ARM: bcm: clean up SMC code

This patch just does some simple cleanup in "bcm_kona_smc.c":
    - Get rid of the secure_bridge_data structure.  Instead, just
      define two globals that record the physical and virtual
      addresses of the SMC arguments buffer.  Use "buffer" instead
      of "bounce" in their names.  Drop of the erroneous __iomem
      annotation for the physical address.
    - Get rid of the initialized flag and just use a non-null buffer
      address to indicate that.
    - Get the size of the memory region when fetching the SMC
      arguments buffer location from the device tree.  Use it to
      call ioremap() directly rather than requiring of_iomap() to
      go look it up again.
    - Do some additional validation on that memory region size.
    - Flush caches unconditionally in __bcm_kona_smc(); nothing
      supplies SSAPI_BRCM_START_VC_CORE as a service id.
    - Drop a needless initialization of "rc" in __bcm_kona_smc().

It also deletes most of the content of "bcm_kona_smc.h" because it's
never actually used and is of questionable value anyway.

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>

1 files changed, 22 insertions, 23 deletions

diff --git a/arch/arm/mach-bcm/bcm_kona_smc.c b/arch/arm/mach-bcm/bcm_kona_smc.c
index ddc2f17217ee..0d2bfe2bcfa8 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;
@@ -41,31 +38,37 @@ 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 */
-	prop_val = of_get_address(node, 0, NULL, NULL);
+	prop_val = of_get_address(node, 0, &prop_size, NULL);
 	if (!prop_val)
 		return -EINVAL;
 
-	bridge_data.buffer_addr = be32_to_cpu(*prop_val);
-	if (!bridge_data.buffer_addr)
+	/* 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.bounce = of_iomap(node, 0);
-	if (!bridge_data.bounce)
-		return -ENOMEM;
+	buffer_phys = be32_to_cpup(prop_val);
+	if (!buffer_phys)
+		return -EINVAL;
 
-	bridge_data.initialized = 1;
+	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");
 
@@ -76,14 +79,11 @@ int __init bcm_kona_smc_init(void)
 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;
+	int rc;
 
-	/* Must run on CPU 0 */
 	BUG_ON(smp_processor_id() != 0);
-
-	/* Check map in the bounce area */
-	BUG_ON(!bridge_data.initialized);
+	BUG_ON(!args);
 
 	/* Copy the four 32 bit argument values into the bounce area */
 	writel_relaxed(data->arg0, args++);
@@ -92,11 +92,10 @@ static void __bcm_kona_smc(void *info)
 	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();
+	flush_cache_all();
 
 	/* Trap into Secure Monitor */
-	rc = bcm_kona_smc_asm(data->service_id, bridge_data.buffer_addr);
+	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);