From b879dc4b3e81069e3f715b7569bb0f43eed76c76 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 21 Aug 2010 01:52:37 +0200 Subject: ACPI/PCI: Reorder checks in acpi_pci_osc_control_set() Make acpi_pci_osc_control_set() attempt to find the handle of the _OSC object under the given PCI root bridge object after verifying that its second argument is correct and that there is a struct acpi_pci_root object for the given root bridge handle, which is more logical than the old code. Signed-off-by: Rafael J. Wysocki Reviewed-by: Hidetoshi Seto Signed-off-by: Jesse Barnes --- drivers/acpi/pci_root.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 1f67057af2a5..e10dbafa0569 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -378,10 +378,6 @@ acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags) acpi_handle tmp; struct acpi_pci_root *root; - status = acpi_get_handle(handle, "_OSC", &tmp); - if (ACPI_FAILURE(status)) - return status; - control_req = (flags & OSC_PCI_CONTROL_MASKS); if (!control_req) return AE_TYPE; @@ -390,6 +386,10 @@ acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags) if (!root) return AE_NOT_EXIST; + status = acpi_get_handle(handle, "_OSC", &tmp); + if (ACPI_FAILURE(status)) + return status; + mutex_lock(&osc_lock); /* No need to evaluate _OSC if the control was already granted. */ if ((root->osc_control_set & control_req) == control_req) -- cgit v1.2.1 From ab8e8957a2ae21c0f036476c6db13e949be730ac Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 21 Aug 2010 01:53:27 +0200 Subject: ACPI/PCI: Make acpi_pci_query_osc() return control bits Make acpi_pci_query_osc() use an additional pointer argument to return the mask of control bits obtained from the BIOS to the caller. Signed-off-by: Rafael J. Wysocki Signed-off-by: Jesse Barnes --- drivers/acpi/pci_root.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index e10dbafa0569..d2ae816df0f5 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -226,22 +226,35 @@ static acpi_status acpi_pci_run_osc(acpi_handle handle, return status; } -static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, u32 flags) +static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, + u32 support, + u32 *control) { acpi_status status; - u32 support_set, result, capbuf[3]; + u32 result, capbuf[3]; + + support &= OSC_PCI_SUPPORT_MASKS; + support |= root->osc_support_set; - /* do _OSC query for all possible controls */ - support_set = root->osc_support_set | (flags & OSC_PCI_SUPPORT_MASKS); capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE; - capbuf[OSC_SUPPORT_TYPE] = support_set; - capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS; + capbuf[OSC_SUPPORT_TYPE] = support; + if (control) { + *control &= OSC_PCI_CONTROL_MASKS; + capbuf[OSC_CONTROL_TYPE] = *control | root->osc_control_set; + } else { + /* Run _OSC query for all possible controls. */ + capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS; + } status = acpi_pci_run_osc(root->device->handle, capbuf, &result); if (ACPI_SUCCESS(status)) { - root->osc_support_set = support_set; - root->osc_control_qry = result; - root->osc_queried = 1; + root->osc_support_set = support; + if (control) { + *control = result; + } else { + root->osc_control_qry = result; + root->osc_queried = 1; + } } return status; } @@ -255,7 +268,7 @@ static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags) if (ACPI_FAILURE(status)) return status; mutex_lock(&osc_lock); - status = acpi_pci_query_osc(root, flags); + status = acpi_pci_query_osc(root, flags, NULL); mutex_unlock(&osc_lock); return status; } @@ -397,7 +410,7 @@ acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags) /* Need to query controls first before requesting them */ if (!root->osc_queried) { - status = acpi_pci_query_osc(root, root->osc_support_set); + status = acpi_pci_query_osc(root, root->osc_support_set, NULL); if (ACPI_FAILURE(status)) goto out; } -- cgit v1.2.1 From 2b8fd9186d9275b07aef43e5bb4e98cd571f9a7d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 23 Aug 2010 23:55:59 +0200 Subject: ACPI/PCI: Do not preserve _OSC control bits returned by a query There is the assumption in acpi_pci_osc_control_set() that it is always sufficient to compare the mask of _OSC control bits to be requested with the result of an _OSC query where all of the known control bits have been checked. However, in general, that need not be the case. For example, if an _OSC feature A depends on an _OSC feature B and control of A, B plus another _OSC feature C is requested simultaneously, the BIOS may return A, B, C, while it would only return C if A and C were requested without B. That may result in passing a wrong mask of _OSC control bits to an _OSC control request, in which case the BIOS may only grant control of a subset of the requested features. Moreover, acpi_pci_run_osc() will return error code if that happens and the caller of acpi_pci_osc_control_set() will not know that it's been granted control of some _OSC features. Consequently, the system will generally not work as expected. Apart from this acpi_pci_osc_control_set() always uses the mask of _OSC control bits returned by the very first invocation of acpi_pci_query_osc(), but that is done with the second argument equal to OSC_PCI_SEGMENT_GROUPS_SUPPORT which generally happens to affect the returned _OSC control bits. For these reasons, make acpi_pci_osc_control_set() always check if control of the requested _OSC features will be granted before making the final control request. As a result, the osc_control_qry and osc_queried members of struct acpi_pci_root are not necessary any more, so drop them and remove the remaining code referring to them. Signed-off-by: Rafael J. Wysocki Signed-off-by: Jesse Barnes --- drivers/acpi/pci_root.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index d2ae816df0f5..77cd19697b1e 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -249,12 +249,8 @@ static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, status = acpi_pci_run_osc(root->device->handle, capbuf, &result); if (ACPI_SUCCESS(status)) { root->osc_support_set = support; - if (control) { + if (control) *control = result; - } else { - root->osc_control_qry = result; - root->osc_queried = 1; - } } return status; } @@ -409,14 +405,12 @@ acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags) goto out; /* Need to query controls first before requesting them */ - if (!root->osc_queried) { - status = acpi_pci_query_osc(root, root->osc_support_set, NULL); - if (ACPI_FAILURE(status)) - goto out; - } - if ((root->osc_control_qry & control_req) != control_req) { - printk(KERN_DEBUG - "Firmware did not grant requested _OSC control\n"); + flags = control_req; + status = acpi_pci_query_osc(root, root->osc_support_set, &flags); + if (ACPI_FAILURE(status)) + goto out; + + if (flags != control_req) { status = AE_SUPPORT; goto out; } -- cgit v1.2.1 From 75fb60f26befb59dbfa05cb122972642b7bdd219 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 23 Aug 2010 23:53:11 +0200 Subject: ACPI/PCI: Negotiate _OSC control bits before requesting them It is possible that the BIOS will not grant control of all _OSC features requested via acpi_pci_osc_control_set(), so it is recommended to negotiate the final set of _OSC features with the query flag set before calling _OSC to request control of these features. To implement it, rework acpi_pci_osc_control_set() so that the caller can specify the mask of _OSC control bits to negotiate and the mask of _OSC control bits that are absolutely necessary to it. Then, acpi_pci_osc_control_set() will run _OSC queries in a loop until the mask of _OSC control bits returned by the BIOS is equal to the mask passed to it. Also, before running the _OSC request acpi_pci_osc_control_set() will check if the caller's required control bits are present in the final mask. Using this mechanism we will be able to avoid situations in which the BIOS doesn't grant control of certain _OSC features, because they depend on some other _OSC features that have not been requested. Signed-off-by: Rafael J. Wysocki Signed-off-by: Jesse Barnes --- drivers/acpi/pci_root.c | 59 +++++++++++++++++++++++++++++++------------------ 1 file changed, 38 insertions(+), 21 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 77cd19697b1e..c34713112520 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -374,21 +374,32 @@ out: EXPORT_SYMBOL_GPL(acpi_get_pci_dev); /** - * acpi_pci_osc_control_set - commit requested control to Firmware - * @handle: acpi_handle for the target ACPI object - * @flags: driver's requested control bits + * acpi_pci_osc_control_set - Request control of PCI root _OSC features. + * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex). + * @mask: Mask of _OSC bits to request control of, place to store control mask. + * @req: Mask of _OSC bits the control of is essential to the caller. * - * Attempt to take control from Firmware on requested control bits. + * Run _OSC query for @mask and if that is successful, compare the returned + * mask of control bits with @req. If all of the @req bits are set in the + * returned mask, run _OSC request for it. + * + * The variable at the @mask address may be modified regardless of whether or + * not the function returns success. On success it will contain the mask of + * _OSC bits the BIOS has granted control of, but its contents are meaningless + * on failure. **/ -acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags) +acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req) { + struct acpi_pci_root *root; acpi_status status; - u32 control_req, result, capbuf[3]; + u32 ctrl, capbuf[3]; acpi_handle tmp; - struct acpi_pci_root *root; - control_req = (flags & OSC_PCI_CONTROL_MASKS); - if (!control_req) + if (!mask) + return AE_BAD_PARAMETER; + + ctrl = *mask & OSC_PCI_CONTROL_MASKS; + if ((ctrl & req) != req) return AE_TYPE; root = acpi_pci_find_root(handle); @@ -400,27 +411,33 @@ acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags) return status; mutex_lock(&osc_lock); + + *mask = ctrl | root->osc_control_set; /* No need to evaluate _OSC if the control was already granted. */ - if ((root->osc_control_set & control_req) == control_req) + if ((root->osc_control_set & ctrl) == ctrl) goto out; - /* Need to query controls first before requesting them */ - flags = control_req; - status = acpi_pci_query_osc(root, root->osc_support_set, &flags); - if (ACPI_FAILURE(status)) - goto out; + /* Need to check the available controls bits before requesting them. */ + while (*mask) { + status = acpi_pci_query_osc(root, root->osc_support_set, mask); + if (ACPI_FAILURE(status)) + goto out; + if (ctrl == *mask) + break; + ctrl = *mask; + } - if (flags != control_req) { + if ((ctrl & req) != req) { status = AE_SUPPORT; goto out; } capbuf[OSC_QUERY_TYPE] = 0; capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set; - capbuf[OSC_CONTROL_TYPE] = root->osc_control_set | control_req; - status = acpi_pci_run_osc(handle, capbuf, &result); + capbuf[OSC_CONTROL_TYPE] = ctrl; + status = acpi_pci_run_osc(handle, capbuf, mask); if (ACPI_SUCCESS(status)) - root->osc_control_set = result; + root->osc_control_set = *mask; out: mutex_unlock(&osc_lock); return status; @@ -551,8 +568,8 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device) if (flags != base_flags) acpi_pci_osc_support(root, flags); - status = acpi_pci_osc_control_set(root->device->handle, - OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL); + flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL; + status = acpi_pci_osc_control_set(root->device->handle, &flags, flags); if (ACPI_FAILURE(status)) { printk(KERN_INFO "Unable to assume PCIe control: Disabling ASPM\n"); -- cgit v1.2.1 From 28eb5f274a305bf3a13b2c80c4804d4515d05c64 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 21 Aug 2010 22:02:38 +0200 Subject: 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 Signed-off-by: Jesse Barnes --- drivers/acpi/pci_root.c | 9 --------- 1 file changed, 9 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index c34713112520..3ba8d1f44a73 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -33,7 +33,6 @@ #include #include #include -#include #include #include #include @@ -568,14 +567,6 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device) if (flags != base_flags) acpi_pci_osc_support(root, flags); - flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL; - status = acpi_pci_osc_control_set(root->device->handle, &flags, flags); - - if (ACPI_FAILURE(status)) { - printk(KERN_INFO "Unable to assume PCIe control: Disabling ASPM\n"); - pcie_no_aspm(); - } - pci_acpi_add_bus_pm_notifier(device, root->bus); if (device->wakeup.flags.run_wake) device_set_run_wake(root->bus->bridge, true); -- cgit v1.2.1