From 2cfda637e29ce9e3df31b59f64516b2e571cc985 Mon Sep 17 00:00:00 2001
From: Yinghai Lu <yinghai@kernel.org>
Date: Mon, 1 Apr 2013 11:48:59 -0600
Subject: [PATCH 1/2] EISA/PCI: Fix bus res reference

Matthew found that 3.8.3 is having problems with an old (ancient)
PCI-to-EISA bridge, the Intel 82375. It worked with the 3.2 kernel.
He identified the 82375, but doesn't assign the struct resource *res
pointer inside the struct eisa_root_device, and panics.

pci_eisa_init() was using bus->resource[] directly instead of
pci_bus_resource_n().  The bus->resource[] array is a PCI-internal
implementation detail, and after commit 45ca9e97 (PCI: add helpers for
building PCI bus resource lists) and commit 0efd5aab (PCI: add struct
pci_host_bridge_window with CPU/bus address offset), bus->resource[] is not
used for PCI root buses any more.

The 82375 is a subtractive-decode PCI device, so handle it the same
way we handle PCI-PCI bridges in subtractive-decode mode in
pci_read_bridge_bases().

[bhelgaas: changelog]
Reported-by: Matthew Whitehead <mwhitehe@redhat.com>
Tested-by: Matthew Whitehead <mwhitehe@redhat.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org	# v3.3+
---
 drivers/eisa/pci_eisa.c | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/eisa/pci_eisa.c b/drivers/eisa/pci_eisa.c
index cdae207028a72..ef5c3ec874320 100644
--- a/drivers/eisa/pci_eisa.c
+++ b/drivers/eisa/pci_eisa.c
@@ -22,7 +22,8 @@ static struct eisa_root_device pci_eisa_root;
 static int __init pci_eisa_init(struct pci_dev *pdev,
 				const struct pci_device_id *ent)
 {
-	int rc;
+	int rc, i;
+	struct resource *res, *bus_res = NULL;
 
 	if ((rc = pci_enable_device (pdev))) {
 		printk (KERN_ERR "pci_eisa : Could not enable device %s\n",
@@ -30,9 +31,30 @@ static int __init pci_eisa_init(struct pci_dev *pdev,
 		return rc;
 	}
 
+	/*
+	 * The Intel 82375 PCI-EISA bridge is a subtractive-decode PCI
+	 * device, so the resources available on EISA are the same as those
+	 * available on the 82375 bus.  This works the same as a PCI-PCI
+	 * bridge in subtractive-decode mode (see pci_read_bridge_bases()).
+	 * We assume other PCI-EISA bridges are similar.
+	 *
+	 * eisa_root_register() can only deal with a single io port resource,
+	*  so we use the first valid io port resource.
+	 */
+	pci_bus_for_each_resource(pdev->bus, res, i)
+		if (res && (res->flags & IORESOURCE_IO)) {
+			bus_res = res;
+			break;
+		}
+
+	if (!bus_res) {
+		dev_err(&pdev->dev, "No resources available\n");
+		return -1;
+	}
+
 	pci_eisa_root.dev              = &pdev->dev;
-	pci_eisa_root.res	       = pdev->bus->resource[0];
-	pci_eisa_root.bus_base_addr    = pdev->bus->resource[0]->start;
+	pci_eisa_root.res	       = bus_res;
+	pci_eisa_root.bus_base_addr    = bus_res->start;
 	pci_eisa_root.slots	       = EISA_MAX_SLOTS;
 	pci_eisa_root.dma_mask         = pdev->dma_mask;
 	dev_set_drvdata(pci_eisa_root.dev, &pci_eisa_root);

From c5fb301ae83bec6892e54984e6ec765c47df8e10 Mon Sep 17 00:00:00 2001
From: Yinghai Lu <yinghai@kernel.org>
Date: Wed, 27 Mar 2013 21:28:05 -0700
Subject: [PATCH 2/2] EISA/PCI: Init EISA early, before PNP

Matthew reported kernels fail the pci_eisa probe and are later successful
with the virtual_eisa_root_init force probe without slot0.

The reason for that is: PNP probing is before pci_eisa_init gets called
as pci_eisa_init is called via pci_driver.

pnp 00:0f has 0xc80 - 0xc84 reserved.
[    9.700409] pnp 00:0f: [io  0x0c80-0x0c84]

so eisa_probe will fail from pci_eisa_init
				==>eisa_root_register
					==>eisa_probe path.
as force_probe is not set in pci_eisa_root, it will bail early when
slot0 is not probed and initialized.

Try to use subsys_initcall_sync instead, and will keep following sequence:
	pci_subsys_init
	pci_eisa_init_early
	pnpacpi_init/isapnp_init

After this patch EISA can be initialized properly, and PNP overlapping
resource will not be reserved.
[   10.104434] system 00:0f: [io  0x0c80-0x0c84] could not be reserved

Reported-by: Matthew Whitehead <mwhitehe@redhat.com>
Tested-by: Matthew Whitehead <mwhitehe@redhat.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org
---
 drivers/eisa/pci_eisa.c | 39 +++++++++++++++++++++------------------
 1 file changed, 21 insertions(+), 18 deletions(-)

diff --git a/drivers/eisa/pci_eisa.c b/drivers/eisa/pci_eisa.c
index ef5c3ec874320..6c3fca97d346d 100644
--- a/drivers/eisa/pci_eisa.c
+++ b/drivers/eisa/pci_eisa.c
@@ -19,8 +19,7 @@
 /* There is only *one* pci_eisa device per machine, right ? */
 static struct eisa_root_device pci_eisa_root;
 
-static int __init pci_eisa_init(struct pci_dev *pdev,
-				const struct pci_device_id *ent)
+static int __init pci_eisa_init(struct pci_dev *pdev)
 {
 	int rc, i;
 	struct resource *res, *bus_res = NULL;
@@ -67,22 +66,26 @@ static int __init pci_eisa_init(struct pci_dev *pdev,
 	return 0;
 }
 
-static struct pci_device_id pci_eisa_pci_tbl[] = {
-	{ PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
-	  PCI_CLASS_BRIDGE_EISA << 8, 0xffff00, 0 },
-	{ 0, }
-};
+/*
+ * We have to call pci_eisa_init_early() before pnpacpi_init()/isapnp_init().
+ *   Otherwise pnp resource will get enabled early and could prevent eisa
+ *   to be initialized.
+ * Also need to make sure pci_eisa_init_early() is called after
+ * x86/pci_subsys_init().
+ * So need to use subsys_initcall_sync with it.
+ */
+static int __init pci_eisa_init_early(void)
+{
+	struct pci_dev *dev = NULL;
+	int ret;
 
-static struct pci_driver __refdata pci_eisa_driver = {
-	.name		= "pci_eisa",
-	.id_table	= pci_eisa_pci_tbl,
-	.probe		= pci_eisa_init,
-};
+	for_each_pci_dev(dev)
+		if ((dev->class >> 8) == PCI_CLASS_BRIDGE_EISA) {
+			ret = pci_eisa_init(dev);
+			if (ret)
+				return ret;
+		}
 
-static int __init pci_eisa_init_module (void)
-{
-	return pci_register_driver (&pci_eisa_driver);
+	return 0;
 }
-
-device_initcall(pci_eisa_init_module);
-MODULE_DEVICE_TABLE(pci, pci_eisa_pci_tbl);
+subsys_initcall_sync(pci_eisa_init_early);