linux-kernel - [Patch v4 6/9] iommu/amd: Add function copy_dev

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Date:	Wed, 25 May 2016 14:28:52 +0800
From:	Baoquan He <bhe@...hat.com>
To:	joro@...tes.org
Cc:	iommu@...ts.linux-foundation.org, vincent.wan@....com,
	xlpang@...hat.com, dyoung@...hat.com, linux-kernel@...r.kernel.org,
	Baoquan He <bhe@...hat.com>
Subject: [Patch v4 6/9] iommu/amd: Add function copy_dev_tables

Add function copy_dev_tables to copy old DTE of the 1st kernel to
the new DTE table. Since all iommu share the same DTE table the
copy only need be done once as long as the physical address of
old DTE table is retrieved from iommu reg. Besides the old domain
id occupied in 1st kernel need be reserved in order to avoid touch
the old translation tables.

Signed-off-by: Baoquan He <bhe@...hat.com>
---
 drivers/iommu/amd_iommu.c       |  2 +-
 drivers/iommu/amd_iommu_init.c  | 38 ++++++++++++++++++++++++++++++++++++++
 drivers/iommu/amd_iommu_types.h |  1 +
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 1c916cc..f3bd7fd 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2081,7 +2081,7 @@ static void set_dte_entry(u16 devid, struct protection_domain *domain, bool ats)
 		flags    |= tmp;
 	}
 
-	flags &= ~(0xffffUL);
+	flags &= ~DEV_DOMID_MASK;
 	flags |= domain->id;
 
 	amd_iommu_dev_table[devid].data[1]  = flags;
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 9c1aa54..71c7ac9 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -664,6 +664,44 @@ static int get_dev_entry_bit(u16 devid, u8 bit)
 }
 
 
+static int copy_dev_tables(void)
+{
+	u64 entry;
+	u32 lo, hi, devid;
+	phys_addr_t old_devtb_phys;
+	struct dev_table_entry *old_devtb;
+	u16 dom_id, dte_v;
+	struct amd_iommu *iommu;
+	static int copied;
+
+        for_each_iommu(iommu) {
+		if (!translation_pre_enabled()) {
+			pr_err("IOMMU:%d is not pre-enabled!/n", iommu->index);
+			return -1;
+		}
+
+		if (copied)
+			continue;
+
+                lo = readl(iommu->mmio_base + MMIO_DEV_TABLE_OFFSET);
+                hi = readl(iommu->mmio_base + MMIO_DEV_TABLE_OFFSET + 4);
+                entry = (((u64) hi) << 32) + lo;
+                old_devtb_phys = entry & PAGE_MASK;
+                old_devtb = memremap(old_devtb_phys, dev_table_size, MEMREMAP_WB);
+                for (devid = 0; devid <= amd_iommu_last_bdf; ++devid) {
+                        amd_iommu_dev_table[devid] = old_devtb[devid];
+                        dom_id = amd_iommu_dev_table[devid].data[1] & DEV_DOMID_MASK;
+			dte_v = amd_iommu_dev_table[devid].data[0] & DTE_FLAG_V;
+			if (!dte_v)
+				continue;
+                        __set_bit(dom_id, amd_iommu_pd_alloc_bitmap);
+                }
+		memunmap(old_devtb);
+		copied = 1;
+        }
+	return 0;
+}
+
 void amd_iommu_apply_erratum_63(u16 devid)
 {
 	int sysmgt;
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index 7796edf..34acd73 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -311,6 +311,7 @@
 #define DTE_FLAG_MASK	(0x3ffULL << 32)
 #define DTE_GLX_SHIFT	(56)
 #define DTE_GLX_MASK	(3)
+#define DEV_DOMID_MASK 	0xffffULL
 
 #define DTE_GCR3_VAL_A(x)	(((x) >> 12) & 0x00007ULL)
 #define DTE_GCR3_VAL_B(x)	(((x) >> 15) & 0x0ffffULL)
-- 
2.5.5