diff options
| -rw-r--r-- | drivers/cxl/acpi.c | 144 | ||||
| -rw-r--r-- | include/linux/ioport.h | 1 | ||||
| -rw-r--r-- | kernel/resource.c | 7 |
3 files changed, 149 insertions, 3 deletions
diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index 62bf22ffb7aa..e2b6cbd04846 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -73,6 +73,8 @@ static int cxl_acpi_cfmws_verify(struct device *dev, struct cxl_cfmws_context { struct device *dev; struct cxl_port *root_port; + struct resource *cxl_res; + int id; }; static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, @@ -81,11 +83,13 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, int target_map[CXL_DECODER_MAX_INTERLEAVE]; struct cxl_cfmws_context *ctx = arg; struct cxl_port *root_port = ctx->root_port; + struct resource *cxl_res = ctx->cxl_res; struct cxl_switch_decoder *cxlsd; struct device *dev = ctx->dev; struct acpi_cedt_cfmws *cfmws; struct cxl_decoder *cxld; unsigned int ways, i, ig; + struct resource *res; int rc; cfmws = (struct acpi_cedt_cfmws *) header; @@ -107,6 +111,23 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, for (i = 0; i < ways; i++) target_map[i] = cfmws->interleave_targets[i]; + res = kzalloc(sizeof(*res), GFP_KERNEL); + if (!res) + return -ENOMEM; + + res->name = kasprintf(GFP_KERNEL, "CXL Window %d", ctx->id++); + if (!res->name) + goto err_name; + + res->start = cfmws->base_hpa; + res->end = cfmws->base_hpa + cfmws->window_size - 1; + res->flags = IORESOURCE_MEM; + + /* add to the local resource tracking to establish a sort order */ + rc = insert_resource(cxl_res, res); + if (rc) + goto err_insert; + cxlsd = cxl_root_decoder_alloc(root_port, ways); if (IS_ERR(cxld)) return 0; @@ -115,8 +136,8 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, cxld->flags = cfmws_to_decoder_flags(cfmws->restrictions); cxld->target_type = CXL_DECODER_EXPANDER; cxld->hpa_range = (struct range) { - .start = cfmws->base_hpa, - .end = cfmws->base_hpa + cfmws->window_size - 1, + .start = res->start, + .end = res->end, }; cxld->interleave_ways = ways; cxld->interleave_granularity = ig; @@ -137,6 +158,12 @@ static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg, cxld->hpa_range.start, cxld->hpa_range.end); return 0; + +err_insert: + kfree(res->name); +err_name: + kfree(res); + return -ENOMEM; } __mock struct acpi_device *to_cxl_host_bridge(struct device *host, @@ -291,9 +318,101 @@ static void cxl_acpi_lock_reset_class(void *dev) device_lock_reset_class(dev); } +static void del_cxl_resource(struct resource *res) +{ + kfree(res->name); + kfree(res); +} + +static void cxl_set_public_resource(struct resource *priv, struct resource *pub) +{ + priv->desc = (unsigned long) pub; +} + +static struct resource *cxl_get_public_resource(struct resource *priv) +{ + return (struct resource *) priv->desc; +} + +static void remove_cxl_resources(void *data) +{ + struct resource *res, *next, *cxl = data; + + for (res = cxl->child; res; res = next) { + struct resource *victim = cxl_get_public_resource(res); + + next = res->sibling; + remove_resource(res); + + if (victim) { + remove_resource(victim); + kfree(victim); + } + + del_cxl_resource(res); + } +} + +/** + * add_cxl_resources() - reflect CXL fixed memory windows in iomem_resource + * @cxl_res: A standalone resource tree where each CXL window is a sibling + * + * Walk each CXL window in @cxl_res and add it to iomem_resource potentially + * expanding its boundaries to ensure that any conflicting resources become + * children. If a window is expanded it may then conflict with a another window + * entry and require the window to be truncated or trimmed. Consider this + * situation: + * + * |-- "CXL Window 0" --||----- "CXL Window 1" -----| + * |--------------- "System RAM" -------------| + * + * ...where platform firmware has established as System RAM resource across 2 + * windows, but has left some portion of window 1 for dynamic CXL region + * provisioning. In this case "Window 0" will span the entirety of the "System + * RAM" span, and "CXL Window 1" is truncated to the remaining tail past the end + * of that "System RAM" resource. + */ +static int add_cxl_resources(struct resource *cxl_res) +{ + struct resource *res, *new, *next; + + for (res = cxl_res->child; res; res = next) { + new = kzalloc(sizeof(*new), GFP_KERNEL); + if (!new) + return -ENOMEM; + new->name = res->name; + new->start = res->start; + new->end = res->end; + new->flags = IORESOURCE_MEM; + new->desc = IORES_DESC_CXL; + + /* + * Record the public resource in the private cxl_res tree for + * later removal. + */ + cxl_set_public_resource(res, new); + + insert_resource_expand_to_fit(&iomem_resource, new); + + next = res->sibling; + while (next && resource_overlaps(new, next)) { + if (resource_contains(new, next)) { + struct resource *_next = next->sibling; + + remove_resource(next); + del_cxl_resource(next); + next = _next; + } else + next->start = new->end + 1; + } + } + return 0; +} + static int cxl_acpi_probe(struct platform_device *pdev) { int rc; + struct resource *cxl_res; struct cxl_port *root_port; struct device *host = &pdev->dev; struct acpi_device *adev = ACPI_COMPANION(host); @@ -305,6 +424,14 @@ static int cxl_acpi_probe(struct platform_device *pdev) if (rc) return rc; + cxl_res = devm_kzalloc(host, sizeof(*cxl_res), GFP_KERNEL); + if (!cxl_res) + return -ENOMEM; + cxl_res->name = "CXL mem"; + cxl_res->start = 0; + 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); @@ -315,11 +442,22 @@ static int cxl_acpi_probe(struct platform_device *pdev) if (rc < 0) return rc; + rc = devm_add_action_or_reset(host, remove_cxl_resources, cxl_res); + if (rc) + return rc; + ctx = (struct cxl_cfmws_context) { .dev = host, .root_port = root_port, + .cxl_res = cxl_res, }; - acpi_table_parse_cedt(ACPI_CEDT_TYPE_CFMWS, cxl_parse_cfmws, &ctx); + rc = acpi_table_parse_cedt(ACPI_CEDT_TYPE_CFMWS, cxl_parse_cfmws, &ctx); + if (rc < 0) + return -ENXIO; + + rc = add_cxl_resources(cxl_res); + if (rc) + return rc; /* * Root level scanned with host-bridge as dports, now scan host-bridges diff --git a/include/linux/ioport.h b/include/linux/ioport.h index ec5f71f7135b..79d1ad6d6275 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -141,6 +141,7 @@ enum { IORES_DESC_DEVICE_PRIVATE_MEMORY = 6, IORES_DESC_RESERVED = 7, IORES_DESC_SOFT_RESERVED = 8, + IORES_DESC_CXL = 9, }; /* diff --git a/kernel/resource.c b/kernel/resource.c index 34eaee179689..53a534db350e 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -891,6 +891,13 @@ void insert_resource_expand_to_fit(struct resource *root, struct resource *new) } write_unlock(&resource_lock); } +/* + * Not for general consumption, only early boot memory map parsing, PCI + * resource discovery, and late discovery of CXL resources are expected + * to use this interface. The former are built-in and only the latter, + * CXL, is a module. + */ +EXPORT_SYMBOL_NS_GPL(insert_resource_expand_to_fit, CXL); /** * remove_resource - Remove a resource in the resource tree |