Add a helper to determine whether a given Soft Reserved memory range is fully contained within the committed CXL region.
This helper provides a primitive for policy decisions in subsequent patches such as co-ordination with dax_hmem to determine whether CXL has fully claimed ownership of Soft Reserved memory ranges. Signed-off-by: Smita Koralahalli <[email protected]> Reviewed-by: Jonathan Cameron <[email protected]> Reviewed-by: Dave Jiang <[email protected]> --- drivers/cxl/core/region.c | 30 ++++++++++++++++++++++++++++++ include/cxl/cxl.h | 15 +++++++++++++++ 2 files changed, 45 insertions(+) create mode 100644 include/cxl/cxl.h diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 45ee598daf95..96ed550bfd2e 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -12,6 +12,7 @@ #include <linux/idr.h> #include <linux/memory-tiers.h> #include <linux/string_choices.h> +#include <cxl/cxl.h> #include <cxlmem.h> #include <cxl.h> #include "core.h" @@ -3875,6 +3876,35 @@ static int cxl_region_debugfs_poison_clear(void *data, u64 offset) DEFINE_DEBUGFS_ATTRIBUTE(cxl_poison_clear_fops, NULL, cxl_region_debugfs_poison_clear, "%llx\n"); +static int region_contains_soft_reserve(struct device *dev, void *data) +{ + struct resource *res = data; + struct cxl_region *cxlr; + struct cxl_region_params *p; + + if (!is_cxl_region(dev)) + return 0; + + cxlr = to_cxl_region(dev); + p = &cxlr->params; + + if (p->state != CXL_CONFIG_COMMIT) + return 0; + + if (!p->res) + return 0; + + return resource_contains(p->res, res) ? 1 : 0; +} + +bool cxl_region_contains_soft_reserve(struct resource *res) +{ + guard(rwsem_read)(&cxl_rwsem.region); + return bus_for_each_dev(&cxl_bus_type, NULL, res, + region_contains_soft_reserve) != 0; +} +EXPORT_SYMBOL_GPL(cxl_region_contains_soft_reserve); + static int cxl_region_can_probe(struct cxl_region *cxlr) { struct cxl_region_params *p = &cxlr->params; diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h new file mode 100644 index 000000000000..db1f588e106c --- /dev/null +++ b/include/cxl/cxl.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright (c) 2026 Advanced Micro Devices, Inc. */ +#ifndef _CXL_H_ +#define _CXL_H_ + +#ifdef CONFIG_CXL_REGION +bool cxl_region_contains_soft_reserve(struct resource *res); +#else +static inline bool cxl_region_contains_soft_reserve(struct resource *res) +{ + return false; +} +#endif + +#endif /* _CXL_H_ */ -- 2.17.1
