ENGR00160722 amd gpu: add best fit algorithm to memory manager

The AMD gpu driver memory manager is stupid to allocating
a memory block from the first free block. Neither check the
best fit free block. Here just add a little codes to
let allocation to find a best size fitted free block.
To avoid memory fragement.

Signed-off-by: Xinyu Chen <xinyu.chen@freescale.com>

1 files changed, 44 insertions, 29 deletions

diff --git a/drivers/mxc/amd-gpu/common/gsl_memmgr.c b/drivers/mxc/amd-gpu/common/gsl_memmgr.c
index 75f250ae59b1..f331bb547542 100644
--- a/drivers/mxc/amd-gpu/common/gsl_memmgr.c
+++ b/drivers/mxc/amd-gpu/common/gsl_memmgr.c
@@ -479,6 +479,8 @@ kgsl_memarena_alloc(gsl_memarena_t *memarena, gsl_flags_t flags, int size, gsl_m
     unsigned int  blksize;
     unsigned int  baseaddr, alignedbaseaddr, alignfragment;
     int           freeblk, alignmentshift;
+    memblk_t *ptrbest = NULL;
+    unsigned int fitsize = ~0UL;
 
     kgsl_log_write( KGSL_LOG_GROUP_MEMORY | KGSL_LOG_LEVEL_TRACE,
                     "--> int kgsl_memarena_alloc(gsl_memarena_t *memarena=0x%08x, gsl_flags_t flags=0x%08x, int size=%d, gsl_memdesc_t *memdesc=%M)\n", memarena, flags, size, memdesc );
@@ -542,17 +544,34 @@ kgsl_memarena_alloc(gsl_memarena_t *memarena, gsl_flags_t flags, int size, gsl_m
 
     do
     { 
+        int aba;
         // align base address
         baseaddr = ptrfree->blkaddr + memarena->gpubaseaddr;
-        alignedbaseaddr = gsl_memarena_alignaddr(baseaddr, alignmentshift);
+        aba = gsl_memarena_alignaddr(baseaddr, alignmentshift);
        
-        alignfragment = alignedbaseaddr - baseaddr;
+        if (aba - baseaddr == 0 && ptrfree->blksize == blksize) {
+            ptrbest = ptrfree;
+            alignfragment = aba - baseaddr;
+            alignedbaseaddr = aba;
+            result  = GSL_SUCCESS;
+            break;
+        }
 
-        if (ptrfree->blksize >= blksize + alignfragment)
+        if ((ptrfree->blksize >= blksize + aba - baseaddr) &&
+            (fitsize > ptrfree->blksize))
         {
+            fitsize = ptrfree->blksize;
+            alignfragment = aba - baseaddr;
+            alignedbaseaddr = aba;
             result  = GSL_SUCCESS;
-            freeblk = 1;
+            ptrbest = ptrfree;
+        }
+
+        ptrfree = ptrfree->next;
+
+    } while (ptrfree != memarena->freelist.allocrover);
 
+    if (ptrbest) {
             memdesc->gpuaddr = alignedbaseaddr;
             memdesc->hostptr = kgsl_memarena_gethostptr(memarena, memdesc->gpuaddr);
             memdesc->size    = blksize;
@@ -561,50 +580,46 @@ kgsl_memarena_alloc(gsl_memarena_t *memarena, gsl_flags_t flags, int size, gsl_m
             {
                 // insert new node to handle newly created (small) fragment
                 p = kgsl_memarena_getmemblknode(memarena);
-                p->blkaddr = ptrfree->blkaddr;
+                p->blkaddr = ptrbest->blkaddr;
                 p->blksize = alignfragment;
 
-                p->next = ptrfree;
-                p->prev = ptrfree->prev;
-                ptrfree->prev->next = p;
-                ptrfree->prev       = p;
+                p->next = ptrbest;
+                p->prev = ptrbest->prev;
+                ptrbest->prev->next = p;
+                ptrbest->prev       = p;
 
-                if (ptrfree == memarena->freelist.head)
+                if (ptrbest == memarena->freelist.head)
                 {
                     memarena->freelist.head = p;
                 }
             }
 
-            ptrfree->blkaddr += alignfragment + blksize;
-            ptrfree->blksize -= alignfragment + blksize;
+            ptrbest->blkaddr += alignfragment + blksize;
+            ptrbest->blksize -= alignfragment + blksize;
 
-            memarena->freelist.allocrover = ptrfree;
+            memarena->freelist.allocrover = ptrbest;
 
-            if (ptrfree->blksize == 0 && ptrfree != ptrlast)
+            if (ptrbest->blksize == 0 && ptrbest != ptrlast)
             {
-                ptrfree->prev->next = ptrfree->next;
-                ptrfree->next->prev = ptrfree->prev;
-                if (ptrfree == memarena->freelist.head)
+                ptrbest->prev->next = ptrbest->next;
+                ptrbest->next->prev = ptrbest->prev;
+                if (ptrbest == memarena->freelist.head)
                 {
-                    memarena->freelist.head = ptrfree->next;
+                    memarena->freelist.head = ptrbest->next;
                 }
-                if (ptrfree == memarena->freelist.allocrover)
+                if (ptrbest == memarena->freelist.allocrover)
                 {
-                    memarena->freelist.allocrover = ptrfree->next;
+                    memarena->freelist.allocrover = ptrbest->next;
                 }
-                if (ptrfree == memarena->freelist.freerover)
+                if (ptrbest == memarena->freelist.freerover)
                 {
-                    memarena->freelist.freerover = ptrfree->prev;
+                    memarena->freelist.freerover = ptrbest->prev;
                 }
-                p       = ptrfree;
-                ptrfree = ptrfree->prev;
+                p       = ptrbest;
+                ptrbest = ptrbest->prev;
                 kgsl_memarena_releasememblknode(memarena, p);
             }
-        }
-
-        ptrfree = ptrfree->next;
-
-    } while (!freeblk && ptrfree != memarena->freelist.allocrover);
+    }
 
     GSL_MEMARENA_UNLOCK();