ARM: bcm: have bcm_kona_smc() return request result

Currently it is assumed that SEC_ROM_RET_OK is the only valid "good"
result of a secure monitor request.  However the values that can be
returned by a secure monitor request are dependent on which service
id was provided.

We therefore should handle the result in a request-dependent way.
The most natural way to do that is to have the initiator of the
request--where bcm_kona_smc() is called--handle the result in a way
appropriate to the request.

An "smc" operation must be performed only on core 0, while the
request can be initiated from any core.  To pass back the request
result, we add a new field to the bcm_kona_smc_data structure, and
have bcm_kona_smc() return that value rather than 0.

There's only one caller right now.  Move the existing check of the
result out of __bcm_kona_smc() and into the kona_l2_cache_init()
where the SSAPI_ENABLE_L2_CACHE request is initiated.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Markus Mayer <markus.mayer@linaro.org>
Reviewed-by: Matt Porter <mporter@linaro.org>
Signed-off-by: Matt Porter <mporter@linaro.org>

arch/arm/mach-bcm/bcm_kona_smc.c

@@ -30,6 +30,7 @@ struct bcm_kona_smc_data {
 	unsigned arg1;
 	unsigned arg2;
 	unsigned arg3;
+	unsigned result;
 };
 
 static const struct of_device_id bcm_kona_smc_ids[] __initconst = {
@@ -80,7 +81,6 @@ static void __bcm_kona_smc(void *info)
 {
 	struct bcm_kona_smc_data *data = info;
 	u32 *args = bcm_smc_buffer;
-	int rc;
 
 	BUG_ON(smp_processor_id() != 0);
 	BUG_ON(!args);
@@ -94,11 +94,8 @@ static void __bcm_kona_smc(void *info)
 	/* Flush caches for input data passed to Secure Monitor */
 	flush_cache_all();
 
-	/* Trap into Secure Monitor */
-	rc = bcm_kona_smc_asm(data->service_id, bcm_smc_buffer_phys);
-
-	if (rc != SEC_ROM_RET_OK)
-		pr_err("Secure Monitor call failed (0x%x)!\n", rc);
+	/* Trap into Secure Monitor and record the request result */
+	data->result = bcm_kona_smc_asm(data->service_id, bcm_smc_buffer_phys);
 }
 
 unsigned bcm_kona_smc(unsigned service_id, unsigned arg0, unsigned arg1,
@@ -111,6 +108,7 @@ unsigned bcm_kona_smc(unsigned service_id, unsigned arg0, unsigned arg1,
 	data.arg1 = arg1;
 	data.arg2 = arg2;
 	data.arg3 = arg3;
+	data.result = 0;
 
 	/*
 	 * Due to a limitation of the secure monitor, we must use the SMP
@@ -123,5 +121,5 @@ unsigned bcm_kona_smc(unsigned service_id, unsigned arg0, unsigned arg1,
 
 	put_cpu();
 
-	return 0;
+	return data.result;
 }

arch/arm/mach-bcm/kona.c

@@ -19,6 +19,7 @@
 
 void __init kona_l2_cache_init(void)
 {
+	unsigned int result;
 	int ret;
 
 	if (!IS_ENABLED(CONFIG_CACHE_L2X0))
@@ -31,7 +32,12 @@ void __init kona_l2_cache_init(void)
 		return;
 	}
 
-	bcm_kona_smc(SSAPI_ENABLE_L2_CACHE, 0, 0, 0, 0);
+	result = bcm_kona_smc(SSAPI_ENABLE_L2_CACHE, 0, 0, 0, 0);
+	if (result != SEC_ROM_RET_OK) {
+		pr_err("Secure Monitor call failed (%u)! Skipping L2 init.\n",
+			result);
+		return;
+	}
 
 	/*
 	 * The aux_val and aux_mask have no effect since L2 cache is already