linux-kernel - [PATCH v1 5/6] iommu/vt-d: Remove global g

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Date:   Sat, 25 Jun 2022 20:52:03 +0800
From:   Lu Baolu <baolu.lu@...ux.intel.com>
To:     Joerg Roedel <joro@...tes.org>, Steve Wahl <steve.wahl@....com>,
        Kevin Tian <kevin.tian@...el.com>
Cc:     David Woodhouse <dwmw2@...radead.org>,
        Jerry Snitselaar <jsnitsel@...hat.com>,
        Mike Travis <mike.travis@....com>,
        Dimitri Sivanich <sivanich@....com>,
        Russ Anderson <russ.anderson@....com>, iommu@...ts.linux.dev,
        iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
        Lu Baolu <baolu.lu@...ux.intel.com>
Subject: [PATCH v1 5/6] iommu/vt-d: Remove global g_iommus array

The g_iommus is not used anywhere. Remove it to avoid dead code.

Signed-off-by: Lu Baolu <baolu.lu@...ux.intel.com>
---
 drivers/iommu/intel/iommu.c | 42 -------------------------------------
 1 file changed, 42 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index f6d7055cffd7..9a284394b2c5 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -126,9 +126,6 @@ static inline unsigned long virt_to_dma_pfn(void *p)
 	return page_to_dma_pfn(virt_to_page(p));
 }
 
-/* global iommu list, set NULL for ignored DMAR units */
-static struct intel_iommu **g_iommus;
-
 static void __init check_tylersburg_isoch(void);
 static int rwbf_quirk;
 
@@ -287,9 +284,6 @@ static LIST_HEAD(dmar_satc_units);
 #define for_each_rmrr_units(rmrr) \
 	list_for_each_entry(rmrr, &dmar_rmrr_units, list)
 
-/* bitmap for indexing intel_iommus */
-static int g_num_of_iommus;
-
 static void dmar_remove_one_dev_info(struct device *dev);
 
 int dmar_disabled = !IS_ENABLED(CONFIG_INTEL_IOMMU_DEFAULT_ON);
@@ -1694,7 +1688,6 @@ static void free_dmar_iommu(struct intel_iommu *iommu)
 		iommu->domain_ids = NULL;
 	}
 
-	g_iommus[iommu->seq_id] = NULL;
 	iommu->flags &= ~VTD_FLAG_IOMMU_PROBED;
 
 	/* free context mapping */
@@ -2899,36 +2892,6 @@ static int __init init_dmars(void)
 	struct intel_iommu *iommu;
 	int ret;
 
-	/*
-	 * for each drhd
-	 *    allocate root
-	 *    initialize and program root entry to not present
-	 * endfor
-	 */
-	for_each_drhd_unit(drhd) {
-		/*
-		 * lock not needed as this is only incremented in the single
-		 * threaded kernel __init code path all other access are read
-		 * only
-		 */
-		if (g_num_of_iommus < DMAR_UNITS_SUPPORTED) {
-			g_num_of_iommus++;
-			continue;
-		}
-		pr_err_once("Exceeded %d IOMMUs\n", DMAR_UNITS_SUPPORTED);
-	}
-
-	/* Preallocate enough resources for IOMMU hot-addition */
-	if (g_num_of_iommus < DMAR_UNITS_SUPPORTED)
-		g_num_of_iommus = DMAR_UNITS_SUPPORTED;
-
-	g_iommus = kcalloc(g_num_of_iommus, sizeof(struct intel_iommu *),
-			GFP_KERNEL);
-	if (!g_iommus) {
-		ret = -ENOMEM;
-		goto error;
-	}
-
 	ret = intel_cap_audit(CAP_AUDIT_STATIC_DMAR, NULL);
 	if (ret)
 		goto free_iommu;
@@ -2951,7 +2914,6 @@ static int __init init_dmars(void)
 						   intel_pasid_max_id);
 		}
 
-		g_iommus[iommu->seq_id] = iommu;
 		iommu->flags |= VTD_FLAG_IOMMU_PROBED;
 
 		intel_iommu_init_qi(iommu);
@@ -3079,9 +3041,6 @@ static int __init init_dmars(void)
 		free_dmar_iommu(iommu);
 	}
 
-	kfree(g_iommus);
-
-error:
 	return ret;
 }
 
@@ -3488,7 +3447,6 @@ static int intel_iommu_add(struct dmar_drhd_unit *dmaru)
 	if (iommu->gcmd & DMA_GCMD_TE)
 		iommu_disable_translation(iommu);
 
-	g_iommus[iommu->seq_id] = iommu;
 	iommu->flags |= VTD_FLAG_IOMMU_PROBED;
 	ret = iommu_init_domains(iommu);
 	if (ret == 0)
-- 
2.25.1