Commit Graph

13 Commits

Author SHA1 Message Date
Anton Blanchard b5f9b6665b powerpc: Hardcode popcnt instructions for old assemblers
The popcnt instructions went into binutils relatively recently. As with a
number of other instructions, create macros and hardcode them.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-12-09 15:35:30 +11:00
Paul Mackerras 0016a4cf55 powerpc: Emulate most Book I instructions in emulate_step()
This extends the emulate_step() function to handle a large proportion
of the Book I instructions implemented on current 64-bit server
processors.  The aim is to handle all the load and store instructions
used in the kernel, plus all of the instructions that appear between
l[wd]arx and st[wd]cx., so this handles the Altivec/VMX lvx and stvx
and the VSX lxv2dx and stxv2dx instructions (implemented in POWER7).

The new code can emulate user mode instructions, and checks the
effective address for a load or store if the saved state is for
user mode.  It doesn't handle little-endian mode at present.

For floating-point, Altivec/VMX and VSX instructions, it checks
that the saved MSR has the enable bit for the relevant facility
set, and if so, assumes that the FP/VMX/VSX registers contain
valid state, and does loads or stores directly to/from the
FP/VMX/VSX registers, using assembly helpers in ldstfp.S.

Instructions supported now include:
* Loads and stores, including some but not all VMX and VSX instructions,
  and lmw/stmw
* Atomic loads and stores (l[dw]arx, st[dw]cx.)
* Arithmetic instructions (add, subtract, multiply, divide, etc.)
* Compare instructions
* Rotate and mask instructions
* Shift instructions
* Logical instructions (and, or, xor, etc.)
* Condition register logical instructions
* mtcrf, cntlz[wd], exts[bhw]
* isync, sync, lwsync, ptesync, eieio
* Cache operations (dcbf, dcbst, dcbt, dcbtst)

The overflow-checking arithmetic instructions are not included, but
they appear not to be ever used in C code.

This uses decimal values for the minor opcodes in the switch statements
because that is what appears in the Power ISA specification, thus it is
easier to check that they are correct if they are in decimal.

If this is used to single-step an instruction where a data breakpoint
interrupt occurred, then there is the possibility that the instruction
is a lwarx or ldarx.  In that case we have to be careful not to lose the
reservation until we get to the matching st[wd]cx., or we'll never make
forward progress.  One alternative is to try to arrange that we can
return from interrupts and handle data breakpoint interrupts without
losing the reservation, which means not using any spinlocks, mutexes,
or atomic ops (including bitops).  That seems rather fragile.  The
other alternative is to emulate the larx/stcx and all the instructions
in between.  This is why this commit adds support for a wide range
of integer instructions.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2010-06-22 19:40:29 +10:00
Kumar Gala d6ccb1f55d powerpc/85xx: Make sure lwarx hint isn't set on ppc32
e500v1/v2 based chips will treat any reserved field being set in an
opcode as illegal.  Thus always setting the hint in the opcode is
a bad idea.

Anton should be kept away from the powerpc opcode map.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2010-03-16 23:24:06 -05:00
Anton Blanchard 864b9e6fd7 powerpc: Use lwarx/ldarx hint in bit locks
This patch implements the lwarx/ldarx hint bit for bit locks.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-17 14:03:15 +11:00
Anton Blanchard 4e14a4d17a powerpc: Use lwarx hint in spinlocks
Recent versions of the PowerPC architecture added a hint bit to the larx
instructions to differentiate between an atomic operation and a lock operation:

> 0 Other programs might attempt to modify the word in storage addressed by EA
> even if the subsequent Store Conditional succeeds.
>
> 1 Other programs will not attempt to modify the word in storage addressed by
> EA until the program that has acquired the lock performs a subsequent store
> releasing the lock.

To avoid a binutils dependency this patch create macros for the extended lwarx
format and uses it in the spinlock code. To test this change I used a simple
test case that acquires and releases a global pthread mutex:

	pthread_mutex_lock(&mutex);
	pthread_mutex_unlock(&mutex);

On a 32 core POWER6, running 32 test threads we spend almost all our time in
the futex spinlock code:

    94.37%     perf  [kernel]                     [k] ._raw_spin_lock
               |
               |--99.95%-- ._raw_spin_lock
               |          |
               |          |--63.29%-- .futex_wake
               |          |
               |          |--36.64%-- .futex_wait_setup

Which is a good test for this patch. The results (in lock/unlock operations per
second) are:

before: 1538203 ops/sec
after:  2189219 ops/sec

An improvement of 42%

A 32 core POWER7 improves even more:

before: 1279529 ops/sec
after:  2282076 ops/sec

An improvement of 78%

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-02-17 14:03:14 +11:00
Benjamin Herrenschmidt 29c09e8fba powerpc/mm: Add opcode definitions for tlbivax and tlbsrx.
This adds the opcode definitions to ppc-opcode.h for the two instructions
tlbivax and tlbsrx. as defined by Book3E 2.06

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-08-20 10:12:38 +10:00
Milton Miller 60dbf43851 powerpc: Add 2.06 tlbie mnemonics
This adds the PowerPC 2.06 tlbie mnemonics and keeps backwards
compatibilty for CPUs before 2.06.

Only useful for bare metal systems.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-05-21 15:44:21 +10:00
Michael Neuling dfb432cb96 powerpc: Move VSX load/stores into ppc-opcode.h
Cleans up the VSX load/store instructions by moving them into
ppc-opcode.h.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-05-21 15:44:21 +10:00
Michael Neuling da6b43c833 powerpc: Cleanup macros in ppc-opcode.h
Make macros more braces happy.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-05-21 15:44:21 +10:00
Kumar Gala 323d23aeac Revert "powerpc: Add support for early tlbilx opcode"
This reverts commit e996557740.  Our HW
guys were able to fix this so it never sees the light of day.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2009-04-23 08:51:22 -05:00
Kumar Gala e996557740 powerpc: Add support for early tlbilx opcode
During the ISA 2.06 development the opcode for tlbilx changed and some
early implementations used to old opcode.  Add support for a MMU_FTR
fixup to deal with this.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2009-04-07 01:36:30 -05:00
Kumar Gala 7281f5dc2c powerpc: Fix tlbilx opcode
The tlbilx opcode was not matching the Power ISA 2.06 arch spec.
The old opcode was an early suggested opcode that changed during the
2.06 architecture process.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2009-04-07 01:36:27 -05:00
Kumar Gala 16c57b3620 powerpc: Unify opcode definitions and support
Create a new header that becomes a single location for defining PowerPC
opcodes used by code that is either generationg instructions
at runtime (fixups, debug, etc.), emulating instructions, or just
compiling instructions old assemblers don't know about.

We currently don't handle the floating point emulation or alignment decode
as both are better handled by the specific decode support they already
have.

Added support for the new dcbzl, dcbal, msgsnd, tlbilx, & wait instructions
since older assemblers don't know about them.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23 10:48:56 +11:00