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linux/arch/powerpc/include/asm
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Michael Ellerman d6265aeaf8 powerpc/kernel: Drop HMT_MEDIUM_PPR_DISCARD 
HMT_MEDIUM_PPR_DISCARD is a macro which is present at the start of most
of our first level exception handlers. It conditionally executes a
HMT_MEDIUM instruction, which sets the processor priority to medium.

On on modern systems, ie. Power7 and later, it is nop'ed out at boot.
All it does is make the exception vectors more cramped, and consume 4
bytes of icache.

On old systems it has the effect of boosting the processor priority at
the start of exception processing. If we were previously in the idle
loop for example, we may be at low or very low priority. This is
desirable as we want to process the exception as fast as possible.

However looking closely at the generated code, we see that in all cases
we execute another HMT_MEDIUM just four instructions later. With code
patching applied, the final code on an old (Power6) system will look
like, eg:

  c000000000000300 <data_access_pSeries>:
  c000000000000300:	7c 42 13 78	mr	r2,r2		<-
  c000000000000304:	7d b2 43 a6	mtsprg	2,r13
  c000000000000308:	7d b1 42 a6	mfsprg	r13,1
  c00000000000030c:	f9 2d 00 80	std	r9,128(r13)
  c000000000000310:	60 00 00 00	nop
  c000000000000314:	7c 42 13 78	mr	r2,r2		<-

So I suggest that the added code complexity of HMT_MEDIUM_PPR_DISCARD is
not justified by the benefit of boosting the processor priority for the
duration of four instructions, and therefore we drop it.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-17 22:40:57 +11:00
..
book3s powerpc/mm: Don't hardcode the hash pte slot shift 2015-12-14 15:19:15 +11:00
nohash powerpc/nohash: we don't use real_pte_t for nohash 2015-12-14 15:19:16 +11:00
8xx_immap.h
agp.h
archrandom.h powerpc: Use hardware RNG for arch_get_random_seed_* not arch_get_random_* 2015-07-23 19:52:03 +10:00
asm-compat.h ppc: bpf: add required compatibility macros for jit 2015-02-20 15:19:43 -05:00
asm-offsets.h
async_tx.h
atomic.h atomic: Provide atomic_{or,xor,and} 2015-07-27 14:06:24 +02:00
backlight.h
barrier.h locking, arch: use WRITE_ONCE()/READ_ONCE() in smp_store_release()/smp_load_acquire() 2015-08-03 10:59:30 +02:00
bitops.h powerpc: Fix comment typos in arch/powerpc/include/asm/bitops.h 2014-11-12 16:31:46 +11:00
bootx.h
btext.h
bug.h powerpc: Remove stale function prototypes 2014-09-25 23:14:43 +10:00
bugs.h
cache.h powerpc: Revert "Use the POWER8 Micro Partition Prefetch Engine in KVM HV on POWER8" 2015-10-21 20:50:30 +11:00
cacheflush.h powerpc/mm: Don't call __flush_dcache_icache_phys() with PA>VA 2015-08-07 22:59:20 -05:00
cell-pmu.h
cell-regs.h
checksum.h powerpc: add support for csum_add() 2015-08-07 22:59:19 -05:00
cmpxchg.h powerpc: Make {cmp}xchg* and their atomic_ versions fully ordered 2015-12-14 20:39:01 +11:00
code-patching.h powerpc: Add ppc_global_function_entry() 2014-06-24 14:05:32 +10:00
compat.h powerpc/kernel: Add SIG_SYS support for compat tasks 2015-07-29 11:56:13 +10:00
context_tracking.h powerpc: No need to use dot symbols when branching to a function 2014-04-23 10:05:16 +10:00
copro.h powerpc/cell: Make spu_flush_all_slbs() generic 2014-10-08 20:15:37 +11:00
cpm1.h
cpm2.h powerpc/cpm: Remove duplicate FCC_GFMR_TTX define 2014-06-11 17:03:28 +10:00
cpm.h
cpuidle.h powernv/cpuidle: Redesign idle states management 2014-12-15 10:46:40 +11:00
cputable.h Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/scottwood/linux into next 2015-06-19 17:23:48 +10:00
cputhreads.h powerpc: Fix cpu_online_cores_map to return only online threads mask 2015-05-22 15:12:30 +10:00
cputime.h Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2014-10-15 07:48:18 +02:00
current.h
dbdma.h powerpc: Move Power Macintosh drivers to generic byteswappers 2015-03-23 14:29:40 +11:00
dbell.h
dcr-generic.h
dcr-mmio.h of: Stop naming platform_device using dcr address 2014-05-23 08:28:02 +09:00
dcr-native.h powerpc: Use bool function return values of true/false not 1/0 2015-03-31 14:19:47 +11:00
dcr-regs.h
dcr.h
debug.h powerpc: Fix smp_processor_id() in preemptible splat in set_breakpoint 2014-05-20 10:54:06 +10:00
delay.h
device.h powerpc/iommu: Remove dma_data union 2015-07-13 10:10:54 +10:00
disassemble.h KVM: PPC: e500: Emulate TMCFG0 TMRN register 2015-10-15 15:58:16 +11:00
dma-mapping.h dma-mapping: consolidate dma_set_mask 2015-09-10 13:29:01 -07:00
dma.h
edac.h EDAC: Cleanup atomic_scrub mess 2015-05-28 15:31:53 +02:00
eeh_event.h powerpc/powernv: Fix killed EEH event 2014-06-11 17:04:33 +10:00
eeh.h powerpc/eeh: Introduce eeh_pe_inject_err() 2015-05-12 20:33:35 +10:00
ehv_pic.h
elf.h mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE 2015-04-14 16:49:05 -07:00
emergency-restart.h
emulated_ops.h powerpc: Add lq/stq emulation 2014-04-09 12:53:28 +10:00
epapr_hcalls.h kvm/powerpc: move kvm_hypercall0() and friends to epapr_hypercall0() 2014-01-09 10:14:57 +01:00
exception-64e.h powerpc/e6500: hw tablewalk: make sure we invalidate and write to the same tlb entry 2015-10-27 18:14:40 -05:00
exception-64s.h powerpc/kernel: Drop HMT_MEDIUM_PPR_DISCARD 2015-12-17 22:40:57 +11:00
exec.h
fadump.h powerpc/fadump: Fix endianess issues in firmware assisted dump handling 2014-10-30 16:52:46 +11:00
fb.h
feature-fixups.h
firmware.h powerpc/powernv: remove FW_FEATURE_OPALv3 and just use FW_FEATURE_OPAL 2015-12-17 22:40:54 +11:00
fixmap.h powerpc: use generic fixmap.h 2014-01-23 16:36:54 -08:00
floppy.h
fs_pd.h powerpc/8xx: Remove empty asm/mpc8xx.h 2014-06-25 18:49:40 -05:00
fsl_85xx_cache_sram.h
fsl_gtm.h
fsl_hcalls.h
fsl_lbc.h uio: uio_fsl_elbc_gpcm: new driver 2015-01-12 05:04:13 -08:00
fsl_pamu_stash.h iommu/fsl: Various cleanups 2015-02-03 18:47:18 +01:00
ftrace.h ftrace: Format MCOUNT_ADDR address as type unsigned long 2015-07-20 22:30:53 -04:00
futex.h
gpio.h
grackle.h
hardirq.h powerpc: Replace __get_cpu_var uses 2014-11-03 12:12:32 +11:00
heathrow.h
highmem.h kmap_atomic_to_page() has no users, remove it 2015-11-09 15:11:24 -08:00
hugetlb.h mm/hugetlb: remove arch_prepare/release_hugepage from arch headers 2015-06-25 17:00:35 -07:00
hvcall.h KVM: PPC: Book3S HV: Add H_SET_MODE hcall handling 2014-07-28 15:22:19 +02:00
hvconsole.h
hvcserver.h
hvsi.h
hw_breakpoint.h powerpc: Fix smp_processor_id() in preemptible splat in set_breakpoint 2014-05-20 10:54:06 +10:00
hw_irq.h powerpc/book3s: Add basic infrastructure to handle HMI in Linux. 2014-08-05 16:33:48 +10:00
hydra.h powerpc: Remove stale function prototypes 2014-09-25 23:14:43 +10:00
i8259.h
ibmebus.h
icswx.h powerpc: Add ICSWX instruction 2015-05-11 15:06:39 +08:00
ide.h
immap_cpm2.h
immap_qe.h
io_event_irq.h
io-defs.h
io-workarounds.h
io.h arch/*/io.h: Add ioremap_uc() to all architectures 2015-07-29 10:02:36 +02:00
iommu.h powerpc/iommu: Remove dma_data union 2015-07-13 10:10:54 +10:00
ipic.h
irq_work.h powerpc: Re-enable dynticks 2015-02-23 14:52:04 +11:00
irq.h powerpc: Remove stale function prototypes 2014-09-25 23:14:43 +10:00
irqflags.h powerpc: Update comments in irqflags.h 2014-07-28 14:11:23 +10:00
jump_label.h locking/static_keys: Add a new static_key interface 2015-08-03 11:34:15 +02:00
Kbuild word-at-a-time.h: fix some Kbuild files 2015-10-06 14:52:48 -04:00
kdebug.h
kdump.h
kexec.h powerpc/kdump: Ignore failure in enabling big endian exception during crash 2014-12-29 15:44:53 +11:00
keylargo.h
kgdb.h
kmap_types.h
kprobes.h powerpc/kprobes: Fix kallsyms lookup across powerpc ABIv1 and ABIv2 2015-01-23 14:02:51 +11:00
kvm_asm.h KVM: PPC: Remove shared defines for SPE and AltiVec interrupts 2014-09-22 10:11:34 +02:00
kvm_book3s_32.h
kvm_book3s_64.h KVM: implement multiple address spaces 2015-06-05 17:26:35 +02:00
kvm_book3s_asm.h KVM: PPC: Book3S: correct width in XER handling 2015-08-22 11:16:19 +02:00
kvm_book3s.h KVM: PPC: Book3S: correct width in XER handling 2015-08-22 11:16:19 +02:00
kvm_booke_hv_asm.h powerpc/booke64: Use SPRG_TLB_EXFRAME on bolted handlers 2014-03-19 19:57:15 -05:00
kvm_booke.h KVM: PPC: Book3S: correct width in XER handling 2015-08-22 11:16:19 +02:00
kvm_fpu.h
kvm_host.h s390: A bunch of fixes and optimizations for interrupt and time 2015-11-05 16:26:26 -08:00
kvm_para.h kvm/powerpc: move kvm_hypercall0() and friends to epapr_hypercall0() 2014-01-09 10:14:57 +01:00
kvm_ppc.h KVM: add "new" argument to kvm_arch_commit_memory_region 2015-05-28 10:42:58 +02:00
libata-portmap.h
linkage.h powerpc: Remove function descriptors and dot symbols on new ABI 2014-04-23 10:05:20 +10:00
local.h
lppaca.h
lv1call.h
machdep.h powerpc: Fix checkstop in native_hpte_clear() with lockdep 2015-10-09 08:01:38 +11:00
macio.h
mc146818rtc.h
mce.h powerpc/book3s: Recover from MC in sapphire on SCOM read via MMIO. 2014-03-07 15:52:10 +11:00
mediabay.h
mm-arch-hooks.h powerpc/mm: tracking vDSO remap 2015-06-24 17:49:41 -07:00
mman.h
mmu_context.h powerpc/mm: tracking vDSO remap 2015-06-24 17:49:41 -07:00
mmu-8xx.h powerpc/8xx: Implementation of PAGE_EXEC 2015-06-02 21:37:28 -05:00
mmu-40x.h
mmu-44x.h
mmu-book3e.h KVM: PPC: Book3e: Add TLBSEL/TSIZE defines for MAS0/1 2014-07-28 15:23:13 +02:00
mmu-hash32.h
mmu-hash64.h powerpc/mm: make a separate copy for book3s 2015-12-14 15:19:05 +11:00
mmu.h powerpc: Remove MMU_FTR_SLB 2014-07-28 14:10:23 +10:00
mmzone.h
module.h powerpc/modules: Create module_trampoline_target() 2014-04-23 10:05:34 +10:00
mpc5xxx.h
mpc6xx.h
mpc52xx_psc.h powerpc: mpc512x: drop bogus and unused psc register bit definitions 2015-10-22 16:06:08 +02:00
mpc52xx.h
mpc85xx.h powerpc/fsl-booke: Add T4080 SVR value 2015-03-31 22:23:17 -05:00
mpc5121.h powerpc/512x: add LocalPlus Bus FIFO device driver 2015-10-22 15:19:40 +02:00
mpc8260.h
mpic_msgr.h
mpic_timer.h
mpic.h powerpc/mpic: Add get_version API both for internal and external use 2015-03-23 19:51:17 -05:00
msi_bitmap.h powerpc/msi: Free the bitmap if it was slab allocated 2015-10-05 21:32:50 +11:00
mutex.h
nmi.h powerpc: Add ppc64 hard lockup detector support 2015-04-11 20:49:27 +10:00
nvram.h powerpc/nvram: Move generic code for nvram and pstore 2015-03-23 14:05:49 +11:00
ohare.h
opal-api.h powerpc updates for 4.3 2015-09-03 16:41:38 -07:00
opal.h powerpc/powernv: Add OPAL interfaces for accessing and modifying system LED states 2015-08-20 18:19:07 +10:00
oprofile_impl.h powerpc: Remove oprofile RS64 support 2014-07-28 14:10:25 +10:00
paca.h powerpc: book3e_64: fix the align size for paca_struct 2015-03-31 22:23:17 -05:00
page_32.h
page_64.h powerpc: Speed up clear_page by unrolling it 2014-10-02 16:04:21 +10:00
page.h powerpc/mm: Move hugetlb related headers 2015-12-14 15:19:13 +11:00
parport.h
pasemi_dma.h
pci-bridge.h powerpc/powernv: move dma_get_required_mask from pnv_phb to pci_controller_ops 2015-08-18 19:32:11 +10:00
pci.h Merge branch 'for-4.2/sg' of git://git.kernel.dk/linux-block 2015-06-25 15:22:36 -07:00
percpu.h
perf_event_fsl_emb.h
perf_event_server.h powerpc/perf: Pass the struct perf_events down to compute_mmcr() 2014-07-28 14:30:47 +10:00
perf_event.h powerpc: Rename __get_SP() to current_stack_pointer() 2014-10-15 11:23:20 +11:00
pgalloc-32.h powerpc/mm: Don't use pmd_val, pud_val and pgd_val as lvalue 2015-12-14 15:19:07 +11:00
pgalloc-64.h powerpc/mm: Don't hardcode page table size 2015-12-14 15:19:15 +11:00
pgalloc.h mmu_gather: move minimal range calculations into generic code 2014-11-17 10:12:42 +00:00
pgtable.h powerpc/booke: Move nohash headers 2015-12-14 15:19:09 +11:00
plpar_wrappers.h powerpc/mm: Use H_READ with H_READ_4 2015-12-14 15:19:17 +11:00
pmac_feature.h
pmac_low_i2c.h
pmac_pfunc.h
pmc.h
pmi.h
pnv-pci.h cxl: Move include file cxl.h -> cxl-base.h 2015-06-03 13:27:19 +10:00
ppc4xx_ocm.h
ppc4xx.h
ppc_asm.h powerpc: Change vsrX register defines to vsX to match gcc and glibc 2015-03-16 18:32:11 +11:00
ppc-opcode.h powerpc: Revert "Use the POWER8 Micro Partition Prefetch Engine in KVM HV on POWER8" 2015-10-21 20:50:30 +11:00
ppc-pci.h powerpc/eeh: Disable automatically blocked PCI config 2015-08-18 19:34:42 +10:00
probes.h
processor.h powerpc: Remove fp_enable() and vec_enable(), use msr_check_and_{set, clear}() 2015-12-01 13:52:26 +11:00
prom.h powerpc: Remove stale function prototypes 2014-09-25 23:14:43 +10:00
ps3.h powerpc: Delete non-required instances of include <linux/init.h> 2014-01-15 13:46:44 +11:00
ps3av.h
ps3gpu.h
ps3stor.h
pte-common.h powerpc/mm: Add a _PAGE_PTE bit 2015-12-14 15:19:14 +11:00
ptrace.h powerpc/perf: Fix ABIv2 kernel backtraces 2014-09-09 19:02:45 +10:00
qe_ic.h genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
qe.h
reg_8xx.h
reg_a2.h powerpc: Remove platforms/wsp and associated pieces 2014-06-11 16:35:38 +10:00
reg_booke.h powerpc/e6500: add TMCFG0 register definition 2015-10-15 15:58:16 +11:00
reg_fsl_emb.h
reg.h powerpc fixes for 4.4 #2 2015-12-14 20:40:32 +11:00
rheap.h
rio.h powerpc: Remove stale function prototypes 2014-09-25 23:14:43 +10:00
rtas.h powerpc/rtas: Make enter_rtas() private 2015-12-17 22:40:56 +11:00
rtc.h
runlatch.h
scom.h
seccomp.h powerpc: switch to using asm-generic for seccomp.h 2015-04-17 09:04:10 -04:00
sections.h Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2014-06-10 18:54:22 -07:00
serial.h
setjmp.h
setup.h powerpc: Replace mem_init_done with slab_is_available() 2015-04-10 20:02:48 +10:00
sfp-machine.h
shmparam.h
signal.h
smp.h powerpc: Drop return value of smp_ops->probe() 2015-04-10 20:02:49 +10:00
smu.h powerpc: Fix comment in smu.h 2015-03-06 23:21:07 +01:00
sparsemem.h
spinlock_types.h
spinlock.h rcu,locking: Privatize smp_mb__after_unlock_lock() 2015-08-04 08:49:21 -07:00
spu_csa.h powerpc/cell: Drop support for 64K local store on 4K kernels 2015-08-18 19:29:49 +10:00
spu_info.h
spu_priv1.h
spu.h powerpc/cell: Move spu_handle_mm_fault() out of cell platform 2014-10-08 20:14:54 +11:00
sstep.h powerpc: Emulate icbi, mcrf and conditional-trap instructions 2014-09-25 23:14:51 +10:00
string.h powerpc: memcpy optimization for 64bit LE 2014-04-30 15:26:18 +10:00
swab.h powerpc: Remove unused st_le*() and ld_le* functions 2015-03-24 13:33:52 +11:00
swiotlb.h
switch_to.h powerpc: clean up asm/switch_to.h 2015-12-02 19:34:41 +11:00
synch.h powerpc: Make value-returning atomics fully ordered 2015-12-14 20:38:18 +11:00
syscall.h powerpc: Change syscall_get_nr() to return int 2015-07-29 11:56:13 +10:00
syscalls.h
systbl.h powerpc: Wire up sys_mlock2() 2015-11-16 17:05:53 +11:00
tce.h
termios.h
thread_info.h arch: Remove exec_domain from remaining archs 2015-04-12 21:03:30 +02:00
time.h powerpc: Remove broken GregorianDay() 2015-12-16 12:54:04 +11:00
timex.h
tlb.h mmu_gather: move minimal range calculations into generic code 2014-11-17 10:12:42 +00:00
tlbflush.h powerpc/mm: don't do tlbie for updatepp request with NO HPTE fault 2014-12-05 16:26:15 +11:00
tm.h Merge branch 'kvm-ppchv-next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-next 2014-03-29 15:44:05 +01:00
topology.h sched/topology: Rename topology_thread_cpumask() to topology_sibling_cpumask() 2015-05-27 15:22:15 +02:00
trace_clock.h powerpc/ftrace: add powerpc timebase as a trace clock source 2015-08-06 16:36:23 +10:00
trace.h powerpc/mm: Add trace point for tracking hash pte fault 2015-06-10 14:06:29 +10:00
tsi108_irq.h
tsi108_pci.h genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
tsi108.h powerpc: Remove stale function prototypes 2014-09-25 23:14:43 +10:00
types.h
uaccess.h powerpc: Fix duplicate const clang warning in user access code 2015-06-11 17:33:05 +10:00
ucc_fast.h
ucc_slow.h powerpc/qe: drop unused ucc_slow_poll_transmitter_now 2015-03-16 18:50:17 +11:00
ucc.h
udbg.h powerpc: Remove stale function prototypes 2014-09-25 23:14:43 +10:00
uic.h
unaligned.h powerpc: Make unaligned accesses endian-safe for powerpc 2013-12-30 14:02:29 +11:00
uninorth.h
unistd.h powerpc: Standardise on NR_syscalls rather than __NR_syscalls. 2015-11-26 22:11:17 +11:00
uprobes.h
user.h
vdso_datapage.h powerpc: Standardise on NR_syscalls rather than __NR_syscalls. 2015-11-26 22:11:17 +11:00
vdso.h powerpc: Link VDSOs at 0x0 2014-02-17 11:19:37 +11:00
vga.h powerpc: Move Power Macintosh drivers to generic byteswappers 2015-03-23 14:29:40 +11:00
vio.h remove <asm/scatterlist.h> 2015-05-05 13:35:39 -06:00
word-at-a-time.h arch/powerpc: provide zero_bytemask() for big-endian 2015-10-08 11:44:12 -04:00
xics.h powerpc: Drop return value of smp_ops->probe() 2015-04-10 20:02:49 +10:00
xilinx_intc.h
xilinx_pci.h
xmon.h
xor.h