From 06e9552f5f12564dc1c3483f0934d96cc4f72f18 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 27 Apr 2018 09:13:24 +0200 Subject: x86/pci-dma: remove the experimental forcesac boot option Limiting the dma mask to avoid PCI (pre-PCIe) DAC cycles while paying the huge overhead of an IOMMU is rather pointless, and this seriously gets in the way of dma mapping work. Signed-off-by: Christoph Hellwig Reviewed-by: Thomas Gleixner --- drivers/net/ethernet/sfc/efx.c | 5 ++--- drivers/net/ethernet/sfc/falcon/efx.c | 5 ++--- 2 files changed, 4 insertions(+), 6 deletions(-) (limited to 'drivers/net') diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c index a4ebd8715494..661828e8fdcf 100644 --- a/drivers/net/ethernet/sfc/efx.c +++ b/drivers/net/ethernet/sfc/efx.c @@ -1289,9 +1289,8 @@ static int efx_init_io(struct efx_nic *efx) pci_set_master(pci_dev); - /* Set the PCI DMA mask. Try all possibilities from our - * genuine mask down to 32 bits, because some architectures - * (e.g. x86_64 with iommu_sac_force set) will allow 40 bit + /* Set the PCI DMA mask. Try all possibilities from our genuine mask + * down to 32 bits, because some architectures will allow 40 bit * masks event though they reject 46 bit masks. */ while (dma_mask > 0x7fffffffUL) { diff --git a/drivers/net/ethernet/sfc/falcon/efx.c b/drivers/net/ethernet/sfc/falcon/efx.c index 3d6c91e96589..dd5530a4f8c8 100644 --- a/drivers/net/ethernet/sfc/falcon/efx.c +++ b/drivers/net/ethernet/sfc/falcon/efx.c @@ -1242,9 +1242,8 @@ static int ef4_init_io(struct ef4_nic *efx) pci_set_master(pci_dev); - /* Set the PCI DMA mask. Try all possibilities from our - * genuine mask down to 32 bits, because some architectures - * (e.g. x86_64 with iommu_sac_force set) will allow 40 bit + /* Set the PCI DMA mask. Try all possibilities from our genuine mask + * down to 32 bits, because some architectures will allow 40 bit * masks event though they reject 46 bit masks. */ while (dma_mask > 0x7fffffffUL) { -- cgit