linux-toradex.git/arch/powerpc/include/asm/ppc-opcode.h, branch v3.3.5

net: filter: BPF 'JIT' compiler for PPC64

2011-07-21T19:38:32+00:00

An implementation of a code generator for BPF programs to speed up packet
filtering on PPC64, inspired by Eric Dumazet's x86-64 version.

Filter code is generated as an ABI-compliant function in module_alloc()'d mem
with stackframe & prologue/epilogue generated if required (simple filters don't
need anything more than an li/blr).  The filter's local variables, M[], live in
registers.  Supports all BPF opcodes, although "complicated" loads from negative
packet offsets (e.g. SKF_LL_OFF) are not yet supported.

There are a couple of further optimisations left for future work; many-pass
assembly with branch-reach reduction and a register allocator to push M[]
variables into volatile registers would improve the code quality further.

This currently supports big-endian 64-bit PowerPC only (but is fairly simple
to port to PPC32 or LE!).

Enabled in the same way as x86-64:

	echo 1 > /proc/sys/net/core/bpf_jit_enable

Or, enabled with extra debug output:

	echo 2 > /proc/sys/net/core/bpf_jit_enable

Signed-off-by: Matt Evans 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

powerpc: Per process DSCR + some fixes (try#4)

2011-04-27T04:18:19+00:00

The DSCR (aka Data Stream Control Register) is supported on some
server PowerPC chips and allow some control over the prefetch
of data streams.

This patch allows the value to be specified per thread by emulating
the corresponding mfspr and mtspr instructions. Children of such
threads inherit the value. Other threads use a default value that
can be specified in sysfs - /sys/devices/system/cpu/dscr_default.

If a thread starts with non default value in the sysfs entry,
all children threads inherit this non default value even if
the sysfs value is changed later.

Signed-off-by: Alexey Kardashevskiy 
Signed-off-by: Benjamin Herrenschmidt

powerpc/a2: Add some #defines for A2 specific instructions

2011-04-20T07:01:19+00:00

Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Michael Ellerman 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Add NAP mode support on Power7 in HV mode

2011-04-20T01:03:24+00:00

Wakeup comes from the system reset handler with a potential loss of
the non-hypervisor CPU state. We save the non-volatile state on the
stack and a pointer to it in the PACA, which the system reset handler
uses to restore things

Signed-off-by: Benjamin Herrenschmidt

powerpc: Hardcode popcnt instructions for old assemblers

2010-12-09T04:35:30+00:00

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 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Emulate most Book I instructions in emulate_step()

2010-06-22T09:40:29+00:00

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

powerpc/85xx: Make sure lwarx hint isn't set on ppc32

2010-03-17T04:24:06+00:00

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

powerpc: Use lwarx/ldarx hint in bit locks

2010-02-17T03:03:15+00:00

This patch implements the lwarx/ldarx hint bit for bit locks.

Signed-off-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt

powerpc: Use lwarx hint in spinlocks

2010-02-17T03:03:14+00:00

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 
Signed-off-by: Benjamin Herrenschmidt

powerpc/mm: Add opcode definitions for tlbivax and tlbsrx.

2009-08-20T00:12:38+00:00

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