Re: [PATCH 1/5] msm: Secure Channel Manager (SCM) support

From: Pavel Machek
Date: Wed Dec 15 2010 - 02:48:36 EST


Hi!

> +/**
> + * struct scm_response - one SCM response buffer
> + * @len: total available memory for response
> + * @buf_offset: start of response data relative to start of scm_response
> + * @is_complete: indicates if the command has finished processing
> + */
> +struct scm_response {
> + u32 len;
> + u32 buf_offset;
> + u32 is_complete;
> +};

Alignment is off here.

> +static u32 smc(dma_addr_t cmd_addr)
> +{
> + int context_id;
> + register u32 r0 asm("r0") = 1;
> + register u32 r1 asm("r1") = (u32)&context_id;
> + register u32 r2 asm("r2") = (u32)cmd_addr;

Are these neccessary?

> + asm(
> + __asmeq("%0", "r0")
> + __asmeq("%1", "r0")
> + __asmeq("%2", "r1")
> + __asmeq("%3", "r2")
> + "smc #0 @ switch to secure world\n"
> + : "=r" (r0)
> + : "r" (r0), "r" (r1), "r" (r2)
> + : "r3");
> + return r0;
> +}

> +u32 scm_get_version(void)
> +{
> + int context_id;
> + static u32 version = -1;
> + register u32 r0 asm("r0") = 0x1 << 8;
> + register u32 r1 asm("r1") = (u32)&context_id;

And does this even work?

> + if (version != -1)
> + return version;
> +
> + mutex_lock(&scm_lock);
> + asm(
> + __asmeq("%0", "r1")
> + __asmeq("%1", "r0")
> + __asmeq("%2", "r1")
> + "smc #0 @ switch to secure world\n"
> + : "=r" (r1)
> + : "r" (r0), "r" (r1)
> + : "r2", "r3");
> + version = r1;
> + mutex_unlock(&scm_lock);
> +
> + return version;
> +}
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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