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| author | ian <ian@FreeBSD.org> | 2015-05-23 23:27:00 +0000 |
|---|---|---|
| committer | ian <ian@FreeBSD.org> | 2015-05-23 23:27:00 +0000 |
| commit | 45e1cf60a142653a0d963cfcc63e4ecd0823a7b5 (patch) | |
| tree | 18ad62c7bf65bb7cdf943aa6bd8e68f54657dec0 /sys/arm/arm/swtch.S | |
| parent | 9e0f8345df115d65713e07d4c02059227fddf47f (diff) | |
| download | FreeBSD-src-45e1cf60a142653a0d963cfcc63e4ecd0823a7b5.zip FreeBSD-src-45e1cf60a142653a0d963cfcc63e4ecd0823a7b5.tar.gz | |
MFC r280278, r280402:
Allow to override default kernel virtual address assignment on ARM.
Do not save/restore the TLS pointer on context switch for armv6.
Diffstat (limited to 'sys/arm/arm/swtch.S')
| -rw-r--r-- | sys/arm/arm/swtch.S | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/sys/arm/arm/swtch.S b/sys/arm/arm/swtch.S index e9d6f61..6972c50 100644 --- a/sys/arm/arm/swtch.S +++ b/sys/arm/arm/swtch.S @@ -255,7 +255,7 @@ ENTRY(cpu_switch) mov r4, r0 /* Save the old thread. */ #ifdef ARM_TP_ADDRESS - /* Store the old tp */ + /* Store the old tp; userland can change it on armv4. */ ldr r3, =ARM_TP_ADDRESS ldr r9, [r3] str r9, [r0, #(TD_MD + MD_TP)] @@ -272,11 +272,10 @@ ENTRY(cpu_switch) ldr r9, [r1, #(TD_MD + MD_RAS_END)] str r9, [r3, #8] #else - /* Store the old tp */ - mrc p15, 0, r9, c13, c0, 3 - str r9, [r0, #(TD_MD + MD_TP)] - - /* Set the new tp */ + /* + * Set new tp. No need to store the old one first, userland can't + * change it directly on armv6. + */ ldr r9, [r1, #(TD_MD + MD_TP)] mcr p15, 0, r9, c13, c0, 3 #endif |
