LF-4436-2 [#imx-2664] allocate scatter list for cacheable pages only

sg_alloc_table_from_pages will consume system memory for gfp allocator,
scatter list is used for the addtional operation on cacheable memory,
check cacheable flag to allocate scatter list when necessary only.

[ 1704.740010] Chrome_InProcGp invoked oom-killer: gfp_mask=0xcc0(GFP_KERNEL), order=0, oom_score_adj=0
[ 1704.749265] CPU: 3 PID: 1251 Comm: Chrome_InProcGp Tainted: G         C        5.10.52-lts-5.10.y+g5788c4507376 #1
[ 1704.759618] Hardware name: NXP i.MX8MNano EVK board (DT)
[ 1704.764929] Call trace:
[ 1704.767385]  dump_backtrace+0x0/0x1a0
[ 1704.771051]  show_stack+0x18/0x70
[ 1704.774368]  dump_stack+0xd0/0x12c
[ 1704.777770]  dump_header+0x48/0x1f4
[ 1704.781259]  oom_kill_process+0x200/0x204
[ 1704.785268]  out_of_memory+0x178/0x560
[ 1704.789018]  __alloc_pages_nodemask+0xb34/0xc24
[ 1704.793549]  alloc_pages_current+0x80/0x13c
[ 1704.797752]  __get_free_pages+0x14/0x50
[ 1704.801595]  __sg_alloc_table_from_pages+0x22c/0x484
[ 1704.806559]  sg_alloc_table_from_pages+0x24/0x3c
[ 1704.811176]  _GFPAlloc+0x2b0/0x670
[ 1704.814579]  gckOS_AllocatePagedMemory+0xf4/0x1fc
[ 1704.819302]  gckVIDMEM_NODE_AllocateVirtual+0xc4/0x190
[ 1704.824446]  gckKERNEL_AllocateVideoMemory+0x2f8/0x380
[ 1704.829584]  _AllocateLinearMemory+0xb8/0x1b4
[ 1704.833943]  gckKERNEL_Dispatch+0x20c/0x13d4
[ 1704.838229]  gckDEVICE_Dispatch+0x80/0x1bc
[ 1704.842328]  drv_ioctl+0x1b4/0x270
[ 1704.845750]  __arm64_sys_ioctl+0xa8/0xf0
[ 1704.849677]  el0_svc_common.constprop.0+0x78/0x1a0
[ 1704.854469]  do_el0_svc+0x24/0x90
[ 1704.857803]  el0_svc+0x14/0x20
[ 1704.860860]  el0_sync_handler+0x1a4/0x1b0
[ 1704.864869]  el0_sync+0x180/0x1c0

Signed-off-by: Xianzhong <xianzhong.li@nxp.com>

drivers/mxc/gpu-viv/hal/os/linux/kernel/allocator/default/gc_hal_kernel_allocator_gfp.c

@@ -625,52 +625,56 @@ _GFPAlloc(
                 gcmkONERROR(_NonContiguousAlloc(mdlPriv, NumPages, gfp));
             }
         }
+
+        if (Flags & gcvALLOC_FLAG_CACHEABLE)
+        {
 #if gcdUSE_Linux_SG_TABLE_API
-        result = sg_alloc_table_from_pages(&mdlPriv->sgt,
-                    mdlPriv->nonContiguousPages, NumPages, 0,
-                    NumPages << PAGE_SHIFT, GFP_KERNEL);
+            result = sg_alloc_table_from_pages(&mdlPriv->sgt,
+                        mdlPriv->nonContiguousPages, NumPages, 0,
+                        NumPages << PAGE_SHIFT, GFP_KERNEL);
 
 #else
-        result = alloc_sg_list_from_pages(&mdlPriv->sgt.sgl,
-                    mdlPriv->nonContiguousPages, NumPages, 0,
-                    NumPages << PAGE_SHIFT, &mdlPriv->sgt.nents);
+            result = alloc_sg_list_from_pages(&mdlPriv->sgt.sgl,
+                        mdlPriv->nonContiguousPages, NumPages, 0,
+                        NumPages << PAGE_SHIFT, &mdlPriv->sgt.nents);
 
-        mdlPriv->sgt.orig_nents = mdlPriv->sgt.nents;
+            mdlPriv->sgt.orig_nents = mdlPriv->sgt.nents;
 #endif
-        if (result < 0)
-        {
-            if (Mdl->pageUnit1M)
+            if (result < 0)
             {
-                _NonContiguous1MPagesFree(mdlPriv, mdlPriv->numPages1M);
-            }
-            else
-            {
-                _NonContiguousFree(mdlPriv->nonContiguousPages, NumPages);
-            }
+                if (Mdl->pageUnit1M)
+                {
+                    _NonContiguous1MPagesFree(mdlPriv, mdlPriv->numPages1M);
+                }
+                else
+                {
+                    _NonContiguousFree(mdlPriv->nonContiguousPages, NumPages);
+                }
 
-            gcmkONERROR(gcvSTATUS_OUT_OF_MEMORY);
-        }
+                gcmkONERROR(gcvSTATUS_OUT_OF_MEMORY);
+            }
 
-        result = dma_map_sg(galcore_device,
-                    mdlPriv->sgt.sgl, mdlPriv->sgt.nents, DMA_FROM_DEVICE);
+            result = dma_map_sg(galcore_device,
+                        mdlPriv->sgt.sgl, mdlPriv->sgt.nents, DMA_FROM_DEVICE);
 
-        if (result != mdlPriv->sgt.nents)
-        {
-            if (Mdl->pageUnit1M)
+            if (result != mdlPriv->sgt.nents)
             {
-                _NonContiguous1MPagesFree(mdlPriv, mdlPriv->numPages1M);
-            }
-            else
-            {
-                _NonContiguousFree(mdlPriv->nonContiguousPages, NumPages);
-            }
+                if (Mdl->pageUnit1M)
+                {
+                    _NonContiguous1MPagesFree(mdlPriv, mdlPriv->numPages1M);
+                }
+                else
+                {
+                    _NonContiguousFree(mdlPriv->nonContiguousPages, NumPages);
+                }
 
 #if gcdUSE_Linux_SG_TABLE_API
-            sg_free_table(&mdlPriv->sgt);
+                sg_free_table(&mdlPriv->sgt);
 #else
-            kfree(mdlPriv->sgt.sgl);
+                kfree(mdlPriv->sgt.sgl);
 #endif
-            gcmkONERROR(gcvSTATUS_OUT_OF_MEMORY);
+                gcmkONERROR(gcvSTATUS_OUT_OF_MEMORY);
+            }
         }
 
 #if defined(CONFIG_X86)
@@ -821,7 +825,7 @@ _GFPFree(
         dma_unmap_page(galcore_device, mdlPriv->dma_addr,
                 Mdl->numPages << PAGE_SHIFT, DMA_FROM_DEVICE);
     }
-    else
+    else if (mdlPriv->sgt.sgl)
     {
         dma_unmap_sg(galcore_device, mdlPriv->sgt.sgl, mdlPriv->sgt.nents,
                 DMA_FROM_DEVICE);