From 790815902ec61ba1715fd67d3cb9036e13c942bc Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Thu, 21 Dec 2023 15:03:32 -0700 Subject: cxl: Add support for _DSM Function for retrieving QTG ID CXL spec v3.0 9.17.3 CXL Root Device Specific Methods (_DSM) Add support to retrieve QTG ID via ACPI _DSM call. The _DSM call requires an input of an ACPI package with 4 dwords (read latency, write latency, read bandwidth, write bandwidth). The call returns a package with 1 WORD that provides the max supported QTG ID and a package that may contain 0 or more WORDs as the recommended QTG IDs in the recommended order. Create a cxl_root container for the root cxl_port and provide a callback ->get_qos_class() in order to retrieve the QoS class. For the ACPI case, the _DSM helper is used to retrieve the QTG ID and returned. A devm_cxl_add_root() function is added for root port setup and registration of the cxl_root callback operation(s). Signed-off-by: Dave Jiang Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/170319621294.2212653.1649682083061569256.stgit@djiang5-mobl3 Signed-off-by: Dan Williams --- drivers/cxl/acpi.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++-- drivers/cxl/core/port.c | 49 ++++++++++++++---- drivers/cxl/cxl.h | 25 +++++++++ 3 files changed, 193 insertions(+), 13 deletions(-) (limited to 'drivers/cxl') diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index 2034eb4ce83f..2f7de910ce57 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include "cxlpci.h" #include "cxl.h" @@ -17,6 +18,10 @@ struct cxl_cxims_data { u64 xormaps[] __counted_by(nr_maps); }; +static const guid_t acpi_cxl_qtg_id_guid = + GUID_INIT(0xF365F9A6, 0xA7DE, 0x4071, + 0xA6, 0x6A, 0xB4, 0x0C, 0x0B, 0x4F, 0x8E, 0x52); + /* * Find a targets entry (n) in the host bridge interleave list. * CXL Specification 3.0 Table 9-22 @@ -194,6 +199,125 @@ struct cxl_cfmws_context { int id; }; +/** + * cxl_acpi_evaluate_qtg_dsm - Retrieve QTG ids via ACPI _DSM + * @handle: ACPI handle + * @coord: performance access coordinates + * @entries: number of QTG IDs to return + * @qos_class: int array provided by caller to return QTG IDs + * + * Return: number of QTG IDs returned, or -errno for errors + * + * Issue QTG _DSM with accompanied bandwidth and latency data in order to get + * the QTG IDs that are suitable for the performance point in order of most + * suitable to least suitable. Write back array of QTG IDs and return the + * actual number of QTG IDs written back. + */ +static int +cxl_acpi_evaluate_qtg_dsm(acpi_handle handle, struct access_coordinate *coord, + int entries, int *qos_class) +{ + union acpi_object *out_obj, *out_buf, *obj; + union acpi_object in_array[4] = { + [0].integer = { ACPI_TYPE_INTEGER, coord->read_latency }, + [1].integer = { ACPI_TYPE_INTEGER, coord->write_latency }, + [2].integer = { ACPI_TYPE_INTEGER, coord->read_bandwidth }, + [3].integer = { ACPI_TYPE_INTEGER, coord->write_bandwidth }, + }; + union acpi_object in_obj = { + .package = { + .type = ACPI_TYPE_PACKAGE, + .count = 4, + .elements = in_array, + }, + }; + int count, pkg_entries, i; + u16 max_qtg; + int rc; + + if (!entries) + return -EINVAL; + + out_obj = acpi_evaluate_dsm(handle, &acpi_cxl_qtg_id_guid, 1, 1, &in_obj); + if (!out_obj) + return -ENXIO; + + if (out_obj->type != ACPI_TYPE_PACKAGE) { + rc = -ENXIO; + goto out; + } + + /* Check Max QTG ID */ + obj = &out_obj->package.elements[0]; + if (obj->type != ACPI_TYPE_INTEGER) { + rc = -ENXIO; + goto out; + } + + max_qtg = obj->integer.value; + + /* It's legal to have 0 QTG entries */ + pkg_entries = out_obj->package.count; + if (pkg_entries <= 1) { + rc = 0; + goto out; + } + + /* Retrieve QTG IDs package */ + obj = &out_obj->package.elements[1]; + if (obj->type != ACPI_TYPE_PACKAGE) { + rc = -ENXIO; + goto out; + } + + pkg_entries = obj->package.count; + count = min(entries, pkg_entries); + for (i = 0; i < count; i++) { + u16 qtg_id; + + out_buf = &obj->package.elements[i]; + if (out_buf->type != ACPI_TYPE_INTEGER) { + rc = -ENXIO; + goto out; + } + + qtg_id = out_buf->integer.value; + if (qtg_id > max_qtg) + pr_warn("QTG ID %u greater than MAX %u\n", + qtg_id, max_qtg); + + qos_class[i] = qtg_id; + } + rc = count; + +out: + ACPI_FREE(out_obj); + return rc; +} + +static int cxl_acpi_qos_class(struct cxl_port *root_port, + struct access_coordinate *coord, int entries, + int *qos_class) +{ + acpi_handle handle; + struct device *dev; + + dev = root_port->uport_dev; + + if (!dev_is_platform(dev)) + return -ENODEV; + + handle = ACPI_HANDLE(dev); + if (!handle) + return -ENODEV; + + return cxl_acpi_evaluate_qtg_dsm(handle, coord, entries, qos_class); +} + +static const struct cxl_root_ops acpi_root_ops = { + .qos_class = cxl_acpi_qos_class, +}; + static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, const unsigned long end) { @@ -656,6 +780,7 @@ static int cxl_acpi_probe(struct platform_device *pdev) { int rc; struct resource *cxl_res; + struct cxl_root *cxl_root; struct cxl_port *root_port; struct device *host = &pdev->dev; struct acpi_device *adev = ACPI_COMPANION(host); @@ -675,9 +800,10 @@ static int cxl_acpi_probe(struct platform_device *pdev) cxl_res->end = -1; cxl_res->flags = IORESOURCE_MEM; - root_port = devm_cxl_add_port(host, host, CXL_RESOURCE_NONE, NULL); - if (IS_ERR(root_port)) - return PTR_ERR(root_port); + cxl_root = devm_cxl_add_root(host, &acpi_root_ops); + if (IS_ERR(cxl_root)) + return PTR_ERR(cxl_root); + root_port = &cxl_root->port; rc = bus_for_each_dev(adev->dev.bus, NULL, root_port, add_host_bridge_dport); diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index b7c93bb18f6e..9393cbf04652 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -541,7 +541,10 @@ static void cxl_port_release(struct device *dev) xa_destroy(&port->dports); xa_destroy(&port->regions); ida_free(&cxl_port_ida, port->id); - kfree(port); + if (is_cxl_root(port)) + kfree(to_cxl_root(port)); + else + kfree(port); } static ssize_t decoders_committed_show(struct device *dev, @@ -669,17 +672,31 @@ static struct lock_class_key cxl_port_key; static struct cxl_port *cxl_port_alloc(struct device *uport_dev, struct cxl_dport *parent_dport) { - struct cxl_port *port; + struct cxl_root *cxl_root __free(kfree) = NULL; + struct cxl_port *port, *_port __free(kfree) = NULL; struct device *dev; int rc; - port = kzalloc(sizeof(*port), GFP_KERNEL); - if (!port) - return ERR_PTR(-ENOMEM); + /* No parent_dport, root cxl_port */ + if (!parent_dport) { + cxl_root = kzalloc(sizeof(*cxl_root), GFP_KERNEL); + if (!cxl_root) + return ERR_PTR(-ENOMEM); + } else { + _port = kzalloc(sizeof(*port), GFP_KERNEL); + if (!_port) + return ERR_PTR(-ENOMEM); + } rc = ida_alloc(&cxl_port_ida, GFP_KERNEL); if (rc < 0) - goto err; + return ERR_PTR(rc); + + if (cxl_root) + port = &no_free_ptr(cxl_root)->port; + else + port = no_free_ptr(_port); + port->id = rc; port->uport_dev = uport_dev; @@ -731,10 +748,6 @@ static struct cxl_port *cxl_port_alloc(struct device *uport_dev, dev->type = &cxl_port_type; return port; - -err: - kfree(port); - return ERR_PTR(rc); } static int cxl_setup_comp_regs(struct device *host, struct cxl_register_map *map, @@ -884,6 +897,22 @@ struct cxl_port *devm_cxl_add_port(struct device *host, } EXPORT_SYMBOL_NS_GPL(devm_cxl_add_port, CXL); +struct cxl_root *devm_cxl_add_root(struct device *host, + const struct cxl_root_ops *ops) +{ + struct cxl_root *cxl_root; + struct cxl_port *port; + + port = devm_cxl_add_port(host, host, CXL_RESOURCE_NONE, NULL); + if (IS_ERR(port)) + return (struct cxl_root *)port; + + cxl_root = to_cxl_root(port); + cxl_root->ops = ops; + return cxl_root; +} +EXPORT_SYMBOL_NS_GPL(devm_cxl_add_root, CXL); + struct pci_bus *cxl_port_to_pci_bus(struct cxl_port *port) { /* There is no pci_bus associated with a CXL platform-root port */ diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 22f664b9f4c6..abbdcd3a7596 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -615,6 +615,29 @@ struct cxl_port { bool cdat_available; }; +struct cxl_root_ops { + int (*qos_class)(struct cxl_port *root_port, + struct access_coordinate *coord, int entries, + int *qos_class); +}; + +/** + * struct cxl_root - logical collection of root cxl_port items + * + * @port: cxl_port member + * @ops: cxl root operations + */ +struct cxl_root { + struct cxl_port port; + const struct cxl_root_ops *ops; +}; + +static inline struct cxl_root * +to_cxl_root(const struct cxl_port *port) +{ + return container_of(port, struct cxl_root, port); +} + static inline struct cxl_dport * cxl_find_dport_by_dev(struct cxl_port *port, const struct device *dport_dev) { @@ -703,6 +726,8 @@ struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport_dev, resource_size_t component_reg_phys, struct cxl_dport *parent_dport); +struct cxl_root *devm_cxl_add_root(struct device *host, + const struct cxl_root_ops *ops); struct cxl_port *find_cxl_root(struct cxl_port *port); int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd); void cxl_bus_rescan(void); -- cgit v1.2.3