kernel/arch/s390/include/asm/ap.h, branch linux-6.2.y

s390/ap: fix status returned by ap_qact()

2023-03-10T08:28:18Z

[ Upstream commit a2522c80f074c35254974fec39fffe8b8d75befe ] Since commit 159491f3b509 ("s390/ap: rework assembler functions to use unions for in/out register variables") the function ap_qact() tries to grab the status from the wrong part of the register. Thus we always end up with zeros. Which is wrong, among others, because we detect failures via status.response_code. Signed-off-by: Halil Pasic Reported-by: Harald Freudenberger Fixes: 159491f3b509 ("s390/ap: rework assembler functions to use unions for in/out register variables") Reviewed-by: Harald Freudenberger Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/ap: fix status returned by ap_aqic()

2023-03-10T08:28:18Z

[ Upstream commit 394740d7645ea767795074287769dd26dbd4d782 ] There function ap_aqic() tries to grab the status from the wrong part of the register. Thus we always end up with zeros. Which is wrong, among others, because we detect failures via status.response_code. Signed-off-by: Halil Pasic Reported-by: Janosch Frank Fixes: 159491f3b509 ("s390/ap: rework assembler functions to use unions for in/out register variables") Reviewed-by: Harald Freudenberger Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

vfio/ap: Pass in physical address of ind to ap_aqic()

2022-07-23T13:29:10Z

The ap_aqic() is called by vfio_ap_irq_enable() where it passes in a virt value that's casted from a physical address "h_nib". Inside the ap_aqic(), it does virt_to_phys() again. Since ap_aqic() needs a physical address, let's just pass in a pa of ind directly. So change the "ind" to "pa_ind". Reviewed-by: Harald Freudenberger Reviewed-by: Jason Gunthorpe Tested-by: Eric Farman Signed-off-by: Nicolin Chen Link: https://lore.kernel.org/r/20220723020256.30081-4-nicolinc@nvidia.com Signed-off-by: Alex Williamson

s390/ap: adjust whitespace

2022-03-27T20:18:39Z

Adjust indentation of inline assemblies, so all comments start at the same position. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/ap: use insn format for new instructions

2022-03-27T20:18:39Z

Use insn format with instruction format specifier instead of plain longs. This way it is also more obvious that code instead of data is generated. The generated code is identical. Reviewed-by: Harald Freudenberger Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/extable: move EX_TABLE define to asm-extable.h

2022-03-07T23:33:00Z

Follow arm64 and riscv and move the EX_TABLE define to asm-extable.h which is a lot less generic than the current linkage.h. Also make sure that all files which contain EX_TABLE usages actually include the new header file. This should make sure that the files always compile and there won't be any random compile breakage due to other header file dependencies. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/ap: add missing virt_to_phys address conversion

2021-12-10T15:14:26Z

The address of the notification-indicator byte is an absolute address. Therefore convert its virtual to a physical address before being used with PQAP(AQIC). Note: this currently doesn't fix a real bug, since virtual addresses are indentical to physical ones. Reviewed-by: Alexander Gordeev Reviewed-by: Harald Freudenberger Signed-off-by: Heiko Carstens

s390/ap: get rid of register asm in ap_dqap()

2021-07-08T20:12:17Z

This is the second part of the cleanup for the header file ap.h to remove the register asm statements. This patch deals with the inline ap_dqap() function where within the assembler code an odd register of an register pair is to be addressed. [hca@linux.ibm.com: this intentionally breaks compilation with any clang compilers prior to llvm-project commit 458eac257377 ("[SystemZ] Support the 'N' code for the odd register in inline-asm."). This is hopefully the last clang kernel compile breakage caused by incompatibilities between gcc and clang.] Signed-off-by: Harald Freudenberger Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/ap: get rid of register asm

2021-07-08T13:37:27Z

Using register asm statements has been proven to be very error prone, especially when using code instrumentation where gcc may add function calls, which clobbers register contents in an unexpected way. Therefore get rid of register asm statements in ap code. There are also potential bugs, depending on inline decisions of the compiler. E.g. for: static inline struct ap_queue_status ap_tapq(ap_qid_t qid, unsigned long *info) { register unsigned long reg0 asm ("0") = qid; register struct ap_queue_status reg1 asm ("1"); register unsigned long reg2 asm ("2"); asm volatile(".long 0xb2af0000" /* PQAP(TAPQ) */ : "=d" (reg1), "=d" (reg2) : "d" (reg0) : "cc"); if (info) *info = reg2; return reg1; } In case of KCOV the "if (info)" line could cause a generated function call, which could clobber the contents of both reg2, and reg1. Similar can happen in case of KASAN for the "*info = reg2" line. Even though compilers will likely inline the function and optimize things away, this is not guaranteed. To get rid of this bug class, simply get rid of register asm constructs. Note: The inline function ap_dqap() will be handled in a separate patch because this one requires an addressing of the odd register of a register pair (which is done with %N[xxx] in the assembler code) and that's currently not supported by clang. Signed-off-by: Heiko Carstens Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik

s390/ap: Rework ap_dqap to deal with messages greater than recv buffer

2021-07-08T13:37:27Z

Rework of the ap_dqap() inline function with the dqap inline assembler invocation and the caller code in ap_queue.c to be able to handle replies which exceed the receive buffer size. ap_dqap() now provides two additional parameters to handle together with the caller the case where a reply in the firmware queue entry exceeds the given message buffer size. It depends on the caller how to exactly handle this. The behavior implemented now by ap_sm_recv() in ap_queue.c is to simple purge this entry from the firmware queue and let the caller 'receive' a -EMSGSIZE for the request without delivering any reply data - not even a truncated reply message. However, the reworked ap_dqap() could now get invoked in a way that the message is received in multiple parts and the caller assembles the parts into one reply message. Signed-off-by: Harald Freudenberger Suggested-by: Juergen Christ Reviewed-by: Juergen Christ Signed-off-by: Vasily Gorbik