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s390/pci: simplify __pciwb_mio() inline asm

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The PCI Write Barrier instruction ignores the registers encoded in it.
There is thus no need to explicitly set the register to zero or to
associate it with a variable at all. In the resulting binary this removes
an unnecessary lghi and it makes the code simpler.

Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Niklas Schnelle 2022-01-05 16:10:54 +01:00 committed by Heiko Carstens
parent c4538d0f19
commit 7b2932162f
1 changed files with 1 additions and 4 deletions
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5
arch/s390/pci/pci_insn.c
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@ -365,10 +365,7 @@ EXPORT_SYMBOL_GPL(zpci_write_block);
static inline void __pciwb_mio(void)
{
unsigned long unused = 0;
asm volatile (".insn rre,0xb9d50000,%[op],%[op]\n"
: [op] "+d" (unused));
asm volatile (".insn rre,0xb9d50000,0,0\n");
}
void zpci_barrier(void)