From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Mon, 14 Mar 2022 07:31:19 +0000 Subject: [PATCH 05/15] arm/xen: don't check for xen_initial_domain() in xen_create_contiguous_region Message-Id: <20220314073129.1862284-6-hch@lst.de> List-Id: References: <20220314073129.1862284-1-hch@lst.de> In-Reply-To: <20220314073129.1862284-1-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: iommu@lists.linux-foundation.org Cc: linux-hyperv@vger.kernel.org, x86@kernel.org, linux-ia64@vger.kernel.org, linux-pci@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, Stefano Stabellini , Konrad Rzeszutek Wilk , tboot-devel@lists.sourceforge.net, xen-devel@lists.xenproject.org, Stefano Stabellini , David Woodhouse , Tom Lendacky , Anshuman Khandual , Boris Ostrovsky , linux-arm-kernel@lists.infradead.org, Juergen Gross , linuxppc-dev@lists.ozlabs.org, linux-mips@vger.kernel.org, Robin Murphy From: Stefano Stabellini It used to be that Linux enabled swiotlb-xen when running a dom0 on ARM. Since f5079a9a2a31 "xen/arm: introduce XENFEAT_direct_mapped and XENFEAT_not_direct_mapped", Linux detects whether to enable or disable swiotlb-xen based on the new feature flags: XENFEAT_direct_mapped and XENFEAT_not_direct_mapped. However, there is still a leftover xen_initial_domain() check in xen_create_contiguous_region. Remove the check as xen_create_contiguous_region is only called by swiotlb-xen during initialization. If xen_create_contiguous_region is called, we know Linux is running 1:1 mapped so there is no need for additional checks. Also update the in-code comment. Signed-off-by: Stefano Stabellini Signed-off-by: Christoph Hellwig --- arch/arm/xen/mm.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index a7e54a087b802..28c2070602535 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -122,10 +122,7 @@ int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, unsigned int address_bits, dma_addr_t *dma_handle) { - if (!xen_initial_domain()) - return -EINVAL; - - /* we assume that dom0 is mapped 1:1 for now */ + /* the domain is 1:1 mapped to use swiotlb-xen */ *dma_handle = pstart; return 0; } -- 2.30.2