On Mon, Mar 21, 2022 at 5:50 PM Sven Peter <sven@xxxxxxxxxxxxx> wrote:
>
> Apple SoCs such as the M1 come with multiple embedded co-processors
> running proprietary firmware. Communication with those is established
> over a simple mailbox using the RTKit IPC protocol.
>
> Signed-off-by: Sven Peter <sven@xxxxxxxxxxxxx>
> +
> +#define rtk_err(format, arg...) dev_err(rtk->dev, "RTKit: " format, ##arg)
> +#define rtk_warn(format, arg...) dev_warn(rtk->dev, "RTKit: " format, ##arg)
> +#define rtk_info(format, arg...) dev_info(rtk->dev, "RTKit: " format, ##arg)
> +#define rtk_dbg(format, arg...) dev_dbg(rtk->dev, "RTKit: " format, ##arg)
I generally don't like the custom printing macros, please just open-code
the prints where they are used, that makes it easier for other kernel
developers to see exactly what is being printed.
> +enum { APPLE_RTKIT_WORK_MSG,
> + APPLE_RTKIT_WORK_REINIT,
> +};
> +
> +enum { APPLE_RTKIT_PWR_STATE_OFF = 0x00,
> + APPLE_RTKIT_PWR_STATE_SLEEP = 0x01,
> + APPLE_RTKIT_PWR_STATE_GATED = 0x02,
> + APPLE_RTKIT_PWR_STATE_QUIESCED = 0x10,
> + APPLE_RTKIT_PWR_STATE_ON = 0x20,
> +};
This is an odd indentation style, I would insert a newline after the 'enum {'
> +static int apple_rtkit_worker(void *data)
> +{
> + struct apple_rtkit *rtk = data;
> + struct apple_rtkit_work work;
> +
> + while (!kthread_should_stop()) {
> + wait_event_interruptible(rtk->wq,
> + kfifo_len(&rtk->work_fifo) > 0 ||
> + kthread_should_stop());
> +
> + if (kthread_should_stop())
> + break;
> +
> + while (kfifo_out_spinlocked(&rtk->work_fifo, &work, 1,
> + &rtk->work_lock) == 1) {
> + switch (work.type) {
> + case APPLE_RTKIT_WORK_MSG:
> + apple_rtkit_rx(rtk, &work.msg);
> + break;
> + case APPLE_RTKIT_WORK_REINIT:
> + apple_rtkit_do_reinit(rtk);
> + break;
> + }
> + }
It looks like you add quite a bit of complexity by using a custom
worker thread implementation. Can you explain what this is
needed for? Isn't this roughly the same thing that one would
get more easily with create_singlethread_workqueue()?
> +#if IS_ENABLED(CONFIG_APPLE_RTKIT)
Instead of allowing the interface to be used without CONFIG_APPLE_RTKIT,
I think it is sufficient to allow the driver itself to be built with
CONFIG_COMPILE_TEST (as you already do), and then have
drivers using it marked as 'depends on APPLE_RTKIT'
unconditionally.
> +/*
> + * Initializes the internal state required to handle RTKit. This
> + * should usually be called within _probe.
> + *
> + * @dev: Pointer to the device node this coprocessor is assocated with
> + * @cookie: opaque cookie passed to all functions defined in rtkit_ops
> + * @mbox_name: mailbox name used to communicate with the co-processor
> + * @mbox_idx: mailbox index to be used if mbox_name is NULL
> + * @ops: pointer to rtkit_ops to be used for this co-processor
> + */
> +struct apple_rtkit *apple_rtkit_init(struct device *dev, void *cookie,
> + const char *mbox_name, int mbox_idx,
> + const struct apple_rtkit_ops *ops);
> +
> +/*
> + * Dev-res managed version of apple_rtkit_init.
> + */
> +struct apple_rtkit *devm_apple_rtkit_init(struct device *dev, void *cookie,
> + const char *mbox_name, int mbox_idx,
> + const struct apple_rtkit_ops *ops);
Do we need to export both of these?
Arnd
