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Commit 87bc359b authored by Jan Glauber's avatar Jan Glauber Committed by Martin Schwidefsky
Browse files

s390/pci: speed up __iowrite64_copy by using pci store block insn 



Benefit from pci store block instruction by writing up to 128 bytes
with a single instruction to MMIO space. Depending on the workload
this can result in a huge performance increase due to the reduced
number of instructions. The ordering guarantees of single stores
vs. one store block are identical.

Signed-off-by: default avatarJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 91630032

arch/s390/pci/pci.c

+6 −0
Original line number Diff line number Diff line
@@ -355,6 +355,12 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, 
	return 0;

}



/* combine single writes by using store-block insn */

void __iowrite64_copy(void __iomem *to, const void *from, size_t count)

{

       zpci_memcpy_toio(to, from, count);

}



/* Create a virtual mapping cookie for a PCI BAR */

void __iomem *pci_iomap(struct pci_dev *pdev, int bar, unsigned long max)

{