From: Dan Williams <[email protected]> Insert Soft Reserved memory into a dedicated soft_reserve_resource tree instead of the iomem_resource tree at boot.
Publishing Soft Reserved ranges into iomem too early causes conflicts with CXL hotplug and region assembly failure, especially when Soft Reserved overlaps CXL regions. Re-inserting these ranges into iomem will be handled in follow-up patches, after ensuring CXL window publication ordering is stabilized and when the dax_hmem is ready to consume them. This avoids trimming or deleting resources later and provides a cleaner handoff between EFI-defined memory and CXL resource management. Signed-off-by: Dan Williams <[email protected]> Co-developed-by: Smita Koralahalli <[email protected]> Signed-off-by: Smita Koralahalli <[email protected]> --- arch/x86/kernel/e820.c | 2 +- drivers/cxl/acpi.c | 2 +- drivers/dax/hmem/device.c | 4 +- drivers/dax/hmem/hmem.c | 7 ++- include/linux/ioport.h | 13 +++++- kernel/resource.c | 92 +++++++++++++++++++++++++++++++++------ 6 files changed, 100 insertions(+), 20 deletions(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index c3acbd26408b..c32f144f0e4a 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -1153,7 +1153,7 @@ void __init e820__reserve_resources_late(void) res = e820_res; for (i = 0; i < e820_table->nr_entries; i++) { if (!res->parent && res->end) - insert_resource_expand_to_fit(&iomem_resource, res); + insert_resource_expand_to_fit(res); res++; } diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index 712624cba2b6..3b73adf80bb4 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -839,7 +839,7 @@ static int add_cxl_resources(struct resource *cxl_res) */ cxl_set_public_resource(res, new); - insert_resource_expand_to_fit(&iomem_resource, new); + __insert_resource_expand_to_fit(&iomem_resource, new); next = res->sibling; while (next && resource_overlaps(new, next)) { diff --git a/drivers/dax/hmem/device.c b/drivers/dax/hmem/device.c index f9e1a76a04a9..22732b729017 100644 --- a/drivers/dax/hmem/device.c +++ b/drivers/dax/hmem/device.c @@ -83,8 +83,8 @@ static __init int hmem_register_one(struct resource *res, void *data) static __init int hmem_init(void) { - walk_iomem_res_desc(IORES_DESC_SOFT_RESERVED, - IORESOURCE_MEM, 0, -1, NULL, hmem_register_one); + walk_soft_reserve_res_desc(IORES_DESC_SOFT_RESERVED, IORESOURCE_MEM, 0, + -1, NULL, hmem_register_one); return 0; } diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c index c18451a37e4f..48f4642f4bb8 100644 --- a/drivers/dax/hmem/hmem.c +++ b/drivers/dax/hmem/hmem.c @@ -73,11 +73,14 @@ static int hmem_register_device(struct device *host, int target_nid, return 0; } - rc = region_intersects(res->start, resource_size(res), IORESOURCE_MEM, - IORES_DESC_SOFT_RESERVED); + rc = region_intersects_soft_reserve(res->start, resource_size(res), + IORESOURCE_MEM, + IORES_DESC_SOFT_RESERVED); if (rc != REGION_INTERSECTS) return 0; + /* TODO: Add Soft-Reserved memory back to iomem */ + id = memregion_alloc(GFP_KERNEL); if (id < 0) { dev_err(host, "memregion allocation failure for %pr\n", res); diff --git a/include/linux/ioport.h b/include/linux/ioport.h index e8b2d6aa4013..e20226870a81 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -232,6 +232,9 @@ struct resource_constraint { /* PC/ISA/whatever - the normal PC address spaces: IO and memory */ extern struct resource ioport_resource; extern struct resource iomem_resource; +#ifdef CONFIG_EFI_SOFT_RESERVE +extern struct resource soft_reserve_resource; +#endif extern struct resource *request_resource_conflict(struct resource *root, struct resource *new); extern int request_resource(struct resource *root, struct resource *new); @@ -242,7 +245,8 @@ extern void reserve_region_with_split(struct resource *root, const char *name); extern struct resource *insert_resource_conflict(struct resource *parent, struct resource *new); extern int insert_resource(struct resource *parent, struct resource *new); -extern void insert_resource_expand_to_fit(struct resource *root, struct resource *new); +extern void __insert_resource_expand_to_fit(struct resource *root, struct resource *new); +extern void insert_resource_expand_to_fit(struct resource *new); extern int remove_resource(struct resource *old); extern void arch_remove_reservations(struct resource *avail); extern int allocate_resource(struct resource *root, struct resource *new, @@ -409,6 +413,13 @@ walk_system_ram_res_rev(u64 start, u64 end, void *arg, extern int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end, void *arg, int (*func)(struct resource *, void *)); +extern int +walk_soft_reserve_res_desc(unsigned long desc, unsigned long flags, + u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)); +extern int +region_intersects_soft_reserve(resource_size_t start, size_t size, + unsigned long flags, unsigned long desc); struct resource *devm_request_free_mem_region(struct device *dev, struct resource *base, unsigned long size); diff --git a/kernel/resource.c b/kernel/resource.c index f9bb5481501a..70e750cc0d7b 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -321,13 +321,14 @@ static bool is_type_match(struct resource *p, unsigned long flags, unsigned long } /** - * find_next_iomem_res - Finds the lowest iomem resource that covers part of - * [@start..@end]. + * find_next_res - Finds the lowest resource that covers part of + * [@start..@end]. * * If a resource is found, returns 0 and @*res is overwritten with the part * of the resource that's within [@start..@end]; if none is found, returns * -ENODEV. Returns -EINVAL for invalid parameters. * + * @parent: resource tree root to search * @start: start address of the resource searched for * @end: end address of same resource * @flags: flags which the resource must have @@ -337,9 +338,9 @@ static bool is_type_match(struct resource *p, unsigned long flags, unsigned long * The caller must specify @start, @end, @flags, and @desc * (which may be IORES_DESC_NONE). */ -static int find_next_iomem_res(resource_size_t start, resource_size_t end, - unsigned long flags, unsigned long desc, - struct resource *res) +static int find_next_res(struct resource *parent, resource_size_t start, + resource_size_t end, unsigned long flags, + unsigned long desc, struct resource *res) { struct resource *p; @@ -351,7 +352,7 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end, read_lock(&resource_lock); - for_each_resource(&iomem_resource, p, false) { + for_each_resource(parent, p, false) { /* If we passed the resource we are looking for, stop */ if (p->start > end) { p = NULL; @@ -382,16 +383,23 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end, return p ? 0 : -ENODEV; } -static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end, - unsigned long flags, unsigned long desc, - void *arg, - int (*func)(struct resource *, void *)) +static int find_next_iomem_res(resource_size_t start, resource_size_t end, + unsigned long flags, unsigned long desc, + struct resource *res) +{ + return find_next_res(&iomem_resource, start, end, flags, desc, res); +} + +static int walk_res_desc(struct resource *parent, resource_size_t start, + resource_size_t end, unsigned long flags, + unsigned long desc, void *arg, + int (*func)(struct resource *, void *)) { struct resource res; int ret = -EINVAL; while (start < end && - !find_next_iomem_res(start, end, flags, desc, &res)) { + !find_next_res(parent, start, end, flags, desc, &res)) { ret = (*func)(&res, arg); if (ret) break; @@ -402,6 +410,15 @@ static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end, return ret; } +static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end, + unsigned long flags, unsigned long desc, + void *arg, + int (*func)(struct resource *, void *)) +{ + return walk_res_desc(&iomem_resource, start, end, flags, desc, arg, func); +} + + /** * walk_iomem_res_desc - Walks through iomem resources and calls func() * with matching resource ranges. @@ -426,6 +443,26 @@ int walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, } EXPORT_SYMBOL_GPL(walk_iomem_res_desc); +#ifdef CONFIG_EFI_SOFT_RESERVE +struct resource soft_reserve_resource = { + .name = "Soft Reserved", + .start = 0, + .end = -1, + .desc = IORES_DESC_SOFT_RESERVED, + .flags = IORESOURCE_MEM, +}; +EXPORT_SYMBOL_GPL(soft_reserve_resource); + +int walk_soft_reserve_res_desc(unsigned long desc, unsigned long flags, + u64 start, u64 end, void *arg, + int (*func)(struct resource *, void *)) +{ + return walk_res_desc(&soft_reserve_resource, start, end, flags, desc, + arg, func); +} +EXPORT_SYMBOL_GPL(walk_soft_reserve_res_desc); +#endif + /* * This function calls the @func callback against all memory ranges of type * System RAM which are marked as IORESOURCE_SYSTEM_RAM and IORESOUCE_BUSY. @@ -648,6 +685,22 @@ int region_intersects(resource_size_t start, size_t size, unsigned long flags, } EXPORT_SYMBOL_GPL(region_intersects); +#ifdef CONFIG_EFI_SOFT_RESERVE +int region_intersects_soft_reserve(resource_size_t start, size_t size, + unsigned long flags, unsigned long desc) +{ + int ret; + + read_lock(&resource_lock); + ret = __region_intersects(&soft_reserve_resource, start, size, flags, + desc); + read_unlock(&resource_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(region_intersects_soft_reserve); +#endif + void __weak arch_remove_reservations(struct resource *avail) { } @@ -966,7 +1019,7 @@ EXPORT_SYMBOL_GPL(insert_resource); * Insert a resource into the resource tree, possibly expanding it in order * to make it encompass any conflicting resources. */ -void insert_resource_expand_to_fit(struct resource *root, struct resource *new) +void __insert_resource_expand_to_fit(struct resource *root, struct resource *new) { if (new->parent) return; @@ -997,7 +1050,20 @@ void insert_resource_expand_to_fit(struct resource *root, struct resource *new) * 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"); +EXPORT_SYMBOL_NS_GPL(__insert_resource_expand_to_fit, "CXL"); + +void insert_resource_expand_to_fit(struct resource *new) +{ + struct resource *root = &iomem_resource; + +#ifdef CONFIG_EFI_SOFT_RESERVE + if (new->desc == IORES_DESC_SOFT_RESERVED) + root = &soft_reserve_resource; +#endif + + __insert_resource_expand_to_fit(root, new); +} +EXPORT_SYMBOL_GPL(insert_resource_expand_to_fit); /** * remove_resource - Remove a resource in the resource tree -- 2.17.1
