linux-kernel - [PATCH v2 2/8] iommu/vt-d: Remove PASID supervisor request support

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Date:   Mon, 27 Mar 2023 16:21:32 -0700
From:   Jacob Pan <jacob.jun.pan@...ux.intel.com>
To:     LKML <linux-kernel@...r.kernel.org>, iommu@...ts.linux.dev,
        Jason Gunthorpe <jgg@...dia.com>,
        "Lu Baolu" <baolu.lu@...ux.intel.com>,
        Joerg Roedel <joro@...tes.org>, dmaengine@...r.kernel.org,
        vkoul@...nel.org
Cc:     "Robin Murphy" <robin.murphy@....com>,
        "Will Deacon" <will@...nel.org>,
        David Woodhouse <dwmw2@...radead.org>,
        Raj Ashok <ashok.raj@...el.com>,
        "Tian, Kevin" <kevin.tian@...el.com>, Yi Liu <yi.l.liu@...el.com>,
        "Yu, Fenghua" <fenghua.yu@...el.com>,
        Dave Jiang <dave.jiang@...el.com>,
        Tony Luck <tony.luck@...el.com>,
        "Zanussi, Tom" <tom.zanussi@...el.com>,
        Jacob Pan <jacob.jun.pan@...ux.intel.com>
Subject: [PATCH v2 2/8] iommu/vt-d: Remove PASID supervisor request support

There's no more usage,  remove PASID supervisor support.

Suggested-by: Lu Baolu <baolu.lu@...ux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@...ux.intel.com>
---
 drivers/iommu/intel/pasid.c | 43 -------------------------------------
 drivers/iommu/intel/pasid.h |  7 ------
 2 files changed, 50 deletions(-)

diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 633e0a4a01e7..c5d479770e12 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -335,15 +335,6 @@ static inline void pasid_set_fault_enable(struct pasid_entry *pe)
 	pasid_set_bits(&pe->val[0], 1 << 1, 0);
 }
 
-/*
- * Setup the SRE(Supervisor Request Enable) field (Bit 128) of a
- * scalable mode PASID entry.
- */
-static inline void pasid_set_sre(struct pasid_entry *pe)
-{
-	pasid_set_bits(&pe->val[2], 1 << 0, 1);
-}
-
 /*
  * Setup the WPE(Write Protect Enable) field (Bit 132) of a
  * scalable mode PASID entry.
@@ -521,23 +512,6 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu,
 		return -EINVAL;
 	}
 
-	if (flags & PASID_FLAG_SUPERVISOR_MODE) {
-#ifdef CONFIG_X86
-		unsigned long cr0 = read_cr0();
-
-		/* CR0.WP is normally set but just to be sure */
-		if (unlikely(!(cr0 & X86_CR0_WP))) {
-			pr_err("No CPU write protect!\n");
-			return -EINVAL;
-		}
-#endif
-		if (!ecap_srs(iommu->ecap)) {
-			pr_err("No supervisor request support on %s\n",
-			       iommu->name);
-			return -EINVAL;
-		}
-	}
-
 	if ((flags & PASID_FLAG_FL5LP) && !cap_fl5lp_support(iommu->cap)) {
 		pr_err("No 5-level paging support for first-level on %s\n",
 		       iommu->name);
@@ -560,10 +534,6 @@ int intel_pasid_setup_first_level(struct intel_iommu *iommu,
 
 	/* Setup the first level page table pointer: */
 	pasid_set_flptr(pte, (u64)__pa(pgd));
-	if (flags & PASID_FLAG_SUPERVISOR_MODE) {
-		pasid_set_sre(pte);
-		pasid_set_wpe(pte);
-	}
 
 	if (flags & PASID_FLAG_FL5LP)
 		pasid_set_flpm(pte, 1);
@@ -658,12 +628,6 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu,
 	pasid_set_fault_enable(pte);
 	pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
 
-	/*
-	 * Since it is a second level only translation setup, we should
-	 * set SRE bit as well (addresses are expected to be GPAs).
-	 */
-	if (pasid != PASID_RID2PASID && ecap_srs(iommu->ecap))
-		pasid_set_sre(pte);
 	pasid_set_present(pte);
 	spin_unlock(&iommu->lock);
 
@@ -700,13 +664,6 @@ int intel_pasid_setup_pass_through(struct intel_iommu *iommu,
 	pasid_set_translation_type(pte, PASID_ENTRY_PGTT_PT);
 	pasid_set_fault_enable(pte);
 	pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
-
-	/*
-	 * We should set SRE bit as well since the addresses are expected
-	 * to be GPAs.
-	 */
-	if (ecap_srs(iommu->ecap))
-		pasid_set_sre(pte);
 	pasid_set_present(pte);
 	spin_unlock(&iommu->lock);
 
diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h
index 20c54e50f533..d6b7d21244b1 100644
--- a/drivers/iommu/intel/pasid.h
+++ b/drivers/iommu/intel/pasid.h
@@ -41,13 +41,6 @@
 #define FLPT_DEFAULT_DID		1
 #define NUM_RESERVED_DID		2
 
-/*
- * The SUPERVISOR_MODE flag indicates a first level translation which
- * can be used for access to kernel addresses. It is valid only for
- * access to the kernel's static 1:1 mapping of physical memory — not
- * to vmalloc or even module mappings.
- */
-#define PASID_FLAG_SUPERVISOR_MODE	BIT(0)
 #define PASID_FLAG_NESTED		BIT(1)
 #define PASID_FLAG_PAGE_SNOOP		BIT(2)
 
-- 
2.25.1