[PATCH 01/13] Xen : Hide UART used by Xen
Stefano Stabellini
stefano.stabellini at eu.citrix.com
Fri Nov 20 08:07:26 PST 2015
CC'ing ACPI maintainers.
Please use ./scripts/get_maintainer.pl to retrieve a list of maintainers
to CC for each patch.
On Tue, 17 Nov 2015, shannon.zhao at linaro.org wrote:
> From: Shannon Zhao <shannon.zhao at linaro.org>
>
> According to the STAO table, hide UART used by Xen from Dom0.
>
> Signed-off-by: Shannon Zhao <shannon.zhao at linaro.org>
> ---
> drivers/acpi/bus.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index a212cef..e93806b 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -46,6 +46,7 @@ ACPI_MODULE_NAME("bus");
> struct acpi_device *acpi_root;
> struct proc_dir_entry *acpi_root_dir;
> EXPORT_SYMBOL(acpi_root_dir);
> +static u64 uart_addr;
I would call this spcr_addr or spcr_uart_addr because there are many
uarts on the system but only one spcr. It might make sense to initialize
this to 0xffffffffffffffff rather than 0, which could actually be a
correct uart address.
> #ifdef CONFIG_X86
> #ifdef CONFIG_ACPI_CUSTOM_DSDT
> @@ -93,6 +94,16 @@ acpi_status acpi_bus_get_status_handle(acpi_handle handle,
> {
> acpi_status status;
>
> + if (uart_addr) {
> + u64 addr;
> + status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL,
> + &addr);
> + if (ACPI_SUCCESS(status) && (addr == uart_addr)) {
> + *sta = 0;
> + return AE_OK;
> + }
> + }
> +
> status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
> if (ACPI_SUCCESS(status))
> return AE_OK;
> @@ -1069,6 +1080,7 @@ EXPORT_SYMBOL_GPL(acpi_kobj);
> static int __init acpi_init(void)
> {
> int result;
> + struct acpi_table_stao *stao_ptr;
>
> if (acpi_disabled) {
> printk(KERN_INFO PREFIX "Interpreter disabled.\n");
> @@ -1081,6 +1093,16 @@ static int __init acpi_init(void)
> acpi_kobj = NULL;
> }
>
> + acpi_get_table(ACPI_SIG_STAO, 1,
> + (struct acpi_table_header **)&stao_ptr);
> + if(stao_ptr->ignore_uart)
> + {
Please follow the linux coding style. You can use
./scripts/checkpatch.pl to check for coding style errors.
> + struct acpi_table_spcr *spcr_ptr;
> + acpi_get_table(ACPI_SIG_SPCR, 1,
> + (struct acpi_table_header **)&spcr_ptr);
> + uart_addr = spcr_ptr->serial_port.address;
> + }
> +
> init_acpi_device_notify();
> result = acpi_bus_init();
> if (result) {
> --
> 2.1.0
>
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