[PATCH 17/19] [POWERPC] Improve resource setup of PowerMac G5 HT bridge
Benjamin Herrenschmidt
benh at kernel.crashing.org
Thu Dec 20 14:55:02 EST 2007
The device node for the HT bridge on G5s doesn't contain useful ranges.
We used to give it a bunch of the known PCI space and then punch a "hole"
in it based on where the AGP or PCIe region was. This reworks it to
use the actual register in the bridge that controls the decoding instead.
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
arch/powerpc/platforms/powermac/pci.c | 146 +++++++++++++++-------------------
1 file changed, 66 insertions(+), 80 deletions(-)
--- linux-merge.orig/arch/powerpc/platforms/powermac/pci.c 2007-12-19 15:53:00.000000000 +1100
+++ linux-merge/arch/powerpc/platforms/powermac/pci.c 2007-12-19 15:55:29.000000000 +1100
@@ -40,8 +40,6 @@
static int has_uninorth;
#ifdef CONFIG_PPC64
static struct pci_controller *u3_agp;
-static struct pci_controller *u4_pcie;
-static struct pci_controller *u3_ht;
#else
static int has_second_ohare;
#endif /* CONFIG_PPC64 */
@@ -779,16 +777,50 @@ static void __init setup_u4_pcie(struct
*/
hose->first_busno = 0x00;
hose->last_busno = 0xff;
- u4_pcie = hose;
+}
+
+static void __init parse_region_decode(struct pci_controller *hose,
+ u32 decode)
+{
+ unsigned long base, end, next = -1;
+ int i, cur = -1;
+
+ /* Iterate through all bits. We ignore the last bit as this region is
+ * reserved for the ROM among other niceties
+ */
+ for (i = 0; i < 31; i++) {
+ if ((decode & (0x80000000 >> i)) == 0)
+ continue;
+ if (i < 16) {
+ base = 0xf0000000 | (((u32)i) << 24);
+ end = base + 0x00ffffff;
+ } else {
+ base = ((u32)i-16) << 28;
+ end = base + 0x0fffffff;
+ }
+ if (base != next) {
+ if (++cur >= 3) {
+ printk(KERN_WARNING "PCI: Too many ranges !\n");
+ break;
+ }
+ hose->mem_resources[cur].flags = IORESOURCE_MEM;
+ hose->mem_resources[cur].name = hose->dn->full_name;
+ hose->mem_resources[cur].start = base;
+ hose->mem_resources[cur].end = end;
+ DBG(" %d: 0x%08lx-0x%08lx\n", cur, base, end);
+ } else {
+ DBG(" : -0x%08lx\n", end);
+ hose->mem_resources[cur].end = end;
+ }
+ next = end + 1;
+ }
}
static void __init setup_u3_ht(struct pci_controller* hose)
{
struct device_node *np = hose->dn;
- struct pci_controller *other = NULL;
struct resource cfg_res, self_res;
- int i, cur;
-
+ u32 decode;
hose->ops = &u3_ht_pci_ops;
@@ -808,12 +840,9 @@ static void __init setup_u3_ht(struct pc
self_res.end - self_res.start + 1);
/*
- * /ht node doesn't expose a "ranges" property, so we "remove"
- * regions that have been allocated to AGP. So far, this version of
- * the code doesn't assign any of the 0xfxxxxxxx "fine" memory regions
- * to /ht. We need to fix that sooner or later by either parsing all
- * child "ranges" properties or figuring out the U3 address space
- * decoding logic and then read its configuration register (if any).
+ * /ht node doesn't expose a "ranges" property, we read the register
+ * that controls the decoding logic and use that for memory regions.
+ * The IO region is hard coded since it is fixed in HW as well.
*/
hose->io_base_phys = 0xf4000000;
hose->pci_io_size = 0x00400000;
@@ -824,76 +853,33 @@ static void __init setup_u3_ht(struct pc
hose->pci_mem_offset = 0;
hose->first_busno = 0;
hose->last_busno = 0xef;
- hose->mem_resources[0].name = np->full_name;
- hose->mem_resources[0].start = 0x80000000;
- hose->mem_resources[0].end = 0xefffffff;
- hose->mem_resources[0].flags = IORESOURCE_MEM;
-
- u3_ht = hose;
-
- if (u3_agp != NULL)
- other = u3_agp;
- else if (u4_pcie != NULL)
- other = u4_pcie;
- if (other == NULL) {
- DBG("U3/4 has no AGP/PCIE, using full resource range\n");
- return;
- }
+ /* Note: fix offset when cfg_addr becomes a void * */
+ decode = in_be32(hose->cfg_addr + 0x80);
- /* Fixup bus range vs. PCIE */
- if (u4_pcie)
- hose->last_busno = u4_pcie->first_busno - 1;
-
- /* We "remove" the AGP resources from the resources allocated to HT,
- * that is we create "holes". However, that code does assumptions
- * that so far happen to be true (cross fingers...), typically that
- * resources in the AGP node are properly ordered
- */
- cur = 0;
- for (i=0; i<3; i++) {
- struct resource *res = &other->mem_resources[i];
- if (res->flags != IORESOURCE_MEM)
- continue;
- /* We don't care about "fine" resources */
- if (res->start >= 0xf0000000)
- continue;
- /* Check if it's just a matter of "shrinking" us in one
- * direction
- */
- if (hose->mem_resources[cur].start == res->start) {
- DBG("U3/HT: shrink start of %d, %08lx -> %08lx\n",
- cur, hose->mem_resources[cur].start,
- res->end + 1);
- hose->mem_resources[cur].start = res->end + 1;
- continue;
- }
- if (hose->mem_resources[cur].end == res->end) {
- DBG("U3/HT: shrink end of %d, %08lx -> %08lx\n",
- cur, hose->mem_resources[cur].end,
- res->start - 1);
- hose->mem_resources[cur].end = res->start - 1;
- continue;
- }
- /* No, it's not the case, we need a hole */
- if (cur == 2) {
- /* not enough resources for a hole, we drop part
- * of the range
- */
- printk(KERN_WARNING "Running out of resources"
- " for /ht host !\n");
- hose->mem_resources[cur].end = res->start - 1;
- continue;
- }
- cur++;
- DBG("U3/HT: hole, %d end at %08lx, %d start at %08lx\n",
- cur-1, res->start - 1, cur, res->end + 1);
- hose->mem_resources[cur].name = np->full_name;
- hose->mem_resources[cur].flags = IORESOURCE_MEM;
- hose->mem_resources[cur].start = res->end + 1;
- hose->mem_resources[cur].end = hose->mem_resources[cur-1].end;
- hose->mem_resources[cur-1].end = res->start - 1;
- }
+ DBG("PCI: Apple HT bridge decode register: 0x%08x\n", decode);
+
+ /* NOTE: The decode register setup is a bit weird... region
+ * 0xf8000000 for example is marked as enabled in there while it's
+ & actually the memory controller registers.
+ * That means that we are incorrectly attributing it to HT.
+ *
+ * In a similar vein, region 0xf4000000 is actually the HT IO space but
+ * also marked as enabled in here and 0xf9000000 is used by some other
+ * internal bits of the northbridge.
+ *
+ * Unfortunately, we can't just mask out those bit as we would end
+ * up with more regions than we can cope (linux can only cope with
+ * 3 memory regions for a PHB at this stage).
+ *
+ * So for now, we just do a little hack. We happen to -know- that
+ * Apple firmware doesn't assign things below 0xfa000000 for that
+ * bridge anyway so we mask out all bits we don't want.
+ */
+ decode &= 0x003fffff;
+
+ /* Now parse the resulting bits and build resources */
+ parse_region_decode(hose, decode);
}
#endif /* CONFIG_PPC64 */
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