Re: [PATCH v2 1/4] soc: Amlogic: Add secure monitor driver

On 23/05/16 13:38, Matthias Brugger wrote:

[...]

quoted

+#include <stdarg.h>
+#include <asm/cacheflush.h>
+#include <asm/compiler.h>
+#include <linux/arm-smccc.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/smp.h>
+
+#include <linux/soc/meson/meson_sm.h>
+
+#define SM_MEM_SIZE	0x1000
+
+/*
+ * To read from / write to the secure monitor we use two bounce buffers. The
+ * physical addresses of the two buffers are obtained by querying the secure
+ * monitor itself.
+ */
+
+static u32 sm_phy_in_base;
+static u32 sm_phy_out_base;

You can put this two variable in meson_sm_probe, right?

Yeah, actually no need to be there.

quoted

+
+static void __iomem *sm_sharemem_in_base;
+static void __iomem *sm_sharemem_out_base;
+
+struct meson_sm_data {
+	u32 cmd;
+	u32 arg0;
+	u32 arg1;
+	u32 arg2;
+	u32 arg3;
+	u32 arg4;
+	u32 ret;
+};
+
+static void __meson_sm_call(void *info)
+{
+	struct meson_sm_data *data = info;
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(data->cmd,
+		      data->arg0, data->arg1, data->arg2,
+		      data->arg3, data->arg4, 0, 0, &res);
+	data->ret = res.a0;
+}
+
+u32 meson_sm_call(u32 cmd, u32 arg0, u32 arg1, u32 arg2, u32 arg3, u32 arg4)

Can the function be static or will it be called from another driver?

It _can_ be called from another driver. It depends on the SMC used, so
better making it available.

quoted

+{
+	struct meson_sm_data data;
+
+	data.cmd = cmd;
+	data.arg0 = arg0;
+	data.arg1 = arg1;
+	data.arg2 = arg2;
+	data.arg3 = arg3;
+	data.arg4 = arg4;
+	data.ret = 0;
+
+	__meson_sm_call(&data);
+
+	return data.ret;
+}
+
+u32 meson_sm_call_read(void *buffer, u32 cmd, u32 arg0, u32 arg1,
+		       u32 arg2, u32 arg3, u32 arg4)
+{
+	u32 size;
+
+	size = meson_sm_call(cmd, arg0, arg1, arg2, arg3, arg4);
+
+	if (!size || size > SM_MEM_SIZE)
+		return -EINVAL;
+
+	memcpy(buffer, sm_sharemem_out_base, size);
+	return size;
+}

This function will be needed to be exported to be callable from modules.

Fix in v3.

quoted

+
+u32 meson_sm_call_write(void *buffer, unsigned int b_size, u32 cmd, u32 arg0,
+			u32 arg1, u32 arg2, u32 arg3, u32 arg4)
+{
+	u32 size;
+
+	if (b_size > SM_MEM_SIZE)
+		return -EINVAL;
+
+	memcpy(sm_sharemem_in_base, buffer, b_size);
+
+	size = meson_sm_call(cmd, arg0, arg1, arg2, arg3, arg4);
+
+	if (!size)
+		return -EINVAL;
+
+	return size;
+}
+

Same here.

Thanks.

Cheers,

-- 
Carlo Caione
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