From 202317a573b20d77a9abb7c16a3fd5b40cef3d9d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 22 Nov 2013 21:54:37 +0100 Subject: ACPI / scan: Add acpi_device objects for all device nodes in the namespace Modify the ACPI namespace scanning code to register a struct acpi_device object for every namespace node representing a device, processor and so on, even if the device represented by that namespace node is reported to be not present and not functional by _STA. There are multiple reasons to do that. First of all, it avoids quite a lot of overhead when struct acpi_device objects are deleted every time acpi_bus_trim() is run and then added again by a subsequent acpi_bus_scan() for the same scope, although the namespace objects they correspond to stay in memory all the time (which always is the case on a vast majority of systems). Second, it will allow user space to see that there are namespace nodes representing devices that are not present at the moment and may be added to the system. It will also allow user space to evaluate _SUN for those nodes to check what physical slots the "missing" devices may be put into and it will make sense to add a sysfs attribute for _STA evaluation after this change (that will be useful for thermal management on some systems). Next, it will help to consolidate the ACPI hotplug handling among subsystems by making it possible to store hotplug-related information in struct acpi_device objects in a standard common way. Finally, it will help to avoid a race condition related to the deletion of ACPI namespace nodes. Namely, namespace nodes may be deleted as a result of a table unload triggered by _EJ0 or _DCK. If a hotplug notification for one of those nodes is triggered right before the deletion and it executes a hotplug callback via acpi_hotplug_execute(), the ACPI handle passed to that callback may be stale when the callback actually runs. One way to work around that is to always pass struct acpi_device pointers to hotplug callbacks after doing a get_device() on the objects in question which eliminates the use-after-free possibility (the ACPI handles in those objects are invalidated by acpi_scan_drop_device(), so they will trigger ACPICA errors on attempts to use them). Signed-off-by: Rafael J. Wysocki Tested-by: Mika Westerberg --- drivers/acpi/pci_root.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/acpi/pci_root.c') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 20360e480bd8..4076491c6ded 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -634,9 +634,10 @@ void __init acpi_pci_root_init(void) static void handle_root_bridge_insertion(acpi_handle handle) { - struct acpi_device *device; + struct acpi_device *device = NULL; - if (!acpi_bus_get_device(handle, &device)) { + acpi_bus_get_device(handle, &device); + if (acpi_device_enumerated(device)) { dev_printk(KERN_DEBUG, &device->dev, "acpi device already exists; ignoring notify\n"); return; -- cgit v1.2.3 From c27b2c33b6215eeb3d5c290ac889ab6d543f6207 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 22 Nov 2013 21:55:07 +0100 Subject: ACPI / hotplug: Introduce common hotplug function acpi_device_hotplug() Modify the common ACPI device hotplug code to always queue up the same function, acpi_device_hotplug(), using acpi_hotplug_execute() and make the PCI host bridge hotplug code use that function too for device hot removal. This allows some code duplication to be reduced and a race condition where the relevant ACPI handle may become invalid between the notification handler and the function queued up by it via acpi_hotplug_execute() to be avoided. Signed-off-by: Rafael J. Wysocki Tested-by: Mika Westerberg --- drivers/acpi/pci_root.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/acpi/pci_root.c') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 4076491c6ded..ca05064f3ff7 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -683,11 +683,13 @@ static void hotplug_event_root(void *data, u32 type) if (!root) break; + acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST, + ACPI_OST_SC_EJECT_IN_PROGRESS, NULL); get_device(&root->device->dev); acpi_scan_lock_release(); - acpi_bus_device_eject(root->device, ACPI_NOTIFY_EJECT_REQUEST); + acpi_device_hotplug(root->device, ACPI_NOTIFY_EJECT_REQUEST); return; default: acpi_handle_warn(handle, -- cgit v1.2.3 From 3338db0057ed9f554050bd06863731c515d79672 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 22 Nov 2013 21:55:20 +0100 Subject: ACPI / hotplug: Make ACPI PCI root hotplug use common hotplug code Rework the common ACPI device hotplug code so that it is suitable for PCI host bridge hotplug and switch the PCI host bridge scan handler to using the common hotplug code. This allows quite a few lines of code that are not necessary any more to be dropped from the PCI host bridge scan handler and removes arbitrary differences in behavior between PCI host bridge hotplug and ACPI-based hotplug of other components, like CPUs and memory. Also acpi_device_hotplug() can be static now. Signed-off-by: Rafael J. Wysocki Tested-by: Mika Westerberg --- drivers/acpi/pci_root.c | 125 +++++------------------------------------------- 1 file changed, 11 insertions(+), 114 deletions(-) (limited to 'drivers/acpi/pci_root.c') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index ca05064f3ff7..2dd11e0bac24 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -51,6 +51,12 @@ static int acpi_pci_root_add(struct acpi_device *device, const struct acpi_device_id *not_used); static void acpi_pci_root_remove(struct acpi_device *device); +static int acpi_pci_root_scan_dependent(struct acpi_device *adev) +{ + acpiphp_check_host_bridge(adev->handle); + return 0; +} + #define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \ | OSC_PCI_ASPM_SUPPORT \ | OSC_PCI_CLOCK_PM_SUPPORT \ @@ -66,7 +72,8 @@ static struct acpi_scan_handler pci_root_handler = { .attach = acpi_pci_root_add, .detach = acpi_pci_root_remove, .hotplug = { - .ignore = true, + .enabled = true, + .scan_dependent = acpi_pci_root_scan_dependent, }, }; @@ -624,119 +631,9 @@ static void acpi_pci_root_remove(struct acpi_device *device) void __init acpi_pci_root_init(void) { acpi_hest_init(); - - if (!acpi_pci_disabled) { - pci_acpi_crs_quirks(); - acpi_scan_add_handler(&pci_root_handler); - } -} -/* Support root bridge hotplug */ - -static void handle_root_bridge_insertion(acpi_handle handle) -{ - struct acpi_device *device = NULL; - - acpi_bus_get_device(handle, &device); - if (acpi_device_enumerated(device)) { - dev_printk(KERN_DEBUG, &device->dev, - "acpi device already exists; ignoring notify\n"); - return; - } - - if (acpi_bus_scan(handle)) - acpi_handle_err(handle, "cannot add bridge to acpi list\n"); -} - -static void hotplug_event_root(void *data, u32 type) -{ - acpi_handle handle = data; - struct acpi_pci_root *root; - - acpi_scan_lock_acquire(); - - root = acpi_pci_find_root(handle); - - switch (type) { - case ACPI_NOTIFY_BUS_CHECK: - /* bus enumerate */ - acpi_handle_printk(KERN_DEBUG, handle, - "Bus check notify on %s\n", __func__); - if (root) - acpiphp_check_host_bridge(handle); - else - handle_root_bridge_insertion(handle); - - break; - - case ACPI_NOTIFY_DEVICE_CHECK: - /* device check */ - acpi_handle_printk(KERN_DEBUG, handle, - "Device check notify on %s\n", __func__); - if (!root) - handle_root_bridge_insertion(handle); - break; - - case ACPI_NOTIFY_EJECT_REQUEST: - /* request device eject */ - acpi_handle_printk(KERN_DEBUG, handle, - "Device eject notify on %s\n", __func__); - if (!root) - break; - - acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST, - ACPI_OST_SC_EJECT_IN_PROGRESS, NULL); - get_device(&root->device->dev); - - acpi_scan_lock_release(); - - acpi_device_hotplug(root->device, ACPI_NOTIFY_EJECT_REQUEST); + if (acpi_pci_disabled) return; - default: - acpi_handle_warn(handle, - "notify_handler: unknown event type 0x%x\n", - type); - break; - } - - acpi_scan_lock_release(); -} - -static void handle_hotplug_event_root(acpi_handle handle, u32 type, - void *context) -{ - acpi_hotplug_execute(hotplug_event_root, handle, type); -} - -static acpi_status __init -find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv) -{ - acpi_status status; - int *count = (int *)context; - - if (!acpi_is_root_bridge(handle)) - return AE_OK; - - (*count)++; - - status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY, - handle_hotplug_event_root, NULL); - if (ACPI_FAILURE(status)) - acpi_handle_printk(KERN_DEBUG, handle, - "notify handler is not installed, exit status: %u\n", - (unsigned int)status); - else - acpi_handle_printk(KERN_DEBUG, handle, - "notify handler is installed\n"); - - return AE_OK; -} - -void __init acpi_pci_root_hp_init(void) -{ - int num = 0; - - acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, - ACPI_UINT32_MAX, find_root_bridges, NULL, &num, NULL); - printk(KERN_DEBUG "Found %d acpi root devices\n", num); + pci_acpi_crs_quirks(); + acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root"); } -- cgit v1.2.3 From 8b48463f89429af408ff695244dc627e1acff4f7 Mon Sep 17 00:00:00 2001 From: Lv Zheng Date: Tue, 3 Dec 2013 08:49:16 +0800 Subject: ACPI: Clean up inclusions of ACPI header files Replace direct inclusions of , and , which are incorrect, with inclusions and remove some inclusions of those files that aren't necessary. First of all, , and should not be included directly from any files that are built for CONFIG_ACPI unset, because that generally leads to build warnings about undefined symbols in !CONFIG_ACPI builds. For CONFIG_ACPI set, includes those files and for CONFIG_ACPI unset it provides stub ACPI symbols to be used in that case. Second, there are ordering dependencies between those files that always have to be met. Namely, it is required that be included prior to so that the acpi_pci_root declarations the latter depends on are always there. And which provides basic ACPICA type declarations should always be included prior to any other ACPI headers in CONFIG_ACPI builds. That also is taken care of including as appropriate. Signed-off-by: Lv Zheng Cc: Greg Kroah-Hartman Cc: Matthew Garrett Cc: Tony Luck Cc: "H. Peter Anvin" Acked-by: Bjorn Helgaas (drivers/pci stuff) Acked-by: Konrad Rzeszutek Wilk (Xen stuff) Signed-off-by: Rafael J. Wysocki --- drivers/acpi/pci_root.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'drivers/acpi/pci_root.c') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 0703bff5e60e..cd20f3486cfa 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -35,9 +35,7 @@ #include #include #include -#include -#include -#include +#include /* for acpi_hest_init() */ #include "internal.h" -- cgit v1.2.3 From 7a3bb55ebd1cb04f08dd68cf60af24b434f8cc2a Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 10 Jan 2014 15:23:14 +0100 Subject: ACPI / PCI: Use global PCI rescan-remove locking in PCI root hotplug Multiple race conditions are possible between the addition and removal of PCI devices during ACPI PCI host bridge hotplug and the generic PCI bus rescan and device removal that can be triggered via sysfs. To avoid those race conditions make the ACPI PCI host bridge addition and removal code use global PCI rescan-remove locking. Signed-off-by: Rafael J. Wysocki Signed-off-by: Bjorn Helgaas --- drivers/acpi/pci_root.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/acpi/pci_root.c') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 0703bff5e60e..07ee02aa3c51 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -596,7 +596,9 @@ static int acpi_pci_root_add(struct acpi_device *device, pci_assign_unassigned_root_bus_resources(root->bus); } + pci_lock_rescan_remove(); pci_bus_add_devices(root->bus); + pci_unlock_rescan_remove(); return 1; end: @@ -608,6 +610,8 @@ static void acpi_pci_root_remove(struct acpi_device *device) { struct acpi_pci_root *root = acpi_driver_data(device); + pci_lock_rescan_remove(); + pci_stop_root_bus(root->bus); device_set_run_wake(root->bus->bridge, false); @@ -615,6 +619,8 @@ static void acpi_pci_root_remove(struct acpi_device *device) pci_remove_root_bus(root->bus); + pci_unlock_rescan_remove(); + kfree(root); } -- cgit v1.2.3