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From: Paul Burton <paul.burton@imgtec.com>
To: "linux-mips@linux-mips.org" <linux-mips@linux-mips.org>
Subject: R2300 (not the hay baler)
Date: Tue, 19 Nov 2013 11:07:22 +0000	[thread overview]
Message-ID: <528B466A.3050906@imgtec.com> (raw)

Hello,

Does anyone still care about the R2300? I ask because I'm working on
the FP context switching code & noticed that I'm pretty sure the
fpu_save_single & fpu_restore_single macros used only from
r2300_switch.S are broken. They store each 32 bit value at the start
of the location of the 64 bit FP registers context in memory, which I
believe:

1) Won't work for odd indexed FP registers with the FPU emulator,
    ptrace or other code which assumes that 32 bit FP data is held in
    the even-indexed 64 bit FP register context.

2) On big endian systems the 32 bit values will get saved to the most
    significant bits of the 64 bit context which I imagine will cause
    yet more problems.

It seems like the only changes to r2300_switch.S for a *long* time have
been to keep it in sync with r4k_switch.S & the CPU is old enough that
all I get when I google for it is information about some hay baler.

In short: does anyone care if I just submit a patch removing the R2300
code instead of blindly attempting to fix it up?

Thanks,
     Paul

             reply	other threads:[~2013-11-19 11:07 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-19 11:07 Paul Burton [this message]
2013-11-19 11:21 ` R2300 (not the hay baler) Ralf Baechle
2013-11-19 11:31   ` Paul Burton
2013-11-19 12:27 ` Maciej W. Rozycki
2013-11-19 12:59   ` Paul Burton
2013-11-21 19:52     ` Maciej W. Rozycki
2013-11-21 22:43       ` Ralf Baechle
2013-11-22  0:32         ` Maciej W. Rozycki
2013-11-27 17:11       ` Paul Burton
2013-12-03 16:49         ` MASS MAILING: " Paul Burton
2013-11-19 13:09 ` Ralf Baechle

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