| Message ID | 20241205-vuart-ns8250-v1-26-e9aa923127eb@ford.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce NS8250 UART emulator | expand |
On Thu, Dec 05, 2024 at 08:41:56PM -0800, Denis Mukhin via B4 Relay wrote: > From: Denis Mukhin <dmukhin@ford.com> > > Add new CONRING_LOG_SHIFT Kconfig parameter to specify the boot console buffer > size as a power of 2. > > Bump default size to 32 KiB. > > Link: https://gitlab.com/xen-project/xen/-/issues/185 > Signed-off-by: Denis Mukhin <dmukhin@ford.com> Thanks for taking care of this. > --- > xen/drivers/char/Kconfig | 23 +++++++++++++++++++++++ > xen/drivers/char/console.c | 4 ++-- > 2 files changed, 25 insertions(+), 2 deletions(-) > > diff --git a/xen/drivers/char/Kconfig b/xen/drivers/char/Kconfig > index e6e12bb4139717f9319031f51f5d20155d2caee2..3bc892fc38d8cdeb3c76ea44d747f712a8d0d372 100644 > --- a/xen/drivers/char/Kconfig > +++ b/xen/drivers/char/Kconfig > @@ -96,6 +96,29 @@ config SERIAL_TX_BUFSIZE > > Default value is 32768 (32KiB). > > +config CONRING_LOG_SHIFT > + int "Console buffer size" > + range 14 25 > + default 15 > + help > + Select the boot console buffer size as a power of 2. > + Run-time console buffer size is the same as the boot console size, > + unless enforced via 'conring_size=' boot parameter. > + > + Examples: > + 25 => 32 MiB > + 24 => 16 MiB > + 23 => 8 MiB > + 22 => 4 MiB > + 21 => 2 MiB > + 20 => 1 MiB > + 19 => 512 KiB > + 18 => 256 KiB > + 17 => 128 KiB > + 16 => 64 KiB > + 15 => 32 KiB > + 14 => 16 KiB It might be better to do something similar to what we do in SERIAL_TX_BUFSIZE, that the user provides a value in KiB which is rounded down to the nearest power of 2? > + > config XHCI > bool "XHCI DbC UART driver" > depends on X86 > diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c > index d22fb4a253af26f9b51d91bd408e1dbf4bb5a7c1..581ee22b85302a54db5b9d5d28e8b2d689d31403 100644 > --- a/xen/drivers/char/console.c > +++ b/xen/drivers/char/console.c > @@ -104,11 +104,11 @@ static int cf_check parse_console_timestamps(const char *s); > custom_runtime_param("console_timestamps", parse_console_timestamps, > con_timestamp_mode_upd); > > -/* conring_size: allows a large console ring than default (16kB). */ > +/* conring_size: allows a large console ring than default (32 KiB). */ > static uint32_t __initdata opt_conring_size; > size_param("conring_size", opt_conring_size); You also need to update xen-command-line.pandoc to mention the default size is now set in Kconfig. And here I would mention CONFIG_CONRING_SIZE rather than explicit 32 KiB, because that's just the default in Kconfig, but might not be the default in the build itself. FWIW, you could define: #define _CONRING_SIZE (CONFIG_CONRING_SIZE & (CONFIG_CONRING_SIZE - 1)) Thanks, Roger.
diff --git a/xen/drivers/char/Kconfig b/xen/drivers/char/Kconfig index e6e12bb4139717f9319031f51f5d20155d2caee2..3bc892fc38d8cdeb3c76ea44d747f712a8d0d372 100644 --- a/xen/drivers/char/Kconfig +++ b/xen/drivers/char/Kconfig @@ -96,6 +96,29 @@ config SERIAL_TX_BUFSIZE Default value is 32768 (32KiB). +config CONRING_LOG_SHIFT + int "Console buffer size" + range 14 25 + default 15 + help + Select the boot console buffer size as a power of 2. + Run-time console buffer size is the same as the boot console size, + unless enforced via 'conring_size=' boot parameter. + + Examples: + 25 => 32 MiB + 24 => 16 MiB + 23 => 8 MiB + 22 => 4 MiB + 21 => 2 MiB + 20 => 1 MiB + 19 => 512 KiB + 18 => 256 KiB + 17 => 128 KiB + 16 => 64 KiB + 15 => 32 KiB + 14 => 16 KiB + config XHCI bool "XHCI DbC UART driver" depends on X86 diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c index d22fb4a253af26f9b51d91bd408e1dbf4bb5a7c1..581ee22b85302a54db5b9d5d28e8b2d689d31403 100644 --- a/xen/drivers/char/console.c +++ b/xen/drivers/char/console.c @@ -104,11 +104,11 @@ static int cf_check parse_console_timestamps(const char *s); custom_runtime_param("console_timestamps", parse_console_timestamps, con_timestamp_mode_upd); -/* conring_size: allows a large console ring than default (16kB). */ +/* conring_size: allows a large console ring than default (32 KiB). */ static uint32_t __initdata opt_conring_size; size_param("conring_size", opt_conring_size); -#define _CONRING_SIZE 16384 +#define _CONRING_SIZE (1U << CONFIG_CONRING_LOG_SHIFT) #define CONRING_IDX_MASK(i) ((i)&(conring_size-1)) static char __initdata _conring[_CONRING_SIZE]; static char *__read_mostly conring = _conring;