From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.ru (ozlabs.ru [107.173.13.209]) by lists.ozlabs.org (Postfix) with ESMTP id 3yWFdl36WBzDrK8 for ; Tue, 7 Nov 2017 14:43:39 +1100 (AEDT) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , David Gibson , Russell Currey , Jonas Pfefferle1 Subject: [PATCH kernel v2] powerpc/powernv/ioda: Remove explicit max window size check Date: Tue, 7 Nov 2017 14:43:01 +1100 Message-Id: <20171107034301.35120-1-aik@ozlabs.ru> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , DMA windows can only have a size of power of two on IODA2 hardware and using memory_hotplug_max() to determine the upper limit won't work correcly if it returns not power of two value. This removes the check as the platform code does this check in pnv_pci_ioda2_setup_default_config() anyway; the other client is VFIO and that thing checks against locked_vm limit which prevents the userspace from locking too much memory. It is expected to impact DPDK on machines with non-power-of-two RAM size, mostly. KVM guests are less likely to be affected as usually guests get less than half of hosts RAM. Signed-off-by: Alexey Kardashevskiy --- Changes: v2: * instead of relaxing the check, this simply removes it --- arch/powerpc/platforms/powernv/pci-ioda.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c index 1de94fb..433cf84 100644 --- a/arch/powerpc/platforms/powernv/pci-ioda.c +++ b/arch/powerpc/platforms/powernv/pci-ioda.c @@ -2776,7 +2776,7 @@ static long pnv_pci_ioda2_table_alloc_pages(int nid, __u64 bus_offset, if (!levels || (levels > POWERNV_IOMMU_MAX_LEVELS)) return -EINVAL; - if ((window_size > memory_hotplug_max()) || !is_power_of_2(window_size)) + if (!is_power_of_2(window_size)) return -EINVAL; /* Adjust direct table size from window_size and levels */ -- 2.11.0