powerpc/pseries: Fix how we iterate over the DTL entries

rnav · mpe · commit 9258227e9dd1 · 2018-10-03T15:40:02.000+10:00
When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not set, we look up dtl_idx in the lppaca to determine the number of entries in the buffer. Since lppaca is in big endian, we need to do an endian conversion before using this in our calculation to determine the number of entries in the buffer. Without this, we do not iterate over the existing entries in the DTL buffer properly. Fixes: 7c105b6 ("powerpc: Add CONFIG_CPU_LITTLE_ENDIAN kernel config option.") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/platforms/pseries/dtl.c b/arch/powerpc/platforms/pseries/dtl.c
@@ -184,7 +184,7 @@ static void dtl_stop(struct dtl *dtl)
 
 static u64 dtl_current_index(struct dtl *dtl)
 {
-	return lppaca_of(dtl->cpu).dtl_idx;
+	return be64_to_cpu(lppaca_of(dtl->cpu).dtl_idx);
 }
 #endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
 

Original file line number	Diff line number	Diff line change
`@@ -184,7 +184,7 @@ static void dtl_stop(struct dtl *dtl)`
`184`	`184`
`185`	`185`	`static u64 dtl_current_index(struct dtl *dtl)`
`186`	`186`	`{`
`187`		`- return lppaca_of(dtl->cpu).dtl_idx;`
	`187`	`+ return be64_to_cpu(lppaca_of(dtl->cpu).dtl_idx);`
`188`	`188`	`}`
`189`	`189`	`#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */`
`190`	`190`