[PATCH 2/4] remoteproc: k3-dsp: Add a sanity check for DSP boot address alignment

[Suman Anna]

The DSP remote processors on K3 SoCs require a boot register to be
programmed with a boot address, and these boot addresses need to be
aligned on certain address boundaries. The current code does not have
any error checks, and relies on the System Firmware to perform the
checking. Add logic to perform this sanity check within the remoteproc
driver itself to detect these anomalies specifically, and print a
meaningful trace. This avoids the cumbersome debug of root-causing
such failures from the corresponding TI-SCI failure.

The C66x and C71x DSP cores have different alignment needs and are
as follows:
	C66x DSP = 1 KB (0x400)
	C71x DSP = 2 MB (0x200000)

Signed-off-by: Suman Anna <s-anna at ti.com>
---
 drivers/remoteproc/ti_k3_dsp_rproc.c | 34 +++++++++++++++++++++++++---
 1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/drivers/remoteproc/ti_k3_dsp_rproc.c b/drivers/remoteproc/ti_k3_dsp_rproc.c
index ff5d7f7f464f..4937fdd0a776 100644
--- a/drivers/remoteproc/ti_k3_dsp_rproc.c
+++ b/drivers/remoteproc/ti_k3_dsp_rproc.c
@@ -2,7 +2,7 @@
 /*
  * Texas Instruments' K3 DSP Remoteproc driver
  *
- * Copyright (C) 2018-2019 Texas Instruments Incorporated - http://www.ti.com/
+ * Copyright (C) 2018-2020 Texas Instruments Incorporated - http://www.ti.com/
  *	Lokesh Vutla <lokeshvutla at ti.com>
  *
  */
@@ -18,6 +18,7 @@
 #include <power-domain.h>
 #include <dm/device_compat.h>
 #include <linux/err.h>
+#include <linux/sizes.h>
 #include <linux/soc/ti/ti_sci_protocol.h>
 #include "ti_sci_proc.h"
 
@@ -37,16 +38,26 @@ struct k3_dsp_mem {
 	size_t size;
 };
 
+/**
+ * struct k3_dsp_boot_data - internal data structure used for boot
+ * @boot_align_addr: Boot vector address alignment granularity
+ */
+struct k3_dsp_boot_data {
+	u32 boot_align_addr;
+};
+
 /**
  * struct k3_dsp_privdata - Structure representing Remote processor data.
  * @rproc_rst:		rproc reset control data
  * @tsp:		Pointer to TISCI proc contrl handle
+ * @data:		Pointer to DSP specific boot data structure
  * @mem:		Array of available memories
  * @num_mem:		Number of available memories
  */
 struct k3_dsp_privdata {
 	struct reset_ctl dsp_rst;
 	struct ti_sci_proc tsp;
+	struct k3_dsp_boot_data *data;
 	struct k3_dsp_mem *mem;
 	int num_mems;
 };
@@ -62,6 +73,7 @@ struct k3_dsp_privdata {
 static int k3_dsp_load(struct udevice *dev, ulong addr, ulong size)
 {
 	struct k3_dsp_privdata *dsp = dev_get_priv(dev);
+	struct k3_dsp_boot_data *data = dsp->data;
 	u32 boot_vector;
 	int ret;
 
@@ -77,6 +89,12 @@ static int k3_dsp_load(struct udevice *dev, ulong addr, ulong size)
 	}
 
 	boot_vector = rproc_elf_get_boot_addr(dev, addr);
+	if (boot_vector & (data->boot_align_addr - 1)) {
+		ret = -EINVAL;
+		dev_err(dev, "Boot vector 0x%x not aligned on 0x%x boundary\n",
+			boot_vector, data->boot_align_addr);
+		goto proc_release;
+	}
 
 	dev_dbg(dev, "%s: Boot vector = 0x%x\n", __func__, boot_vector);
 
@@ -300,6 +318,8 @@ static int k3_dsp_of_to_priv(struct udevice *dev, struct k3_dsp_privdata *dsp)
 	if (ret)
 		return ret;
 
+	dsp->data = (struct k3_dsp_boot_data *)dev_get_driver_data(dev);
+
 	return 0;
 }
 
@@ -338,9 +358,17 @@ static int k3_dsp_remove(struct udevice *dev)
 	return 0;
 }
 
+static const struct k3_dsp_boot_data c66_data = {
+	.boot_align_addr = SZ_1K,
+};
+
+static const struct k3_dsp_boot_data c71_data = {
+	.boot_align_addr = SZ_2M,
+};
+
 static const struct udevice_id k3_dsp_ids[] = {
-	{ .compatible = "ti,j721e-c66-dsp"},
-	{ .compatible = "ti,j721e-c71-dsp"},
+	{ .compatible = "ti,j721e-c66-dsp", .data = (ulong)&c66_data, },
+	{ .compatible = "ti,j721e-c71-dsp", .data = (ulong)&c71_data, },
 	{}
 };
 
-- 
2.23.0