From: Denis Mukhin <dmuk...@ford.com> Add new CONRING_SHIFT Kconfig parameter to specify the boot console buffer size as a power of 2.
The supported range is [14..27] -> [16KiB..128MiB]. Set default to 15 (32 KiB). Link: https://gitlab.com/xen-project/xen/-/issues/185 Signed-off-by: Denis Mukhin <dmuk...@ford.com> --- Changes v2->v3: - Corrected xen-command-line.pandoc and Kconfig setting descriptions - Corrected _CONRING_SIZE definition --- docs/misc/xen-command-line.pandoc | 5 +++-- xen/drivers/char/Kconfig | 24 ++++++++++++++++++++++++ xen/drivers/char/console.c | 6 +++--- 3 files changed, 30 insertions(+), 5 deletions(-) diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc index 89db6e83be..a471a9f7ce 100644 --- a/docs/misc/xen-command-line.pandoc +++ b/docs/misc/xen-command-line.pandoc @@ -425,10 +425,11 @@ The following are examples of correct specifications: ### conring_size > `= <size>` -> Default: `conring_size=16k` - Specify the size of the console ring buffer. +The default console ring buffer size is selected at build time via +CONFIG_CONRING_SHIFT setting. + ### console > `= List of [ vga | com1[H,L] | com2[H,L] | pv | dbgp | ehci | xhci | none ]` diff --git a/xen/drivers/char/Kconfig b/xen/drivers/char/Kconfig index e6e12bb413..e238d4eccf 100644 --- a/xen/drivers/char/Kconfig +++ b/xen/drivers/char/Kconfig @@ -96,6 +96,30 @@ config SERIAL_TX_BUFSIZE Default value is 32768 (32KiB). +config CONRING_SHIFT + int "Console ring buffer size (power of 2)" + range 14 27 + default 15 + help + Select the boot console ring buffer size as a power of 2. + Run-time console ring buffer size is the same as the boot console ring + buffer size, unless overridden via 'conring_size=' boot parameter. + + 27 => 128 MiB + 26 => 64 MiB + 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 (default) + 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 ba428199d2..78794b74e9 100644 --- a/xen/drivers/char/console.c +++ b/xen/drivers/char/console.c @@ -101,12 +101,12 @@ 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: override build-time CONFIG_CONRING_SHIFT setting. */ static uint32_t __initdata opt_conring_size; size_param("conring_size", opt_conring_size); -#define _CONRING_SIZE 16384 -#define CONRING_IDX_MASK(i) ((i)&(conring_size-1)) +#define _CONRING_SIZE (1U << CONFIG_CONRING_SHIFT) +#define CONRING_IDX_MASK(i) ((i) & (conring_size - 1)) static char __initdata _conring[_CONRING_SIZE]; static char *__read_mostly conring = _conring; static uint32_t __read_mostly conring_size = _CONRING_SIZE; -- 2.34.1
