Re: [PATCH v5 02/11] powerpc/kernel/iommu: Add new iommu_table_in_use() helper
From: Frederic Barrat <hidden>
Date: 2021-07-19 13:54:18
Also in:
lkml
On 16/07/2021 10:27, Leonardo Bras wrote:
quoted hunk ↗ jump to hunk
@@ -1099,18 +1105,13 @@ int iommu_take_ownership(struct iommu_table *tbl) for (i = 0; i < tbl->nr_pools; i++) spin_lock_nest_lock(&tbl->pools[i].lock, &tbl->large_pool.lock); - iommu_table_release_pages(tbl); - - if (!bitmap_empty(tbl->it_map, tbl->it_size)) { + if (iommu_table_in_use(tbl)) { pr_err("iommu_tce: it_map is not empty"); ret = -EBUSY; - /* Undo iommu_table_release_pages, i.e. restore bit#0, etc */ - iommu_table_reserve_pages(tbl, tbl->it_reserved_start, - tbl->it_reserved_end); - } else { - memset(tbl->it_map, 0xff, sz); } + memset(tbl->it_map, 0xff, sz); +
So if the table is not empty, we fail (EBUSY) but we now also completely overwrite the bitmap. It was in an unexpected state, but we're making it worse. Or am I missing something? Fred
for (i = 0; i < tbl->nr_pools; i++) spin_unlock(&tbl->pools[i].lock); spin_unlock_irqrestore(&tbl->large_pool.lock, flags);