diff options
| author | John David Anglin <dave.anglin@bell.net> | 2020-07-28 19:13:20 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-19 08:16:26 +0200 |
| commit | 8dfab46620017e96cb5907a5eecba76f45c50c17 (patch) | |
| tree | 7f74af626e1fea1a0e713039522509de96334f66 /arch/parisc/kernel | |
| parent | 638e45c39f30ca6e76da6fc06097886c4b0ebf5c (diff) | |
parisc: Do not use an ordered store in pa_tlb_lock()
commit e72b23dec1da5e62a0090c5da1d926778284e230 upstream.
No need to use an ordered store in pa_tlb_lock() and update the comment
regarng usage of the sid register to unlocak a spinlock in
tlb_unlock0().
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v5.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/parisc/kernel')
| -rw-r--r-- | arch/parisc/kernel/entry.S | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index 5d48efcb2683..873bf3434da9 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -455,7 +455,7 @@ LDREG 0(\ptp),\pte bb,<,n \pte,_PAGE_PRESENT_BIT,3f b \fault - stw,ma \spc,0(\tmp) + stw \spc,0(\tmp) 99: ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP) #endif 2: LDREG 0(\ptp),\pte @@ -463,7 +463,12 @@ 3: .endm - /* Release pa_tlb_lock lock without reloading lock address. */ + /* Release pa_tlb_lock lock without reloading lock address. + Note that the values in the register spc are limited to + NR_SPACE_IDS (262144). Thus, the stw instruction always + stores a nonzero value even when register spc is 64 bits. + We use an ordered store to ensure all prior accesses are + performed prior to releasing the lock. */ .macro tlb_unlock0 spc,tmp #ifdef CONFIG_SMP 98: or,COND(=) %r0,\spc,%r0 |