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

Carlo Caione
2016-05-23T11:43:58Z

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

[...]
> >+#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.

> >+
> >+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.

>
> >+{
> >+ 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.

> >+
> >+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