spi_flash: move cache operations into separate file

components/spi_flash/cache_utils.h

@@ -0,0 +1,44 @@
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed 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.
+
+#ifndef ESP_SPI_FLASH_CACHE_UTILS_H
+#define ESP_SPI_FLASH_CACHE_UTILS_H
+
+/**
+ * This header file contains declarations of cache manipulation functions
+ * used both in flash_ops.c and flash_mmap.c.
+ *
+ * These functions are considered internal and are not designed to be called from applications.
+ */
+
+// Init mutex protecting access to spi_flash_* APIs
+void spi_flash_init_lock();
+
+// Take mutex protecting access to spi_flash_* APIs
+void spi_flash_op_lock();
+
+// Release said mutex
+void spi_flash_op_unlock();
+
+// Suspend the scheduler on both CPUs, disable cache.
+// Contrary to its name this doesn't do anything with interrupts, yet.
+// Interrupt disabling capability will be added once we implement
+// interrupt allocation API.
+void spi_flash_disable_interrupts_caches_and_other_cpu();
+
+// Enable cache, enable interrupts (to be added in future), resume scheduler
+void spi_flash_enable_interrupts_caches_and_other_cpu();
+
+
+#endif //ESP_SPI_FLASH_CACHE_UTILS_H