return path only when neither thread was context switched while
executing syscall code nor syscall explicitely modified LDT or MSRs.
Save segment registers in trap handlers before interrupts are enabled,
to not allow context switches to happen before registers are saved.
Use separated byte in pcb for indication of fast/full return, since
pcb_flags are not synchronized with context switches.
The change puts back syscall microbenchmark numbers that were slowed
down after commit of the support for LDT on amd64.
Reviewed by: jeff
Tested (and tested, and tested ...) by: pho
Approved by: re (kensmith)
o add to platforms where it was missing (arm, i386, powerpc, sparc64, sun4v)
o define as "1" on amd64 and i386 where there is no restriction
o make the type returned consistent with ALIGN
o remove _ALIGNED_POINTER
o make associated comments consistent
Reviewed by: bde, imp, marcel
Approved by: re (kensmith)
- For x86, change the interrupt source method to assign an interrupt source
to a specific CPU to return an error value instead of void, thus allowing
it to fail.
- If moving an interrupt to a CPU fails due to a lack of IDT vectors in the
destination CPU, fail the request with ENOSPC rather than panicing.
- For MSI interrupts on x86 (but not MSI-X), only allow cpuset to be used
on the first interrupt in a group. Moving the first interrupt in a group
moves the entire group.
- Use the icu_lock to protect intr_next_cpu() on x86 instead of the
intr_table_lock to fix a LOR introduced in the last set of MSI changes.
- Add a new privilege PRIV_SCHED_CPUSET_INTR for using cpuset with
interrupts. Previously, binding an interrupt to a CPU only performed a
privilege check if the interrupt had an interrupt thread. Interrupts
without a thread could be bound by non-root users as a result.
- If an interrupt event's assign_cpu method fails, then restore the original
cpuset mask for the associated interrupt thread.
Approved by: re (kib)
required by video card drivers. Specifically, this change introduces
vm_cache_mode_t with an appropriate VM_CACHE_DEFAULT definition on all
architectures. In addition, this changes adds a vm_cache_mode_t parameter
to kmem_alloc_contig() and vm_phys_alloc_contig(). These will be the
interfaces for allocating mapped kernel memory and physical memory,
respectively, with non-default cache modes.
In collaboration with: jhb
This is mostly important for the multiple MSI message case where the
IDT vectors for the entire group need to be allocated together. This
also restores the assumptions made by the PCI bus code that it could
invoke PCIB_MAP_MSI() once MSI vectors were allocated.
- To avoid whiplash with CPU assignments, change the way that CPUs are
assigned to interrupt sources on activation. Instead of assigning the
CPU via pic_assign_cpu() before calling enable_intr(), allow the
different interrupt source drivers to ask the MD interrupt code which
CPU to use when they allocate an IDT vector. I/O APIC interrupt pins
do this in their pic_enable_intr() routines giving the same behavior as
before. MSI sources do it when the IDT vectors are allocated during
msi_alloc() and msix_alloc().
- Change the intr_table_lock from an sx lock to a mutex.
Tested by: rnoland
With the arrival of 128+ cores it is necessary to handle more than that.
One of the first thing to change is the support for cpumask_t that needs
to handle more than 32 bits masking (which happens now). Some places,
however, still assume that cpumask_t is a 32 bits mask.
Fix that situation by using always correctly cpumask_t when needed.
While here, remove the part under STOP_NMI for the Xen support as it
is broken in any case.
Additively make ipi_nmi_pending as static.
Reviewed by: jhb, kmacy
Tested by: Giovanni Trematerra <giovanni dot trematerra at gmail dot com>
- For CPUs that only support MCE (the machine check exception) but not MCA
(i.e. Pentium), all this does is print out the value of the machine check
registers and then panic when a machine check exception occurs.
- For CPUs that support MCA (the machine check architecture), the support is
a bit more involved.
- First, there is limited support for decoding the CPU-independent MCA
error codes in the kernel, and the kernel uses this to output a short
description of any machine check events that occur.
- When a machine check exception occurs, all of the MCx banks on the
current CPU are scanned and any events are reported to the console
before panic'ing.
- To catch events for correctable errors, a periodic timer kicks off a
task which scans the MCx banks on all CPUs. The frequency of these
checks is controlled via the "hw.mca.interval" sysctl.
- Userland can request an immediate scan of the MCx banks by writing
a non-zero value to "hw.mca.force_scan".
- If any correctable events are encountered, the appropriate details
are stored in a 'struct mca_record' (defined in <machine/mca.h>).
The "hw.mca.count" is a count of such records and each record may
be queried via the "hw.mca.records" tree by specifying the record
index (0 .. count - 1) as the next name in the MIB similar to using
PIDs with the kern.proc.* sysctls. The idea is to export machine
check events to userland for more detailed processing.
- The periodic timer and hw.mca sysctls are only present if the CPU
supports MCA.
Discussed with: emaste (briefly)
MFC after: 1 month
and hide it inside of atrtc driver. Add new tunable hint.atrtc.0.clock
controlling it. Setting it to 0 disables using RTC clock as stat-/
profclock sources.
Teach i386 and amd64 SMP platforms to emulate stat-/profclocks using i8254
hardclock, when LAPIC and RTC clocks are disabled.
This allows to reduce global interrupt rate of idle system down to about
100 interrupts per core, permitting C3 and deeper C-states provide maximum
CPU power efficiency.
topology of nehalem/corei7 based systems.
- Remove the cpu_cores/cpu_logical detection from identcpu.
- Describe the layout of the system in cpu_mp_announce().
Sponsored by: Nokia
a fair number of static data structures, making this an unlikely
option to try to change without also changing source code. [1]
Change default cache line size on ia64, sparc64, and sun4v to 128
bytes, as this was what rtld-elf was already using on those
platforms. [2]
Suggested by: bde [1], jhb [2]
MFC after: 2 weeks
CACHE_LINE_SIZE constant. These constants are intended to
over-estimate the cache line size, and be used at compile-time
when a run-time tuning alternative isn't appropriate or
available.
Defaults for all architectures are 64 bytes, except powerpc
where it is 128 bytes (used on G5 systems).
MFC after: 2 weeks
Discussed on: arch@
- Do not iterate int 15h, function e820h twice. Instead, we use STAILQ to
store each return buffer and copy all at once.
- Export optional extended attributes defined in ACPI 3.0 as separate
metadata. Currently, there are only two bits defined in the specification.
For example, if the descriptor has extended attributes and it is not
enabled, it has to be ignored by OS. We may implement it in the kernel
later if it is necessary and proven correct in reality.
- Check return buffer size strictly as suggested in ACPI 3.0.
Reviewed by: jhb
Remove a hack to generate more efficient code for port numbers below
0x100, which has been obsolete for at least ten years, because GCC has
an asm constraint to specify that.
Submitted by: Christoph Mallon <christoph mallon gmx de>
Most compilers nowadays (including GCC) are smart enough to know what's
going on and generate more efficient code anyway.
Submitted by: Christoph Mallon <christoph.mallon@gmx.de>
Because the "c" input constaint is used, the compiler will already place
the MSR_FSBASE/MSR_GSBASE constants in ecx. Using __asm("ecx") makes
LLVM crash. Even though this is also an LLVM bug, we'd better remove the
unnecessary GCCism as well.
Submitted by: Christoph Mallon <christoph.mallon@gmx.de>
the kernel on amd64. Fill and read segment registers for mcontext and
signals. Handle traps caused by restoration of the
invalidated selectors.
Implement user-mode creation and manipulation of the process-specific
LDT descriptors for amd64, see sysarch(2).
Implement support for TSS i/o port access permission bitmap for amd64.
Context-switch LDT and TSS. Do not save and restore segment registers on
the context switch, that is handled by kernel enter/leave trampolines
now. Remove segment restore code from the signal trampolines for
freebsd/amd64, freebsd/ia32 and linux/i386 for the same reason.
Implement amd64-specific compat shims for sysarch.
Linuxolator (temporary ?) switched to use gsbase for thread_area pointer.
TODO:
Currently, gdb is not adapted to show segment registers from struct reg.
Also, no machine-depended ptrace command is added to set segment
registers for debugged process.
In collaboration with: pho
Discussed with: peter
Reviewed by: jhb
Linuxolator tested by: dchagin
Reorder amd64 gdt descriptors so that user-accessible selectors are the
same as on i386. At least Wine hard-codes this into the binary.
In collaboration with: pho
Reviewed by: jhb
Provides i386/freebsd API-compatible definitions for the argument
structures of the above sysarch commands. struct i386_ioperm_args
definition is ABI-compatible.
In collaboration with: pho
Reviewed by: jhb
To keep these structures ABI-compatible, half the size of r_trapno,
r_err, mc_trapno, mc_flags.
Add fsbase and gsbase to mcontext on both amd64 and i386.
Add flags to amd64 mcontext to indicate that it contains valid segments
or bases.
In collaboration with: pho
Discussed with: peter
Reviewed by: jhb
stored in the pmap is from the direct map region. The two exceptions have
been the kernel pmap and the swapper's pmap. These pmaps have used a
kernel virtual address established by pmap_bootstrap() for their shared
pml4 page table page. However, there is no reason not to use the direct
map for these pmaps as well.
to the full path of the image that is being executed.
Increase AT_COUNT.
Remove no longer true comment about types used in Linux ELF binaries,
listed types contain FreeBSD-specific entries.
Reviewed by: kan
This code is heavily inspired by Takanori Watanabe's experimental SMP patch
for i386 and large portion was shamelessly cut and pasted from Peter Wemm's
AP boot code.
ABIs:
- Store the FPU initial control word in the pcb for each thread.
- When first using the FPU, load the initial control word after restoring
the clean state if it is not the standard control word.
- Provide a correct control word for Linux/i386 binaries under
FreeBSD/amd64.
- Adjust the control word returned for fpugetregs()/npxgetregs() when a
thread hasn't used the FPU yet to reflect the real initial control
word for the current ABI.
- The Linux/i386 ABI for FreeBSD/i386 now properly sets the right control
word instead of trashing whatever the current state of the FPU is.
Reviewed by: bde
- fpudna() always returned 1 since amd64 CPUs always have FPUs. Change
the function to return void and adjust the calling code in trap() to
assume the return 1 case is the only case.
- Remove fpu_cleanstate_ready as it is always true when it is tested.
Also, only initialize fpu_cleanstate when fpuinit() is called on the BSP.
Reviewed by: bde
mode.
- Make the NMI handler run on its own stack (TSS_IST2).
- Store the GSBASE value for each CPU just before the start of
each NMI stack, permitting efficient retrieval using %rsp-relative
addressing.
- For NMIs taken from kernel mode, program MSR_GSBASE explicitly
since one or both of MSR_GSBASE and MSR_KGSBASE can be potentially
invalid. The current contents of MSR_GSBASE are saved and restored
at exit.
- For NMIs handled from user mode, continue to use 'swapgs' to
load the per-CPU GSBASE.
Reviewed by: jeff
Debugging help: jeff
Tested by: gnn, Artem Belevich <artemb at gmail dot com>
more irqs as we have more cpus. This is principally useful on systems
with msi devices which may want many irqs per-cpu.
Discussed with: jhb
Sponsored by: Nokia
32-bit processes. The value matches the initial setting used by
FreeBSD/i386. Otherwise, 32-bit binaries using floating point would use
a slightly different initial state when run on FreeBSD/amd64.
MFC after: 1 week
