spi_flash: Add spi_flash_cache_enabled() test function

components/spi_flash/cache_utils.c

@@ -275,3 +275,9 @@ static void IRAM_ATTR spi_flash_restore_cache(uint32_t cpuid, uint32_t saved_sta
     }
 }
 
+
+IRAM_ATTR bool spi_flash_cache_enabled()
+{
+    return REG_GET_BIT(DPORT_PRO_CACHE_CTRL_REG, DPORT_PRO_CACHE_ENABLE)
+        && REG_GET_BIT(DPORT_APP_CACHE_CTRL_REG, DPORT_APP_CACHE_ENABLE);
+}

components/spi_flash/include/esp_spi_flash.h

@@ -197,6 +197,47 @@ void spi_flash_munmap(spi_flash_mmap_handle_t handle);
  */
 void spi_flash_mmap_dump();
 
+#define SPI_FLASH_CACHE2PHYS_FAIL UINT32_MAX /*<! Result from spi_flash_cache2phys() if flash cache address is invalid */
+
+/**
+ * @brief Given a memory address where flash is mapped, return the corresponding physical flash offset.
+ *
+ * Cache address does not have have been assigned via spi_flash_mmap(), any address in flash map space can be looked up.
+ *
+ * @param cached Pointer to flashed cached memory.
+ *
+ * @return
+ * - SPI_FLASH_CACHE2PHYS_FAIL If cache address is outside flash cache region, or the address is not mapped.
+ * - Otherwise, returns physical offset in flash
+ */
+size_t spi_flash_cache2phys(const void *cached);
+
+/** @brief Given a physical offset in flash, return the address where it is mapped in the memory space.
+ *
+ * Physical address does not have to have been assigned via spi_flash_mmap(), any address in flash can be looked up.
+ *
+ * @note Only the first matching cache address is returned. If MMU flash cache table is configured so multiple entries
+ * point to the same physical address, there may be more than one cache address corresponding to that physical
+ * address. It is also possible for a single physical address to be mapped to both the IROM and DROM regions.
+ *
+ * @note This function doesn't impose any alignment constraints, but if memory argument is SPI_FLASH_MMAP_INST and
+ * phys_offs is not 4-byte aligned, then reading from the returned pointer will result in a crash.
+ *
+ * @param phys_offs Physical offset in flash memory to look up.
+ * @param memory Memory type to look up a flash cache address mapping for (IROM or DROM)
+ *
+ * @return
+ * - NULL if the physical address is invalid or not mapped to flash cache of the specified memory type.
+ * - Cached memory address (in IROM or DROM space) corresponding to phys_offs.
+ */
+const void *spi_flash_phys2cache(size_t phys_offs, spi_flash_mmap_memory_t memory);
+
+/** @brief Check at runtime if flash cache is enabled on both CPUs
+ *
+ * @return true if both CPUs have flash cache enabled, false otherwise.
+ */
+bool spi_flash_cache_enabled();
+
 /**
  * @brief SPI flash critical section enter function.
  */

components/spi_flash/test/test_cache_disabled.c

@@ -0,0 +1,53 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <freertos/FreeRTOS.h>
+#include <freertos/task.h>
+#include <freertos/semphr.h>
+
+#include <unity.h>
+#include <esp_spi_flash.h>
+#include <esp_attr.h>
+#include <esp_flash_encrypt.h>
+
+#include "../cache_utils.h"
+
+static QueueHandle_t result_queue;
+
+static IRAM_ATTR void cache_test_task(void *arg)
+{
+    bool do_disable = (bool)arg;
+    bool result;
+    if(do_disable) {
+        spi_flash_disable_interrupts_caches_and_other_cpu();
+    }
+    result = spi_flash_cache_enabled();
+    if (do_disable) {
+        spi_flash_enable_interrupts_caches_and_other_cpu();
+    }
+
+    TEST_ASSERT( xQueueSendToBack(result_queue, &result, 0) );
+    vTaskDelete(NULL);
+}
+
+TEST_CASE("spi_flash_cache_enabled() works on both CPUs", "[spi_flash]")
+{
+    result_queue = xQueueCreate(1, sizeof(bool));
+
+    for(int cpu = 0; cpu < portNUM_PROCESSORS; cpu++) {
+        for(int disable = 0; disable <= 1; disable++) {
+            bool do_disable = disable;
+            bool result;
+            printf("Testing cpu %d disabled %d\n", cpu, do_disable);
+
+            xTaskCreatePinnedToCore(cache_test_task, "cache_check_task",
+                                    2048, (void *)do_disable, configMAX_PRIORITIES-1, NULL, cpu);
+
+            TEST_ASSERT( xQueueReceive(result_queue, &result, 2) );
+            TEST_ASSERT_EQUAL(!do_disable, result);
+        }
+    }
+
+    vQueueDelete(result_queue);
+}
+

docs/api/storage/spi_flash.rst

@@ -52,6 +52,9 @@ Functions
 .. doxygenfunction:: spi_flash_mmap
 .. doxygenfunction:: spi_flash_munmap
 .. doxygenfunction:: spi_flash_mmap_dump
+.. doxygenfunction:: spi_flash_cache2phys
+.. doxygenfunction:: spi_flash_phys2cache
+.. doxygenfunction:: spi_flash_cache_enabled
 .. doxygenfunction:: esp_partition_find
 .. doxygenfunction:: esp_partition_find_first
 .. doxygenfunction:: esp_partition_get