncate_pat_collision:  Deal with overlaps or outright collisions

 *			between PAT PDC reported ranges.

 *

 *   Broken PA8800 firmware will report lmmio range that

 *   overlaps with CPU HPA. Just truncate the lmmio range.

 *

 *   BEWARE: conflicts with this lmmio range may be an

 *   elmmio range which is pointing down another rope.

 *

 *  FIXME: only deals with one collision per range...theoretically we

 *  could have several. Supporting more than one collision will get messy.

 */

static unsigned long

truncate_pat_collision(struct resource *root, struct resource *new)

{

	unsigned long start = new->start;

	unsigned long end = new->end;

	struct resource *tmp = root->child;



	if (end <= start || start < root->start || !tmp)

		return 0;



	/* find first overlap */

	while (tmp && tmp->end < start)

		tmp = tmp->sibling;



	/* no entries overlap */

	if (!tmp)  return 0;



	/* found one that starts behind the new one

	** Don't need to do anything.

	*/

	if (tmp->start >= end) return 0;



	if (tmp->start <= start) {

		/* "front" of new one overlaps */

		new->start = tmp->end + 1;



		if (tmp->end >= end) {

			/* AACCKK! totally overlaps! drop this range. */

			return 1;

		}

	} 



	if (tmp->end < end ) {

		/* "end" of new one overlaps */

		new->end = tmp->start - 1;

	}



	printk(KERN_WARNING "LBA: Truncating lmmio_space [%lx/%lx] "

					"to [%lx,%lx]\n",

			start, end,

			new->start, new->end );



	return 0;	/* truncation successful */

}



#else

#define lba_claim_dev_resources(dev)

#define lba_claim_dev_resources(dev) do { } while (0)

#define truncate_pat_collision(r,n)  (0)

#endif





/*

** The algorithm is generic code.

** But it needs to access local data structures to get the IRQ base.
@@ -747,6 +807,9 @@ lba_fixup_bus(struct pci_bus *bus) 
			lba_dump_res(&ioport_resource, 2);

			BUG();

		}

		/* advertize Host bridge resources to PCI bus */

		bus->resource[0] = &(ldev->hba.io_space);

		i = 1;



		if (ldev->hba.elmmio_space.start) {

			err = request_resource(&iomem_resource,
@@ -760,23 +823,35 @@ lba_fixup_bus(struct pci_bus *bus) 


				/* lba_dump_res(&iomem_resource, 2); */

				/* BUG(); */

			}

			} else

				bus->resource[i++] = &(ldev->hba.elmmio_space);

		}



		err = request_resource(&iomem_resource, &(ldev->hba.lmmio_space));

		if (err < 0) {

			/*   FIXME  overlaps with elmmio will fail here.

			 *   Need to prune (or disable) the distributed range.



		/*   Overlaps with elmmio can (and should) fail here.

		 *   We will prune (or ignore) the distributed range.

		 *

			 *   BEWARE: conflicts with this lmmio range may be

			 *   elmmio range which is pointing down another rope.

		 *   FIXME: SBA code should register all elmmio ranges first.

		 *      that would take care of elmmio ranges routed

		 *	to a different rope (already discovered) from

		 *	getting registered *after* LBA code has already

		 *	registered it's distributed lmmio range.

		 */

		if (truncate_pat_collision(&iomem_resource,

				       	&(ldev->hba.lmmio_space))) {



			printk("FAILED: lba_fixup_bus() request for "

			printk(KERN_WARNING "LBA: lmmio_space [%lx/%lx] duplicate!\n",

					ldev->hba.lmmio_space.start,

					ldev->hba.lmmio_space.end);

		} else {

			err = request_resource(&iomem_resource, &(ldev->hba.lmmio_space));

			if (err < 0) {

				printk(KERN_ERR "FAILED: lba_fixup_bus() request for "

					"lmmio_space [%lx/%lx]\n",

					ldev->hba.lmmio_space.start,

					ldev->hba.lmmio_space.end);

			/* lba_dump_res(&iomem_resource, 2); */

			} else

				bus->resource[i++] = &(ldev->hba.lmmio_space);

		}



#ifdef CONFIG_64BIT
@@ -791,18 +866,10 @@ lba_fixup_bus(struct pci_bus *bus) 
				lba_dump_res(&iomem_resource, 2);

				BUG();

			}

			bus->resource[i++] = &(ldev->hba.gmmio_space);

		}

#endif



		/* advertize Host bridge resources to PCI bus */

		bus->resource[0] = &(ldev->hba.io_space);

		bus->resource[1] = &(ldev->hba.lmmio_space);

		i=2;

		if (ldev->hba.elmmio_space.start)

			bus->resource[i++] = &(ldev->hba.elmmio_space);

		if (ldev->hba.gmmio_space.start)

			bus->resource[i++] = &(ldev->hba.gmmio_space);

			

	}



	list_for_each(ln, &bus->devices) {

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