'ARM Server Base Boot Requirements' [1] mentions SPCR (Serial Port Console Redirection Table) [2] as a mandatory ACPI table that specifies the configuration of serial console. Introduce a new function acpi_console_check(). At the uart port registration, this function checks if the ACPI SPCR table specifies its argument of type struct uart_port to be a console and if so calls add_preferred_console(). Use SPCR to tell if SBSA serial driver should use 32-bit access to registers. Based on the work by Leif Lindholm [3] Should be applied to next-20160229. Tested on QEMU. SPCR support is included in QEMU's ARM mach-virt since 2.4 release. v4: - drop patch "ACPI: change __init to __ref for early_acpi_os_unmap_memory()" ACPI developers work on a new API and asked not to do that. Instead, use acpi_get_table_with_size()/early_acpi_os_unmap_memory() once and cache the result. (Lv Zheng) - fix some style issues (Yury Norov) v3: https://lkml.kernel.org/g/1455559532-8305-1-git-send-email-aleksey.makarov@xxxxxxxxxx Greg Kroah-Hartman did not like v2 so I have rewritten this patchset: - drop acpi_match() member of struct console - drop implementations of this member for pl011 and 8250 - drop the patch that renames some vars in printk.c as it is not needed anymore - drop patch that introduces system wide acpi_table_parse2(). Instead introduce a custom acpi_table_parse_spcr() in spcr.c Instead of introducing a new match_acpi() member of struct console, this patchset introduces a new function acpi_console_check(). This function is called when a new uart is registered at serial_core.c the same way OF code checks for console. If the registered uart is the console specified by SPCR table, this function calls add_preferred_console() The restrictions of this approach are: - only serial consoles can be set up - only consoles specified by the memory/io address can be set up (SPCR can specify devices by PCI id/PCI address) v2: https://lkml.kernel.org/g/1455299022-11641-1-git-send-email-aleksey.makarov@xxxxxxxxxx - don't use SPCR if user specified console in command line - fix initialization order of newcon->index = 0 - rename some variables at printk.c (Joe Perches, Peter Hurley) - enable ACPI_SPCR_TABLE in a separate patch (Andy Shevchenko) - remove the retry loop for console registering (Peter Hurley). Instead, obtain SPCR with acpi_get_table(). That works after call to acpi_early_init() i. e. in any *_initcall() - describe design decision behind introducing acpi_match() (Peter Hurley) - fix compilation for x86 + ACPI (Graeme Gregory) - introduce DBG2 constants in a separate patch (Andy Shevchenko) - fix a typo in DBG2 constants (Andy Shevchenko) - add ACPI_DBG2_ARM_SBSA_32BIT constant (Christopher Covington) - add support for ACPI_DBG2_ARM_SBSA_* consoles (Christopher Covington) - add documentation for functions - add a patch that uses SPCR to find if SBSA serial driver should use 32-bit accessor functions (Christopher Covington) - change __init to __ref for early_acpi_os_unmap_memory() in a separate patch - introduce acpi_table_parse2() in a separate patch - fix fetching the SPCR table early (Mark Salter) - add a patch from Mark Salter that introduces support for matching 8250-based consoles v1: https://lkml.kernel.org/g/1453722324-22407-1-git-send-email-aleksey.makarov@xxxxxxxxxx [1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0044a/index.html [2] https://msdn.microsoft.com/en-us/library/windows/hardware/dn639132(v=vs.85).aspx [3] https://lkml.kernel.org/g/1441716217-23786-1-git-send-email-leif.lindholm@xxxxxxxxxx Aleksey Makarov (4): ACPI: parse SPCR and enable matching console ACPI: enable ACPI_SPCR_TABLE on ARM64 ACPI: add definitions of DBG2 subtypes serial: pl011: use ACPI SPCR to setup 32-bit access arch/arm64/Kconfig | 1 + drivers/acpi/Kconfig | 3 + drivers/acpi/Makefile | 1 + drivers/acpi/spcr.c | 138 +++++++++++++++++++++++++++++++++++++++ drivers/tty/serial/amba-pl011.c | 2 + drivers/tty/serial/serial_core.c | 14 +++- include/acpi/actbl2.h | 5 ++ include/linux/acpi.h | 15 +++++ 8 files changed, 177 insertions(+), 2 deletions(-) create mode 100644 drivers/acpi/spcr.c -- 2.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
