On 18.10.2018 22:01, John David Anglin wrote:
> On 2018-10-18 3:20 PM, Helge Deller wrote:
>> According to the PARISC 1.1 Instruction Set Reference Manual, PA1.1 does
>> *not* support the depw,z instruction, but only the dep (depw)
>> instruction, e.g.:
> No. This is a mnemonics issue. PA 1.1 has zdep instruction that is the same as PA 2.0 depw,z.
> The have same instruction encoding.
Ok.
>> d5 8b 08 f6 depw,z r11,24,10,r12 # NOT PA1.1
>> d5 8b 0c f6 depw r11,24,10,r12 # OK for PA1.1
>>
>> And in the Linux kernel source (arch/parisc/include/asm/assembly.h) I see
>>
>> /* Shift Left - note the r and t can NOT be the same! */
>> .macro shl r, sa, t
>> dep,z \r, 31-(\sa), 32-(\sa), \t
> Should be zdep.
Ok.
What about the note "r and t can NOT be the same!" ?
Is that bogus or true for the dep case at least?
If it's bogus we could replace in entry.S:
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -426,8 +426,7 @@
ldw,s \index(\pmd),\pmd
bb,>=,n \pmd,_PxD_PRESENT_BIT,\fault
dep %r0,31,PxD_FLAG_SHIFT,\pmd /* clear flags */
- copy \pmd,%r9
- SHLREG %r9,PxD_VALUE_SHIFT,\pmd
+ SHLREG \pmd,PxD_VALUE_SHIFT,\pmd
Thanks for the explanation,
Helge
