Commit Graph

21 Commits

Author SHA1 Message Date
Barry Song
91c2ebb90b ARM: 7114/1: cache-l2x0: add resume entry for l2 in secure mode
we save the l2x0 registers at the first initialization, and platform codes
can get them to restore l2x0 status after wakeup.

Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-10-17 09:11:51 +01:00
Russell King
f8f2a8522a ARM: vfp: fix a hole in VFP thread migration
Fix a hole in the VFP thread migration.  Lets define two threads.

Thread 1, we'll call 'interesting_thread' which is a thread which is
running on CPU0, using VFP (so vfp_current_hw_state[0] =
&interesting_thread->vfpstate) and gets migrated off to CPU1, where
it continues execution of VFP instructions.

Thread 2, we'll call 'new_cpu0_thread' which is the thread which takes
over on CPU0.  This has also been using VFP, and last used VFP on CPU0,
but doesn't use it again.

The following code will be executed twice:

		cpu = thread->cpu;

		/*
		 * On SMP, if VFP is enabled, save the old state in
		 * case the thread migrates to a different CPU. The
		 * restoring is done lazily.
		 */
		if ((fpexc & FPEXC_EN) && vfp_current_hw_state[cpu]) {
			vfp_save_state(vfp_current_hw_state[cpu], fpexc);
			vfp_current_hw_state[cpu]->hard.cpu = cpu;
		}
		/*
		 * Thread migration, just force the reloading of the
		 * state on the new CPU in case the VFP registers
		 * contain stale data.
		 */
		if (thread->vfpstate.hard.cpu != cpu)
			vfp_current_hw_state[cpu] = NULL;

The first execution will be on CPU0 to switch away from 'interesting_thread'.
interesting_thread->cpu will be 0.

So, vfp_current_hw_state[0] points at interesting_thread->vfpstate.
The hardware state will be saved, along with the CPU number (0) that
it was executing on.

'thread' will be 'new_cpu0_thread' with new_cpu0_thread->cpu = 0.
Also, because it was executing on CPU0, new_cpu0_thread->vfpstate.hard.cpu = 0,
and so the thread migration check is not triggered.

This means that vfp_current_hw_state[0] remains pointing at interesting_thread.

The second execution will be on CPU1 to switch _to_ 'interesting_thread'.
So, 'thread' will be 'interesting_thread' and interesting_thread->cpu now
will be 1.  The previous thread executing on CPU1 is not relevant to this
so we shall ignore that.

We get to the thread migration check.  Here, we discover that
interesting_thread->vfpstate.hard.cpu = 0, yet interesting_thread->cpu is
now 1, indicating thread migration.  We set vfp_current_hw_state[1] to
NULL.

So, at this point vfp_current_hw_state[] contains the following:

[0] = &interesting_thread->vfpstate
[1] = NULL

Our interesting thread now executes a VFP instruction, takes a fault
which loads the state into the VFP hardware.  Now, through the assembly
we now have:

[0] = &interesting_thread->vfpstate
[1] = &interesting_thread->vfpstate

CPU1 stops due to ptrace (and so saves its VFP state) using the thread
switch code above), and CPU0 calls vfp_sync_hwstate().

	if (vfp_current_hw_state[cpu] == &thread->vfpstate) {
		vfp_save_state(&thread->vfpstate, fpexc | FPEXC_EN);

BANG, we corrupt interesting_thread's VFP state by overwriting the
more up-to-date state saved by CPU1 with the old VFP state from CPU0.

Fix this by ensuring that we have sane semantics for the various state
describing variables:

1. vfp_current_hw_state[] points to the current owner of the context
   information stored in each CPUs hardware, or NULL if that state
   information is invalid.
2. thread->vfpstate.hard.cpu always contains the most recent CPU number
   which the state was loaded into or NR_CPUS if no CPU owns the state.

So, for a particular CPU to be a valid owner of the VFP state for a
particular thread t, two things must be true:

 vfp_current_hw_state[cpu] == &t->vfpstate && t->vfpstate.hard.cpu == cpu.

and that is valid from the moment a CPU loads the saved VFP context
into the hardware.  This gives clear and consistent semantics to
interpreting these variables.

This patch also fixes thread copying, ensuring that t->vfpstate.hard.cpu
is invalidated, otherwise CPU0 may believe it was the last owner.  The
hole can happen thus:

- thread1 runs on CPU2 using VFP, migrates to CPU3, exits and thread_info
  freed.
- New thread allocated from a previously running thread on CPU2, reusing
  memory for thread1 and copying vfp.hard.cpu.

At this point, the following are true:

	new_thread1->vfpstate.hard.cpu == 2
	&new_thread1->vfpstate == vfp_current_hw_state[2]

Lastly, this also addresses thread flushing in a similar way to thread
copying.  Hole is:

- thread runs on CPU0, using VFP, migrates to CPU1 but does not use VFP.
- thread calls execve(), so thread flush happens, leaving
  vfp_current_hw_state[0] intact.  This vfpstate is memset to 0 causing
  thread->vfpstate.hard.cpu = 0.
- thread migrates back to CPU0 before using VFP.

At this point, the following are true:

	thread->vfpstate.hard.cpu == 0
	&thread->vfpstate == vfp_current_hw_state[0]

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-09 17:22:12 +01:00
Russell King
f6b0fa02e8 ARM: pm: add generic CPU suspend/resume support
This adds core support for saving and restoring CPU coprocessor
registers for suspend/resume support.  This contains support for suspend
with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs.
Tested on Assabet and Tegra 2.

Tested-by: Colin Cross <ccross@android.com>
Tested-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-22 17:11:23 +00:00
Russell King
753790e713 ARM: move cache/processor/fault glue to separate include files
This allows the cache/processor/fault glue to be more easily used
from assembler code.  Tested on Assabet and Tegra 2.

Tested-by: Colin Cross <ccross@android.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-12 11:52:21 +00:00
Nicolas Pitre
6451d7783b arm: remove machine_desc.io_pg_offst and .phys_io
Since we're now using addruart to establish the debug mapping, we can
remove the io_pg_offst and phys_io members of struct machine_desc.

The various declarations were removed using the following script:

  grep -rl MACHINE_START arch/arm | xargs \
  sed -i '/MACHINE_START/,/MACHINE_END/ { /\.\(phys_io\|io_pg_offst\)/d }'

[ Initial patch was from Jeremy Kerr, example script from Russell King ]

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Eric Miao <eric.miao at canonical.com>
2010-10-20 00:27:46 -04:00
Nicolas Pitre
df0698be14 ARM: stack protector: change the canary value per task
A new random value for the canary is stored in the task struct whenever
a new task is forked.  This is meant to allow for different canary values
per task.  On ARM, GCC expects the canary value to be found in a global
variable called __stack_chk_guard.  So this variable has to be updated
with the value stored in the task struct whenever a task switch occurs.

Because the variable GCC expects is global, this cannot work on SMP
unfortunately.  So, on SMP, the same initial canary value is kept
throughout, making this feature a bit less effective although it is still
useful.

One way to overcome this GCC limitation would be to locate the
__stack_chk_guard variable into a memory page of its own for each CPU,
and then use TLB locking to have each CPU see its own page at the same
virtual address for each of them.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2010-06-14 21:31:01 -04:00
Russell King
a9c9147eb9 ARM: dma-mapping: provide per-cpu type map/unmap functions
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
2010-02-15 15:22:20 +00:00
Christoph Lameter
02cbe4749a arm: use kbuild.h instead of macros in asm-offsets.c
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:29 -07:00
Paul Brook
48d7927bdf Add a prefetch abort handler
This patch adds a prefetch abort handler similar to the data abort one
and renames the latter for consistency. Initial implementation by Paul
Brook with some renaming by Catalin Marinas.

Signed-off-by: Paul Brook <paul@codesourcery.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2008-04-18 22:43:07 +01:00
Catalin Marinas
d7f864be83 ARMv7: Add support for the ThumbEE state saving/restoring
This patch adds the detection and handling of the ThumbEE extension on
ARMv7 CPUs.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2008-04-18 22:43:06 +01:00
Russell King
516793c61b [ARM] ARMv6: add CPU_HAS_ASID configuration
Presently, we check for the minimum ARM architecture that we're
building for to determine whether we need ASID support.  This is
wrong - if we're going to support a range of CPUs which include
ARMv6 or higher, we need the ASID.

Convert the checks to use a new configuration symbol, and arrange
for ARMv6 and higher CPU entries to select it.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-05-17 10:19:23 +01:00
Russell King
ee90dabcad [ARM] Include asm/elf.h instead of asm/procinfo.h
These files want to provide/access ELF hwcap information, so should
be including asm/elf.h rather than asm/procinfo.h

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-11-30 12:24:46 +00:00
Russell King
8799ee9f49 [ARM] Set bit 4 on section mappings correctly depending on CPU
On some CPUs, bit 4 of section mappings means "update the
cache when written to".  On others, this bit is required to
be one, and others it's required to be zero.  Finally, on
ARMv6 and above, setting it turns on "no execute" and prevents
speculative prefetches.

With all these combinations, no one value fits all CPUs, so we
have to pick a value depending on the CPU type, and the area
we're mapping.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-29 18:24:21 +01:00
Lennert Buytenhek
c17fad11f3 [ARM] 3370/2: ep93xx: add crunch support
Patch from Lennert Buytenhek

Add the necessary kernel bits for crunch task switching.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-06-28 17:55:01 +01:00
Uwe Zeisberger
2ceec0c8c6 [ARM] 3517/1: move definition of PROC_INFO_SZ from procinfo.h to asm-offsets.h
Patch from Uwe Zeisberger

The symbol is only used in arch/arm/kernel/head-common.S.  This in turn
is included from arch/arm/kernel/head.S and arch/arm/kernel/head-nommu.S
which include asm-offsets.h .

Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-05-16 11:39:30 +01:00
Uwe Zeisberger
2eb9d31571 [ARM] 3496/1: more constants for asm-offsets.h
Patch from Uwe Zeisberger

added the following constants:
- MACHINFO_TYPE
- MACHINFO_NAME
- MACHINFO_PHYSIO
- MACHINFO_PGOFFIO
- PROCINFO_INITFUNC
- PROCINFO_MMUFLAGS

and removed their definition from head.S and head-nommu.S

Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-05-05 15:11:14 +01:00
Russell King
cdaabbd74b [ARM] iwmmxt thread state alignment
This patch removes the reliance of iwmmxt on hand coded alignments.
Since thread_info is always 8K aligned, specifying that fpstate is
8-byte aligned achieves the same effect without needing to resort
to hand coded alignments.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-12 22:36:06 +00:00
Andrew Morton
a136564702 [PATCH] remove gcc-2 checks
Remove various things which were checking for gcc-1.x and gcc-2.x compilers.

From: Adrian Bunk <bunk@stusta.de>

    Some documentation updates and removes some code paths for gcc < 3.2.

Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08 20:14:02 -08:00
Nicolas Pitre
f09b997999 [ARM] 3060/1: allow constants found in asm/memory.h to be used in asm code
Patch from Nicolas Pitre

This patch allows for assorted type of cleanups by letting assembly code
use the same set of defines for constant values and avoid duplicated
definitions that might not always be in sync, or that might simply be
confusing due to the different names for the same thing.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-10-29 21:44:55 +01:00
Russell King
925c8a1a8c [PATCH] ARM: pt_regs offsets
Generate pt_regs S_xx offsets from the structure itself instead
of #defining them.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-26 15:18:59 +01:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00