On Sun, Aug 13, 2023 at 01:48:21PM -0500, Scott Cheloha wrote: > This is the next patch in the clock interrupt reorganization series. > > Before we continue breaking up the hardclock(9) we need to detour into > the MD code. > > This patch divides the "initialization" parts of cpu_initclocks() from > the "start the clock interrupt" parts. Seprating the two parts leaves > initclocks() an opportunity to prepare the primary CPU for clock > interrupt dispatch in a machine-independent manner before actually > pulling the trigger. It's nearly impossible to do any MI setup during > initclocks() because cpu_initclocks() does everything in one go: both > initialization and kickoff are done when cpu_initclocks() returns. > > Many platforms have a "cpu_startclock()" function, so this patch takes > that de facto standard and makes it a rule: cpu_startclock() is now > required. It is prototyped in sys/systm.h and every platform must > implement it. > > The revised initclocks() sequence is then: > > 1. Call cpu_initclocks(). At minimum, cpu_initclocks() ensures > hz, stathz, and profhz are initialized. All the machine > independent setup in step (2) (currently) depends upon > these machine-dependent values. > > 2. Compute intervals using hz, stathz, and profhz. > > In a later step I will move the full contents of clockintr_init() > up into initclocks() and get rid of clockintr_init() entirely. > > 3. Call cpu_startclock(). At minimum, cpu_startclock() starts the > clock interrupt dispatch cycle on the primary CPU. > > I have compiled/booted this patch on amd64 (lapic path), arm64, i386 > (lapic path), macppc, octeon, and sparc64 (sun4v). > > I am looking for compile/boot tests on alpha, armv7, hppa, landisk, > luna88k, powerpc64, and riscv64. I think armv7 is the tricky one > here. Everything else is relatively straightforward, though I may > have missed a few stray variables here or there. > > Test results? Ok?
Compiles on armv7 and boots on an Allwinner A20 machine using agtimer(4). I don't think I have any armv7 systems using other timer devices.
