datapath: Improve robustness of this_cpu_ptr definition in compat layer

Current autoconfig detection logic for HAVE_PER_CPU_PTR is not robust. Depends on linux kernel version, the definition can be in either linux/percpu.h or asm/percpu.h Turns out it is simpler and safer to handle missing percpu.h definitions in linux/percpu.h rather than asm/percpu.h. With this change, there is no need for the autoconfig detection logic above. Signed-off-by: Andy Zhou <[email protected]> Acked-by: Pravin B Shelar <[email protected]>
robin-zhou · Sep 15, 2014 · 00e01dd · 00e01dd
1 parent 3bacde2
commit 00e01dd
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Showing 4 changed files with 4 additions and 13 deletions.
diff --git a/acinclude.m4 b/acinclude.m4
@@ -366,8 +366,6 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
   OVS_GREP_IFELSE([$KSRC/include/linux/if_vlan.h], [ADD_ALL_VLANS_CMD],
                   [OVS_DEFINE([HAVE_VLAN_BUG_WORKAROUND])])
 
-  OVS_GREP_IFELSE([$KSRC/include/linux/percpu.h], [this_cpu_ptr])
-
   OVS_GREP_IFELSE([$KSRC/include/linux/u64_stats_sync.h], [u64_stats_fetch_begin_irq])
 
   OVS_GREP_IFELSE([$KSRC/include/linux/openvswitch.h], [openvswitch_handle_frame_hook],

diff --git a/datapath/linux/Modules.mk b/datapath/linux/Modules.mk
@@ -18,7 +18,6 @@ openvswitch_sources += \
 openvswitch_headers += \
 	linux/compat/gso.h \
 	linux/compat/include/asm/hash.h \
-	linux/compat/include/asm/percpu.h \
 	linux/compat/include/linux/percpu.h \
 	linux/compat/include/linux/bug.h \
 	linux/compat/include/linux/compiler.h \

diff --git a/datapath/linux/compat/include/asm/percpu.h b/datapath/linux/compat/include/asm/percpu.h
diff --git a/datapath/linux/compat/include/linux/percpu.h b/datapath/linux/compat/include/linux/percpu.h
@@ -3,6 +3,10 @@
 
 #include_next <linux/percpu.h>
 
+#if !defined this_cpu_ptr
+#define this_cpu_ptr(ptr) per_cpu_ptr(ptr, smp_processor_id())
+#endif
+
 #if !defined this_cpu_read
 #define this_cpu_read(ptr) percpu_read(ptr)
 #endif