esp_hw_support: Update memory ptr location/property checks

- to acknowledge the unused DCACHE added to DRAM for ESP32-S3

- For ESP32-S3, when the DCACHE size is set to 16 kB, the unused 48 kB is added to
  the heap in 2 blocks of 32 kB (from 0x3FCF0000) and 16 kB (from 0x3C000000).
- But, if we try allocating memory from the 16 kB block and run an `esp_ptr_internal`
  check on that memory pointer, it fails as the address block from 0x3C000000
  corresponds to the external memory symbols SOC_DROM_LOW and SOC_EXTRAM_DATA_LOW.
  (E.g. freertos - If the IDLE task stack buffer gets allocated from this region,
  the firmware will abort due to this failure).
- Thus, the checks `esp_ptr_internal`, `esp_ptr_in_drom` and `esp_ptr_byte_accessible`
  have been updated to acknowledge this memory as a part of the DRAM.

Co-authored-by: Mahavir Jain <mahavir@espressif.com>

components/esp_hw_support/esp_memory_utils.c

@@ -42,6 +42,15 @@ bool esp_ptr_byte_accessible(const void *p)
 #endif
 #if CONFIG_SPIRAM
     r |= esp_psram_check_ptr_addr(p);
+#endif
+#if CONFIG_ESP32S3_DATA_CACHE_16KB
+    /* For ESP32-S3, when the DCACHE size is set to 16 kB, the unused 48 kB is
+     * added to the heap in 2 blocks of 32 kB (from 0x3FCF0000) and 16 kB
+     * (from 0x3C000000 (SOC_DROM_LOW) - 0x3C004000).
+     * Though this memory lies in the external memory vaddr, it is no different
+     * from the internal RAM in terms of hardware attributes. It is a part of
+     * the internal RAM when added to the heap and is byte-accessible .*/
+    r |= (ip >= SOC_DROM_LOW && ip < (SOC_DROM_LOW + 0x4000));
 #endif
     return r;
 }

components/esp_hw_support/include/esp_memory_utils.h

@@ -256,6 +256,17 @@ inline static bool esp_ptr_internal(const void *p) {
      * additional check is required */
     r |= ((intptr_t)p >= SOC_RTC_DRAM_LOW && (intptr_t)p < SOC_RTC_DRAM_HIGH);
 #endif
+
+#if CONFIG_ESP32S3_DATA_CACHE_16KB
+    /* For ESP32-S3, when the DCACHE size is set to 16 kB, the unused 48 kB is
+     * added to the heap in 2 blocks of 32 kB (from 0x3FCF0000) and 16 kB
+     * (from 0x3C000000 (SOC_DROM_LOW) - 0x3C004000).
+     * Though this memory lies in the external memory vaddr, it is no different
+     * from the internal RAM in terms of hardware attributes and it is a part of
+     * the internal RAM when added to the heap.*/
+    r |= ((intptr_t)p >= SOC_DROM_LOW && (intptr_t)p < (SOC_DROM_LOW + 0x4000));
+#endif
+
     return r;
 }
 
@@ -277,7 +288,17 @@ bool esp_ptr_external_ram(const void *p);
  */
 __attribute__((always_inline))
 inline static bool esp_ptr_in_drom(const void *p) {
-    return ((intptr_t)p >= SOC_DROM_LOW && (intptr_t)p < SOC_DROM_HIGH);
+    uint32_t drom_start_addr = SOC_DROM_LOW;
+#if CONFIG_ESP32S3_DATA_CACHE_16KB
+    /* For ESP32-S3, when the DCACHE size is set to 16 kB, the unused 48 kB is
+     * added to the heap in 2 blocks of 32 kB (from 0x3FCF0000) and 16 kB
+     * (from 0x3C000000 (SOC_DROM_LOW) - 0x3C004000).
+     * The drom_start_addr has to be moved by 0x4000 (16kB) to accomodate
+     * this addition. */
+    drom_start_addr += 0x4000;
+#endif
+
+    return ((intptr_t)p >= drom_start_addr && (intptr_t)p < SOC_DROM_HIGH);
 }
 
 /**