In CXL subsystem, many functions need to check an address availability
by checking if the resource range contains the address. Providing a new
helper function resource_contains_addr() to check if the resource range
contains the input address.

Suggested-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Li Ming <ming.li@zohomail.com>
Tested-by: Shiju Jose <shiju.jose@huawei.com>
---
 drivers/cxl/core/core.h | 1 +
 drivers/cxl/core/hdm.c  | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 29b61828a847..3798e9047175 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -80,6 +80,7 @@ int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, u64 size);
 int cxl_dpa_free(struct cxl_endpoint_decoder *cxled);
 resource_size_t cxl_dpa_size(struct cxl_endpoint_decoder *cxled);
 resource_size_t cxl_dpa_resource_start(struct cxl_endpoint_decoder *cxled);
+bool resource_contains_addr(const struct resource *res, const resource_size_t addr);
 
 enum cxl_rcrb {
 	CXL_RCRB_DOWNSTREAM,
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index ab1007495f6b..701a6a3baa6a 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -547,6 +547,14 @@ resource_size_t cxl_dpa_resource_start(struct cxl_endpoint_decoder *cxled)
 	return base;
 }
 
+bool resource_contains_addr(const struct resource *res, const resource_size_t addr)
+{
+	if (res->flags & IORESOURCE_MEM)
+		return res->start <= addr && addr <= res->end;
+
+	return false;
+}
+
 int cxl_dpa_free(struct cxl_endpoint_decoder *cxled)
 {
 	struct cxl_port *port = cxled_to_port(cxled);
-- 
2.34.1

On Tue, Jul 08, 2025 at 01:15:34PM +0800, Li Ming wrote:
> In CXL subsystem, many functions need to check an address availability
> by checking if the resource range contains the address. Providing a new
> helper function resource_contains_addr() to check if the resource range
> contains the input address.

with the cxl_ prefix added to the new helper, you can add:

Reviewed-by: Alison Schofield <alison.schofield@intel.com>

--snip

On Tue, Jul 08, 2025 at 01:15:34PM +0800, Li Ming wrote:
> In CXL subsystem, many functions need to check an address availability
> by checking if the resource range contains the address. Providing a new
> helper function resource_contains_addr() to check if the resource range
> contains the input address.

...

> +bool resource_contains_addr(const struct resource *res, const resource_size_t addr);

Right, the problem is that it collides with the resource namespace. Please, add a prefix.

bool cxl_resource_contains_addr(const struct resource *res, const resource_size_t addr);

...

> +bool resource_contains_addr(const struct resource *res, const resource_size_t addr)
> +{
> +	if (res->flags & IORESOURCE_MEM)

resource_type() ?

> +		return res->start <= addr && addr <= res->end;
> +
> +	return false;

I still think using DEFINE_RES_MEM() with resource_contains() is a better
approach.

> +}

-- 
With Best Regards,
Andy Shevchenko

On 7/8/2025 9:20 PM, Andy Shevchenko wrote:
> On Tue, Jul 08, 2025 at 01:15:34PM +0800, Li Ming wrote:
>> In CXL subsystem, many functions need to check an address availability
>> by checking if the resource range contains the address. Providing a new
>> helper function resource_contains_addr() to check if the resource range
>> contains the input address.
> ...
>
>> +bool resource_contains_addr(const struct resource *res, const resource_size_t addr);
> Right, the problem is that it collides with the resource namespace. Please, add a prefix.
>
> bool cxl_resource_contains_addr(const struct resource *res, const resource_size_t addr);
>
> ...
>
>> +bool resource_contains_addr(const struct resource *res, const resource_size_t addr)
>> +{
>> +	if (res->flags & IORESOURCE_MEM)
> resource_type() ?
>
>> +		return res->start <= addr && addr <= res->end;
>> +
>> +	return false;
> I still think using DEFINE_RES_MEM() with resource_contains() is a better
> approach.

Will do all you mentioned, thanks


Ming