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180902e08f
This patch adds clock_gettime_fallback() function that wraps assembly invocation of clock_gettime() syscall using __NR_clock_gettime. This function is used if pure VDSO implementation of clock_gettime() does not succeed for any reason. For example, it is called if the clkid parameter of clock_gettime() is not one of the clkids listed in the switch-case block of the function __vdso_clock_gettime() (one such case for clkid is CLOCK_BOOTIME). If syscall invocation via __NR_clock_gettime fails, register a3 will be set. So, after the syscall, register a3 is tested and the return value is negated if it's set. Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com> Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com> Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com> Cc: Douglas Leung <douglas.leung@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Petar Jovanovic <petar.jovanovic@imgtec.com> Cc: Raghu Gandham <raghu.gandham@imgtec.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/16639/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.