From: Brad Boyer <flar@allandria.com>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michael Schmitz <schmitzmic@gmail.com>,
Arnd Bergmann <arnd@kernel.org>,
Finn Thain <fthain@telegraphics.com.au>,
"Song Bao Hua (Barry Song)" <song.bao.hua@hisilicon.com>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
"arnd@arndb.de" <arnd@arndb.de>,
"funaho@jurai.org" <funaho@jurai.org>,
"philb@gnu.org" <philb@gnu.org>,
"corbet@lwn.net" <corbet@lwn.net>,
"mingo@redhat.com" <mingo@redhat.com>,
"linux-m68k@lists.linux-m68k.org"
<linux-m68k@lists.linux-m68k.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] IRQ handlers run with some high-priority interrupts(not NMI) enabled on some platform
Date: Fri, 19 Feb 2021 14:30:32 -0800 [thread overview]
Message-ID: <20210219223032.GA1343@allandria.com> (raw)
In-Reply-To: <CAMuHMdWBsupz06wVyVENHfjxP0uQ+1b7cnz6xGEMyqQkJFTeAA@mail.gmail.com>
On Fri, Feb 19, 2021 at 09:10:57AM +0100, Geert Uytterhoeven wrote:
> Hi Michael,
>
> On Thu, Feb 18, 2021 at 11:11 PM Michael Schmitz <schmitzmic@gmail.com> wrote:
> > On 19/02/21 12:19 am, Arnd Bergmann wrote:
> > > drivers/net/ethernet/8390/apne.c
> > > drivers/net/ethernet/8390/ax88796.c
> > > drivers/net/ethernet/8390/hydra.c
> > > drivers/net/ethernet/8390/mac8390.c
> > > drivers/net/ethernet/8390/ne.c
> > > drivers/net/ethernet/8390/zorro8390.c
> > [...]
> > > Most of these are normal short-lived interrupts that only transfer
> > > a few bytes or schedule deferred processing of some sort.
> > > Most of the scsi and network drivers process the data in
> > > a softirq, so those are generally fine here, but I do see that 8390
> > > (ne2000) ethernet and the drivers/ide drivers do transfer their
> > > data in hardirq context.
> > >
> > > Arnd
> >
> > 8390 ethernet drivers are widely used on m68k platforms (Amiga and
> > Atari). At least on Amiga, the corresponding interrupt is a hardirq so
> > I'd advise caution. That said, the 8390 drivers might benefit from some
> > refactoring (the way these drivers are compiled does prevent e.g. the
> > APNE driver from being used with two different variants of PCMCIA
> > interfaces. I had begun some work on making IO primitives runtime
> > selected two years ago but that ended up looking too ugly ...).
> >
> > Can't recall what IPL the 8390 interrupts operate at - Geert?
>
> #define IRQ_AMIGA_PORTS IRQ_AUTO_2
>
> Zorro expansion boards can also use
>
> #define IRQ_AMIGA_EXTER IRQ_AUTO_6
>
> and some boards may have a jumper to select the latter, but all Amiga
> Linux drivers use IRQ_AMIGA_PORTS.
The mac8390 driver will show up wherever NuBus interrupts are routed,
which varies by hardware. It's frequently IRQ_AUTO_2 (due to being
routed through the second VIA chip on most models), but it can be in
other places on systems that don't use a second VIA chip. On the IIfx,
NuBus interrupts get routed through OSS to IRQ_AUTO_3. I don't see any
cases that use other interrupt levels, but some of the logic is a
little harder to follow.
It's not an 8390, but it looks like macmace actually uses two levels. The
regular interrupt should show up at IRQ_AUTO_3 and the DMA interrupts at
IRQ_AUTO_4. Most Macs only use 4 for serial, but this is an exception.
Brad Boyer
flar@allandria.com
next prev parent reply other threads:[~2021-02-19 23:06 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-12 1:18 [RFC] IRQ handlers run with some high-priority interrupts(not NMI) enabled on some platform Song Bao Hua (Barry Song)
2021-02-12 22:34 ` Arnd Bergmann
2021-02-12 23:00 ` Song Bao Hua (Barry Song)
2021-02-12 23:05 ` Arnd Bergmann
2021-02-12 23:46 ` Song Bao Hua (Barry Song)
2021-02-13 16:32 ` Arnd Bergmann
2021-02-13 22:18 ` Song Bao Hua (Barry Song)
2021-02-13 23:18 ` Song Bao Hua (Barry Song)
2021-02-14 5:10 ` Finn Thain
2021-02-15 13:06 ` Andy Shevchenko
2021-02-15 22:22 ` Finn Thain
2021-02-17 22:41 ` Song Bao Hua (Barry Song)
2021-02-18 5:30 ` Finn Thain
2021-02-18 11:19 ` Arnd Bergmann
2021-02-18 12:30 ` Geert Uytterhoeven
2021-02-18 13:59 ` Arnd Bergmann
2021-02-18 15:38 ` Geert Uytterhoeven
2021-02-18 22:11 ` Michael Schmitz
2021-02-19 8:10 ` Geert Uytterhoeven
2021-02-19 22:30 ` Brad Boyer [this message]
2021-02-20 6:32 ` Finn Thain
2021-02-20 7:08 ` Brad Boyer
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