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* [Resend with Ack][PATCH v1] PCI: allow acpiphp to handle PCIe ports without native PCIe hotplug capability
@ 2012-06-04  7:44 Jiang Liu
  2012-06-04  8:23 ` Kenji Kaneshige
                   ` (2 more replies)
  0 siblings, 3 replies; 48+ messages in thread
From: Jiang Liu @ 2012-06-04  7:44 UTC (permalink / raw)
  To: Bjorn Helgaas, Rafael J. Wysocki
  Cc: Jiang Liu, Yinghai Lu, Kenji Kaneshige, Taku Izumi, Don Dutile,
	Yijing Wang, Keping Chen, linux-pci, linux-kernel, Jiang Liu

Commit 0d52f54e2ef64c189dedc332e680b2eb4a34590a (PCI / ACPI: Make acpiphp
ignore root bridges using PCIe native hotplug) added code that made the
acpiphp driver completely ignore PCIe root complexes for which the kernel
had been granted control of the native PCIe hotplug feature by the BIOS
through _OSC. Later commit 619a5182d1f38a3d629ee48e04fa182ef9170052
"PCI hotplug: Always allow acpiphp to handle non-PCIe bridges" relaxed
the constraints to allow acpiphp driver handle non-PCIe bridges under
such a complex. The constraint needs to be relaxed further to allow
acpiphp driver to hanlde PCIe ports without native PCIe hotplug capability.

Some MR-IOV switch chipsets, such PLX8696, support multiple virtual PCIe
switches and may migrate downstream ports among virtual switches.
To migrate a downstream port from the source virtual switch to the target,
the port needs to be hot-removed from the source and hot-added into the
target. pciehp driver can't be used here because there's no slots within
the virtual PCIe switch. So acpiphp driver is used to support downstream
port migration. A typical configuration is as below:
[Root w/o native PCIe HP]
	[Upstream port of vswitch w/o native PCIe HP]
		[Downstream port of vswitch w/ native PCIe HP]
			[PCIe enpoint]

Here acpiphp driver will be used to handle root ports and upstream port
in the virtual switch, and pciehp driver will be used to handle downstream
ports in the virtual switch.

Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jiang Liu <liuj97@gmail.com>

---
 drivers/pci/hotplug/acpiphp_glue.c |   49 ++++++++++++++++++++++++++++-------
 1 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index 806c44f..4889448 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -115,6 +115,43 @@ static const struct acpi_dock_ops acpiphp_dock_ops = {
 	.handler = handle_hotplug_event_func,
 };
 
+/* Check whether device is managed by native PCIe hotplug driver */
+static bool device_is_managed_by_native_pciehp(struct pci_dev *pdev)
+{
+	int pos;
+	u16 reg16;
+	u32 reg32;
+	acpi_handle tmp;
+	struct acpi_pci_root *root;
+
+	if (!pci_is_pcie(pdev))
+		return false;
+
+	/* Check whether PCIe port supports native PCIe hotplug */
+	pos = pci_pcie_cap(pdev);
+	pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
+	if (!(reg16 & PCI_EXP_FLAGS_SLOT))
+		return false;
+	pci_read_config_dword(pdev, pos + PCI_EXP_SLTCAP, &reg32);
+	if (!(reg32 & PCI_EXP_SLTCAP_HPC))
+		return false;
+
+	/*
+	 * Check whether native PCIe hotplug has been enabled for
+	 * this PCIe hierarchy.
+	 */
+	tmp = acpi_find_root_bridge_handle(pdev);
+	if (!tmp)
+		return false;
+	root = acpi_pci_find_root(tmp);
+	if (!root)
+		return false;
+	if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
+		return false;
+
+	return true;
+}
+
 /* callback routine to register each ACPI PCI slot object */
 static acpi_status
 register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
@@ -133,16 +170,8 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
 		return AE_OK;
 
 	pdev = pbus->self;
-	if (pdev && pci_is_pcie(pdev)) {
-		tmp = acpi_find_root_bridge_handle(pdev);
-		if (tmp) {
-			struct acpi_pci_root *root = acpi_pci_find_root(tmp);
-
-			if (root && (root->osc_control_set &
-					OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
-				return AE_OK;
-		}
-	}
+	if (pdev && device_is_managed_by_native_pciehp(pdev))
+		return AE_OK;
 
 	acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
 	device = (adr >> 16) & 0xffff;
-- 
1.7.1



^ permalink raw reply related	[flat|nested] 48+ messages in thread

end of thread, other threads:[~2012-09-25 15:16 UTC | newest]

Thread overview: 48+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-06-04  7:44 [Resend with Ack][PATCH v1] PCI: allow acpiphp to handle PCIe ports without native PCIe hotplug capability Jiang Liu
2012-06-04  8:23 ` Kenji Kaneshige
2012-07-03  4:16 ` Bjorn Helgaas
2012-07-03 15:59   ` Bjorn Helgaas
2012-07-03 19:50     ` Don Dutile
2012-07-04 18:07       ` Bjorn Helgaas
2012-07-09 10:05         ` Jiang Liu
2012-07-09 17:05           ` Bjorn Helgaas
2012-07-04  2:52     ` Jiang Liu
2012-07-10 15:54     ` [RFC PATCH 00/14] improve PCIe capabilities registers handling Jiang Liu
2012-07-10 18:44       ` Bjorn Helgaas
2012-07-10 15:54     ` [RFC PATCH 01/14] PCI: add pcie_flags into struct pci_dev to cache PCIe capabilities register Jiang Liu
2012-07-11  9:01       ` Taku Izumi
2012-07-11 14:27         ` Jiang Liu
2012-07-10 15:54     ` [RFC PATCH 02/14] PCI: introduce pci_pcie_type(dev) to replace pci_dev->pcie_type Jiang Liu
2012-07-10 15:54     ` [RFC PATCH 03/14] PCI: remove unused field pcie_type from struct pci_dev Jiang Liu
2012-07-10 15:54     ` [RFC PATCH 04/14] PCI: refine and move pcie_cap_has_*() macros to include/linux/pci.h Jiang Liu
2012-07-10 18:49       ` Bjorn Helgaas
2012-07-10 15:54     ` [RFC PATCH 05/14] PCI: add access functions for PCIe capabilities to hide PCIe spec differences Jiang Liu
2012-07-10 18:35       ` Bjorn Helgaas
2012-07-11  3:07         ` Jiang Liu
2012-07-11  3:40           ` Bjorn Helgaas
2012-07-11  6:40             ` Jiang Liu
2012-07-11 17:52               ` Bjorn Helgaas
2012-07-12  2:56                 ` Jiang Liu
2012-07-12 20:49                   ` Bjorn Helgaas
2012-07-15 16:47                     ` Jiang Liu
2012-07-16 17:29                       ` Bjorn Helgaas
2012-07-16 18:57                         ` Don Dutile
2012-07-17  0:09                         ` Jiang Liu
2012-07-17  0:14                           ` Bjorn Helgaas
2012-07-10 15:54     ` [RFC PATCH 06/14] PCI: use PCIe cap access functions to simplify PCI core implementation Jiang Liu
2012-07-10 18:35       ` Bjorn Helgaas
2012-07-11  2:49         ` Jiang Liu
2012-07-10 15:54     ` [RFC PATCH 07/14] hotplug/PCI: use PCIe cap access functions to simplify implementation Jiang Liu
2012-07-10 18:35       ` Bjorn Helgaas
2012-07-10 15:54     ` [RFC PATCH 08/14] portdrv/PCI: " Jiang Liu
2012-07-10 15:54     ` [RFC PATCH 09/14] pciehp/PCI: " Jiang Liu
2012-07-10 15:54     ` [RFC PATCH 10/14] PME/PCI: " Jiang Liu
2012-07-10 15:54     ` [RFC PATCH 11/14] AER/PCI: " Jiang Liu
2012-07-10 15:54     ` [RFC PATCH 12/14] ASPM/PCI: " Jiang Liu
2012-07-10 15:54     ` [RFC PATCH 13/14] r8169/PCI: " Jiang Liu
2012-07-10 15:54     ` [RFC PATCH 14/14] qib/PCI: " Jiang Liu
2012-08-15 19:12 ` [Resend with Ack][PATCH v1] PCI: allow acpiphp to handle PCIe ports without native PCIe hotplug capability Bjorn Helgaas
2012-08-16 15:15   ` Jiang Liu
2012-08-22 15:16   ` [PATCH v2] PCI: allow acpiphp to handle PCIe ports w/o " Jiang Liu
2012-09-24 22:10     ` Bjorn Helgaas
2012-09-25 15:16       ` Jiang Liu

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