leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity
e13d918a19
linux/arch/arm64
History
Lorenzo Pieralisi e13d918a19 arm64: kernel: fix tcr_el1.t0sz restore on systems with extended idmap 
Commit dd006da216 ("arm64: mm: increase VA range of identity map")
introduced a mechanism to extend the virtual memory map range
to support arm64 systems with system RAM located at very high offset,
where the identity mapping used to enable/disable the MMU requires
additional translation levels to map the physical memory at an equal
virtual offset.

The kernel detects at boot time the tcr_el1.t0sz value required by the
identity mapping and sets-up the tcr_el1.t0sz register field accordingly,
any time the identity map is required in the kernel (ie when enabling the
MMU).

After enabling the MMU, in the cold boot path the kernel resets the
tcr_el1.t0sz to its default value (ie the actual configuration value for
the system virtual address space) so that after enabling the MMU the
memory space translated by ttbr0_el1 is restored as expected.

Commit dd006da216 ("arm64: mm: increase VA range of identity map")
also added code to set-up the tcr_el1.t0sz value when the kernel resumes
from low-power states with the MMU off through cpu_resume() in order to
effectively use the identity mapping to enable the MMU but failed to add
the code required to restore the tcr_el1.t0sz to its default value, when
the core returns to the kernel with the MMU enabled, so that the kernel
might end up running with tcr_el1.t0sz value set-up for the identity
mapping which can be lower than the value required by the actual virtual
address space, resulting in an erroneous set-up.

This patchs adds code in the resume path that restores the tcr_el1.t0sz
default value upon core resume, mirroring this way the cold boot path
behaviour therefore fixing the issue.

Cc: <stable@vger.kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Fixes: dd006da216 ("arm64: mm: increase VA range of identity map")
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-10-28 17:07:07 +00:00
..
boot Documentation: arm: Fix typo in the idle-states bindings examples 2015-09-24 17:55:32 -05:00
configs arm64: Enable Marvell Berlin SoC family in defconfig 2015-08-06 10:15:57 +02:00
crypto crypto: aead - Remove CRYPTO_ALG_AEAD_NEW flag 2015-08-17 16:53:53 +08:00
include arm64: compat: wire up new syscalls 2015-10-14 13:51:41 +01:00
kernel arm64: kernel: fix tcr_el1.t0sz restore on systems with extended idmap 2015-10-28 17:07:07 +00:00
kvm Second set of KVM/ARM changes for 4.3-rc2 2015-09-17 16:51:59 +02:00
lib arm64: atomics: prefetch the destination word for write prior to stxr 2015-07-27 15:28:53 +01:00
mm arm64: readahead: fault retry breaks mmap file read random detection 2015-10-05 16:30:50 +01:00
net arm64: bpf: fix endianness conversion bugs 2015-06-26 14:15:39 +01:00
xen
Kconfig arm64: errata: add module build workaround for erratum #843419 2015-09-17 11:57:03 +01:00
Kconfig.debug coresight: moving to new "hwtracing" directory 2015-04-03 16:17:04 +02:00
Kconfig.platforms arm64: Enable Marvell Berlin SoC family in Kconfig 2015-08-06 10:15:01 +02:00
Makefile arm64: errata: use KBUILD_CFLAGS_MODULE for erratum #843419 2015-10-12 17:40:12 +01:00