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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: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Jan Glauber 2012-12-06 14:30:28 +01:00 committed by Martin Schwidefsky
parent 9163003236
commit 87bc359b98
1 changed files with 6 additions and 0 deletions
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6
arch/s390/pci/pci.c
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@ -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)
{