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| author | John David Anglin <dave.anglin@bell.net> | 2020-07-28 19:13:20 +0200 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2020-07-28 19:29:38 +0200 |
| commit | e72b23dec1da5e62a0090c5da1d926778284e230 (patch) | |
| tree | 715b1334dd13ee9dbea9d960f25cef1addbce778 /arch/parisc/kernel/entry.S | |
| parent | 157e9afcc4fa25068b0e8743bc254a9b56010e13 (diff) | |
| download | linux-e72b23dec1da5e62a0090c5da1d926778284e230.tar.gz | |
parisc: Do not use an ordered store in pa_tlb_lock()
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+
Diffstat (limited to 'arch/parisc/kernel/entry.S')
| -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 06455f1a40f5a..519f9056fd00b 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 |