PCI: PCIe: Ask BIOS for control of all native services at once

After commit 852972acff8f10f3a15679be2059bb94916cba5d (ACPI: Disable
ASPM if the platform won't provide _OSC control for PCIe) control of
the PCIe Capability Structure is unconditionally requested by
acpi_pci_root_add(), which in principle may cause problems to
happen in two ways.  First, the BIOS may refuse to give control of
the PCIe Capability Structure if it is not asked for any of the
_OSC features depending on it at the same time.  Second, the BIOS may
assume that control of the _OSC features depending on the PCIe
Capability Structure will be requested in the future and may behave
incorrectly if that doesn't happen.  For this reason, control of
the PCIe Capability Structure should always be requested along with
control of any other _OSC features that may depend on it (ie. PCIe
native PME, PCIe native hot-plug, PCIe AER).

Rework the PCIe port driver so that (1) it checks which native PCIe
port services can be enabled, according to the BIOS, and (2) it
requests control of all these services simultaneously.  In
particular, this causes pcie_portdrv_probe() to fail if the BIOS
refuses to grant control of the PCIe Capability Structure, which
means that no native PCIe port services can be enabled for the PCIe
Root Complex the given port belongs to.  If that happens, ASPM is
disabled to avoid problems with mishandling it by the part of the
PCIe hierarchy for which control of the PCIe Capability Structure
has not been received.

Make it possible to override this behavior using 'pcie_ports=native'
(use the PCIe native services regardless of the BIOS response to the
control request), or 'pcie_ports=compat' (do not use the PCIe native
services at all).

Accordingly, rework the existing PCIe port service drivers so that
they don't request control of the services directly.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

4 files changed, 6 insertions, 147 deletions

diff --git a/drivers/pci/pcie/pme/Makefile b/drivers/pci/pcie/pme/Makefile
index 8b9238053080..3c67bf4d26cf 100644
--- a/drivers/pci/pcie/pme/Makefile
+++ b/drivers/pci/pcie/pme/Makefile
@@ -2,7 +2,4 @@
 # Makefile for PCI-Express Root Port PME signaling driver
 #
 
-obj-$(CONFIG_PCIE_PME) += pmedriver.o
-
-pmedriver-objs := pcie_pme.o
-pmedriver-$(CONFIG_ACPI) += pcie_pme_acpi.o
+obj-$(CONFIG_PCIE_PME) += pcie_pme.o
diff --git a/drivers/pci/pcie/pme/pcie_pme.c b/drivers/pci/pcie/pme/pcie_pme.c
index bbdea18693d9..9d1361e1a776 100644
--- a/drivers/pci/pcie/pme/pcie_pme.c
+++ b/drivers/pci/pcie/pme/pcie_pme.c
@@ -24,37 +24,12 @@
 #include <linux/pm_runtime.h>
 
 #include "../../pci.h"
-#include "pcie_pme.h"
+#include "../portdrv.h"
 
 #define PCI_EXP_RTSTA_PME       0x10000 /* PME status */
 #define PCI_EXP_RTSTA_PENDING   0x20000 /* PME pending */
 
 /*
- * If set, this switch will prevent the PCIe root port PME service driver from
- * being registered.  Consequently, the interrupt-based PCIe PME signaling will
- * not be used by any PCIe root ports in that case.
- */
-static bool pcie_pme_disabled = true;
-
-/*
- * The PCI Express Base Specification 2.0, Section 6.1.8, states the following:
- * "In order to maintain compatibility with non-PCI Express-aware system
- * software, system power management logic must be configured by firmware to use
- * the legacy mechanism of signaling PME by default.  PCI Express-aware system
- * software must notify the firmware prior to enabling native, interrupt-based
- * PME signaling."  However, if the platform doesn't provide us with a suitable
- * notification mechanism or the notification fails, it is not clear whether or
- * not we are supposed to use the interrupt-based PCIe PME signaling.  The
- * switch below can be used to indicate the desired behaviour.  When set, it
- * will make the kernel use the interrupt-based PCIe PME signaling regardless of
- * the platform notification status, although the kernel will attempt to notify
- * the platform anyway.  When unset, it will prevent the kernel from using the
- * the interrupt-based PCIe PME signaling if the platform notification fails,
- * which is the default.
- */
-static bool pcie_pme_force_enable;
-
-/*
  * If this switch is set, MSI will not be used for PCIe PME signaling.  This
  * causes the PCIe port driver to use INTx interrupts only, but it turns out
  * that using MSI for PCIe PME signaling doesn't play well with PCIe PME-based
@@ -64,38 +39,13 @@ bool pcie_pme_msi_disabled;
 
 static int __init pcie_pme_setup(char *str)
 {
-        if (!strncmp(str, "auto", 4))
-                pcie_pme_disabled = false;
-        else if (!strncmp(str, "force", 5))
-                pcie_pme_force_enable = true;
-
-        str = strchr(str, ',');
-        if (str) {
-                str++;
-                str += strspn(str, " \t");
-                if (*str && !strcmp(str, "nomsi"))
-                        pcie_pme_msi_disabled = true;
-        }
+        if (!strncmp(str, "nomsi", 5))
+                pcie_pme_msi_disabled = true;
 
         return 1;
 }
 __setup("pcie_pme=", pcie_pme_setup);
 
-/**
- * pcie_pme_platform_setup - Ensure that the kernel controls the PCIe PME.
- * @srv: PCIe PME root port service to use for carrying out the check.
- *
- * Notify the platform that the native PCIe PME is going to be used and return
- * 'true' if the control of the PCIe PME registers has been acquired from the
- * platform.
- */
-static bool pcie_pme_platform_setup(struct pcie_device *srv)
-{
-        if (!pcie_pme_platform_notify(srv))
-                return true;
-        return pcie_pme_force_enable;
-}
-
 struct pcie_pme_service_data {
         spinlock_t lock;
         struct pcie_device *srv;
@@ -108,7 +58,7 @@ struct pcie_pme_service_data {
  * @dev: PCIe root port or event collector.
  * @enable: Enable or disable the interrupt.
  */
-static void pcie_pme_interrupt_enable(struct pci_dev *dev, bool enable)
+void pcie_pme_interrupt_enable(struct pci_dev *dev, bool enable)
 {
         int rtctl_pos;
         u16 rtctl;
@@ -417,9 +367,6 @@ static int pcie_pme_probe(struct pcie_device *srv)
         struct pcie_pme_service_data *data;
         int ret;
 
-        if (!pcie_pme_platform_setup(srv))
-                return -EACCES;
-
         data = kzalloc(sizeof(*data), GFP_KERNEL);
         if (!data)
                 return -ENOMEM;
@@ -509,8 +456,7 @@ static struct pcie_port_service_driver pcie_pme_driver = {
  */
 static int __init pcie_pme_service_init(void)
 {
-        return pcie_pme_disabled ?
-                -ENODEV : pcie_port_service_register(&pcie_pme_driver);
+        return pcie_port_service_register(&pcie_pme_driver);
 }
 
 module_init(pcie_pme_service_init);
diff --git a/drivers/pci/pcie/pme/pcie_pme.h b/drivers/pci/pcie/pme/pcie_pme.h
deleted file mode 100644
index b30d2b7c9775..000000000000
--- a/drivers/pci/pcie/pme/pcie_pme.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- * drivers/pci/pcie/pme/pcie_pme.h
- *
- * PCI Express Root Port PME signaling support
- *
- * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
- */
-
-#ifndef _PCIE_PME_H_
-#define _PCIE_PME_H_
-
-struct pcie_device;
-
-#ifdef CONFIG_ACPI
-extern int pcie_pme_acpi_setup(struct pcie_device *srv);
-
-static inline int pcie_pme_platform_notify(struct pcie_device *srv)
-{
-        return pcie_pme_acpi_setup(srv);
-}
-#else /* !CONFIG_ACPI */
-static inline int pcie_pme_platform_notify(struct pcie_device *srv)
-{
-        return 0;
-}
-#endif /* !CONFIG_ACPI */
-
-#endif
diff --git a/drivers/pci/pcie/pme/pcie_pme_acpi.c b/drivers/pci/pcie/pme/pcie_pme_acpi.c
deleted file mode 100644
index be20222b12d3..000000000000
--- a/drivers/pci/pcie/pme/pcie_pme_acpi.c
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * PCIe Native PME support, ACPI-related part
- *
- * Copyright (C) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License V2.  See the file "COPYING" in the main directory of this archive
- * for more details.
- */
-
-#include <linux/pci.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/acpi.h>
-#include <linux/pci-acpi.h>
-#include <linux/pcieport_if.h>
-
-/**
- * pcie_pme_acpi_setup - Request the ACPI BIOS to release control over PCIe PME.
- * @srv - PCIe PME service for a root port or event collector.
- *
- * Invoked when the PCIe bus type loads PCIe PME service driver.  To avoid
- * conflict with the BIOS PCIe support requires the BIOS to yield PCIe PME
- * control to the kernel.
- */
-int pcie_pme_acpi_setup(struct pcie_device *srv)
-{
-        acpi_status status = AE_NOT_FOUND;
-        struct pci_dev *port = srv->port;
-        acpi_handle handle;
-        u32 flags;
-        int error = 0;
-
-        if (acpi_pci_disabled)
-                return -ENOSYS;
-
-        dev_info(&port->dev, "Requesting control of PCIe PME from ACPI BIOS\n");
-
-        handle = acpi_find_root_bridge_handle(port);
-        if (!handle)
-                return -EINVAL;
-
-        flags = OSC_PCI_EXPRESS_PME_CONTROL |
-                OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL;
-
-        status = acpi_pci_osc_control_set(handle, &flags, flags);
-        if (ACPI_FAILURE(status)) {
-                dev_info(&port->dev,
-                        "Failed to receive control of PCIe PME service: %s\n",
-                        (status == AE_SUPPORT || status == AE_NOT_FOUND) ?
-                        "no _OSC support" : "ACPI _OSC failed");
-                error = -ENODEV;
-        }
-
-        return error;
-}