Re: [Xen-devel] [PATCH 3/8] gnttab: type adjustments

[Andrew Cooper]

On 15/08/17 15:40, Jan Beulich wrote:
> In particular use grant_ref_t and grant_handle_t where appropriate.
> Also switch other nearby type uses to their canonical variants where
> appropriate and introduce INVALID_MAPTRACK_HANDLE.
>
> Signed-by: Jan Beulich 

Reviewed-by: Andrew Cooper 

This needs rebasing over my change to simplify
gnttab_copy_lock_domain(), where I ended up with the same net change as
you've proposed.

~Andrew

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[Xen-devel] [PATCH 3/8] gnttab: type adjustments

[Jan Beulich]

In particular use grant_ref_t and grant_handle_t where appropriate.
Also switch other nearby type uses to their canonical variants where
appropriate and introduce INVALID_MAPTRACK_HANDLE.

Signed-by: Jan Beulich 

--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -96,7 +96,7 @@ struct gnttab_unmap_common {
 int16_t status;
 
 /* Shared state beteen *_unmap and *_unmap_complete */
-u16 done;
+uint16_t done;
 unsigned long frame;
 struct domain *rd;
 grant_ref_t ref;
@@ -118,11 +118,11 @@ struct gnttab_unmap_common {
  * table of these, indexes into which are returned as a 'mapping handle'.
  */
 struct grant_mapping {
-u32  ref;   /* grant ref */
-u16  flags; /* 0-4: GNTMAP_* ; 5-15: unused */
+grant_ref_t ref;/* grant ref */
+uint16_t flags; /* 0-4: GNTMAP_* ; 5-15: unused */
 domid_t  domid; /* granting domain */
-u32  vcpu;  /* vcpu which created the grant mapping */
-u32  pad;   /* round size to a power of 2 */
+uint32_t vcpu;  /* vcpu which created the grant mapping */
+uint32_t pad;   /* round size to a power of 2 */
 };
 
 #define MAPTRACK_PER_PAGE (PAGE_SIZE / sizeof(struct grant_mapping))
@@ -158,10 +158,10 @@ shared_entry_header(struct grant_table *
 
 /* Active grant entry - used for shadowing GTF_permit_access grants. */
 struct active_grant_entry {
-u32   pin;/* Reference count information. */
+uint32_t  pin;/* Reference count information. */
 domid_t   domid;  /* Domain being granted access. */
 struct domain *trans_domain;
-uint32_t  trans_gref;
+grant_ref_t   trans_gref;
 unsigned long frame;  /* Frame being granted. */
 unsigned long gfn;/* Guest's idea of the frame being granted. */
 unsigned  is_sub_page:1; /* True if this is a sub-page grant. */
@@ -297,7 +297,9 @@ double_gt_unlock(struct grant_table *lgt
 grant_write_unlock(rgt);
 }
 
-static inline int
+#define INVALID_MAPTRACK_HANDLE UINT_MAX
+
+static inline grant_handle_t
 __get_maptrack_handle(
 struct grant_table *t,
 struct vcpu *v)
@@ -312,7 +314,7 @@ __get_maptrack_handle(
 if ( unlikely(head == MAPTRACK_TAIL) )
 {
 spin_unlock(>maptrack_freelist_lock);
-return -1;
+return INVALID_MAPTRACK_HANDLE;
 }
 
 /*
@@ -323,7 +325,7 @@ __get_maptrack_handle(
 if ( unlikely(next == MAPTRACK_TAIL) )
 {
 spin_unlock(>maptrack_freelist_lock);
-return -1;
+return INVALID_MAPTRACK_HANDLE;
 }
 
 prev_head = head;
@@ -345,8 +347,8 @@ __get_maptrack_handle(
  * each VCPU and to avoid two VCPU repeatedly stealing entries from
  * each other, the initial victim VCPU is selected randomly.
  */
-static int steal_maptrack_handle(struct grant_table *t,
- const struct vcpu *curr)
+static grant_handle_t steal_maptrack_handle(struct grant_table *t,
+const struct vcpu *curr)
 {
 const struct domain *currd = curr->domain;
 unsigned int first, i;
@@ -357,10 +359,10 @@ static int steal_maptrack_handle(struct
 do {
 if ( currd->vcpu[i] )
 {
-int handle;
+grant_handle_t handle;
 
 handle = __get_maptrack_handle(t, currd->vcpu[i]);
-if ( handle != -1 )
+if ( handle != INVALID_MAPTRACK_HANDLE )
 {
 maptrack_entry(t, handle).vcpu = curr->vcpu_id;
 return handle;
@@ -373,12 +375,12 @@ static int steal_maptrack_handle(struct
 } while ( i != first );
 
 /* No free handles on any VCPU. */
-return -1;
+return INVALID_MAPTRACK_HANDLE;
 }
 
 static inline void
 put_maptrack_handle(
-struct grant_table *t, int handle)
+struct grant_table *t, grant_handle_t handle)
 {
 struct domain *currd = current->domain;
 struct vcpu *v;
@@ -404,7 +406,7 @@ put_maptrack_handle(
 spin_unlock(>maptrack_freelist_lock);
 }
 
-static inline int
+static inline grant_handle_t
 get_maptrack_handle(
 struct grant_table *lgt)
 {
@@ -414,7 +416,7 @@ get_maptrack_handle(
 struct grant_mapping *new_mt = NULL;
 
 handle = __get_maptrack_handle(lgt, curr);
-if ( likely(handle != -1) )
+if ( likely(handle != INVALID_MAPTRACK_HANDLE) )
 return handle;
 
 spin_lock(>maptrack_lock);
@@ -439,8 +441,8 @@ get_maptrack_handle(
 if ( curr->maptrack_tail == MAPTRACK_TAIL )
 {
 handle = steal_maptrack_handle(lgt, curr);
-if ( handle == -1 )
-return -1;
+if ( handle == INVALID_MAPTRACK_HANDLE )
+return handle;
 spin_lock(>maptrack_freelist_lock);
 maptrack_entry(lgt,