diff options
Diffstat (limited to 'drivers/acpi/pci_root.c')
-rw-r--r-- | drivers/acpi/pci_root.c | 319 |
1 files changed, 224 insertions, 95 deletions
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index b76db99cced3..4e3db20e9cbb 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -22,8 +22,6 @@ #include <linux/slab.h> #include <linux/dmi.h> #include <linux/platform_data/x86/apple.h> -#include <acpi/apei.h> /* for acpi_hest_init() */ - #include "internal.h" #define ACPI_PCI_ROOT_CLASS "pci_bridge" @@ -142,6 +140,17 @@ static struct pci_osc_bit_struct pci_osc_control_bit[] = { { OSC_PCI_EXPRESS_DPC_CONTROL, "DPC" }, }; +static struct pci_osc_bit_struct cxl_osc_support_bit[] = { + { OSC_CXL_1_1_PORT_REG_ACCESS_SUPPORT, "CXL11PortRegAccess" }, + { OSC_CXL_2_0_PORT_DEV_REG_ACCESS_SUPPORT, "CXL20PortDevRegAccess" }, + { OSC_CXL_PROTOCOL_ERR_REPORTING_SUPPORT, "CXLProtocolErrorReporting" }, + { OSC_CXL_NATIVE_HP_SUPPORT, "CXLNativeHotPlug" }, +}; + +static struct pci_osc_bit_struct cxl_osc_control_bit[] = { + { OSC_CXL_ERROR_REPORTING_CONTROL, "CXLMemErrorReporting" }, +}; + static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word, struct pci_osc_bit_struct *table, int size) { @@ -170,33 +179,73 @@ static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word) ARRAY_SIZE(pci_osc_control_bit)); } +static void decode_cxl_osc_support(struct acpi_pci_root *root, char *msg, u32 word) +{ + decode_osc_bits(root, msg, word, cxl_osc_support_bit, + ARRAY_SIZE(cxl_osc_support_bit)); +} + +static void decode_cxl_osc_control(struct acpi_pci_root *root, char *msg, u32 word) +{ + decode_osc_bits(root, msg, word, cxl_osc_control_bit, + ARRAY_SIZE(cxl_osc_control_bit)); +} + +static inline bool is_pcie(struct acpi_pci_root *root) +{ + return root->bridge_type == ACPI_BRIDGE_TYPE_PCIE; +} + +static inline bool is_cxl(struct acpi_pci_root *root) +{ + return root->bridge_type == ACPI_BRIDGE_TYPE_CXL; +} + static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766"; +static u8 cxl_osc_uuid_str[] = "68F2D50B-C469-4d8A-BD3D-941A103FD3FC"; + +static char *to_uuid(struct acpi_pci_root *root) +{ + if (is_cxl(root)) + return cxl_osc_uuid_str; + return pci_osc_uuid_str; +} + +static int cap_length(struct acpi_pci_root *root) +{ + if (is_cxl(root)) + return sizeof(u32) * OSC_CXL_CAPABILITY_DWORDS; + return sizeof(u32) * OSC_PCI_CAPABILITY_DWORDS; +} -static acpi_status acpi_pci_run_osc(acpi_handle handle, - const u32 *capbuf, u32 *retval) +static acpi_status acpi_pci_run_osc(struct acpi_pci_root *root, + const u32 *capbuf, u32 *pci_control, + u32 *cxl_control) { struct acpi_osc_context context = { - .uuid_str = pci_osc_uuid_str, + .uuid_str = to_uuid(root), .rev = 1, - .cap.length = 12, + .cap.length = cap_length(root), .cap.pointer = (void *)capbuf, }; acpi_status status; - status = acpi_run_osc(handle, &context); + status = acpi_run_osc(root->device->handle, &context); if (ACPI_SUCCESS(status)) { - *retval = *((u32 *)(context.ret.pointer + 8)); + *pci_control = acpi_osc_ctx_get_pci_control(&context); + if (is_cxl(root)) + *cxl_control = acpi_osc_ctx_get_cxl_control(&context); kfree(context.ret.pointer); } return status; } -static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, - u32 support, - u32 *control) +static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, u32 support, + u32 *control, u32 cxl_support, + u32 *cxl_control) { acpi_status status; - u32 result, capbuf[3]; + u32 pci_result, cxl_result, capbuf[OSC_CXL_CAPABILITY_DWORDS]; support |= root->osc_support_set; @@ -204,10 +253,28 @@ static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, capbuf[OSC_SUPPORT_DWORD] = support; capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set; - status = acpi_pci_run_osc(root->device->handle, capbuf, &result); + if (is_cxl(root)) { + cxl_support |= root->osc_ext_support_set; + capbuf[OSC_EXT_SUPPORT_DWORD] = cxl_support; + capbuf[OSC_EXT_CONTROL_DWORD] = *cxl_control | root->osc_ext_control_set; + } + +retry: + status = acpi_pci_run_osc(root, capbuf, &pci_result, &cxl_result); if (ACPI_SUCCESS(status)) { root->osc_support_set = support; - *control = result; + *control = pci_result; + if (is_cxl(root)) { + root->osc_ext_support_set = cxl_support; + *cxl_control = cxl_result; + } + } else if (is_cxl(root)) { + /* + * CXL _OSC is optional on CXL 1.1 hosts. Fall back to PCIe _OSC + * upon any failure using CXL _OSC. + */ + root->bridge_type = ACPI_BRIDGE_TYPE_PCIE; + goto retry; } return status; } @@ -245,76 +312,26 @@ struct acpi_handle_node { */ struct pci_dev *acpi_get_pci_dev(acpi_handle handle) { - int dev, fn; - unsigned long long adr; - acpi_status status; - acpi_handle phandle; - struct pci_bus *pbus; - struct pci_dev *pdev = NULL; - struct acpi_handle_node *node, *tmp; - struct acpi_pci_root *root; - LIST_HEAD(device_list); - - /* - * Walk up the ACPI CA namespace until we reach a PCI root bridge. - */ - phandle = handle; - while (!acpi_is_root_bridge(phandle)) { - node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL); - if (!node) - goto out; - - INIT_LIST_HEAD(&node->node); - node->handle = phandle; - list_add(&node->node, &device_list); - - status = acpi_get_parent(phandle, &phandle); - if (ACPI_FAILURE(status)) - goto out; - } - - root = acpi_pci_find_root(phandle); - if (!root) - goto out; - - pbus = root->bus; - - /* - * Now, walk back down the PCI device tree until we return to our - * original handle. Assumes that everything between the PCI root - * bridge and the device we're looking for must be a P2P bridge. - */ - list_for_each_entry(node, &device_list, node) { - acpi_handle hnd = node->handle; - status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr); - if (ACPI_FAILURE(status)) - goto out; - dev = (adr >> 16) & 0xffff; - fn = adr & 0xffff; + struct acpi_device *adev = acpi_fetch_acpi_dev(handle); + struct acpi_device_physical_node *pn; + struct pci_dev *pci_dev = NULL; - pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn)); - if (!pdev || hnd == handle) - break; + if (!adev) + return NULL; - pbus = pdev->subordinate; - pci_dev_put(pdev); + mutex_lock(&adev->physical_node_lock); - /* - * This function may be called for a non-PCI device that has a - * PCI parent (eg. a disk under a PCI SATA controller). In that - * case pdev->subordinate will be NULL for the parent. - */ - if (!pbus) { - dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n"); - pdev = NULL; + list_for_each_entry(pn, &adev->physical_node_list, node) { + if (dev_is_pci(pn->dev)) { + get_device(pn->dev); + pci_dev = to_pci_dev(pn->dev); break; } } -out: - list_for_each_entry_safe(node, tmp, &device_list, node) - kfree(node); - return pdev; + mutex_unlock(&adev->physical_node_lock); + + return pci_dev; } EXPORT_SYMBOL_GPL(acpi_get_pci_dev); @@ -323,6 +340,8 @@ EXPORT_SYMBOL_GPL(acpi_get_pci_dev); * @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. * @support: _OSC supported capability. + * @cxl_mask: Mask of CXL _OSC control bits, place to store control mask. + * @cxl_support: CXL _OSC supported capability. * * 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 @@ -333,12 +352,14 @@ EXPORT_SYMBOL_GPL(acpi_get_pci_dev); * _OSC bits the BIOS has granted control of, but its contents are meaningless * on failure. **/ -static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 support) +static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, + u32 support, u32 *cxl_mask, + u32 cxl_support) { u32 req = OSC_PCI_EXPRESS_CAPABILITY_CONTROL; struct acpi_pci_root *root; acpi_status status; - u32 ctrl, capbuf[3]; + u32 ctrl, cxl_ctrl = 0, capbuf[OSC_CXL_CAPABILITY_DWORDS]; if (!mask) return AE_BAD_PARAMETER; @@ -350,20 +371,42 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 s ctrl = *mask; *mask |= root->osc_control_set; + if (is_cxl(root)) { + cxl_ctrl = *cxl_mask; + *cxl_mask |= root->osc_ext_control_set; + } + /* Need to check the available controls bits before requesting them. */ do { - status = acpi_pci_query_osc(root, support, mask); + u32 pci_missing = 0, cxl_missing = 0; + + status = acpi_pci_query_osc(root, support, mask, cxl_support, + cxl_mask); if (ACPI_FAILURE(status)) return status; - if (ctrl == *mask) - break; - decode_osc_control(root, "platform does not support", - ctrl & ~(*mask)); + if (is_cxl(root)) { + if (ctrl == *mask && cxl_ctrl == *cxl_mask) + break; + pci_missing = ctrl & ~(*mask); + cxl_missing = cxl_ctrl & ~(*cxl_mask); + } else { + if (ctrl == *mask) + break; + pci_missing = ctrl & ~(*mask); + } + if (pci_missing) + decode_osc_control(root, "platform does not support", + pci_missing); + if (cxl_missing) + decode_cxl_osc_control(root, "CXL platform does not support", + cxl_missing); ctrl = *mask; - } while (*mask); + cxl_ctrl = *cxl_mask; + } while (*mask || *cxl_mask); /* No need to request _OSC if the control was already granted. */ - if ((root->osc_control_set & ctrl) == ctrl) + if ((root->osc_control_set & ctrl) == ctrl && + (root->osc_ext_control_set & cxl_ctrl) == cxl_ctrl) return AE_OK; if ((ctrl & req) != req) { @@ -375,11 +418,17 @@ static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 s 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 (is_cxl(root)) { + capbuf[OSC_EXT_SUPPORT_DWORD] = root->osc_ext_support_set; + capbuf[OSC_EXT_CONTROL_DWORD] = cxl_ctrl; + } + + status = acpi_pci_run_osc(root, capbuf, mask, cxl_mask); if (ACPI_FAILURE(status)) return status; root->osc_control_set = *mask; + root->osc_ext_control_set = *cxl_mask; return AE_OK; } @@ -405,6 +454,53 @@ static u32 calculate_support(void) return support; } +/* + * Background on hotplug support, and making it depend on only + * CONFIG_HOTPLUG_PCI_PCIE vs. also considering CONFIG_MEMORY_HOTPLUG: + * + * CONFIG_ACPI_HOTPLUG_MEMORY does depend on CONFIG_MEMORY_HOTPLUG, but + * there is no existing _OSC for memory hotplug support. The reason is that + * ACPI memory hotplug requires the OS to acknowledge / coordinate with + * memory plug events via a scan handler. On the CXL side the equivalent + * would be if Linux supported the Mechanical Retention Lock [1], or + * otherwise had some coordination for the driver of a PCI device + * undergoing hotplug to be consulted on whether the hotplug should + * proceed or not. + * + * The concern is that if Linux says no to supporting CXL hotplug then + * the BIOS may say no to giving the OS hotplug control of any other PCIe + * device. So the question here is not whether hotplug is enabled, it's + * whether it is handled natively by the at all OS, and if + * CONFIG_HOTPLUG_PCI_PCIE is enabled then the answer is "yes". + * + * Otherwise, the plan for CXL coordinated remove, since the kernel does + * not support blocking hotplug, is to require the memory device to be + * disabled before hotplug is attempted. When CONFIG_MEMORY_HOTPLUG is + * disabled that step will fail and the remove attempt cancelled by the + * user. If that is not honored and the card is removed anyway then it + * does not matter if CONFIG_MEMORY_HOTPLUG is enabled or not, it will + * cause a crash and other badness. + * + * Therefore, just say yes to CXL hotplug and require removal to + * be coordinated by userspace unless and until the kernel grows better + * mechanisms for doing "managed" removal of devices in consultation with + * the driver. + * + * [1]: https://lore.kernel.org/all/20201122014203.4706-1-ashok.raj@intel.com/ + */ +static u32 calculate_cxl_support(void) +{ + u32 support; + + support = OSC_CXL_2_0_PORT_DEV_REG_ACCESS_SUPPORT; + if (pci_aer_available()) + support |= OSC_CXL_PROTOCOL_ERR_REPORTING_SUPPORT; + if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE)) + support |= OSC_CXL_NATIVE_HP_SUPPORT; + + return support; +} + static u32 calculate_control(void) { u32 control; @@ -436,6 +532,16 @@ static u32 calculate_control(void) return control; } +static u32 calculate_cxl_control(void) +{ + u32 control = 0; + + if (IS_ENABLED(CONFIG_MEMORY_FAILURE)) + control |= OSC_CXL_ERROR_REPORTING_CONTROL; + + return control; +} + static bool os_control_query_checks(struct acpi_pci_root *root, u32 support) { struct acpi_device *device = root->device; @@ -454,10 +560,10 @@ static bool os_control_query_checks(struct acpi_pci_root *root, u32 support) return true; } -static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, - bool is_pcie) +static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm) { u32 support, control = 0, requested = 0; + u32 cxl_support = 0, cxl_control = 0, cxl_requested = 0; acpi_status status; struct acpi_device *device = root->device; acpi_handle handle = device->handle; @@ -481,10 +587,20 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, if (os_control_query_checks(root, support)) requested = control = calculate_control(); - status = acpi_pci_osc_control_set(handle, &control, support); + if (is_cxl(root)) { + cxl_support = calculate_cxl_support(); + decode_cxl_osc_support(root, "OS supports", cxl_support); + cxl_requested = cxl_control = calculate_cxl_control(); + } + + status = acpi_pci_osc_control_set(handle, &control, support, + &cxl_control, cxl_support); if (ACPI_SUCCESS(status)) { if (control) decode_osc_control(root, "OS now controls", control); + if (cxl_control) + decode_cxl_osc_control(root, "OS now controls", + cxl_control); if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { /* @@ -506,13 +622,18 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, *no_aspm = 1; /* _OSC is optional for PCI host bridges */ - if ((status == AE_NOT_FOUND) && !is_pcie) + if (status == AE_NOT_FOUND && !is_pcie(root)) return; if (control) { decode_osc_control(root, "OS requested", requested); decode_osc_control(root, "platform willing to grant", control); } + if (cxl_control) { + decode_cxl_osc_control(root, "OS requested", cxl_requested); + decode_cxl_osc_control(root, "platform willing to grant", + cxl_control); + } dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n", acpi_format_exception(status)); @@ -529,7 +650,7 @@ static int acpi_pci_root_add(struct acpi_device *device, acpi_handle handle = device->handle; int no_aspm = 0; bool hotadd = system_state == SYSTEM_RUNNING; - bool is_pcie; + const char *acpi_hid; root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL); if (!root) @@ -587,8 +708,15 @@ static int acpi_pci_root_add(struct acpi_device *device, root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle); - is_pcie = strcmp(acpi_device_hid(device), "PNP0A08") == 0; - negotiate_os_control(root, &no_aspm, is_pcie); + acpi_hid = acpi_device_hid(root->device); + if (strcmp(acpi_hid, "PNP0A08") == 0) + root->bridge_type = ACPI_BRIDGE_TYPE_PCIE; + else if (strcmp(acpi_hid, "ACPI0016") == 0) + root->bridge_type = ACPI_BRIDGE_TYPE_CXL; + else + dev_dbg(&device->dev, "Assuming non-PCIe host bridge\n"); + + negotiate_os_control(root, &no_aspm); /* * TBD: Need PCI interface for enumeration/configuration of roots. @@ -929,6 +1057,8 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root, host_bridge->preserve_config = 1; ACPI_FREE(obj); + acpi_dev_power_up_children_with_adr(device); + pci_scan_child_bus(bus); pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info, info); @@ -943,7 +1073,6 @@ out_release_info: void __init acpi_pci_root_init(void) { - acpi_hest_init(); if (acpi_pci_disabled) return; |