From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lu Baolu Date: Thu, 15 Aug 2019 05:01:57 +0000 Subject: Re: [PATCH 06/10] iommu: Remember when default domain type was set on kernel command line Message-Id: <754a526e-a6d4-8a3f-0b35-9dd3def5d24b@linux.intel.com> List-Id: References: <20190814133841.7095-1-joro@8bytes.org> <20190814133841.7095-7-joro@8bytes.org> In-Reply-To: <20190814133841.7095-7-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Joerg Roedel Cc: baolu.lu@linux.intel.com, corbet@lwn.net, tony.luck@intel.com, fenghua.yu@intel.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, x86@kernel.org, linux-doc@vger.kernel.org, linux-ia64@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Thomas.Lendacky@amd.com, Suravee.Suthikulpanit@amd.com, Joerg Roedel Hi, On 8/14/19 9:38 PM, Joerg Roedel wrote: > From: Joerg Roedel > > Introduce an extensible concept to remember when certain > configuration settings for the IOMMU code have been set on > the kernel command line. > > This will be used later to prevent overwriting these > settings with other defaults. > > Signed-off-by: Joerg Roedel > --- > drivers/iommu/iommu.c | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index f187e85a074b..e1feb4061b8b 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -32,6 +32,7 @@ static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY; > static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_DMA; > #endif > static bool iommu_dma_strict __read_mostly = true; > +static u32 iommu_cmd_line __read_mostly; > > struct iommu_group { > struct kobject kobj; > @@ -68,6 +69,18 @@ static const char * const iommu_group_resv_type_string[] = { > [IOMMU_RESV_SW_MSI] = "msi", > }; > > +#define IOMMU_CMD_LINE_DMA_API (1 << 0) Prefer BIT() micro? > + > +static void iommu_set_cmd_line_dma_api(void) > +{ > + iommu_cmd_line |= IOMMU_CMD_LINE_DMA_API; > +} > + > +static bool __maybe_unused iommu_cmd_line_dma_api(void) > +{ > + return !!(iommu_cmd_line & IOMMU_CMD_LINE_DMA_API); > +} > + > #define IOMMU_GROUP_ATTR(_name, _mode, _show, _store) \ > struct iommu_group_attribute iommu_group_attr_##_name = \ > __ATTR(_name, _mode, _show, _store) > @@ -165,6 +178,8 @@ static int __init iommu_set_def_domain_type(char *str) > if (ret) > return ret; > > + iommu_set_cmd_line_dma_api(); IOMMU command line is also set in other places, for example, iommu_setup() (arch/x86/kernel/pci-dma.c). Need to call this there as well? Best regards, Lu Baolu > + > iommu_def_domain_type = pt ? IOMMU_DOMAIN_IDENTITY : IOMMU_DOMAIN_DMA; > return 0; > } >