| Message ID | 1453519184-11908-2-git-send-email-zhaoshenglong@huawei.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Sat, 23 Jan 2016, Shannon Zhao wrote: > From: Shannon Zhao <shannon.zhao@linaro.org> > > ACPI 6.0 introduces a new table STAO to list the devices which are used > by Xen and can't be used by Dom0. On Xen virtual platforms, the physical > UART is used by Xen. So here it hides UART from Dom0. > > Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> > --- > CC: "Rafael J. Wysocki" <rjw@rjwysocki.net> (supporter:ACPI) > CC: Len Brown <lenb@kernel.org> (supporter:ACPI) > CC: linux-acpi@vger.kernel.org (open list:ACPI) > --- > drivers/acpi/bus.c | 36 +++++++++++++++++++++++++++++++++++- > 1 file changed, 35 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c > index a212cef..7f85b54 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 spcr_uart_addr; > > #ifdef CONFIG_X86 > #ifdef CONFIG_ACPI_CUSTOM_DSDT > @@ -105,6 +106,22 @@ acpi_status acpi_bus_get_status_handle(acpi_handle handle, > return status; > } > > +static bool acpi_check_device_is_ignored(acpi_handle handle) > +{ > + acpi_status status; > + u64 addr; > + > + /* Check if it should ignore the UART device */ > + if (spcr_uart_addr != 0) { > + status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, > + &addr); > + if (ACPI_SUCCESS(status) && addr == spcr_uart_addr) > + return true; > + } > + > + return false; > +} > + > int acpi_bus_get_status(struct acpi_device *device) > { > acpi_status status; > @@ -114,7 +131,8 @@ int acpi_bus_get_status(struct acpi_device *device) > if (ACPI_FAILURE(status)) > return -ENODEV; > > - acpi_set_device_status(device, sta); > + if (!acpi_check_device_is_ignored(device->handle)) > + acpi_set_device_status(device, sta); > > if (device->status.functional && !device->status.present) { > ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: " > @@ -1069,6 +1087,8 @@ EXPORT_SYMBOL_GPL(acpi_kobj); > static int __init acpi_init(void) > { > int result; > + acpi_status status; > + struct acpi_table_stao *stao_ptr; > > if (acpi_disabled) { > printk(KERN_INFO PREFIX "Interpreter disabled.\n"); > @@ -1081,6 +1101,20 @@ static int __init acpi_init(void) > acpi_kobj = NULL; > } > > + /* If there is STAO table, check whether it needs to ignore the UART > + * device in SPCR table. > + */ > + status = acpi_get_table(ACPI_SIG_STAO, 0, > + (struct acpi_table_header **)&stao_ptr); > + if (ACPI_SUCCESS(status) && stao_ptr->ignore_uart) { > + struct acpi_table_spcr *spcr_ptr; > + > + status = acpi_get_table(ACPI_SIG_SPCR, 0, > + (struct acpi_table_header **)&spcr_ptr); > + if (ACPI_SUCCESS(status)) > + spcr_uart_addr = spcr_ptr->serial_port.address; else printk(KERN_WARNING "STAO table present, but SPCR is missing.\n"); In any case: Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > + } > + > init_acpi_device_notify(); > result = acpi_bus_init(); > if (result) { -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index a212cef..7f85b54 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 spcr_uart_addr; #ifdef CONFIG_X86 #ifdef CONFIG_ACPI_CUSTOM_DSDT @@ -105,6 +106,22 @@ acpi_status acpi_bus_get_status_handle(acpi_handle handle, return status; } +static bool acpi_check_device_is_ignored(acpi_handle handle) +{ + acpi_status status; + u64 addr; + + /* Check if it should ignore the UART device */ + if (spcr_uart_addr != 0) { + status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, + &addr); + if (ACPI_SUCCESS(status) && addr == spcr_uart_addr) + return true; + } + + return false; +} + int acpi_bus_get_status(struct acpi_device *device) { acpi_status status; @@ -114,7 +131,8 @@ int acpi_bus_get_status(struct acpi_device *device) if (ACPI_FAILURE(status)) return -ENODEV; - acpi_set_device_status(device, sta); + if (!acpi_check_device_is_ignored(device->handle)) + acpi_set_device_status(device, sta); if (device->status.functional && !device->status.present) { ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: " @@ -1069,6 +1087,8 @@ EXPORT_SYMBOL_GPL(acpi_kobj); static int __init acpi_init(void) { int result; + acpi_status status; + struct acpi_table_stao *stao_ptr; if (acpi_disabled) { printk(KERN_INFO PREFIX "Interpreter disabled.\n"); @@ -1081,6 +1101,20 @@ static int __init acpi_init(void) acpi_kobj = NULL; } + /* If there is STAO table, check whether it needs to ignore the UART + * device in SPCR table. + */ + status = acpi_get_table(ACPI_SIG_STAO, 0, + (struct acpi_table_header **)&stao_ptr); + if (ACPI_SUCCESS(status) && stao_ptr->ignore_uart) { + struct acpi_table_spcr *spcr_ptr; + + status = acpi_get_table(ACPI_SIG_SPCR, 0, + (struct acpi_table_header **)&spcr_ptr); + if (ACPI_SUCCESS(status)) + spcr_uart_addr = spcr_ptr->serial_port.address; + } + init_acpi_device_notify(); result = acpi_bus_init(); if (result) {