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70a7dd5d5b
freebsd-skq/sys/i386/include
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Konstantin Belousov 70a7dd5d5b Fix issues with zeroing and fetching the counters, on x86 and ppc64. 
Issues were noted by Bruce Evans and are present on all architectures.

On i386, a counter fetch should use atomic read of 64bit value,
otherwise carry from the increment on other CPU could be lost for the
given fetch, making error of 2^32.  If 64bit read (cmpxchg8b) is not
available on the machine, it cannot be SMP and it is enough to disable
preemption around read to avoid the split read.

On x86 the counter increment is not atomic on purpose, which makes it
possible for the store of the incremented result to override just
zeroed per-cpu slot.  The effect would be a counter going off by
arbitrary value after zeroing.  Perform the counter zeroing on the
same processor which does the increments, making the operations
mutually exclusive.  On i386, same as for the fetching, if the
cmpxchg8b is not available, machine is not SMP and we disable
preemption for zeroing.

PowerPC64 is treated the same as amd64.

For other architectures, the changes made to allow the compilation to
succeed, without fixing the issues with zeroing or fetching.  It
should be possible to handle them by using the 64bit loads and stores
atomic WRT preemption (assuming the architectures also converted from
using critical sections to proper asm).  If architecture does not
provide the facility, using global (spin) mutex would be non-optimal
but working solution.

Noted by:  bde
Sponsored by:	The FreeBSD Foundation
2013-07-01 02:48:27 +00:00
..
pc - Re-shuffle the <machine/pc/bios.h> headers to move all kernel-specific 2012-09-28 11:59:32 +00:00
xen Adjust i386 Xen PV support for updated Xen interface files. 2013-06-17 01:43:07 +00:00
_align.h Merge amd64/i386 _align.h by aligning on the size of register_t (copied 2010-11-26 10:59:20 +00:00
_bus.h
_inttypes.h Copy powerpc/include/_inttypes.h to x86 and replace i386/amd64/pc98 2011-01-08 18:09:48 +00:00
_limits.h Copy amd64 _limits.h to x86 and merge with i386 _limits.h. Replace 2012-02-28 18:24:28 +00:00
_stdint.h Copy amd64 _stdint.h to x86 and merge with i386 _stdint.h. Replace 2012-02-28 18:38:33 +00:00
_types.h Copy amd64 _types.h to x86 and merge with i386 _types.h. Replace existing 2012-02-28 18:15:28 +00:00
acpica_machdep.h Move definitions required by userland applications out of acpica_machdep.h. 2013-06-27 00:22:40 +00:00
apicvar.h Add SMP/i386 suspend/resume support. 2012-05-18 18:55:58 +00:00
apm_bios.h Move identical copies of apm_bios.h to sys/x86/include, replace them with 2010-11-11 19:36:21 +00:00
apm_segments.h
asm.h Also import WEAK_ALIAS() from the MIPS code. 2012-01-05 08:51:06 +00:00
asmacros.h
atomic.h Add an unified macro to deny ability from the compiler to reorder 2012-10-09 14:32:30 +00:00
bootinfo.h i386 bootinfo: re-arrange EFI fields for natural alignment and packing 2012-05-13 09:25:39 +00:00
bus_dma.h
bus.h Revert r243960 based on feedback regarding keeping x86 headers unified 2012-12-13 21:27:20 +00:00
clock.h Implement boot-time TSC synchronization test for SMP. This test is executed 2011-05-09 17:34:00 +00:00
counter.h Fix issues with zeroing and fetching the counters, on x86 and ppc64. 2013-07-01 02:48:27 +00:00
cpu.h Use cpu_ticks() for get_cyclecount(9) rather than checking existence of TSC 2011-04-04 22:56:33 +00:00
cpufunc.h Add lfence(). 2012-08-01 17:24:53 +00:00
cputypes.h
cserial.h
db_machdep.h
elan_mmcr.h
elf.h Convert machine/elf.h, machine/frame.h, machine/sigframe.h, 2013-02-20 17:39:52 +00:00
endian.h Copy amd64 endian.h to x86 and merge with i386 endian.h. Replace 2012-02-28 19:39:54 +00:00
exec.h
fdt.h Add basic support for FDT to i386 & amd64. This change includes: 2013-05-21 03:05:49 +00:00
float.h Copy amd64 float.h to x86 and merge with i386 float.h. Replace 2012-03-04 14:00:32 +00:00
floatingpoint.h
frame.h Convert machine/elf.h, machine/frame.h, machine/sigframe.h, 2013-02-20 17:39:52 +00:00
gdb_machdep.h
ieeefp.h People porting FreeBSD to new architectures ought not have to 2011-10-21 06:41:46 +00:00
if_wl_wavelan.h
in_cksum.h MFp4 bz_ipv6_fast: 2012-05-24 22:00:48 +00:00
intr_machdep.h x86 suspend/resume: suspend pics and pseudo-pics in reverse order 2013-02-02 12:02:42 +00:00
ioctl_bt848.h
ioctl_meteor.h
iodev.h
kdb.h
limits.h
md_var.h Add SMP/i386 suspend/resume support. 2012-05-18 18:55:58 +00:00
memdev.h Add reader/writer lock around mem_range_attr_get() and mem_range_attr_set(). 2011-01-17 22:58:28 +00:00
metadata.h Add basic support for FDT to i386 & amd64. This change includes: 2013-05-21 03:05:49 +00:00
minidump.h
mp_watchdog.h
nexusvar.h
npx.h MFCamd64 r238598: 2012-07-21 21:52:48 +00:00
ofw_machdep.h Add basic support for FDT to i386 & amd64. This change includes: 2013-05-21 03:05:49 +00:00
param.h Rename VM_NDOMAIN into MAXMEMDOM and move it into machine/param.h in 2013-05-07 22:46:24 +00:00
pcaudioio.h Convert files to UTF-8 2012-01-15 13:23:18 +00:00
pcb_ext.h
pcb.h - Fix resumectx() prototypes to reflect reality. 2012-06-13 21:03:01 +00:00
pci_cfgreg.h Move {amd64,i386}/pci/pci_bus.c and {amd64,i386}/include/pci_cfgreg.h to 2011-06-22 21:04:13 +00:00
pcpu.h Merge from projects/counters: 2013-04-08 19:19:10 +00:00
perfmon.h
pmap.h Sync back vmcontention branch into HEAD: 2013-03-18 00:25:02 +00:00
pmc_mdep.h Add software PMC support. 2012-03-28 20:58:30 +00:00
ppireg.h
privatespace.h
proc.h Handle spurious page faults that may occur in no-fault sections of the 2012-03-22 04:52:51 +00:00
profile.h Use intr_disable() and intr_restore() instead of frobbing the flags register 2010-10-25 15:28:03 +00:00
psl.h Copy i386 psl.h to x86 and replace amd64/i386/pc98 psl.h with stubs. 2012-03-19 21:29:57 +00:00
ptrace.h Copy amd64 ptrace.h to x86 and merge with i386 ptrace.h. Replace 2012-03-04 20:24:28 +00:00
reg.h Copy i386 reg.h to x86 and merge with amd64 reg.h. Replace i386/amd64/pc98 2012-03-18 19:06:38 +00:00
reloc.h
resource.h
runq.h
segments.h Move userland bits (and some common kernel bits) from amd64 and i386 2012-03-19 21:24:50 +00:00
setjmp.h Copy amd64 setjmp.h to x86 and replace amd64/i386/pc98 setjmp.h with stubs. 2012-02-28 22:17:52 +00:00
sf_buf.h Commit the support for removing cpumask_t and replacing it directly with 2011-05-05 14:39:14 +00:00
sigframe.h Convert machine/elf.h, machine/frame.h, machine/sigframe.h, 2013-02-20 17:39:52 +00:00
signal.h Convert machine/elf.h, machine/frame.h, machine/sigframe.h, 2013-02-20 17:39:52 +00:00
smapi.h
smp.h Share IPI init and startup code of mp_machdep.c with acpi_wakeup.c 2012-06-12 00:14:54 +00:00
speaker.h
specialreg.h Copy i386 specialreg.h to x86 and merge with amd64 specialreg.h. Replace 2012-03-19 21:34:11 +00:00
stack.h
stdarg.h Copy amd64 stdarg.h to x86 and replace amd64/i386/pc98 stdarg.h with stubs. 2012-02-28 22:30:58 +00:00
sysarch.h Copy amd64 sysarch.h to x86 and merge with i386 sysarch.h. Replace 2012-03-19 21:57:31 +00:00
timerreg.h
trap.h Copy amd64 trap.h to x86 and replace amd64/i386/pc98 trap.h with stubs. 2012-03-04 14:12:57 +00:00
tss.h
ucontext.h Convert machine/elf.h, machine/frame.h, machine/sigframe.h, 2013-02-20 17:39:52 +00:00
varargs.h
vdso.h Implement mechanism to export some kernel timekeeping data to 2012-06-22 07:06:40 +00:00
vm86.h Increase maximum number of page table entries per VM86 context from 8 to 24 2010-08-25 21:13:23 +00:00
vm.h - Rename VM_MEMATTR_UNCACHED to VM_MEMATTR_WEAK_UNCACHEABLE on x86 to 2012-03-29 16:51:22 +00:00
vmparam.h Rename VM_NDOMAIN into MAXMEMDOM and move it into machine/param.h in 2013-05-07 22:46:24 +00:00
xbox.h