diff mbox series

[v3,1/4] ida: Add ida_find_first_range()

Message ID 20240912131729.14951-2-yi.l.liu@intel.com (mailing list archive)
State New
Headers show
Series vfio-pci support pasid attach/detach | expand

Commit Message

Yi Liu Sept. 12, 2024, 1:17 p.m. UTC
There is no helpers for user to check if a given ID is allocated or not,
neither a helper to loop all the allocated IDs in an IDA and do something
for cleanup. With the two needs, a helper to get the lowest allocated ID
of a range and two variants based on it.

Caller can check if a given ID is allocated or not by:

	bool ida_exists(struct ida *ida, unsigned int id)

Caller can iterate all allocated IDs by:

	int id;
	while ((id = ida_find_first(&pasid_ida)) > 0) {
		//anything to do with the allocated ID
		ida_free(pasid_ida, pasid);
	}

Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
 include/linux/idr.h | 11 ++++++++
 lib/idr.c           | 67 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+)

Comments

Matthew Wilcox (Oracle) Sept. 12, 2024, 3:11 p.m. UTC | #1
On Thu, Sep 12, 2024 at 06:17:26AM -0700, Yi Liu wrote:
> There is no helpers for user to check if a given ID is allocated or not,
> neither a helper to loop all the allocated IDs in an IDA and do something
> for cleanup. With the two needs, a helper to get the lowest allocated ID
> of a range and two variants based on it.
> 
> Caller can check if a given ID is allocated or not by:
> 
> 	bool ida_exists(struct ida *ida, unsigned int id)
> 
> Caller can iterate all allocated IDs by:
> 
> 	int id;
> 	while ((id = ida_find_first(&pasid_ida)) > 0) {
> 		//anything to do with the allocated ID
> 		ida_free(pasid_ida, pasid);
> 	}
> 
> Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> ---
>  include/linux/idr.h | 11 ++++++++
>  lib/idr.c           | 67 +++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 78 insertions(+)

No test cases for the test suite?  ;-(
Yi Liu Sept. 13, 2024, 11:45 a.m. UTC | #2
On 2024/9/12 23:11, Matthew Wilcox wrote:
> On Thu, Sep 12, 2024 at 06:17:26AM -0700, Yi Liu wrote:
>> There is no helpers for user to check if a given ID is allocated or not,
>> neither a helper to loop all the allocated IDs in an IDA and do something
>> for cleanup. With the two needs, a helper to get the lowest allocated ID
>> of a range and two variants based on it.
>>
>> Caller can check if a given ID is allocated or not by:
>>
>> 	bool ida_exists(struct ida *ida, unsigned int id)
>>
>> Caller can iterate all allocated IDs by:
>>
>> 	int id;
>> 	while ((id = ida_find_first(&pasid_ida)) > 0) {
>> 		//anything to do with the allocated ID
>> 		ida_free(pasid_ida, pasid);
>> 	}
>>
>> Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
>> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
>> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
>> ---
>>   include/linux/idr.h | 11 ++++++++
>>   lib/idr.c           | 67 +++++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 78 insertions(+)
> 
> No test cases for the test suite?  ;-(

let me add something like the below. :)

diff --git a/lib/test_ida.c b/lib/test_ida.c
index c80155a1956d..d89554ff5719 100644
--- a/lib/test_ida.c
+++ b/lib/test_ida.c
@@ -189,6 +189,75 @@ static void ida_check_bad_free(struct ida *ida)
  	IDA_BUG_ON(ida, !ida_is_empty(ida));
  }

+/*
+ * Check ida_find_first_range() and varriants.
+ */
+static void ida_check_find_first(struct ida *ida)
+{
+	/* IDA is empty; all of the below should be not exist */
+	IDA_BUG_ON(ida, ida_exists(ida, 0));
+	IDA_BUG_ON(ida, ida_exists(ida, 3));
+	IDA_BUG_ON(ida, ida_exists(ida, 63));
+	IDA_BUG_ON(ida, ida_exists(ida, 1023));
+	IDA_BUG_ON(ida, ida_exists(ida, (1 << 20) - 1));
+	/* IDA contains a single value entry */
+
+	IDA_BUG_ON(ida, ida_alloc_min(ida, 3, GFP_KERNEL) != 3);
+	IDA_BUG_ON(ida, ida_exists(ida, 0));
+	IDA_BUG_ON(ida, !ida_exists(ida, 3));
+	IDA_BUG_ON(ida, ida_exists(ida, 63));
+	IDA_BUG_ON(ida, ida_exists(ida, 1023));
+	IDA_BUG_ON(ida, ida_exists(ida, (1 << 20) - 1));
+
+	IDA_BUG_ON(ida, ida_alloc_min(ida, 63, GFP_KERNEL) != 63);
+	IDA_BUG_ON(ida, ida_exists(ida, 0));
+	IDA_BUG_ON(ida, !ida_exists(ida, 3));
+	IDA_BUG_ON(ida, !ida_exists(ida, 63));
+	IDA_BUG_ON(ida, ida_exists(ida, 1023));
+	IDA_BUG_ON(ida, ida_exists(ida, (1 << 20) - 1));
+
+	/* IDA contains a single bitmap */
+	IDA_BUG_ON(ida, ida_alloc_min(ida, 1023, GFP_KERNEL) != 1023);
+	IDA_BUG_ON(ida, ida_exists(ida, 0));
+	IDA_BUG_ON(ida, !ida_exists(ida, 3));
+	IDA_BUG_ON(ida, !ida_exists(ida, 63));
+	IDA_BUG_ON(ida, !ida_exists(ida, 1023));
+	IDA_BUG_ON(ida, ida_exists(ida, (1 << 20) - 1));
+
+	/* IDA contains a tree */
+	IDA_BUG_ON(ida, ida_alloc_min(ida, (1 << 20) - 1, GFP_KERNEL) != (1 << 
20) - 1);
+	IDA_BUG_ON(ida, ida_exists(ida, 0));
+	IDA_BUG_ON(ida, !ida_exists(ida, 3));
+	IDA_BUG_ON(ida, !ida_exists(ida, 63));
+	IDA_BUG_ON(ida, !ida_exists(ida, 1023));
+	IDA_BUG_ON(ida, !ida_exists(ida, (1 << 20) - 1));
+
+	/* Now try to find first */
+	IDA_BUG_ON(ida, ida_find_first(ida) != 3);
+	IDA_BUG_ON(ida, ida_find_first_range(ida, -1, 2) != -EINVAL);
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 0, 2) != -ENOENT); // no used ID
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 0, 3) != 3);
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 1, 3) != 3);
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 3, 3) != 3);
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 2, 4) != 3);
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 4, 3) != -ENOENT); // min > 
max, fail
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 4, 60) != -ENOENT); // no used ID
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 4, 64) != 63);
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 63, 63) != 63);
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 64, 1026) != 1023);
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 1023, 1023) != 1023);
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 1023, (1 << 20) - 1) != 1023);
+	IDA_BUG_ON(ida, ida_find_first_range(ida, 1024, (1 << 20) - 1) != (1 << 
20) - 1);
+	IDA_BUG_ON(ida, ida_find_first_range(ida, (1 << 20), INT_MAX) != -ENOENT);
+
+	ida_free(ida, 3);
+	ida_free(ida, 63);
+	ida_free(ida, 1023);
+	ida_free(ida, (1 << 20) - 1);
+
+	IDA_BUG_ON(ida, !ida_is_empty(ida));
+}
+
  static DEFINE_IDA(ida);

  static int ida_checks(void)
@@ -202,6 +270,7 @@ static int ida_checks(void)
  	ida_check_max(&ida);
  	ida_check_conv(&ida);
  	ida_check_bad_free(&ida);
+	ida_check_find_first(&ida);

  	printk("IDA: %u of %u tests passed\n", tests_passed, tests_run);
  	return (tests_run != tests_passed) ? 0 : -EINVAL;
Matthew Wilcox (Oracle) Sept. 13, 2024, 3:09 p.m. UTC | #3
On Fri, Sep 13, 2024 at 07:45:55PM +0800, Yi Liu wrote:
> > No test cases for the test suite?  ;-(
> 
> let me add something like the below. :)

That looks pretty comprehensive, thanks!

Acked-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Yi Liu Sept. 14, 2024, 4:16 a.m. UTC | #4
On 2024/9/13 23:09, Matthew Wilcox wrote:
> On Fri, Sep 13, 2024 at 07:45:55PM +0800, Yi Liu wrote:
>>> No test cases for the test suite?  ;-(
>>
>> let me add something like the below. :)
> 
> That looks pretty comprehensive, thanks!
> 
> Acked-by: Matthew Wilcox (Oracle) <willy@infradead.org>

thanks, and FYI. I found a bug when running the unit test. will fix it
in the next version. it's really helpful suggestion.

diff --git a/lib/idr.c b/lib/idr.c
index 6644d3d1af02..f16eb3d172bc 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -494,6 +494,7 @@ int ida_find_first_range(struct ida *ida, unsigned int 
min, unsigned int max)
  	unsigned int offset = min % IDA_BITMAP_BITS;
  	unsigned long *addr, size, bit;
  	unsigned long flags;
+	unsigned long tmp = 0;
  	void *entry;
  	int ret;

@@ -518,8 +519,7 @@ int ida_find_first_range(struct ida *ida, unsigned int 
min, unsigned int max)
  	}

  	if (xa_is_value(entry)) {
-		unsigned long tmp = xa_to_value(entry);
-
+		tmp = xa_to_value(entry);
  		addr = &tmp;
  		size = BITS_PER_XA_VALUE;
  	} else {
Jason Gunthorpe Sept. 26, 2024, 7:11 p.m. UTC | #5
On Thu, Sep 12, 2024 at 06:17:26AM -0700, Yi Liu wrote:
> There is no helpers for user to check if a given ID is allocated or not,
> neither a helper to loop all the allocated IDs in an IDA and do something
> for cleanup. With the two needs, a helper to get the lowest allocated ID
> of a range and two variants based on it.
> 
> Caller can check if a given ID is allocated or not by:
> 
> 	bool ida_exists(struct ida *ida, unsigned int id)
> 
> Caller can iterate all allocated IDs by:
> 
> 	int id;
> 	while ((id = ida_find_first(&pasid_ida)) > 0) {
> 		//anything to do with the allocated ID
> 		ida_free(pasid_ida, pasid);
> 	}
> 
> Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> ---
>  include/linux/idr.h | 11 ++++++++
>  lib/idr.c           | 67 +++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 78 insertions(+)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason
Tian, Kevin Sept. 30, 2024, 7:49 a.m. UTC | #6
> From: Liu, Yi L <yi.l.liu@intel.com>
> Sent: Thursday, September 12, 2024 9:17 PM
> 
> There is no helpers for user to check if a given ID is allocated or not,
> neither a helper to loop all the allocated IDs in an IDA and do something
> for cleanup. With the two needs, a helper to get the lowest allocated ID
> of a range and two variants based on it.
> 
> Caller can check if a given ID is allocated or not by:
> 
> 	bool ida_exists(struct ida *ida, unsigned int id)
> 
> Caller can iterate all allocated IDs by:
> 
> 	int id;
> 	while ((id = ida_find_first(&pasid_ida)) > 0) {
> 		//anything to do with the allocated ID
> 		ida_free(pasid_ida, pasid);
> 	}
> 
> Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
> Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
diff mbox series

Patch

diff --git a/include/linux/idr.h b/include/linux/idr.h
index da5f5fa4a3a6..718f9b1b91af 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -257,6 +257,7 @@  struct ida {
 int ida_alloc_range(struct ida *, unsigned int min, unsigned int max, gfp_t);
 void ida_free(struct ida *, unsigned int id);
 void ida_destroy(struct ida *ida);
+int ida_find_first_range(struct ida *ida, unsigned int min, unsigned int max);
 
 /**
  * ida_alloc() - Allocate an unused ID.
@@ -328,4 +329,14 @@  static inline bool ida_is_empty(const struct ida *ida)
 {
 	return xa_empty(&ida->xa);
 }
+
+static inline bool ida_exists(struct ida *ida, unsigned int id)
+{
+	return ida_find_first_range(ida, id, id) == id;
+}
+
+static inline int ida_find_first(struct ida *ida)
+{
+	return ida_find_first_range(ida, 0, ~0);
+}
 #endif /* __IDR_H__ */
diff --git a/lib/idr.c b/lib/idr.c
index da36054c3ca0..6644d3d1af02 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -476,6 +476,73 @@  int ida_alloc_range(struct ida *ida, unsigned int min, unsigned int max,
 }
 EXPORT_SYMBOL(ida_alloc_range);
 
+/**
+ * ida_find_first_range - Get the lowest used ID.
+ * @ida: IDA handle.
+ * @min: Lowest ID to get.
+ * @max: Highest ID to get.
+ *
+ * Get the lowest used ID between @min and @max, inclusive.  The returned
+ * ID will not exceed %INT_MAX, even if @max is larger.
+ *
+ * Context: Any context. Takes and releases the xa_lock.
+ * Return: The lowest used ID, or errno if no used ID is found.
+ */
+int ida_find_first_range(struct ida *ida, unsigned int min, unsigned int max)
+{
+	unsigned long index = min / IDA_BITMAP_BITS;
+	unsigned int offset = min % IDA_BITMAP_BITS;
+	unsigned long *addr, size, bit;
+	unsigned long flags;
+	void *entry;
+	int ret;
+
+	if ((int)min < 0)
+		return -EINVAL;
+	if ((int)max < 0)
+		max = INT_MAX;
+
+	xa_lock_irqsave(&ida->xa, flags);
+
+	entry = xa_find(&ida->xa, &index, max / IDA_BITMAP_BITS, XA_PRESENT);
+	if (!entry) {
+		ret = -ENOENT;
+		goto err_unlock;
+	}
+
+	if (index > min / IDA_BITMAP_BITS)
+		offset = 0;
+	if (index * IDA_BITMAP_BITS + offset > max) {
+		ret = -ENOENT;
+		goto err_unlock;
+	}
+
+	if (xa_is_value(entry)) {
+		unsigned long tmp = xa_to_value(entry);
+
+		addr = &tmp;
+		size = BITS_PER_XA_VALUE;
+	} else {
+		addr = ((struct ida_bitmap *)entry)->bitmap;
+		size = IDA_BITMAP_BITS;
+	}
+
+	bit = find_next_bit(addr, size, offset);
+
+	xa_unlock_irqrestore(&ida->xa, flags);
+
+	if (bit == size ||
+	    index * IDA_BITMAP_BITS + bit > max)
+		return -ENOENT;
+
+	return index * IDA_BITMAP_BITS + bit;
+
+err_unlock:
+	xa_unlock_irqrestore(&ida->xa, flags);
+	return ret;
+}
+EXPORT_SYMBOL(ida_find_first_range);
+
 /**
  * ida_free() - Release an allocated ID.
  * @ida: IDA handle.