From 21c1f9021f0e7d28c3edfcc70e1ca1926ea3774e Mon Sep 17 00:00:00 2001 From: Niklas Schnelle Date: Wed, 9 Nov 2022 15:29:03 +0100 Subject: s390/pci: use lock-free I/O translation updates I/O translation tables on s390 use 8 byte page table entries and tables which are allocated lazily but only freed when the entire I/O translation table is torn down. Also each IOVA can at any time only translate to one physical address Furthermore I/O table accesses by the IOMMU hardware are cache coherent. With a bit of care we can thus use atomic updates to manipulate the translation table without having to use a global lock at all. This is done analogous to the existing I/O translation table handling code used on Intel and AMD x86 systems. Signed-off-by: Niklas Schnelle Link: https://lore.kernel.org/r/20221109142903.4080275-6-schnelle@linux.ibm.com Signed-off-by: Joerg Roedel --- arch/s390/include/asm/pci.h | 1 - 1 file changed, 1 deletion(-) (limited to 'arch/s390/include') diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h index e4c3e4e04d30..b248694e0024 100644 --- a/arch/s390/include/asm/pci.h +++ b/arch/s390/include/asm/pci.h @@ -157,7 +157,6 @@ struct zpci_dev { /* DMA stuff */ unsigned long *dma_table; - spinlock_t dma_table_lock; int tlb_refresh; spinlock_t iommu_bitmap_lock; -- cgit v1.2.3