Commit graph

51 commits

Author SHA1 Message Date
David van Moolenbroek
c8c9565a03 Kernel: only reset/reload FPU state when necessary 2012-03-05 22:32:14 +01:00
David van Moolenbroek
a615a7d4d2 Kernel: retain FPU state upon save
On the x86, saving FPU state has the side effect of resetting this
state. In some cases (fork, getcontext), this would cause the state
to be lost. This patch restores the FPU state right after saving it,
except when different state is loaded immediately after.
2012-03-05 22:32:14 +01:00
David van Moolenbroek
0a8a2ecfb5 Kernel: pass FPU restore exception to user process
Previously, user processes could cause a kernel panic upon FPU state
restore, by passing bogus FPU state to the kernel (through e.g.
sigreturn). With this patch, the process is now sent a SIGFPE signal
instead.
2012-03-05 22:32:14 +01:00
Tomas Hruby
036ce9d4db Revert "SMP - no_apic=0 and acpi=1 set when CONFIG_SMP=y"
This reverts commit c468f4efa5.

Since we use the new boot loader, this hack is no longer necessary.
2012-02-24 10:16:55 +01:00
Ben Gras
ca47635d0a try multiple reset methods
. fixes reboot-hang under vbox
	. makes experience nicer under vmware
	. taken from netbsd reset code
2012-02-20 23:46:38 +01:00
Antoine Leca
3fb8cb760c More cleaning up 2012-02-15 19:04:58 +00:00
Evgeniy Ivanov
2487445f5f make panic() work for multiboot/elf case
. we cannot use the boot monitor to print the system diag buffer
	. for serial, we do nothing, just reset, everything is already printed
	. for not-serial, we print the current diag buffer using direct video
	  memory access from the kernel
2012-02-14 14:48:10 +01:00
Tomas Hruby
c468f4efa5 SMP - no_apic=0 and acpi=1 set when CONFIG_SMP=y
- this is a temporary change which makes images compiled for SMP
  boot in SMP mode by default.

- this change is needed until we can configure the multiboot
  images from the boot loader again.
2012-01-25 19:02:13 +00:00
Tomas Hruby
9cd53f1cc0 SMP - fixed compilation and removed warnings 2011-12-20 12:58:20 +00:00
Arun Thomas
46581e701a Add MKBOOTPARAM option 2011-09-16 17:31:07 +02:00
Arun Thomas
27c0e801f2 Cleaner MKSYSDEBUG option 2011-08-18 15:21:29 +02:00
Arun Thomas
40592de32d Optionally disable kernel debug code 2011-08-16 17:18:55 +02:00
Arun Thomas
ae561b8f12 Add MKAPIC and MKACPI options 2011-07-31 16:22:43 +02:00
Ben Gras
b984fa41df Revert "print kernel stacktrace for exceptions in kernel"
This reverts commit eff1369cab.

This was in a working branch and I only intended to commit
exception.c. But I committed the exact inverse. Sorry.
2011-07-22 15:01:44 +02:00
Ben Gras
eff1369cab print kernel stacktrace for exceptions in kernel
fpu alignment check feature, checksum feature
2011-07-22 11:03:45 +00:00
Arun Thomas
93ae43f577 boot: Add multiboot support
Not yet fully spec-compliant; work in progress
2011-06-24 17:21:51 +02:00
Ben Gras
a77c2973b3 fix clang warnings -R in kernel/ and servers/ 2011-06-09 16:09:13 +02:00
Arun Thomas
350b60661a ELF multiboot support 2011-05-04 18:51:43 +02:00
Tomas Hruby
8200e91073 Fixed smp compilation
- missing u64.h include after 64bit routines for gcc got inlined
2011-04-08 11:52:30 +00:00
Erik van der Kouwe
03a7d0e8ae Add cttybaud boot monitor variable to control speed of serial console (combine with ctty 0) 2011-03-16 12:25:10 +00:00
Arun Thomas
25a790a631 VM and kernel support for ELF 2011-02-26 23:00:55 +00:00
Arun Thomas
aaaad89244 Use int64 functions consistently
Instead of manipulating the u64_t type directly, use the
ex64hi()/ex64lo()/make64() functions.
2010-11-07 23:35:29 +00:00
Tomas Hruby
c9bfb13cdb Kernel keeps information about each cpu
- kernel maintains a cpu_info array which contains various
  information about each cpu as filled when each cpu boots

- the information contains idetification, features etc.
2010-10-26 21:07:27 +00:00
Tomas Hruby
8eece1c00c CPU type detection
- sometimes the system needs to know precisely on what type of cpu is
  running. The cpu type id detected during arch specific
  initialization and kept in the machine structure for later use.

- as a side-effect the information is exported to userland
2010-09-23 14:42:19 +00:00
Tomas Hruby
13bda81ee0 Fixed FPU for single cpu 2010-09-16 09:51:45 +00:00
Tomas Hruby
5b8b623765 SMP - lazy FPU
- when a process is migrated to a different CPU it may have an active
  FPU context in the processor registers. We must save it and migrate
  it together with the process.
2010-09-15 14:11:25 +00:00
Tomas Hruby
454589debd SMP - Print cpu of the process
- adds '4' to print processes assigned to each cpu without printing
  the process it is blocked on (a lightweight '1')
2010-09-15 14:11:01 +00:00
Tomas Hruby
c554aef0e1 SMP - BKL statistics
- pressing 'B' on the serial cnsole prints statistics for BKL per cpu.

- 'b' resets the counters

- it presents number of cycles each CPU spends in kernel, how many
  cycyles it spends spinning while waiting for the BKL

- it shows optimistic estimation in how many cases we get the lock
  immediately without spinning. As the test is not atomic the lock may
  be already held by some other cpu before we actually try to acquire
  it.
2010-09-15 14:10:37 +00:00
Tomas Hruby
fac5fbfdbf SMP - CPU local run queues
- each CPU has its own runqueues

- processes on BSP are put on the runqueues later after a switch to
  the final stack when cpuid works to avoid special cases

- enqueue() and dequeue() use the run queues of the cpu the process is
  assigned to

- pick_proc() uses the local run queues

- printing of per-CPU run queues ('2') on serial console
2010-09-15 14:10:18 +00:00
Tomas Hruby
62c666566e SMP - We boot APs
- kernel detects CPUs by searching ACPI tables for local apic nodes

- each CPU has its own TSS that points to its own stack. All cpus boot
  on the same boot stack (in sequence) but switch to its private stack
  as soon as they can.

- final booting code in main() placed in bsp_finish_booting() which is
  executed only after the BSP switches to its final stack

- apic functions to send startup interrupts

- assembler functions to handle CPU features not needed for single cpu
  mode like memory barries, HT detection etc.

- new files kernel/smp.[ch], kernel/arch/i386/arch_smp.c and
  kernel/arch/i386/include/arch_smp.h

- 16-bit trampoline code for the APs. It is executed by each AP after
  receiving startup IPIs it brings up the CPUs to 32bit mode and let
  them spin in an infinite loop so they don't do any damage.

- implementation of kernel spinlock

- CONFIG_SMP and CONFIG_MAX_CPUS set by the build system
2010-09-15 14:09:52 +00:00
Tomas Hruby
13a0d5fa5e SMP - Cpu local variables
- most global variables carry information which is specific to the
  local CPU and each CPU must have its own copy

- cpu local variable must be declared in cpulocal.h between
  DECLARE_CPULOCAL_START and DECLARE_CPULOCAL_END markers using
  DECLARE_CPULOCAL macro

- to access the cpu local data the provided macros must be used

	get_cpu_var(cpu, name)
	get_cpu_var_ptr(cpu, name)

	get_cpulocal_var(name)
	get_cpulocal_var_ptr(name)

- using this macros makes future changes in the implementation
  possible

- switching to ELF will make the declaration of cpu local data much
  simpler, e.g.

  CPULOCAL int blah;

  anywhere in the kernel source code
2010-09-15 14:09:46 +00:00
Tomas Hruby
6c3b981cd6 arch proto.h renamed to arch_proto.h
- the file moved to the arch include dir
2010-09-15 14:09:36 +00:00
Tomas Hruby
e6ebac015d APIC mode uses IO APICs
- kernel turns on IO APICs if no_apic is _not_ set or is equal 0

- pci driver must use the acpi driver to setup IRQ routing otherwise
  the system cannot work correctly except systems like KVM that use
  only legacy (E)ISA IRQs 0-15
2010-09-07 07:18:11 +00:00
Tomas Hruby
45badf4c05 ACPI in kernel
- the ability for kernel to use ACPI tables to detect IO APICs. It is
  the bare minimum the kernel needs to know about ACPI tables.

- it will be used to find out about processors as the MPS tables are
  deprecated by ACPI and not all vendorsprovide them.
2010-09-02 15:43:51 +00:00
Erik van der Kouwe
1f2054c89c Shutdown changes for multiboot: CTRL-ALT-DEL resets, panic halts 2010-08-30 19:01:58 +00:00
Tomas Hruby
f7ef192c02 Fixed warning noreturn function returns in arch_system.c 2010-08-06 12:48:26 +00:00
Erik van der Kouwe
25397ef756 Deal all shutdown cases with multiboot as either reset or poweroff depending on their type (contributed by Feiran 'Fam' Zheng) 2010-08-02 14:41:45 +00:00
Erik van der Kouwe
df0ba02a38 Multiboot support (contributed by Feiran "Fam" Zheng);
keep in mind that GRUB needs to be patched to read MFS for now;
use /boot/image_latest to boot the last compiled image in GRUB
2010-07-23 14:24:34 +00:00
Ben Gras
f6f814cb02 include, kernel: minor fixes to make compiling and linking work with clang.
(fixing warnings)
2010-07-06 11:59:19 +00:00
Tomas Hruby
7920d48156 FPU cleanup
- last reference to MF_USED_FPU removed

- proc_used_fpu() used to test for MF_FPU_INITIALIZED
2010-07-01 12:23:25 +00:00
Ben Gras
a09a8d4f3e kernel: fix for vm_init that triggered assert(ptproc == newptproc)
- zero cr3 in vm_init() to avoid switch_address_space() not doing anything.

 - add vm_stop() to disable paging on shutdown.
2010-06-07 22:21:45 +00:00
Tomas Hruby
cbc9586c13 Lazy FPU
- FPU context is stored only if conflict between 2 FPU users or while
  exporting context of a process to userspace while it is the active
  user of FPU

- FPU has its owner (fpu_owner) which points to the process whose
  state is currently loaded in FPU

- the FPU exception is only turned on when scheduling a process which
  is not the owner of FPU

- FPU state is restored for the process that generated the FPU
  exception. This process runs immediately without letting scheduler
  to pick a new process to resolve the FPU conflict asap, to minimize
  the FPU thrashing and FPU exception hadler execution

- faster all non-FPU-exception kernel entries as FPU state is not
  checked nor saved

- removed MF_USED_FPU flag, only MF_FPU_INITIALIZED remains to signal
  that a process has used FPU in the past
2010-06-07 07:43:17 +00:00
Ben Gras
2f892aca91 kernel fpu context switching: fix race condition
There seems to have been a broken assumption in the fpu context
restoring code.  It restores the context of the running process, without
guarantee that the current process is the one that will be scheduled.
This caused fpu saving for a different process to be triggered without
fpu hardware being enabled, causing an fpu exception in the kernel. This
practically only shows up with DEBUG_RACE on. Fix my thruby+me.

The fix
 . is to only set the fpu-in-use-by-this-process flag in the
   exception handler, and then take care of fpu restoring when
   actually returning to userspace

And the patch
 . translates fpu saving and restoring to c in arch_system.c,
   getting rid of a juicy chunk of assembly
 . makes osfxsr_feature private to arch_system.c
 . removes most of the arch dependent code from do_sigsend
2010-06-03 11:32:22 +00:00
Ben Gras
6d0e53c2ca use oxpcie only if enabled to avoid baud bottleneck of uart. 2010-05-19 10:18:46 +00:00
Ben Gras
9ba760e603 kernel: oxpcie serial card support.
ask to map in oxpcie i/o memory and support serial i/o for it in the
kernel. set oxpcie=<address> in boot monitor (retrieve address using
pci_debug=1 output). (no sanity checking is done on the address
currently.) disabled by default.

The change also contains some other minor cleanup (a new serial.h to set
register info common to UART and the OXPCIe card, in-kernel memory
mapping a little more structured and env_get() to get sysenv variables
without knowing about the params_buffer).
2010-05-19 10:00:02 +00:00
Tomas Hruby
b90c2d7026 rename of mode/context switching functions
- this patch only renames schedcheck() to switch_to_user(),
  cycles_accounting_stop() to context_stop() and restart() to
  +restore_user_context()

- the motivation is that since the introduction of schedcheck() it has
  been abused for many things. It deserves a better name.  It should
  express the fact that from the moment we call the function we are in
  the process of switching to user.

- cycles_accounting_stop() was originally a single purpose function.
  As this function is called at were convenient places it is used in
  for other things too, e.g. (un)locking the kernel. Thus it deserves
  a better name too.

- using the old name, restart() does not call schedcheck(), however
  calls to restart are replaced by calls to schedcheck()
  [switch_to_user] and it calls restart() [restore_user_context]
2010-05-18 13:00:39 +00:00
Tomas Hruby
57a88ce708 debugging - printing processes on serial
- this patch moves the former printslot() from arch_system.c to
  debug.c and reimplements it slightly. The output is not changed,
  however, the process information is printed in a separate function
  print_proc() in debug.c as such a function is also handy in other
  situations and should be publicly available when debugging.
2010-05-03 17:37:18 +00:00
Ben Gras
50335291ae kernel: fpu_init: only enable OSXMMEXCPT in CR4 on at least SSE1 machines.
Found and debugged by totalinux at yandex.ru and Evgeniy Ivanov, thanks!
2010-04-28 13:51:02 +00:00
Ben Gras
c37401f23f kernel: fpu init to separate function; also move fpu init down
moving the fpu code causes exceptions raised by it to be trapped
neatly instead of causing a triple fault, before the IDT is initialized.
2010-04-28 13:25:29 +00:00
Tomas Hruby
a774cc832f do_ipc() rearrangements
this patch does not add or change any functionality of do_ipc(), it
only makes things a little cleaner (hopefully).

Until now do_ipc() was responsible for handling all ipc calls. The
catch is that SENDA is fairly different which results in some ugly
code like this typecasting and variables naming which does not make
much sense for SENDA and makes the code hard to read.

result = mini_senda(caller_ptr, (asynmsg_t *)m_ptr, (size_t)src_dst_e);

As it is called directly from assembly, the new do_ipc() takes as
input values of 3 registers in reg_t variables (it used to be 4,
however, bit_map wasn't used so I removed it), does the checks common
to all ipc calls and call the appropriate handler either for
do_sync_ipc() (all except SENDA) or mini_senda() (for SENDA) while
typecasting the reg_t values correctly. As a result, handling SENDA
differences in do_sync_ipc() is no more needed. Also the code that
uses msg_size variable is improved a little bit.

arch_do_syscall() is simplified too.
2010-04-06 11:24:26 +00:00