s390 doesn't use irq_domains, so it has no place to set IRQ_DOMAIN_FLAG_ISOLATED_MSI. Instead of continuing to abuse the iommu subsystem to convey this information add a simple define which s390 can make statically true. The define will cause msi_device_has_isolated() to return true. Remove IOMMU_CAP_INTR_REMAP from the s390 iommu driver. Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx> Cc: Eric Farman <farman@xxxxxxxxxxxxx> Reviewed-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx> Tested-by: Matthew Rosato <mjrosato@xxxxxxxxxxxxx> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx> --- arch/s390/include/asm/msi.h | 17 +++++++++++++++++ drivers/iommu/s390-iommu.c | 2 -- include/linux/msi.h | 10 +++++++--- kernel/irq/msi.c | 2 +- 4 files changed, 25 insertions(+), 6 deletions(-) create mode 100644 arch/s390/include/asm/msi.h diff --git a/arch/s390/include/asm/msi.h b/arch/s390/include/asm/msi.h new file mode 100644 index 00000000000000..399343ed9ffbc6 --- /dev/null +++ b/arch/s390/include/asm/msi.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_S390_MSI_H +#define _ASM_S390_MSI_H +#include <asm-generic/msi.h> + +/* + * Work around S390 not using irq_domain at all so we can't set + * IRQ_DOMAIN_FLAG_ISOLATED_MSI. See for an explanation how it works: + * + * https://lore.kernel.org/r/31af8174-35e9-ebeb-b9ef-74c90d4bfd93@xxxxxxxxxxxxx/ + * + * Note this is less isolated than the ARM/x86 versions as userspace can trigger + * MSI belonging to kernel devices within the same gisa. + */ +#define arch_is_isolated_msi() true + +#endif diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c index ed33c6cce08362..bb00580a30d84d 100644 --- a/drivers/iommu/s390-iommu.c +++ b/drivers/iommu/s390-iommu.c @@ -34,8 +34,6 @@ static bool s390_iommu_capable(struct device *dev, enum iommu_cap cap) switch (cap) { case IOMMU_CAP_CACHE_COHERENCY: return true; - case IOMMU_CAP_INTR_REMAP: - return true; default: return false; } diff --git a/include/linux/msi.h b/include/linux/msi.h index e8a3f3a8a7f427..13c9b74a4575aa 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -48,6 +48,10 @@ typedef struct arch_msi_msg_data { } __attribute__ ((packed)) arch_msi_msg_data_t; #endif +#ifndef arch_is_isolated_msi +#define arch_is_isolated_msi() false +#endif + /** * msi_msg - Representation of a MSI message * @address_lo: Low 32 bits of msi message address @@ -657,10 +661,10 @@ static inline bool msi_device_has_isolated_msi(struct device *dev) /* * Arguably if the platform does not enable MSI support then it has * "isolated MSI", as an interrupt controller that cannot receive MSIs - * is inherently isolated by our definition. As nobody seems to needs - * this be conservative and return false anyhow. + * is inherently isolated by our definition. The default definition for + * arch_is_isolated_msi() is conservative and returns false anyhow. */ - return false; + return arch_is_isolated_msi(); } #endif /* CONFIG_GENERIC_MSI_IRQ */ diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c index ac5e224a11b9aa..4dec57fc4ea639 100644 --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -1647,6 +1647,6 @@ bool msi_device_has_isolated_msi(struct device *dev) for (; domain; domain = domain->parent) if (domain->flags & IRQ_DOMAIN_FLAG_ISOLATED_MSI) return true; - return false; + return arch_is_isolated_msi(); } EXPORT_SYMBOL_GPL(msi_device_has_isolated_msi); -- 2.39.0
