On 9/25/22 22:02, John David Anglin wrote:
On 2022-09-25 2:57 p.m., Helge Deller wrote:
+#ifdef CONFIG_PA20
+#define ALT_COND_PACACHE ALT_COND_ALWAYS
+#else
+#define ALT_COND_PACACHE ALT_COND_NO_SMP
+#endif
+
ENTRY_CFI(flush_tlb_all_local)
/*
* The pitlbe and pdtlbe instructions should only be used to
@@ -539,15 +545,10 @@ ENTRY_CFI(copy_user_page_asm)
/* Purge any old translations */
-#ifdef CONFIG_PA20
- pdtlb,l %r0(%r28)
- pdtlb,l %r0(%r29)
-#else
0: pdtlb %r0(%r28)
1: pdtlb %r0(%r29)
- ALTERNATIVE(0b, 0b+4, ALT_COND_NO_SMP, INSN_PxTLB)
- ALTERNATIVE(1b, 1b+4, ALT_COND_NO_SMP, INSN_PxTLB)
-#endif
+ ALTERNATIVE(0b, 0b+4, ALT_COND_PACACHE, INSN_PxTLB)
+ ALTERNATIVE(1b, 1b+4, ALT_COND_PACACHE, INSN_PxTLB)
This doesn't look correct. If ALT_COND_PACACHE is defined as ALT_COND_NO_SMP, the pdtlb
instructions will be converted to pdtlb,l instructions when running UP. These are not supported
on PA 1.1.
Your concern is correct, but there is an additonal check in the alternative-coding,
which prevents enabling the local flag if we're not running on a PA2.0 CPU.
So, those ALTERNATIVE() macros will only apply on PA2.0 machines.
When running SMP, we have pdtlb purges. For these, we need bus serialization.
These also don't look correct:
#define pdtlb(sr, addr) asm volatile("pdtlb 0(%%sr%0,%1)" \
ALTERNATIVE(ALT_COND_NO_SMP, INSN_PxTLB) \
: : "i"(sr), "r" (addr) : "memory")
#define pitlb(sr, addr) asm volatile("pitlb 0(%%sr%0,%1)" \
ALTERNATIVE(ALT_COND_NO_SMP, INSN_PxTLB) \
ALTERNATIVE(ALT_COND_NO_SPLIT_TLB, INSN_NOP) \
: : "i"(sr), "r" (addr) : "memory")
We only have local purge on PA 2.0 machines.
Same as above.
Helge
