[nrf fromtree] soc: nordic: s2ram: Align s2ram marking procedures

Rework Nordic specific S2RAM marking procedures.
The S2RAM marking procedures must not disrupt the stack due to
the TLS pointer not yet being initialized during their execution.

Signed-off-by: Adam Kondraciuk <[email protected]>

(cherry picked from commit 59629d0)

Author: adamkondraciuk

soc/nordic/nrf54h/pm_s2ram.c

@@ -127,25 +127,48 @@ int soc_s2ram_suspend(pm_s2ram_system_off_fn_t system_off)
 	return ret;
 }
 
-void pm_s2ram_mark_set(void)
+void __attribute__((naked)) pm_s2ram_mark_set(void)
 {
 	/* empty */
+	__asm__ volatile("bx	lr\n");
 }
 
-bool pm_s2ram_mark_check_and_clear(void)
+bool __attribute__((naked)) pm_s2ram_mark_check_and_clear(void)
 {
-	bool unretained_wake;
-	bool restore_valid;
-	uint32_t reset_reason = nrf_resetinfo_resetreas_local_get(NRF_RESETINFO);
+	__asm__ volatile(
+		/* Set return value to 0 */
+		"mov	r0, #0\n"
 
-	if (reset_reason != NRF_RESETINFO_RESETREAS_LOCAL_UNRETAINED_MASK) {
-		return false;
-	}
-	unretained_wake = reset_reason & NRF_RESETINFO_RESETREAS_LOCAL_UNRETAINED_MASK;
-	nrf_resetinfo_resetreas_local_set(NRF_RESETINFO, 0);
+		/* Load and check RESETREAS register */
+		"ldr	r3, [%[resetinfo_addr], %[resetreas_offs]]\n"
+		"cmp	r3, %[resetreas_unretained_mask]\n"
+
+		"bne	exit\n"
+
+		/* Clear RESETREAS register */
+		"str	r0, [%[resetinfo_addr], %[resetreas_offs]]\n"
+
+		/* Load RESTOREVALID register */
+		"ldr	r3, [%[resetinfo_addr], %[restorevalid_offs]]\n"
+
+		/* Clear RESTOREVALID */
+		"str	r0, [%[resetinfo_addr], %[restorevalid_offs]]\n"
+
+		/* Check RESTOREVALID register */
+		"cmp	r3, %[restorevalid_present_mask]\n"
+		"bne	exit\n"
+
+		/* Set return value to 1 */
+		"mov	r0, #1\n"
 
-	restore_valid = nrf_resetinfo_restore_valid_check(NRF_RESETINFO);
-	nrf_resetinfo_restore_valid_set(NRF_RESETINFO, false);
+		"exit:\n"
+		"bx	lr\n"
+		:
+		: [resetinfo_addr] "r"(NRF_RESETINFO),
+		  [resetreas_offs] "r"(offsetof(NRF_RESETINFO_Type, RESETREAS.LOCAL)),
+		  [resetreas_unretained_mask] "r"(NRF_RESETINFO_RESETREAS_LOCAL_UNRETAINED_MASK),
+		  [restorevalid_offs] "r"(offsetof(NRF_RESETINFO_Type, RESTOREVALID)),
+		  [restorevalid_present_mask] "r"(RESETINFO_RESTOREVALID_RESTOREVALID_Msk)
 
-	return (unretained_wake & restore_valid) ? true : false;
+		: "r0", "r1", "r3", "r4", "memory");
 }