From 4e14176ab13fb6986dd079c711d46b70712da2f1 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Wed, 22 Mar 2023 13:08:00 -0700 Subject: [PATCH] iommu/sva: Stop using ioasid_set for SVA Instead SVA drivers can use a simple global IDA to allocate PASIDs for each mm_struct. Future work would be to allow drivers using the SVA APIs to reserve global PASIDs from this IDA for their internal use, eg with the DMA API PASID support. Reviewed-by: Lu Baolu Signed-off-by: Jason Gunthorpe Signed-off-by: Jacob Pan Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20230322200803.869130-5-jacob.jun.pan@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/iommu-sva.c | 41 +++++++++++++-------------------------- drivers/iommu/iommu-sva.h | 2 -- 2 files changed, 14 insertions(+), 29 deletions(-) diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c index 4f357ef14f04e..48e8a15ddc9b1 100644 --- a/drivers/iommu/iommu-sva.c +++ b/drivers/iommu/iommu-sva.c @@ -9,47 +9,34 @@ #include "iommu-sva.h" static DEFINE_MUTEX(iommu_sva_lock); -static DECLARE_IOASID_SET(iommu_sva_pasid); +static DEFINE_IDA(iommu_global_pasid_ida); -/** - * iommu_sva_alloc_pasid - Allocate a PASID for the mm - * @mm: the mm - * @min: minimum PASID value (inclusive) - * @max: maximum PASID value (inclusive) - * - * Try to allocate a PASID for this mm, or take a reference to the existing one - * provided it fits within the [@min, @max] range. On success the PASID is - * available in mm->pasid and will be available for the lifetime of the mm. - * - * Returns 0 on success and < 0 on error. - */ -int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) +/* Allocate a PASID for the mm within range (inclusive) */ +static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) { int ret = 0; - ioasid_t pasid; - if (min == INVALID_IOASID || max == INVALID_IOASID || + if (!pasid_valid(min) || !pasid_valid(max) || min == 0 || max < min) return -EINVAL; mutex_lock(&iommu_sva_lock); /* Is a PASID already associated with this mm? */ if (pasid_valid(mm->pasid)) { - if (mm->pasid < min || mm->pasid >= max) + if (mm->pasid < min || mm->pasid > max) ret = -EOVERFLOW; goto out; } - pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm); - if (!pasid_valid(pasid)) - ret = -ENOMEM; - else - mm->pasid = pasid; + ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_ATOMIC); + if (ret < 0) + goto out; + mm->pasid = ret; + ret = 0; out: mutex_unlock(&iommu_sva_lock); return ret; } -EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid); /** * iommu_sva_bind_device() - Bind a process address space to a device @@ -221,8 +208,8 @@ out_put_mm: void mm_pasid_drop(struct mm_struct *mm) { - if (pasid_valid(mm->pasid)) { - ioasid_free(mm->pasid); - mm->pasid = INVALID_IOASID; - } + if (likely(!pasid_valid(mm->pasid))) + return; + + ida_free(&iommu_global_pasid_ida, mm->pasid); } diff --git a/drivers/iommu/iommu-sva.h b/drivers/iommu/iommu-sva.h index 102eae1817a27..c22d0174ad611 100644 --- a/drivers/iommu/iommu-sva.h +++ b/drivers/iommu/iommu-sva.h @@ -8,8 +8,6 @@ #include #include -int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max); - /* I/O Page fault */ struct device; struct iommu_fault; -- 2.30.2