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authorSven Schnelle <svens@linux.ibm.com>2026-09-09 11:29:53 +0200
committerMasami Hiramatsu (Google) <mhiramat@kernel.org>2026-09-10 08:43:35 +0900
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selftests/ftrace: Fix unique symbol check in kprobe_non_uniq_symbol.tcgrafted
The current regex also matches symbols in modules, which makes the test fail on s390 where name_show is present only once in the kernel, but also multiple times in modules: 000001b1401cdc20 t name_show 000001b0c05e6c40 t name_show [mdev] 000001b0c0495f30 t name_show [i2c_core] Fix this by changing the regular expression to only match the function name. Link: https://lore.kernel.org/all/20260909092954.2200558-1-svens@linux.ibm.com/ Fixes: 03b80ff8023a ("selftests/ftrace: Add new test case which checks non unique symbol") Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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+===========================================
+Atomic Operation Control (ATOMCTL) Register
+===========================================
+
+We Have Atomic Operation Control (ATOMCTL) Register.
+This register determines the effect of using a S32C1I instruction
+with various combinations of:
+
+ 1. With and without an Coherent Cache Controller which
+ can do Atomic Transactions to the memory internally.
+
+ 2. With and without An Intelligent Memory Controller which
+ can do Atomic Transactions itself.
+
+The Core comes up with a default value of for the three types of cache ops::
+
+ 0x28: (WB: Internal, WT: Internal, BY:Exception)
+
+On the FPGA Cards we typically simulate an Intelligent Memory controller
+which can implement RCW transactions. For FPGA cards with an External
+Memory controller we let it to the atomic operations internally while
+doing a Cached (WB) transaction and use the Memory RCW for un-cached
+operations.
+
+For systems without an coherent cache controller, non-MX, we always
+use the memory controllers RCW, though non-MX controllers likely
+support the Internal Operation.
+
+CUSTOMER-WARNING:
+ Virtually all customers buy their memory controllers from vendors that
+ don't support atomic RCW memory transactions and will likely want to
+ configure this register to not use RCW.
+
+Developers might find using RCW in Bypass mode convenient when testing
+with the cache being bypassed; for example studying cache alias problems.
+
+See Section 4.3.12.4 of ISA; Bits::
+
+ WB WT BY
+ 5 4 | 3 2 | 1 0
+
+========= ================== ================== ===============
+ 2 Bit
+ Field
+ Values WB - Write Back WT - Write Thru BY - Bypass
+========= ================== ================== ===============
+ 0 Exception Exception Exception
+ 1 RCW Transaction RCW Transaction RCW Transaction
+ 2 Internal Operation Internal Operation Reserved
+ 3 Reserved Reserved Reserved
+========= ================== ================== ===============