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<damo22>i wonder if i can replace sti/cli in linux drivers to use spl0() and splhi()
<youpi>that should work
<damo22>i hope so
<damo22>it compiled
<damo22>dang it crashed and rebooted
<damo22>really fast
<youpi>note that it's __sti() that you want to replace
<damo22>yeah i did that
<damo22>+-#define __sti() __asm__ __volatile__ ("sti": : :"memory")
<damo22>+-#define __cli() __asm__ __volatile__ ("cli": : :"memory")
<damo22>++#define __sti() spl0()
<damo22>++#define __cli() splhi()
<damo22>and removed all references to pic mask
<damo22>oh but spl0() has some stuff for linux handling
<damo22>maybe the interrupt handler is calling itself
<damo22> <--- youpi can you please read my spl0()
<youpi>if I manage to find the time
<damo22>i think i need spl0linux
<damo22>that skips all the linux handling when in a linux driver because its already handling the interrupt
<damo22>so the only way to get to the linux handler is via mach spl0
<damo22>what if i make sti/cli = no operation
<damo22>in linux
<damo22>i might try that
<damo22>i found only one cli() in ahci.c, it seems to time out with no port->status, but if interrupts are disabled, how can the interrupt happen?
<damo22>it doesnt make sense why the call to cli() is there
<damo22>oh its polling the port with sleep_on() ?
<youpi>damo22: note that restore_flags() is supposed to restore the interrupt flag
<damo22>its using some kind of internal linux timer scheduling to wait for the port->status but its broken when i get rid of pic mask
<youpi>sleep_on probably also restores the interrupt flag
<youpi>yes, __sleep_on does sti before schedul(
<youpi>timers have to work, yes
<damo22>i dont understand what i should do
<damo22>i have 2 states now
<damo22>do i need a third state where timers work but nothing else?
<youpi>timers will work in the ahci case because sleep_on does sti
<damo22>why cant i just modify the ahci driver to poll for the interrupt status without a timer
<youpi>because we need to be able to time out
<damo22>it still has jiffies
<damo22>which is a timer based thing and doesnt need to call cli
<youpi>jiffies don't avance if the clock interrupt does not work
<damo22>im suggesting to remove the cli call
<damo22>and just poll the status
<youpi>you don't want to do that, that would make it unsafe
<damo22>why would it make it unsafe?
<damo22>jiffies will advance
<damo22>it will still timeout
<youpi>I mean, cli was most probably there for a reason
<damo22>most of the other calls just poll, just not this one
<youpi>that being said it's just at probing time
<youpi>so you may not care if it's unsafe
<youpi>you'll still be able to work
<damo22> while (!readl(&ahci_port->is)) {
<damo22> if (jiffies >= timeout) {
<damo22>something like that
<youpi>that's not polling for the status field
<youpi>in ahci_identify it's polling for something that is set by the interrupt handler
<youpi>that's why it makes sense to disable the interrupt before trying to synchronize that way with it
<damo22>it issues a command writel(1 << slot, &ahci_port->ci)
<damo22>is that handled by the interrupt handler?
<youpi>only the interrupt handler writes to the status variable
<damo22>so you want to disable interrupts before calling that, and somehow process it slowly
<youpi>more precisely, you do not want the interrupt to happen between the !potr->status test and the sleep_on() call
<youpi>if that happened, the probing thread would be stuck forever
<damo22>i changed the printk
<damo22>it times out on the second timeout twice
<damo22>after the cli() call
<youpi>did you fix save_flags / restore_flags to use spl?
<youpi>restore_flags is supposed to restore the interrupt flag
<youpi>so that has to interact with spl
<damo22>so it needs to save it to curr_ipl
<youpi>err, rather to return the value of curr_ipl
<youpi>(I mean save_flags)
<youpi>and restore_flags would basically be an splx call
<youpi>ideally it'd only store the info in the appropriate interrupt bit of the flags
<youpi>probably no driver uses other flags than the interrupt flag, but possibly some do
<youpi>I don't think the ahci does
<youpi>so probably you can leave that aside
<damo22>#define __save_flags(x) \
<damo22>__asm__ __volatile__("pushf ; pop %0" : "=r" (x): /* no input */ :"memory")
<damo22>doesnt that save the current flags to x
<youpi>it does
<youpi>you want to replace that with copying curr_ipl to x
<damo22>#define restore_flags(x) splx(x)
<damo22>#define __save_flags(x) (x = curr_ipl > 0 ? 0x400 : 0)
<youpi>isn't the interrupt flag 0x200 ?
<youpi>(better use (1 << EFLAGS_IF_SHIFT) )
<damo22>lets see if this thing works
***Glider_IRC_ is now known as Glider_IRC
<AlmuHS>I got outstanding for my final degree thesis about Hurd SMP!! :-)
<AlmuHS>outstanding with honours
<AlmuHS>youpi: I got a outstanding with honours for my Hurd SMP final degree project
<gnu_srs2>AlmuHS: Congrats :)
<AlmuHS>ty. It was a big effort (and continues)
<youpi>AlmuHS: yay!
<youpi>you deserve it :)
<AlmuHS>you can get a copy in this web: (select "Grado en Ingenieria Informatica" and "2019" in the menu)
<jrtc27>under Cualquiera at the moment
<AlmuHS>jrtc27: thanks. It seems this index is bad
<jrtc27>oh it's all written in spanish :(
<AlmuHS>yes. Maybe I will write a paper about this, but the final degree thesis is in spanish
<jrtc27>yeah sure it makes sense for internal things (although papers are generally english so an argument could be made there) but unfortunate for those who don't speak it :)
<AlmuHS>btw, jrtc27 , youpi and damo22 are quoted in the document
<jrtc27>if I applied my brain enough I could *probably* get by with my basic french/italian knowledge
<AlmuHS>in a few months I will write a paper
<jrtc27>(and domain-specific knowledge... technical writings in non-english language tend to be amusingly high in words that look a lot like the english tech terms)
<AlmuHS>yes, but some of my selection board are not familiarized with english terms, and I had to translate these to spanish
<AlmuHS>even I had to explain terms as "BSP", "AP"...
<jrtc27>:/ annoyting
<youpi>AlmuHS: impressive technical writing :)
<youpi>did you get some teacher to actually understand it ? :)
<AlmuHS>my tutor is a operating systems teacher
<youpi>ok :)
<AlmuHS>the notes about scheduling and MMU in the operating system subject of my degree has been written by him
<AlmuHS>but these notes are so generic, don't explain about how x86 apply this concepts
<AlmuHS>*the notes don't explain about
<gnu_srs2>youpi: How important are libblkid-dev, libparted-dev, libpciaccess-dev, uuid-dev?
<gnu_srs2>Can lwip be built with GNU tools: Cross-building cmake is just too much...
<youpi>gnu_srs2: libpciaccess is needed for netdde
<youpi>I don't know about lwip with GNU tools
<youpi>(blkid/parted/uuid are needed only for userland partition support)
<AlmuHS>jrtc27: some interesting translations ;)
<AlmuHS>jrtc27: more translations
<AlmuHS>better in gist: