Commit Graph

20 Commits

Author SHA1 Message Date
Will Deacon d675d0bc47 ARM: LPAE: add ISBs around MMU enabling code
Before we enable the MMU, we must ensure that the TTBR registers contain
sane values. After the MMU has been enabled, we jump to the *virtual*
address of the following function, so we also need to ensure that the
SCTLR write has taken effect.

This patch adds ISB instructions around the SCTLR write to ensure the
visibility of the above.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2011-12-08 10:30:38 +00:00
Will Deacon e6eadc6787 ARM: suspend: use idmap_pgd instead of suspend_pgd
The ARM CPU suspend code requires cpu_resume_mmu to be identity mapped
in order to re-enable the MMU when coming out of suspend. Currently,
this is accomplished by maintaining a suspend_pgd with the relevant
mapping put in place at init time.

This patch replaces the use of suspend_pgd with the new idmap_pgd.
cpu_resume_mmu is placed in the .idmap.text section so that it is
included in the identity map.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Dave Martin <dave.martin@linaro.org>
Tested-by: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-12-06 14:04:14 +00:00
Russell King abda1bd5f4 ARM: pm: convert some assembly to C
Convert some of the sleep.S guts to C code, which makes it easier to
use our macros and to add L2 cache handling.  We provide a helper
function, __cpu_suspend_save(), which deals with saving the common
state, setting up for resume, and flushing caches.

The remainder left as assembly code is the saving of the CPU general
purpose registers, and allocating space on the stack to save the CPU
specific registers and resume state.

Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-20 23:33:44 +01:00
Russell King 62b2d07c0e ARM: pm: get rid of cpu_resume_turn_mmu_on
We don't require cpu_resume_turn_mmu_on as we can combine the ldr
instruction with the following code provided we ensure that
cpu_resume_mmu is aligned for older CPUs.  Note that we also align
to a 32-byte boundary to ensure that the code can't cross a section
boundary.

Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-20 23:33:42 +01:00
Russell King de8e71ca4f ARM: pm: only use preallocated page table during resume
Only use the preallocated page table during the resume, not while
suspending.  This avoids the overhead of having to switch unnecessarily
to the resume page table in the suspend path.

Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-20 23:33:38 +01:00
Russell King e8ce0eb5e2 ARM: pm: preallocate a page table for suspend/resume
Preallocate a page table and setup an identity mapping for the MMU
enable code.  This means we don't have to "borrow" a page table to
do this, avoiding complexities with L2 cache coherency.

Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-20 23:33:36 +01:00
Russell King f5fa68d967 ARM: pm: force non-zero return value from __cpu_suspend when aborting
Ensure that the return value from __cpu_suspend is non-zero when
aborting.  Zero indicates a successful suspend occurred.

Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-20 23:33:28 +01:00
Russell King 29cb3cd208 ARM: pm: allow suspend finisher to return error codes
There are SoCs where attempting to enter a low power state is ignored,
and the CPU continues executing instructions with all state preserved.
It is over-complex at that point to disable the MMU just to call the
resume path.

Instead, allow the suspend finisher to return error codes to abort
suspend in this circumstance, where the cpu_suspend internals will then
unwind the saved state on the stack.  Also omit the tlb flush as no
changes to the page tables will have happened.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-07-02 09:54:01 +01:00
Russell King 2c74a0cefa ARM: pm: hide 1st and 2nd arguments to cpu_suspend from platform code
The first and second arguments shouldn't concern platform code, so
hide them from each platforms caller.

Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-24 09:54:39 +01:00
Russell King 14cd8fd574 ARM: pm: move cpu_init() call into core code
As we have core code dealing with CPU suspend/resume, we can
re-initialize the CPUs exception banked registers via that code rather
than having platforms deal with that level of detail.  So, move the
call to cpu_init() out of platform code into core code.

Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-24 08:48:43 +01:00
Russell King e8856a8797 ARM: pm: convert cpu_suspend() to a normal function
cpu_suspend() has a weird calling method which makes it only possible to
call from assembly code: it returns with a modified stack pointer to
finish the suspend, but on resume, it 'returns' via a provided pointer.

We can make cpu_suspend() appear to be a normal function merely by
swapping the resume pointer argument and the link register.

Do so, and update all callers to take account of this more traditional
behaviour.

Acked-by: Frank Hofmann <frank.hofmann@tomtom.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-24 08:48:43 +01:00
Russell King 3799bbe578 ARM: pm: rejig suspend follow-on function calling convention
Save the suspend function pointer onto the stack for use when returning.
Allocate r2 to pass an argument to the suspend function.

Acked-by: Frank Hofmann <frank.hofmann@tomtom.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-24 08:47:36 +01:00
Russell King 8111eaa6d4 ARM: pm: reallocate registers to avoid r2, r3
Avoid using r2 and r3 in the suspend code, allowing these to be
passed further into the function as arguments.

Acked-by: Frank Hofmann <frank.hofmann@tomtom.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-24 08:47:32 +01:00
Russell King 5fa94c812c ARM: pm: preserve r4 - r11 across a suspend
Make cpu_suspend()..return function preserve r4 to r11 across a suspend
cycle.  This is in preparation of relieving platform support code from
this task.

Acked-by: Frank Hofmann <frank.hofmann@tomtom.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-24 08:47:29 +01:00
Russell King 3fd431bd0c ARM: pm: extract common code from MULTI_CPU/!MULTI_CPU paths
Very little code is different between these two paths now, so extract
the common code.

Acked-by: Frank Hofmann <frank.hofmann@tomtom.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-24 08:47:26 +01:00
Russell King 2fefbcd585 ARM: pm: move return address (for cpu_resume) to top of stack
Move the return address for cpu_resume to the top of stack so that
cpu_resume looks more like a normal function.

Acked-by: Frank Hofmann <frank.hofmann@tomtom.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-24 08:47:23 +01:00
Russell King 6b5f6ab0e1 ARM: pm: make MULTI_CPU and !MULTI_CPU resume paths the same
Eliminate the differences between MULTI_CPU and non-MULTI_CPU resume
paths, making the saved structure identical irrespective of the way
the kernel was configured.

Acked-by: Frank Hofmann <frank.hofmann@tomtom.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-24 08:47:20 +01:00
Nicolas Pitre fb4fe87d79 ARM: 6825/1: kernel/sleep.S: fix Thumb2 compilation issues
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-03-26 10:06:08 +00:00
Russell King 941aefac4c ARM: pm: allow generic sleep code to be used with SMP CPU idle
Allow the generic sleep code to be used with SMP CPU idle by storing
N CPU stack pointers rather than just one.  Tested on Assabet and
Tegra 2.

Tested-by: Colin Cross <ccross@android.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-22 17:11:26 +00:00
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