| Message ID | 1452840929-19612-2-git-send-email-zhaoshenglong@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 15 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 | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c > index a212cef..d7a559f 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 > @@ -93,6 +94,17 @@ acpi_status acpi_bus_get_status_handle(acpi_handle handle, > { > acpi_status status; > > + if (spcr_uart_addr != 0xffffffffffffffff) { Please #define something like EFI_INVALID_TABLE_ADDR and use it here instead of 0xffffffffffffffff for readability. Also spcr_uart_addr could be initialized where it is defined. Maybe it could be better to move this check into a separate function and only call acpi_set_device_status if spcr_uart_addr != addr? > + u64 addr; > + > + status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, > + &addr); > + if (ACPI_SUCCESS(status) && (addr == spcr_uart_addr)) { > + *sta = 0; > + return AE_OK; > + } > + } > + > status = acpi_evaluate_integer(handle, "_STA", NULL, sta); > if (ACPI_SUCCESS(status)) > return AE_OK; > @@ -1069,6 +1081,8 @@ 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 +1095,22 @@ 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. > + */ > + spcr_uart_addr = 0xffffffffffffffff; > + status = acpi_get_table(ACPI_SIG_STAO, 0, > + (struct acpi_table_header **)&stao_ptr); > + if (ACPI_SUCCESS(status)) { > + if (stao_ptr->ignore_uart) { if (ACPI_SUCCESS(status) && stao_ptr->ignore_uart) { > + struct acpi_table_spcr *spcr_ptr; > + > + acpi_get_table(ACPI_SIG_SPCR, 0, > + (struct acpi_table_header **)&spcr_ptr); Maybe we should check that acpi_get_table succeeded, even though it should at this point. > + spcr_uart_addr = spcr_ptr->serial_port.address; > + } > + } > + > init_acpi_device_notify(); > result = acpi_bus_init(); > if (result) {
On Fri, Jan 15, 2016 at 02:55:14PM +0800, 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 | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c > index a212cef..d7a559f 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 > @@ -93,6 +94,17 @@ acpi_status acpi_bus_get_status_handle(acpi_handle handle, > { > acpi_status status; > > + if (spcr_uart_addr != 0xffffffffffffffff) { The SPCR spec says that the Base Address fields being zero means that console redirection is disabled (though I'm not clear on whether or not that requires the whole acpi_generic_address to be zero). Can we not use that here? Mark. > + u64 addr; > + > + status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, > + &addr); > + if (ACPI_SUCCESS(status) && (addr == spcr_uart_addr)) { > + *sta = 0; > + return AE_OK; > + } > + } > + > status = acpi_evaluate_integer(handle, "_STA", NULL, sta); > if (ACPI_SUCCESS(status)) > return AE_OK; > @@ -1069,6 +1081,8 @@ 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 +1095,22 @@ 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. > + */ > + spcr_uart_addr = 0xffffffffffffffff; > + status = acpi_get_table(ACPI_SIG_STAO, 0, > + (struct acpi_table_header **)&stao_ptr); > + if (ACPI_SUCCESS(status)) { > + if (stao_ptr->ignore_uart) { > + struct acpi_table_spcr *spcr_ptr; > + > + acpi_get_table(ACPI_SIG_SPCR, 0, > + (struct acpi_table_header **)&spcr_ptr); > + spcr_uart_addr = spcr_ptr->serial_port.address; > + } > + } > + > init_acpi_device_notify(); > result = acpi_bus_init(); > if (result) { > -- > 2.0.4 > > > -- > To unsubscribe from this list: send the line "unsubscribe devicetree" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
On Mon, 18 Jan 2016, Mark Rutland wrote: > On Fri, Jan 15, 2016 at 02:55:14PM +0800, 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 | 30 ++++++++++++++++++++++++++++++ > > 1 file changed, 30 insertions(+) > > > > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c > > index a212cef..d7a559f 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 > > @@ -93,6 +94,17 @@ acpi_status acpi_bus_get_status_handle(acpi_handle handle, > > { > > acpi_status status; > > > > + if (spcr_uart_addr != 0xffffffffffffffff) { > > The SPCR spec says that the Base Address fields being zero means that > console redirection is disabled (though I'm not clear on whether or not > that requires the whole acpi_generic_address to be zero). > > Can we not use that here? Shannon changed the code from 0 to 0xffffffffffffffff following my suggestion to his previous series, but I didn't realize that the SPCR spec says 0 means no console redirection. In that case using 0 is better.
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c index a212cef..d7a559f 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 @@ -93,6 +94,17 @@ acpi_status acpi_bus_get_status_handle(acpi_handle handle, { acpi_status status; + if (spcr_uart_addr != 0xffffffffffffffff) { + u64 addr; + + status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, + &addr); + if (ACPI_SUCCESS(status) && (addr == spcr_uart_addr)) { + *sta = 0; + return AE_OK; + } + } + status = acpi_evaluate_integer(handle, "_STA", NULL, sta); if (ACPI_SUCCESS(status)) return AE_OK; @@ -1069,6 +1081,8 @@ 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 +1095,22 @@ 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. + */ + spcr_uart_addr = 0xffffffffffffffff; + status = acpi_get_table(ACPI_SIG_STAO, 0, + (struct acpi_table_header **)&stao_ptr); + if (ACPI_SUCCESS(status)) { + if (stao_ptr->ignore_uart) { + struct acpi_table_spcr *spcr_ptr; + + acpi_get_table(ACPI_SIG_SPCR, 0, + (struct acpi_table_header **)&spcr_ptr); + spcr_uart_addr = spcr_ptr->serial_port.address; + } + } + init_acpi_device_notify(); result = acpi_bus_init(); if (result) {