Commit Graph

2 Commits

Author SHA1 Message Date
Mark Rutland
0a7d87a777 arm64: hibernate: reduce TLB maintenance scope
In break_before_make_ttbr_switch we perform broadcast TLB maintenance
for the inner shareable domain, and use a DSB ISH to complete this.
However, at the point we execute this, secondary CPUs are either
physically offline, or executing code outside of the kernel. Upon
entering the kernel, secondary CPUs will invalidate their TLBs before
enabling their MMUs.

Thus we do not need to invalidate TLBs of other CPUs, and as with
idmap_cpu_replace_ttbr1 we can reduce the scope of maintenance to the
TLBs of the local CPU. This keeps our TLB maintenance code consistent,
and is a minor optimisation.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: James Morse <james.morse@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-22 10:00:48 +01:00
James Morse
82869ac57b arm64: kernel: Add support for hibernate/suspend-to-disk
Add support for hibernate/suspend-to-disk.

Suspend borrows code from cpu_suspend() to write cpu state onto the stack,
before calling swsusp_save() to save the memory image.

Restore creates a set of temporary page tables, covering only the
linear map, copies the restore code to a 'safe' page, then uses the copy to
restore the memory image. The copied code executes in the lower half of the
address space, and once complete, restores the original kernel's page
tables. It then calls into cpu_resume(), and follows the normal
cpu_suspend() path back into the suspend code.

To restore a kernel using KASLR, the address of the page tables, and
cpu_resume() are stored in the hibernate arch-header and the el2
vectors are pivotted via the 'safe' page in low memory.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Kevin Hilman <khilman@baylibre.com> # Tested on Juno R2
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-28 13:36:22 +01:00