arch: imx6: Add the pgheap for imx6

Summary:
- This commit adds the pgheap for imx6

Impact:
- None

Testing:
- Tested with sabre-6quad:netknsh (not merged yet)

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

arch/arm/src/imx6/Kconfig

@@ -197,4 +197,30 @@ config IMX6_BOOT_SRAM
 
 endchoice # i.MX6 Boot Configuration
 
+config IMX6_DDRCS_PGHEAP
+	bool "Include DDR-SDRAM in page cache"
+	default y
+	depends on IMX6_BOOT_SDRAM && ARCH_ADDRENV
+	---help---
+		Include a portion of DDR-SDRAM memory in the page cache.
+
+if IMX6_DDRCS_PGHEAP
+
+config IMX6_DDRCS_PGHEAP_OFFSET
+	hex "DDR-SDRAM heap offset"
+	default 0x0
+	---help---
+		Preserve this number of bytes at the beginning of SDRAM.  The
+		portion of DRAM beginning at this offset from the DDRCS base will
+		be added to the heap.
+
+config IMX6_DDRCS_PGHEAP_SIZE
+	int "DDR-SDRAM heap size"
+	default 0
+	---help---
+		Add the region of DDR-SDRAM beginning at IMX6_DDRCS_PGHEAP_OFFSET
+		and of size IMX6_DDRCS_PGHEAP_SIZE to the heap.
+
+endif # IMX6_DDRCS_PGHEAP
+
 endif # ARCH_CHIP_IMX6

arch/arm/src/imx6/Make.defs

@@ -149,3 +149,7 @@ endif
 ifeq ($(CONFIG_IMX6_ENET),y)
 CHIP_CSRCS += imx_enet.c
 endif
+
+ifeq ($(CONFIG_MM_PGALLOC),y)
+CHIP_CSRCS += imx_pgalloc.c
+endif

arch/arm/src/imx6/imx_pgalloc.c

@@ -0,0 +1,104 @@
+/****************************************************************************
+ * arch/arm/src/imx6/imx_pgalloc.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/addrenv.h>
+#include <nuttx/pgalloc.h>
+
+#include "chip.h"
+#include "mmu.h"
+
+#ifdef CONFIG_MM_PGALLOC
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Currently, page cache memory must be allocated in DRAM.  There are other
+ * possibilities, but the logic in this file will have to extended in order
+ * handle any other possibility.
+ */
+
+#ifndef CONFIG_ARCH_PGPOOL_MAPPING
+#  error CONFIG_ARCH_PGPOOL_MAPPING must be selected
+#endif
+
+#ifndef CONFIG_IMX6_DDRCS_PGHEAP
+#  error CONFIG_IMX6_DDRCS_PGHEAP must be selected
+#endif
+
+#ifndef CONFIG_IMX6_DDRCS_PGHEAP_OFFSET
+#  error CONFIG_IMX6_DDRCS_PGHEAP_OFFSET must be specified
+#endif
+
+#if (CONFIG_IMX6_DDRCS_PGHEAP_OFFSET & MM_PGMASK) != 0
+#  warning CONFIG_IMX6_DDRCS_PGHEAP_OFFSET is not aligned to a page boundary
+#endif
+
+#ifndef CONFIG_IMX6_DDRCS_PGHEAP_SIZE
+#  error CONFIG_IMX6_DDRCS_PGHEAP_SIZE must be specified
+#endif
+
+#if (CONFIG_IMX6_DDRCS_PGHEAP_SIZE & MM_PGMASK) != 0
+#  warning CONFIG_IMX6_DDRCS_PGHEAP_SIZE is not aligned to a page boundary
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_allocate_pgheap
+ *
+ * Description:
+ *   If there is a page allocator in the configuration, then this function
+ *   must be provided by the platform-specific code.  The OS initialization
+ *   logic will call this function early in the initialization sequence to
+ *   get the page heap information needed to configure the page allocator.
+ *
+ * Input parameters:
+ *   heap_start - A double pointer to the start address of the pgheap
+ *   heap_size - A pointer to the size of the pgheap
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void up_allocate_pgheap(FAR void **heap_start, size_t *heap_size)
+{
+  DEBUGASSERT(heap_start && heap_size);
+
+  *heap_start = (FAR void *)((uintptr_t)IMX_MMDCDDR_PSECTION +
+                             CONFIG_IMX6_DDRCS_PGHEAP_OFFSET);
+  *heap_size  = CONFIG_IMX6_DDRCS_PGHEAP_SIZE;
+}
+
+#endif /* CONFIG_MM_PGALLOC */