On Fri, May 20, 2016 at 04:03:23PM +0300, Aleksey Makarov wrote:
> This patch adds function pl011_console_match() that implements
> method match of struct console. It allows to match consoles against
> data specified in a string, for example taken from command line or
> compiled by ACPI SPCR table handler.
>
> Signed-off-by: Aleksey Makarov <aleksey.makarov@xxxxxxxxxx>
> Reviewed-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/tty/serial/amba-pl011.c | 56 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 56 insertions(+)
>
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index a2aa655..388edc8 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -2288,12 +2288,68 @@ static int __init pl011_console_setup(struct console *co, char *options)
> return uart_set_options(&uap->port, co, baud, parity, bits, flow);
> }
>
> +/**
> + * pl011_console_match - non-standard console matching
> + * @co: registering console
> + * @name: name from console command line
> + * @idx: index from console command line
> + * @options: ptr to option string from console command line
> + *
> + * Only attempts to match console command lines of the form:
> + * console=pl011,mmio|mmio32,<addr>[,<options>]
> + * console=pl011,0x<addr>[,<options>]
> + * This form is used to register an initial earlycon boot console and
> + * replace it with the amba_console at pl011 driver init.
> + *
> + * Performs console setup for a match (as required by interface)
> + * If no <options> are specified, then assume the h/w is already setup.
> + *
> + * Returns 0 if console matches; otherwise non-zero to use default matching
> + */
> +static int __init pl011_console_match(struct console *co, char *name, int idx,
> + char *options)
> +{
> + char match[] = "pl011"; /* pl011-specific earlycon name */
> + unsigned char iotype;
> + unsigned long addr;
> + int i;
> +
> + if (strncmp(name, match, 5) != 0)
> + return -ENODEV;
> +
> + if (uart_parse_earlycon(options, &iotype, &addr, &options))
> + return -ENODEV;
> +
> + /* try to match the port specified on the command line */
> + for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {
> + struct uart_port *port;
> +
> + if (!amba_ports[i])
> + continue;
> +
> + port = &amba_ports[i]->port;
> +
> + if (iotype != UPIO_MEM && iotype != UPIO_MEM32)
> + continue;
So it looks like iotype is constant inside the loop, and UPIO_MEM
and UPIO_MEM32 too, of course. It means you can move this check out of
cycle and avoid ports traversing at all in specific case. Am I wrong?
> +
> + if (port->mapbase != addr)
> + continue;
> +
> + co->index = i;
> + port->cons = co;
> + return pl011_console_setup(co, options);
> + }
> +
> + return -ENODEV;
> +}
> +
> static struct uart_driver amba_reg;
> static struct console amba_console = {
> .name = "ttyAMA",
> .write = pl011_console_write,
> .device = uart_console_device,
> .setup = pl011_console_setup,
> + .match = pl011_console_match,
> .flags = CON_PRINTBUFFER,
> .index = -1,
> .data = &amba_reg,
> --
> 2.8.2
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