From eb5b20114b9710d1dcd4118dbf01b081c104bbc0 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Mon, 26 Sep 2022 21:15:28 +0800 Subject: [PATCH] iommu/vt-d: Avoid unnecessary global IRTE cache invalidation Some VT-d hardware implementations invalidate all interrupt remapping hardware translation caches as part of SIRTP flow. The VT-d spec adds a ESIRTPS (Enhanced Set Interrupt Remap Table Pointer Support, section 11.4.2 in VT-d spec) capability bit to indicate this. The spec also states in 11.4.4 that hardware also performs global invalidation on all interrupt remapping caches as part of Interrupt Remapping Disable operation if ESIRTPS capability bit is set. This checks the ESIRTPS capability bit and skip software global cache invalidation if it's set. Signed-off-by: Jacob Pan Signed-off-by: Lu Baolu Reviewed-by: Jerry Snitselaar Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20220921065741.3572495-1-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/intel/iommu.h | 1 + drivers/iommu/intel/irq_remapping.c | 6 ++++-- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index 99cc75e..bddf6c6 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -146,6 +146,7 @@ /* * Decoding Capability Register */ +#define cap_esirtps(c) (((c) >> 62) & 1) #define cap_fl5lp_support(c) (((c) >> 60) & 1) #define cap_pi_support(c) (((c) >> 59) & 1) #define cap_fl1gp_support(c) (((c) >> 56) & 1) diff --git a/drivers/iommu/intel/irq_remapping.c b/drivers/iommu/intel/irq_remapping.c index 2e9683e..5962bb5 100644 --- a/drivers/iommu/intel/irq_remapping.c +++ b/drivers/iommu/intel/irq_remapping.c @@ -494,7 +494,8 @@ static void iommu_set_irq_remapping(struct intel_iommu *iommu, int mode) * Global invalidation of interrupt entry cache to make sure the * hardware uses the new irq remapping table. */ - qi_global_iec(iommu); + if (!cap_esirtps(iommu->cap)) + qi_global_iec(iommu); } static void iommu_enable_irq_remapping(struct intel_iommu *iommu) @@ -680,7 +681,8 @@ static void iommu_disable_irq_remapping(struct intel_iommu *iommu) * global invalidation of interrupt entry cache before disabling * interrupt-remapping. */ - qi_global_iec(iommu); + if (!cap_esirtps(iommu->cap)) + qi_global_iec(iommu); raw_spin_lock_irqsave(&iommu->register_lock, flags); -- 2.7.4