From 1423de718e6a0ce00372ab119fa40060ff50883e Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 2 Jun 2020 15:56:55 -0500 Subject: PCI/ACPI: Make acpi_pci_osc_control_set() static acpi_pci_osc_control_set() is only called from pci_root.c, so stop exporting it and make it static. Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki --- drivers/acpi/pci_root.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 0bf072cef6cf..7d5a4bd4207c 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -353,7 +353,7 @@ EXPORT_SYMBOL_GPL(acpi_get_pci_dev); * _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 *mask, u32 req) +static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req) { struct acpi_pci_root *root; acpi_status status = AE_OK; @@ -406,7 +406,6 @@ out: mutex_unlock(&osc_lock); return status; } -EXPORT_SYMBOL(acpi_pci_osc_control_set); static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, bool is_pcie) -- cgit v1.2.3 From 866e61fc40c96e7adba62c9e149e96912b10663c Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 2 Jun 2020 17:27:33 -0500 Subject: PCI/ACPI: Remove unnecessary osc_lock 9778c14b4ca2 ("ACPI/PCI: Fix possible race condition on _OSC evaluation") added locking around _OSC calls to protect the acpi_osc_data_list that stored the results. 63f10f0f6df4 ("PCI/ACPI: move _OSC code to pci_root.c") moved the results from acpi_osc_data_list to the struct acpi_pci_root, where it no longer needs locking, but did not remove the lock. Remove the unnecessary locking around _OSC calls. Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki --- drivers/acpi/pci_root.c | 30 ++++++++++-------------------- 1 file changed, 10 insertions(+), 20 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index 7d5a4bd4207c..ea08b3298e73 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -56,8 +56,6 @@ static struct acpi_scan_handler pci_root_handler = { }, }; -static DEFINE_MUTEX(osc_lock); - /** * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge * @handle: the ACPI CA node in question. @@ -223,12 +221,7 @@ static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags) { - acpi_status status; - - mutex_lock(&osc_lock); - status = acpi_pci_query_osc(root, flags, NULL); - mutex_unlock(&osc_lock); - return status; + return acpi_pci_query_osc(root, flags, NULL); } struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle) @@ -356,7 +349,7 @@ EXPORT_SYMBOL_GPL(acpi_get_pci_dev); static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req) { struct acpi_pci_root *root; - acpi_status status = AE_OK; + acpi_status status; u32 ctrl, capbuf[3]; if (!mask) @@ -370,18 +363,16 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 r if (!root) return AE_NOT_EXIST; - 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 & ctrl) == ctrl) - goto out; + return AE_OK; /* 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; + return status; if (ctrl == *mask) break; decode_osc_control(root, "platform does not support", @@ -392,19 +383,18 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 r if ((ctrl & req) != req) { decode_osc_control(root, "not requesting control; platform does not support", req & ~(ctrl)); - status = AE_SUPPORT; - goto out; + return AE_SUPPORT; } capbuf[OSC_QUERY_DWORD] = 0; capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set; capbuf[OSC_CONTROL_DWORD] = ctrl; status = acpi_pci_run_osc(handle, capbuf, mask); - if (ACPI_SUCCESS(status)) - root->osc_control_set = *mask; -out: - mutex_unlock(&osc_lock); - return status; + if (ACPI_FAILURE(status)) + return status; + + root->osc_control_set = *mask; + return AE_OK; } static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, -- cgit v1.2.3 From 508d392ae0bb3729d4c18628e021968a1b11b32c Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 2 Jun 2020 16:42:33 -0500 Subject: PCI/ACPI: Clarify message about _OSC failure This message: acpi PNP0A08:02: _OSC failed (AE_NOT_FOUND); disabling ASPM is alarming and slightly misleading. Per the PCI Firmware Spec, r3.2, sec 4.5.1, _OSC is required for PCIe hierarchies. If _OSC is absent or fails, the OS must not attempt to use any of the features defined for _OSC. That includes native hotplug, native PME, AER, and other things as well as ASPM. Rephrase the message to: acpi PNP0A08:02: _OSC: platform retains control of PCIe features (AE_NOT_FOUND) Previous discussion at https://lore.kernel.org/r/20200602223618.GA845676@bjorn-Precision-5520/ Signed-off-by: Bjorn Helgaas Reviewed-by: Sinan Kaya Acked-by: Rafael J. Wysocki Cc: Yicong Yang --- drivers/acpi/pci_root.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index ea08b3298e73..dcd593766a64 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -441,9 +441,8 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, if ((status == AE_NOT_FOUND) && !is_pcie) return; - dev_info(&device->dev, "_OSC failed (%s)%s\n", - acpi_format_exception(status), - pcie_aspm_support_enabled() ? "; disabling ASPM" : ""); + dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n", + acpi_format_exception(status)); return; } @@ -499,7 +498,7 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, } else { decode_osc_control(root, "OS requested", requested); decode_osc_control(root, "platform willing to grant", control); - dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n", + dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n", acpi_format_exception(status)); /* -- cgit v1.2.3