[PATCH 5.0 018/123] arm64: Save and restore OSDLR_EL1 across suspend/resume

From: Greg Kroah-Hartman
Date: Mon May 20 2019 - 08:30:20 EST


From: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx>

commit 827a108e354db633698f0b4a10c1ffd2b1f8d1d0 upstream.

When the CPU comes out of suspend, the firmware may have modified the OS
Double Lock Register. Save it in an unused slot of cpu_suspend_ctx, and
restore it on resume.

Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/arm64/mm/proc.S | 34 ++++++++++++++++++----------------
1 file changed, 18 insertions(+), 16 deletions(-)

--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -76,24 +76,25 @@ ENTRY(cpu_do_suspend)
mrs x2, tpidr_el0
mrs x3, tpidrro_el0
mrs x4, contextidr_el1
- mrs x5, cpacr_el1
- mrs x6, tcr_el1
- mrs x7, vbar_el1
- mrs x8, mdscr_el1
- mrs x9, oslsr_el1
- mrs x10, sctlr_el1
+ mrs x5, osdlr_el1
+ mrs x6, cpacr_el1
+ mrs x7, tcr_el1
+ mrs x8, vbar_el1
+ mrs x9, mdscr_el1
+ mrs x10, oslsr_el1
+ mrs x11, sctlr_el1
alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
- mrs x11, tpidr_el1
+ mrs x12, tpidr_el1
alternative_else
- mrs x11, tpidr_el2
+ mrs x12, tpidr_el2
alternative_endif
- mrs x12, sp_el0
+ mrs x13, sp_el0
stp x2, x3, [x0]
- stp x4, xzr, [x0, #16]
- stp x5, x6, [x0, #32]
- stp x7, x8, [x0, #48]
- stp x9, x10, [x0, #64]
- stp x11, x12, [x0, #80]
+ stp x4, x5, [x0, #16]
+ stp x6, x7, [x0, #32]
+ stp x8, x9, [x0, #48]
+ stp x10, x11, [x0, #64]
+ stp x12, x13, [x0, #80]
ret
ENDPROC(cpu_do_suspend)

@@ -116,8 +117,8 @@ ENTRY(cpu_do_resume)
msr cpacr_el1, x6

/* Don't change t0sz here, mask those bits when restoring */
- mrs x5, tcr_el1
- bfi x8, x5, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH
+ mrs x7, tcr_el1
+ bfi x8, x7, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH

msr tcr_el1, x8
msr vbar_el1, x9
@@ -141,6 +142,7 @@ alternative_endif
/*
* Restore oslsr_el1 by writing oslar_el1
*/
+ msr osdlr_el1, x5
ubfx x11, x11, #1, #1
msr oslar_el1, x11
reset_pmuserenr_el0 x0 // Disable PMU access from EL0