Patch "Revert "PCI, x86: Implement pcibios_alloc_irq() and pcibios_free_irq()"" has been added to the 4.4-stable tree

Patch "Revert "PCI, x86: Implement pcibios_alloc_irq() and pcibios_free_irq()"" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    Revert "PCI, x86: Implement pcibios_alloc_irq() and pcibios_free_irq()"

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     revert-pci-x86-implement-pcibios_alloc_irq-and-pcibios_free_irq.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 6c777e8799a93e3bdb67bec622429e1b48dc90fb Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bhelgaas@google.com>
Date: Wed, 17 Feb 2016 12:26:42 -0600
Subject: Revert "PCI, x86: Implement pcibios_alloc_irq() and pcibios_free_irq()"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Bjorn Helgaas <bhelgaas@google.com>

commit 6c777e8799a93e3bdb67bec622429e1b48dc90fb upstream.

991de2e59090 ("PCI, x86: Implement pcibios_alloc_irq() and
pcibios_free_irq()") appeared in v4.3 and helps support IOAPIC hotplug.

Олег reported that the Elcus-1553 TA1-PCI driver worked in v4.2 but not
v4.3 and bisected it to 991de2e59090.  Sunjin reported that the RocketRAID
272x driver worked in v4.2 but not v4.3.  In both cases booting with
"pci=routirq" is a workaround.

I think the problem is that after 991de2e59090, we no longer call
pcibios_enable_irq() for upstream bridges.  Prior to 991de2e59090, when a
driver called pci_enable_device(), we recursively called
pcibios_enable_irq() for upstream bridges via pci_enable_bridge().

After 991de2e59090, we call pcibios_enable_irq() from pci_device_probe()
instead of the pci_enable_device() path, which does *not* call
pcibios_enable_irq() for upstream bridges.

Revert 991de2e59090 to fix these driver regressions.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=111211
Fixes: 991de2e59090 ("PCI, x86: Implement pcibios_alloc_irq() and pcibios_free_irq()")
Reported-and-tested-by: Олег Мороз <oleg.moroz@mcc.vniiem.ru>
Reported-by: Sunjin Yang <fan4326@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
CC: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/include/asm/pci_x86.h |    2 ++
 arch/x86/pci/common.c          |   20 +++++++++++---------
 arch/x86/pci/intel_mid_pci.c   |    7 ++-----
 arch/x86/pci/irq.c             |   15 ++++++++++++++-
 drivers/acpi/pci_irq.c         |    9 ++++++++-
 5 files changed, 37 insertions(+), 16 deletions(-)

--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -93,6 +93,8 @@ extern raw_spinlock_t pci_config_lock;
 extern int (*pcibios_enable_irq)(struct pci_dev *dev);
 extern void (*pcibios_disable_irq)(struct pci_dev *dev);
 
+extern bool mp_should_keep_irq(struct device *dev);
+
 struct pci_raw_ops {
 	int (*read)(unsigned int domain, unsigned int bus, unsigned int devfn,
 						int reg, int len, u32 *val);
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -673,20 +673,22 @@ int pcibios_add_device(struct pci_dev *d
 	return 0;
 }
 
-int pcibios_alloc_irq(struct pci_dev *dev)
+int pcibios_enable_device(struct pci_dev *dev, int mask)
 {
-	return pcibios_enable_irq(dev);
-}
+	int err;
 
-void pcibios_free_irq(struct pci_dev *dev)
-{
-	if (pcibios_disable_irq)
-		pcibios_disable_irq(dev);
+	if ((err = pci_enable_resources(dev, mask)) < 0)
+		return err;
+
+	if (!pci_dev_msi_enabled(dev))
+		return pcibios_enable_irq(dev);
+	return 0;
 }
 
-int pcibios_enable_device(struct pci_dev *dev, int mask)
+void pcibios_disable_device (struct pci_dev *dev)
 {
-	return pci_enable_resources(dev, mask);
+	if (!pci_dev_msi_enabled(dev) && pcibios_disable_irq)
+		pcibios_disable_irq(dev);
 }
 
 int pci_ext_cfg_avail(void)
--- a/arch/x86/pci/intel_mid_pci.c
+++ b/arch/x86/pci/intel_mid_pci.c
@@ -256,13 +256,10 @@ static int intel_mid_pci_irq_enable(stru
 
 static void intel_mid_pci_irq_disable(struct pci_dev *dev)
 {
-	if (dev->irq_managed && dev->irq > 0) {
+	if (!mp_should_keep_irq(&dev->dev) && dev->irq_managed &&
+	    dev->irq > 0) {
 		mp_unmap_irq(dev->irq);
 		dev->irq_managed = 0;
-		/*
-		 * Don't reset dev->irq here, otherwise
-		 * intel_mid_pci_irq_enable() will fail on next call.
-		 */
 	}
 }
 
--- a/arch/x86/pci/irq.c
+++ b/arch/x86/pci/irq.c
@@ -1257,9 +1257,22 @@ static int pirq_enable_irq(struct pci_de
 	return 0;
 }
 
+bool mp_should_keep_irq(struct device *dev)
+{
+	if (dev->power.is_prepared)
+		return true;
+#ifdef CONFIG_PM
+	if (dev->power.runtime_status == RPM_SUSPENDING)
+		return true;
+#endif
+
+	return false;
+}
+
 static void pirq_disable_irq(struct pci_dev *dev)
 {
-	if (io_apic_assign_pci_irqs && dev->irq_managed && dev->irq) {
+	if (io_apic_assign_pci_irqs && !mp_should_keep_irq(&dev->dev) &&
+	    dev->irq_managed && dev->irq) {
 		mp_unmap_irq(dev->irq);
 		dev->irq = 0;
 		dev->irq_managed = 0;
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -481,6 +481,14 @@ void acpi_pci_irq_disable(struct pci_dev
 	if (!pin || !dev->irq_managed || dev->irq <= 0)
 		return;
 
+	/* Keep IOAPIC pin configuration when suspending */
+	if (dev->dev.power.is_prepared)
+		return;
+#ifdef	CONFIG_PM
+	if (dev->dev.power.runtime_status == RPM_SUSPENDING)
+		return;
+#endif
+
 	entry = acpi_pci_irq_lookup(dev, pin);
 	if (!entry)
 		return;
@@ -501,6 +509,5 @@ void acpi_pci_irq_disable(struct pci_dev
 	if (gsi >= 0) {
 		acpi_unregister_gsi(gsi);
 		dev->irq_managed = 0;
-		dev->irq = 0;
 	}
 }


Patches currently in stable-queue which might be from bhelgaas@google.com are

queue-4.4/revert-pci-add-helpers-to-manage-pci_dev-irq-and-pci_dev-irq_managed.patch
queue-4.4/revert-pci-x86-implement-pcibios_alloc_irq-and-pcibios_free_irq.patch
queue-4.4/revert-x86-pci-don-t-alloc-pcibios-irq-when-msi-is-enabled.patch