fix(riscv): supports 1 byte and larger than 64byte range watchpoint setting

components/esp_hw_support/cpu.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2020-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2020-2023 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -575,11 +575,19 @@ esp_err_t esp_cpu_set_watchpoint(int wp_num, const void *wp_addr, size_t size, e
 {
     /*
     Todo:
-    - Check that wp_num is in range
     - Check if the wp_num is already in use
     */
-    // Check if size is 2^n, where n is in [0...6]
+    if (wp_num < 0 || wp_num >= SOC_CPU_WATCHPOINTS_NUM) {
-    if (size < 1 || size > 64 || (size & (size - 1)) != 0) {
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    // Check that the watched region's start address is naturally aligned to the size of the region
+    if ((uint32_t)wp_addr % size) {
+        return ESP_ERR_INVALID_ARG;
+    }
+
+    // Check if size is 2^n, and size is in the range of [1 ... SOC_CPU_WATCHPOINT_MAX_REGION_SIZE]
+    if (size < 1 || size > SOC_CPU_WATCHPOINT_MAX_REGION_SIZE || (size & (size - 1)) != 0) {
         return ESP_ERR_INVALID_ARG;
     }
     bool on_read = (trigger == ESP_CPU_WATCHPOINT_LOAD || trigger == ESP_CPU_WATCHPOINT_ACCESS);

components/esp_hw_support/include/esp_cpu.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2020-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2020-2023 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -468,9 +468,15 @@ esp_err_t esp_cpu_clear_breakpoint(int bp_num);
  * the CPU accesses (according to the trigger type) on a certain memory range.
  *
  * @note Overwrites previously set watchpoint with same watchpoint number.
+ *       On RISC-V chips, this API uses method0(Exact matching) and method1(NAPOT matching) according to the
+ *       riscv-debug-spec-0.13 specification for address matching.
+ *       If the watch region size is 1byte, it uses exact matching (method 0).
+ *       If the watch region size is larger than 1byte, it uses NAPOT matching (method 1). This mode requires
+ *       the watching region start address to be aligned to the watching region size.
+ *
  * @param wp_num Hardware watchpoint number [0..SOC_CPU_WATCHPOINTS_NUM - 1]
- * @param wp_addr Watchpoint's base address
+ * @param wp_addr Watchpoint's base address, must be naturally aligned to the size of the region
- * @param size Size of the region to watch. Must be one of 2^n, with n in [0..6].
+ * @param size Size of the region to watch. Must be one of 2^n and in the range of [1 ... SOC_CPU_WATCHPOINT_MAX_REGION_SIZE]
  * @param trigger Trigger type
  * @return ESP_ERR_INVALID_ARG on invalid arg, ESP_OK otherwise
  */

components/riscv/include/riscv/csr.h

@@ -99,7 +99,8 @@ extern "C" {
 #define TDATA1_EXECUTE   (1<<2)  /*R/W,Fire trigger on instruction fetch address match*/
 #define TDATA1_USER      (1<<3)  /*R/W,allow trigger to be fired in user mode*/
 #define TDATA1_MACHINE   (1<<6)  /*R/W,Allow trigger to be fired while hart is executing in machine mode*/
-#define TDATA1_MATCH     (1<<7)
+#define TDATA1_MATCH_EXACT  (0)
+#define TDATA1_MATCH_NAPOT  (1<<7)
 #define TDATA1_MATCH_V   (0xF)   /*R/W,Address match type :0 : Exact byte match  1 : NAPOT range match */
 #define TDATA1_MATCH_S   (7)
 #define TDATA1_HIT_S     (20)

components/riscv/include/riscv/rv_utils.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2020-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2020-2023 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -147,30 +147,32 @@ FORCE_INLINE_ATTR void rv_utils_set_watchpoint(int wp_num,
     RV_WRITE_CSR(tcontrol, TCONTROL_MPTE | TCONTROL_MTE);
     RV_WRITE_CSR(tdata1, TDATA1_USER                   |
                          TDATA1_MACHINE                |
-                         TDATA1_MATCH                  |
+                         ((size == 1) ? TDATA1_MATCH_EXACT : TDATA1_MATCH_NAPOT) |
                          (on_read  ? TDATA1_LOAD  : 0) |
                          (on_write ? TDATA1_STORE : 0));
     /* From RISC-V Debug Specification:
-     * NAPOT (Naturally Aligned Power-Of-Two):
+     * tdata1(mcontrol) match = 0 : Exact byte match
+     *
+     * tdata1(mcontrol) match = 1 : NAPOT (Naturally Aligned Power-Of-Two):
      * Matches when the top M bits of any compare value match the top M bits of tdata2.
      * M is XLEN − 1 minus the index of the least-significant bit containing 0 in tdata2.
+     * Note: Expecting that size is number power of 2 (numbers should be in the range of 1 ~ 31)
      *
-     * Note: Expectng that size is number power of 2
+     * Examples for understanding how to calculate match pattern to tdata2:
-     *
-     * Examples for understanding how to calculate NAPOT:
      *
+     * nnnn...nnnnn 1-byte  Exact byte match
      * nnnn...nnnn0 2-byte  NAPOT range
      * nnnn...nnn01 4-byte  NAPOT range
      * nnnn...nn011 8-byte  NAPOT range
      * nnnn...n0111 16-byte NAPOT range
      * nnnn...01111 32-byte NAPOT range
+     * ...
+     * n011...11111 2^31 byte NAPOT range
      *  * where n are bits from original address
      */
-    const uint32_t half_size = size >> 1;
+    uint32_t match_pattern = (wp_addr & ~(size-1)) | ((size-1) >> 1);
-    uint32_t napot = wp_addr;
+
-    napot &= ~half_size;      /* set the least-significant bit with zero */
+    RV_WRITE_CSR(tdata2, match_pattern);
-    napot |= half_size - 1;   /* fill all bits with ones after least-significant bit */
-    RV_WRITE_CSR(tdata2, napot);
 }
 
 FORCE_INLINE_ATTR void rv_utils_clear_breakpoint(int bp_num)