1. Patchew
  2. linux
  3. [PATCH 0/2] amd/iommu: Preserve domain ids inside the kdump kernel
  4. View patch

[PATCH 2/2] amd/iommu: Make protection domain ID functions non-static

Sairaj Kodilkar posted 2 patches 2 months, 3 weeks ago
There is a newer version of this series
[PATCH 2/2] amd/iommu: Make protection domain ID functions non-static
Posted by Sairaj Kodilkar 2 months, 3 weeks ago 
So that both iommu.c and init.c can utilize them. Also define a new
function 'pdom_id_destroy()' to destroy 'pdom_ids' instead of directly
calling ida functions.

Signed-off-by: Sairaj Kodilkar <sarunkod@amd.com>
---
 drivers/iommu/amd/amd_iommu.h |  5 +++++
 drivers/iommu/amd/init.c      |  7 ++-----
 drivers/iommu/amd/iommu.c     | 27 ++++++++++++++++++---------
 3 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index 25044d28f28a..6335b577f80d 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -173,6 +173,11 @@ static inline struct protection_domain *to_pdomain(struct iommu_domain *dom)
 bool translation_pre_enabled(struct amd_iommu *iommu);
 int __init add_special_device(u8 type, u8 id, u32 *devid, bool cmd_line);
 
+int amd_iommu_pdom_id_alloc(void);
+int amd_iommu_pdom_id_reserve(int id);
+void amd_iommu_pdom_id_free(int id);
+void amd_iommu_pdom_id_destroy(void);
+
 #ifdef CONFIG_DMI
 void amd_iommu_apply_ivrs_quirks(void);
 #else
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 9375fba1071c..c78fa67f34c6 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -1142,7 +1142,6 @@ static bool __reuse_device_table(struct amd_iommu *iommu)
 	u16 dom_id;
 	bool dte_v;
 	u64 entry;
-	int ret;
 
 	/* Each IOMMU use separate device table with the same size */
 	lo = readl(iommu->mmio_base + MMIO_DEV_TABLE_OFFSET);
@@ -1189,8 +1188,7 @@ static bool __reuse_device_table(struct amd_iommu *iommu)
 		 * are multiple devices present in the same domain,
 		 * hence check only for -ENOMEM.
 		 */
-		ret = ida_alloc_range(&pdom_ids, dom_id, dom_id, GFP_ATOMIC);
-		if (ret == -ENOMEM) {
+		if (amd_iommu_pdom_id_reserve(dom_id) == -ENOMEM) {
 			pr_err("Failed to reserve domain ID 0x%x\n", dom_id);
 			return false;
 		}
@@ -3134,8 +3132,7 @@ static bool __init check_ioapic_information(void)
 
 static void __init free_dma_resources(void)
 {
-	ida_destroy(&pdom_ids);
-
+	amd_iommu_pdom_id_destroy();
 	free_unity_maps();
 }
 
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 48bca4dc8eb6..4d57e820b824 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1785,17 +1785,26 @@ int amd_iommu_complete_ppr(struct device *dev, u32 pasid, int status, int tag)
  * contain.
  *
  ****************************************************************************/
-
-static int pdom_id_alloc(void)
+int amd_iommu_pdom_id_alloc(void)
 {
 	return ida_alloc_range(&pdom_ids, 1, MAX_DOMAIN_ID - 1, GFP_ATOMIC);
 }
 
-static void pdom_id_free(int id)
+int amd_iommu_pdom_id_reserve(int id)
+{
+	return ida_alloc_range(&pdom_ids, id, id, GFP_ATOMIC);
+}
+
+void amd_iommu_pdom_id_free(int id)
 {
 	ida_free(&pdom_ids, id);
 }
 
+void amd_iommu_pdom_id_destroy(void)
+{
+	ida_destroy(&pdom_ids);
+}
+
 static void free_gcr3_tbl_level1(u64 *tbl)
 {
 	u64 *ptr;
@@ -1838,7 +1847,7 @@ static void free_gcr3_table(struct gcr3_tbl_info *gcr3_info)
 	gcr3_info->glx = 0;
 
 	/* Free per device domain ID */
-	pdom_id_free(gcr3_info->domid);
+	amd_iommu_pdom_id_free(gcr3_info->domid);
 
 	iommu_free_pages(gcr3_info->gcr3_tbl);
 	gcr3_info->gcr3_tbl = NULL;
@@ -1874,14 +1883,14 @@ static int setup_gcr3_table(struct gcr3_tbl_info *gcr3_info,
 		return -EBUSY;
 
 	/* Allocate per device domain ID */
-	domid = pdom_id_alloc();
+	domid = amd_iommu_pdom_id_alloc();
 	if (domid <= 0)
 		return -ENOSPC;
 	gcr3_info->domid = domid;
 
 	gcr3_info->gcr3_tbl = iommu_alloc_pages_node_sz(nid, GFP_ATOMIC, SZ_4K);
 	if (gcr3_info->gcr3_tbl == NULL) {
-		pdom_id_free(domid);
+		amd_iommu_pdom_id_free(domid);
 		return -ENOMEM;
 	}
 
@@ -2477,7 +2486,7 @@ struct protection_domain *protection_domain_alloc(void)
 	if (!domain)
 		return NULL;
 
-	domid = pdom_id_alloc();
+	domid = amd_iommu_pdom_id_alloc();
 	if (domid <= 0) {
 		kfree(domain);
 		return NULL;
@@ -2773,7 +2782,7 @@ void amd_iommu_domain_free(struct iommu_domain *dom)
 
 	WARN_ON(!list_empty(&domain->dev_list));
 	pt_iommu_deinit(&domain->iommu);
-	pdom_id_free(domain->id);
+	amd_iommu_pdom_id_free(domain->id);
 	kfree(domain);
 }
 
@@ -2824,7 +2833,7 @@ void amd_iommu_init_identity_domain(void)
 	domain->ops = &identity_domain_ops;
 	domain->owner = &amd_iommu_ops;
 
-	identity_domain.id = pdom_id_alloc();
+	identity_domain.id = amd_iommu_pdom_id_alloc();
 
 	protection_domain_init(&identity_domain);
 }
-- 
2.34.1
Re: [PATCH 2/2] amd/iommu: Make protection domain ID functions non-static
Posted by Jason Gunthorpe 2 months, 2 weeks ago 
On Fri, Nov 14, 2025 at 04:14:42PM +0530, Sairaj Kodilkar wrote:
> So that both iommu.c and init.c can utilize them. Also define a new
> function 'pdom_id_destroy()' to destroy 'pdom_ids' instead of directly
> calling ida functions.
> 
> Signed-off-by: Sairaj Kodilkar <sarunkod@amd.com>
> ---
>  drivers/iommu/amd/amd_iommu.h |  5 +++++
>  drivers/iommu/amd/init.c      |  7 ++-----
>  drivers/iommu/amd/iommu.c     | 27 ++++++++++++++++++---------
>  3 files changed, 25 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
> index 25044d28f28a..6335b577f80d 100644
> --- a/drivers/iommu/amd/amd_iommu.h
> +++ b/drivers/iommu/amd/amd_iommu.h
> @@ -173,6 +173,11 @@ static inline struct protection_domain *to_pdomain(struct iommu_domain *dom)
>  bool translation_pre_enabled(struct amd_iommu *iommu);
>  int __init add_special_device(u8 type, u8 id, u32 *devid, bool cmd_line);
>  
> +int amd_iommu_pdom_id_alloc(void);
> +int amd_iommu_pdom_id_reserve(int id);
> +void amd_iommu_pdom_id_free(int id);
> +void amd_iommu_pdom_id_destroy(void);

Domain IDs are not signed integers. Use u32.

> diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
> index 48bca4dc8eb6..4d57e820b824 100644
> --- a/drivers/iommu/amd/iommu.c
> +++ b/drivers/iommu/amd/iommu.c
> @@ -1785,17 +1785,26 @@ int amd_iommu_complete_ppr(struct device *dev, u32 pasid, int status, int tag)
>   * contain.
>   *
>   ****************************************************************************/
> -
> -static int pdom_id_alloc(void)
> +int amd_iommu_pdom_id_alloc(void)
>  {
>  	return ida_alloc_range(&pdom_ids, 1, MAX_DOMAIN_ID - 1, GFP_ATOMIC);
>  }
>
> -static void pdom_id_free(int id)
> +int amd_iommu_pdom_id_reserve(int id)
> +{
> +	return ida_alloc_range(&pdom_ids, id, id, GFP_ATOMIC);
> +}

The GFP should probably be passed in as a function argument

Jason
Re: [PATCH 2/2] amd/iommu: Make protection domain ID functions non-static
Posted by Vasant Hegde 2 months, 3 weeks ago 

On 11/14/2025 4:14 PM, Sairaj Kodilkar wrote:
> So that both iommu.c and init.c can utilize them. Also define a new
> function 'pdom_id_destroy()' to destroy 'pdom_ids' instead of directly
> calling ida functions.
> 
> Signed-off-by: Sairaj Kodilkar <sarunkod@amd.com>

Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>


-Vasant

Patchew 2.1-devel-b67e4c2

© 2016 - 2026 Red Hat, Inc.