[PATCH 8/16 v6] PCI: add boot options to reassign resources

[Yu Zhao]

This patch adds boot options so user can reassign device resources
of all devices under a bus.

The boot options can be used as:
	pci=assign-mmio=0000:01,assign-pio=0000:02
'[dddd:]bb' is the domain and bus number.

Cc: Alex Chiang <achiang@xxxxxx>
Cc: Grant Grundler <grundler@xxxxxxxxxxxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <matthew@xxxxxx>
Cc: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
Cc: Roland Dreier <rdreier@xxxxxxxxx>
Signed-off-by: Yu Zhao <yu.zhao@xxxxxxxxx>

---
 arch/x86/pci/common.c |   73 +++++++++++++++++++++++++++++++++++++++++++++++++
 arch/x86/pci/i386.c   |   10 ++++---
 arch/x86/pci/pci.h    |    3 ++
 3 files changed, 82 insertions(+), 4 deletions(-)

diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index b67732b..06e1ce0 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -137,6 +137,72 @@ static void __devinit pcibios_fixup_device_resources(struct pci_dev *dev)
 	}
 }
 
+static char *pci_assign_pio;
+static char *pci_assign_mmio;
+
+static int pcibios_bus_resource_needs_fixup(struct pci_bus *bus)
+{
+	int i;
+	int type = 0;
+	int domain, busnr;
+
+	if (!bus->self)
+		return 0;
+
+	for (i = 0; i < 2; i++) {
+		char *str = i ? pci_assign_pio : pci_assign_mmio;
+
+		while (str && *str) {
+			if (sscanf(str, "%04x:%02x", &domain, &busnr) != 2) {
+				if (sscanf(str, "%02x", &busnr) != 1)
+					break;
+				domain = 0;
+			}
+
+			if (pci_domain_nr(bus) == domain &&
+			    bus->number == busnr) {
+				type |= i ? IORESOURCE_IO : IORESOURCE_MEM;
+				break;
+			}
+
+			str = strchr(str, ';');
+			if (str)
+				str++;
+		}
+	}
+
+	return type;
+}
+
+static void __devinit pcibios_fixup_bus_resources(struct pci_bus *bus)
+{
+	int i;
+	int type = pcibios_bus_resource_needs_fixup(bus);
+
+	if (!type)
+		return;
+
+	for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
+		struct resource *res = bus->resource[i];
+
+		if (!res)
+			continue;
+		if (res->flags & type)
+			res->flags = 0;
+	}
+}
+
+int pcibios_resource_needs_fixup(struct pci_dev *dev, int resno)
+{
+	struct pci_bus *bus;
+
+	for (bus = dev->bus; bus && bus != pci_root_bus; bus = bus->parent)
+		if (pcibios_bus_resource_needs_fixup(bus))
+			return 1;
+
+	return 0;
+}
+
 /*
  *  Called after each bus is probed, but before its children
  *  are examined.
@@ -147,6 +213,7 @@ void __devinit  pcibios_fixup_bus(struct pci_bus *b)
 	struct pci_dev *dev;
 
 	pci_read_bridge_bases(b);
+	pcibios_fixup_bus_resources(b);
 	list_for_each_entry(dev, &b->devices, bus_list)
 		pcibios_fixup_device_resources(dev);
 }
@@ -519,6 +586,12 @@ char * __devinit  pcibios_setup(char *str)
 	} else if (!strcmp(str, "skip_isa_align")) {
 		pci_probe |= PCI_CAN_SKIP_ISA_ALIGN;
 		return NULL;
+	} else if (!strncmp(str, "assign-pio=", 11)) {
+		pci_assign_pio = str + 11;
+		return NULL;
+	} else if (!strncmp(str, "assign-mmio=", 12)) {
+		pci_assign_mmio = str + 12;
+		return NULL;
 	}
 	return str;
 }
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index 8729bde..ea82a5b 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -169,10 +169,12 @@ static void __init pcibios_allocate_resources(int pass)
 					(unsigned long long) r->start,
 					(unsigned long long) r->end,
 					r->flags, enabled, pass);
-			pr = pci_find_parent_resource(dev, r);
-			if (pr && !request_resource(pr, r))
-				continue;
-			dev_err(&dev->dev, "BAR %d: can't allocate resource\n", idx);
+			if (!pcibios_resource_needs_fixup(dev, idx)) {
+				pr = pci_find_parent_resource(dev, r);
+				if (pr && !request_resource(pr, r))
+					continue;
+				dev_err(&dev->dev, "BAR %d: can't allocate resource\n", idx);
+			}
 			/* We'll assign a new address later */
 			r->end -= r->start;
 			r->start = 0;
diff --git a/arch/x86/pci/pci.h b/arch/x86/pci/pci.h
index 15b9cf6..f22737d 100644
--- a/arch/x86/pci/pci.h
+++ b/arch/x86/pci/pci.h
@@ -117,6 +117,9 @@ extern int __init pcibios_init(void);
 extern int __init pci_mmcfg_arch_init(void);
 extern void __init pci_mmcfg_arch_free(void);
 
+/* pci-common.c */
+extern int pcibios_resource_needs_fixup(struct pci_dev *dev, int resno);
+
 /*
  * AMD Fam10h CPUs are buggy, and cannot access MMIO config space
  * on their northbrige except through the * %eax register. As such, you MUST
-- 
1.5.6.4

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