parisc: fix LMMIO mismatch between PAT length and MASK register

The LMMIO length reported by PAT and the length given by the LBA MASK
register are not consistent. This leads e.g. to a not-working ATI FireGL
card with the radeon DRM driver since the memory can't be mapped.

Fix this by correctly adjusting the resource sizes.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # 3.10

drivers/parisc/lba_pci.c

@@ -613,6 +613,54 @@ truncate_pat_collision(struct resource *root, struct resource *new)
 	return 0;	/* truncation successful */
 }
 
+/*
+ * extend_lmmio_len: extend lmmio range to maximum length
+ *
+ * This is needed at least on C8000 systems to get the ATI FireGL card
+ * working. On other systems we will currently not extend the lmmio space.
+ */
+static unsigned long
+extend_lmmio_len(unsigned long start, unsigned long end, unsigned long lba_len)
+{
+	struct resource *tmp;
+
+	pr_debug("LMMIO mismatch: PAT length = 0x%lx, MASK register = 0x%lx\n",
+		end - start, lba_len);
+
+	lba_len = min(lba_len+1, 256UL*1024*1024); /* limit to 256 MB */
+
+	pr_debug("LBA: lmmio_space [0x%lx-0x%lx] - original\n", start, end);
+
+	if (boot_cpu_data.cpu_type < mako) {
+		pr_info("LBA: Not a C8000 system - not extending LMMIO range.\n");
+		return end;
+	}
+
+	end += lba_len;
+	if (end < start) /* fix overflow */
+		end = -1ULL;
+
+	pr_debug("LBA: lmmio_space [0x%lx-0x%lx] - current\n", start, end);
+
+	/* first overlap */
+	for (tmp = iomem_resource.child; tmp; tmp = tmp->sibling) {
+		pr_debug("LBA: testing %pR\n", tmp);
+		if (tmp->start == start)
+			continue; /* ignore ourself */
+		if (tmp->end < start)
+			continue;
+		if (tmp->start > end)
+			continue;
+		if (end >= tmp->start)
+			end = tmp->start - 1;
+	}
+
+	pr_info("LBA: lmmio_space [0x%lx-0x%lx] - new\n", start, end);
+
+	/* return new end */
+	return end;
+}
+
 #else
 #define truncate_pat_collision(r,n)  (0)
 #endif
@@ -994,6 +1042,14 @@ lba_pat_resources(struct parisc_device *pa_dev, struct lba_device *lba_dev)
 		case PAT_LMMIO:
 			/* used to fix up pre-initialized MEM BARs */
 			if (!lba_dev->hba.lmmio_space.flags) {
+				unsigned long lba_len;
+
+				lba_len = ~READ_REG32(lba_dev->hba.base_addr
+						+ LBA_LMMIO_MASK);
+				if ((p->end - p->start) != lba_len)
+					p->end = extend_lmmio_len(p->start,
+						p->end, lba_len);
+
 				sprintf(lba_dev->hba.lmmio_name,
 						"PCI%02x LMMIO",
 						(int)lba_dev->hba.bus_num.start);