From 10ebd8556b7990499c896a550e3d416b444211e6 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 02:23:07 +0000
Subject: [PATCH] add led
---
kernel/drivers/iommu/intel/pasid.c | 28 ++++++++++++++++++++--------
1 files changed, 20 insertions(+), 8 deletions(-)
diff --git a/kernel/drivers/iommu/intel/pasid.c b/kernel/drivers/iommu/intel/pasid.c
index 86fd49a..9b24e82 100644
--- a/kernel/drivers/iommu/intel/pasid.c
+++ b/kernel/drivers/iommu/intel/pasid.c
@@ -24,7 +24,6 @@
/*
* Intel IOMMU system wide PASID name space:
*/
-static DEFINE_SPINLOCK(pasid_lock);
u32 intel_pasid_max_id = PASID_MAX;
int vcmd_alloc_pasid(struct intel_iommu *iommu, u32 *pasid)
@@ -187,6 +186,9 @@
attach_out:
device_attach_pasid_table(info, pasid_table);
+ if (!ecap_coherent(info->iommu->ecap))
+ clflush_cache_range(pasid_table->table, (1 << order) * PAGE_SIZE);
+
return 0;
}
@@ -259,19 +261,29 @@
dir_index = pasid >> PASID_PDE_SHIFT;
index = pasid & PASID_PTE_MASK;
- spin_lock(&pasid_lock);
+retry:
entries = get_pasid_table_from_pde(&dir[dir_index]);
if (!entries) {
entries = alloc_pgtable_page(info->iommu->node);
- if (!entries) {
- spin_unlock(&pasid_lock);
+ if (!entries)
return NULL;
- }
- WRITE_ONCE(dir[dir_index].val,
- (u64)virt_to_phys(entries) | PASID_PTE_PRESENT);
+ /*
+ * The pasid directory table entry won't be freed after
+ * allocation. No worry about the race with free and
+ * clear. However, this entry might be populated by others
+ * while we are preparing it. Use theirs with a retry.
+ */
+ if (cmpxchg64(&dir[dir_index].val, 0ULL,
+ (u64)virt_to_phys(entries) | PASID_PTE_PRESENT)) {
+ free_pgtable_page(entries);
+ goto retry;
+ }
+ if (!ecap_coherent(info->iommu->ecap)) {
+ clflush_cache_range(entries, VTD_PAGE_SIZE);
+ clflush_cache_range(&dir[dir_index].val, sizeof(*dir));
+ }
}
- spin_unlock(&pasid_lock);
return &entries[index];
}
--
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