[PATCH 4/6] mach-snapdragon: fixup CPUs with PSCI enable-method

[Sam Day]

If there's no PSCI implementation, then change the enable-method of all
CPUs from "psci" to "spin-table". Later, when spin_table_update_dt runs,
it will further patch the CPU nodes with the necessary cpu-release-addr.

This new fixup is only applied when CONFIG_ARMV8_SPIN_TABLE is enabled,
since that also determines whether spin_table_update_dt runs.

Signed-off-by: Sam Day <me at samcday.com>
---
 arch/arm/mach-snapdragon/board.c | 41 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/arch/arm/mach-snapdragon/board.c b/arch/arm/mach-snapdragon/board.c
index 75b9cf1a8a1b3383665eb2d4e6725efe59718de0..396898e270bb744151ffd2f0f4ea319f6018dcd4 100644
--- a/arch/arm/mach-snapdragon/board.c
+++ b/arch/arm/mach-snapdragon/board.c
@@ -181,7 +181,9 @@ static void show_psci_version(void)
 static void qcom_psci_fixup(void *fdt)
 {
 	int offset, ret;
+	uint reg;
 	struct arm_smccc_res res;
+	const char *prop;
 
 	arm_smccc_smc(ARM_PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0, 0, 0, 0, 0, &res);
 
@@ -196,6 +198,45 @@ static void qcom_psci_fixup(void *fdt)
 	ret = fdt_del_node(fdt, offset);
 	if (ret)
 		log_err("Failed to delete /psci node: %d\n", ret);
+
+	if (!CONFIG_IS_ENABLED(ARMV8_SPIN_TABLE))
+		return;
+
+	/* If spin-table support is enabled, make sure any CPU nodes with a
+	 * PSCI enable-method are updated to spin-table. Further, any PSCI
+	 * power-domains properties are removed.
+	 */
+
+	offset = fdt_path_offset(fdt, "/cpus");
+	if (offset < 0)
+		return;
+
+	for (offset = fdt_first_subnode(fdt, offset);
+	     offset >= 0;
+	     offset = fdt_next_subnode(fdt, offset)) {
+		prop = fdt_getprop(fdt, offset, "device_type", NULL);
+		if (!prop || strcmp(prop, "cpu"))
+			continue;
+
+		prop = fdt_getprop(fdt, offset, "enable-method", NULL);
+		if (!prop || strcmp(prop, "psci"))
+			continue;
+
+		reg = fdtdec_get_uint(fdt, offset, "reg", 0);
+		ret = fdt_setprop_string(fdt, offset,
+					 "enable-method", "spin-table");
+		if (ret)
+			log_err("Failed to set CPU%d enable-method to 'spin-table', this CPU will not be available to booted OS! %d\n",
+				reg, ret);
+
+		log_info("Patched CPU%d enable-method to 'spin-table'\n", reg);
+
+		prop = fdt_getprop(fdt, offset, "power-domain-names", NULL);
+		if (prop && !strcmp(prop, "psci")) {
+			fdt_delprop(fdt, offset, "power-domains");
+			fdt_delprop(fdt, offset, "power-domain-names");
+		}
+	}
 }
 
 /* We support booting U-Boot with an internal DT when running as a first-stage bootloader

-- 
2.47.1