1 files changed, 98 insertions, 38 deletions

diff --git a/arch/arm/mach-bcm/bcm_kona_smc.c b/arch/arm/mach-bcm/bcm_kona_smc.c
index 5e31e918f325..a55a7ecf146a 100644
--- a/arch/arm/mach-bcm/bcm_kona_smc.c
+++ b/arch/arm/mach-bcm/bcm_kona_smc.c
@@ -21,11 +21,8 @@
 
 #include "bcm_kona_smc.h"
 
-struct secure_bridge_data {
-	void __iomem *bounce;		/* virtual address */
-	u32 __iomem buffer_addr;	/* physical address */
-	int initialized;
-} bridge_data;
+static u32		bcm_smc_buffer_phys;	/* physical address */
+static void __iomem	*bcm_smc_buffer;	/* virtual address */
 
 struct bcm_kona_smc_data {
 	unsigned service_id;
@@ -33,6 +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 = {
@@ -41,59 +39,125 @@ static const struct of_device_id bcm_kona_smc_ids[] __initconst = {
 	{},
 };
 
-/* Map in the bounce area */
+/* Map in the args buffer area */
 int __init bcm_kona_smc_init(void)
 {
 	struct device_node *node;
+	const __be32 *prop_val;
+	u64 prop_size = 0;
+	unsigned long buffer_size;
+	u32 buffer_phys;
 
 	/* Read buffer addr and size from the device tree node */
 	node = of_find_matching_node(NULL, bcm_kona_smc_ids);
 	if (!node)
 		return -ENODEV;
 
-	/* Don't care about size or flags of the DT node */
-	bridge_data.buffer_addr =
-		be32_to_cpu(*of_get_address(node, 0, NULL, NULL));
-	BUG_ON(!bridge_data.buffer_addr);
+	prop_val = of_get_address(node, 0, &prop_size, NULL);
+	if (!prop_val)
+		return -EINVAL;
 
-	bridge_data.bounce = of_iomap(node, 0);
-	BUG_ON(!bridge_data.bounce);
+	/* We assume space for four 32-bit arguments */
+	if (prop_size < 4 * sizeof(u32) || prop_size > (u64)ULONG_MAX)
+		return -EINVAL;
+	buffer_size = (unsigned long)prop_size;
 
-	bridge_data.initialized = 1;
+	buffer_phys = be32_to_cpup(prop_val);
+	if (!buffer_phys)
+		return -EINVAL;
+
+	bcm_smc_buffer = ioremap(buffer_phys, buffer_size);
+	if (!bcm_smc_buffer)
+		return -ENOMEM;
+	bcm_smc_buffer_phys = buffer_phys;
 
 	pr_info("Kona Secure API initialized\n");
 
 	return 0;
 }
 
+/*
+ * int bcm_kona_do_smc(u32 service_id, u32 buffer_addr)
+ *
+ * Only core 0 can run the secure monitor code.  If an "smc" request
+ * is initiated on a different core it must be redirected to core 0
+ * for execution.  We rely on the caller to handle this.
+ *
+ * Each "smc" request supplies a service id and the address of a
+ * buffer containing parameters related to the service to be
+ * performed.  A flags value defines the behavior of the level 2
+ * cache and interrupt handling while the secure monitor executes.
+ *
+ * Parameters to the "smc" request are passed in r4-r6 as follows:
+ *     r4	service id
+ *     r5	flags (SEC_ROM_*)
+ *     r6	physical address of buffer with other parameters
+ *
+ * Execution of an "smc" request produces two distinct results.
+ *
+ * First, the secure monitor call itself (regardless of the specific
+ * service request) can succeed, or can produce an error.  When an
+ * "smc" request completes this value is found in r12; it should
+ * always be SEC_EXIT_NORMAL.
+ *
+ * In addition, the particular service performed produces a result.
+ * The values that should be expected depend on the service.  We
+ * therefore return this value to the caller, so it can handle the
+ * request result appropriately.  This result value is found in r0
+ * when the "smc" request completes.
+ */
+static int bcm_kona_do_smc(u32 service_id, u32 buffer_phys)
+{
+	register u32 ip asm("ip");	/* Also called r12 */
+	register u32 r0 asm("r0");
+	register u32 r4 asm("r4");
+	register u32 r5 asm("r5");
+	register u32 r6 asm("r6");
+
+	r4 = service_id;
+	r5 = 0x3;		/* Keep IRQ and FIQ off in SM */
+	r6 = buffer_phys;
+
+	asm volatile (
+		/* Make sure we got the registers we want */
+		__asmeq("%0", "ip")
+		__asmeq("%1", "r0")
+		__asmeq("%2", "r4")
+		__asmeq("%3", "r5")
+		__asmeq("%4", "r6")
+#ifdef REQUIRES_SEC
+		".arch_extension sec\n"
+#endif
+		"	smc    #0\n"
+		: "=r" (ip), "=r" (r0)
+		: "r" (r4), "r" (r5), "r" (r6)
+		: "r1", "r2", "r3", "r7", "lr");
+
+	BUG_ON(ip != SEC_EXIT_NORMAL);
+
+	return r0;
+}
+
 /* __bcm_kona_smc() should only run on CPU 0, with pre-emption disabled */
 static void __bcm_kona_smc(void *info)
 {
 	struct bcm_kona_smc_data *data = info;
-	u32 *args = bridge_data.bounce;
-	int rc = 0;
+	u32 *args = bcm_smc_buffer;
 
-	/* Must run on CPU 0 */
 	BUG_ON(smp_processor_id() != 0);
+	BUG_ON(!args);
 
-	/* Check map in the bounce area */
-	BUG_ON(!bridge_data.initialized);
-
-	/* Copy one 32 bit word into the bounce area */
-	args[0] = data->arg0;
-	args[1] = data->arg1;
-	args[2] = data->arg2;
-	args[3] = data->arg3;
+	/* Copy the four 32 bit argument values into the bounce area */
+	writel_relaxed(data->arg0, args++);
+	writel_relaxed(data->arg1, args++);
+	writel_relaxed(data->arg2, args++);
+	writel(data->arg3, args);
 
 	/* Flush caches for input data passed to Secure Monitor */
-	if (data->service_id != SSAPI_BRCM_START_VC_CORE)
-		flush_cache_all();
-
-	/* Trap into Secure Monitor */
-	rc = bcm_kona_smc_asm(data->service_id, bridge_data.buffer_addr);
+	flush_cache_all();
 
-	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_do_smc(data->service_id, bcm_smc_buffer_phys);
 }
 
 unsigned bcm_kona_smc(unsigned service_id, unsigned arg0, unsigned arg1,
@@ -106,17 +170,13 @@ 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
 	 * infrastructure to forward all secure monitor calls to Core 0.
 	 */
-	if (get_cpu() != 0)
-		smp_call_function_single(0, __bcm_kona_smc, (void *)&data, 1);
-	else
-		__bcm_kona_smc(&data);
+	smp_call_function_single(0, __bcm_kona_smc, &data, 1);
 
-	put_cpu();
-
-	return 0;
+	return data.result;
 }