[PATCH][RFC] PCI: Workaround to enable poweroff on Mac Pro 11

[Chen Yu <yu.c.chen@intel.com>]

Currently there are many people reported that they can not
do a poweroff nor a suspend to memory on their Mac Pro 11.
After some investigations it was found that, once the PCI bridge
0000:00:1c.0 reassigns its mm windows([mem 0x7fa00000-0x7fbfffff]
and [mem 0x7fc00000-0x7fdfffff 64bit pref]), the region of ACPI
io resource 0x1804 becomes unaccessible immediately, where the
ACPI Sleep register is located, as a result neither poweroff(S5)
nor suspend to memory(S3) works.

I don't know why setting the base/limit of PCI bridge mem resource
would affect another io resource region, so this quirk just simply
bypass the assignment of these mm resources on 0000:00:1c.0, by
resetting the resource flag to 0 before updating the base/limit registers.
This patch also introduces a new pci fixup phase before the actual bridge
resource assignment.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=103211
Tested-by: Cedric Le Goater <clg@kaod.org>
Tested-by: pkozlov <pkozlov.vrn@gmail.com>
Tested-by: Zach Norman <zach@nor.mn>
Tested-by: Pablo Catalina <pablo.catalina@gmail.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
---
 drivers/pci/quirks.c              | 25 +++++++++++++++++++++++++
 drivers/pci/setup-bus.c           |  2 ++
 include/asm-generic/vmlinux.lds.h |  3 +++
 include/linux/pci.h               |  4 ++++
 scripts/mod/modpost.c             |  1 +
 5 files changed, 35 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index ee72ebe..e347047 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3370,6 +3370,8 @@ extern struct pci_fixup __start_pci_fixups_header[];
 extern struct pci_fixup __end_pci_fixups_header[];
 extern struct pci_fixup __start_pci_fixups_final[];
 extern struct pci_fixup __end_pci_fixups_final[];
+extern struct pci_fixup __start_pci_fixups_assign[];
+extern struct pci_fixup __end_pci_fixups_assign[];
 extern struct pci_fixup __start_pci_fixups_enable[];
 extern struct pci_fixup __end_pci_fixups_enable[];
 extern struct pci_fixup __start_pci_fixups_resume[];
@@ -3405,6 +3407,11 @@ void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev)
 		end = __end_pci_fixups_final;
 		break;
 
+	case pci_fixup_assign:
+		start = __start_pci_fixups_assign;
+		end = __end_pci_fixups_assign;
+		break;
+
 	case pci_fixup_enable:
 		start = __start_pci_fixups_enable;
 		end = __end_pci_fixups_enable;
@@ -4419,3 +4426,21 @@ static void quirk_intel_qat_vf_cap(struct pci_dev *pdev)
 	}
 }
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x443, quirk_intel_qat_vf_cap);
+
+/*
+ * On Mac Pro 11, the allocation of pci bridge memory resource
+ * broke ACPI Sleep Type register region.
+ */
+static void quirk_mac_disable_mmio_bar(struct pci_dev *dev)
+{
+	struct resource *b_res;
+
+	dev_info(&dev->dev, "[Quirk] Disable mmio on Mac Pro 11\n");
+	if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
+		return;
+
+	b_res = &dev->resource[PCI_BRIDGE_RESOURCES];
+	b_res[1].flags = 0;
+	b_res[2].flags = 0;
+}
+DECLARE_PCI_FIXUP_ASSIGN(PCI_VENDOR_ID_INTEL, 0x8c10, quirk_mac_disable_mmio_bar);
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 55641a3..730d6fd 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1256,6 +1256,8 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 			additional_io_size  = pci_hotplug_io_size;
 			additional_mem_size = pci_hotplug_mem_size;
 		}
+
+		pci_fixup_device(pci_fixup_assign, bus->self);
 		/* Fall through */
 	default:
 		pbus_size_io(bus, realloc_head ? 0 : additional_io_size,
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 6a67ab9..3ba05f0 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -283,6 +283,9 @@
 		VMLINUX_SYMBOL(__start_pci_fixups_final) = .;		\
 		*(.pci_fixup_final)					\
 		VMLINUX_SYMBOL(__end_pci_fixups_final) = .;		\
+		VMLINUX_SYMBOL(__start_pci_fixups_assign) = .;		\
+		*(.pci_fixup_assign)					\
+		VMLINUX_SYMBOL(__end_pci_fixups_assign) = .;		\
 		VMLINUX_SYMBOL(__start_pci_fixups_enable) = .;		\
 		*(.pci_fixup_enable)					\
 		VMLINUX_SYMBOL(__end_pci_fixups_enable) = .;		\
diff --git a/include/linux/pci.h b/include/linux/pci.h
index b67e4df..14a35bb 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1584,6 +1584,7 @@ enum pci_fixup_pass {
 	pci_fixup_early,	/* Before probing BARs */
 	pci_fixup_header,	/* After reading configuration header */
 	pci_fixup_final,	/* Final phase of device fixups */
+	pci_fixup_assign,	/* Before resource assignment */
 	pci_fixup_enable,	/* pci_enable_device() time */
 	pci_fixup_resume,	/* pci_device_resume() */
 	pci_fixup_suspend,	/* pci_device_suspend() */
@@ -1644,6 +1645,9 @@ enum pci_fixup_pass {
 #define DECLARE_PCI_FIXUP_FINAL(vendor, device, hook)			\
 	DECLARE_PCI_FIXUP_SECTION(.pci_fixup_final,			\
 		hook, vendor, device, PCI_ANY_ID, 0, hook)
+#define DECLARE_PCI_FIXUP_ASSIGN(vendor, device, hook)			\
+	DECLARE_PCI_FIXUP_SECTION(.pci_fixup_assign,			\
+		hook, vendor, device, PCI_ANY_ID, 0, hook)
 #define DECLARE_PCI_FIXUP_ENABLE(vendor, device, hook)			\
 	DECLARE_PCI_FIXUP_SECTION(.pci_fixup_enable,			\
 		hook, vendor, device, PCI_ANY_ID, 0, hook)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 48958d3..248acdb 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -877,6 +877,7 @@ static void check_section(const char *modname, struct elf_info *elf,
 
 #define ALL_PCI_INIT_SECTIONS	\
 	".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
+	".pci_fixup_assign", \
 	".pci_fixup_enable", ".pci_fixup_resume", \
 	".pci_fixup_resume_early", ".pci_fixup_suspend"
 
-- 
2.7.4