[PATCH v4 13/13] iommu/amd: Adopt IO page table framework for AMD IOMMU v1 page table

From: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
To: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org
Cc: joro@8bytes.org, will@kernel.org,
	Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Subject: [PATCH v4 13/13] iommu/amd: Adopt IO page table framework for AMD IOMMU v1 page table
Date: Tue, 15 Dec 2020 01:37:05 -0600	[thread overview]
Message-ID: <20201215073705.123786-14-suravee.suthikulpanit@amd.com> (raw)
In-Reply-To: <20201215073705.123786-1-suravee.suthikulpanit@amd.com>

Switch to using IO page table framework for AMD IOMMU v1 page table.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 drivers/iommu/amd/amd_iommu.h |  1 +
 drivers/iommu/amd/init.c      |  2 ++
 drivers/iommu/amd/iommu.c     | 48 ++++++++++++++++++++++++++---------
 3 files changed, 39 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index 3770b1a4d51c..91452e0ff072 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -36,6 +36,7 @@ extern void amd_iommu_disable(void);
 extern int amd_iommu_reenable(int);
 extern int amd_iommu_enable_faulting(void);
 extern int amd_iommu_guest_ir;
+extern enum io_pgtable_fmt amd_iommu_pgtable;
 
 /* IOMMUv2 specific functions */
 struct iommu_domain;
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 23a790f8f550..5fb4bea14cc4 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -147,6 +147,8 @@ struct ivmd_header {
 bool amd_iommu_dump;
 bool amd_iommu_irq_remap __read_mostly;
 
+enum io_pgtable_fmt amd_iommu_pgtable = AMD_IOMMU_V1;
+
 int amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_VAPIC;
 static int amd_iommu_xt_mode = IRQ_REMAP_XAPIC_MODE;
 
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 1f04b251f0c6..571e8806e4a1 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -31,6 +31,7 @@
 #include <linux/irqdomain.h>
 #include <linux/percpu.h>
 #include <linux/iova.h>
+#include <linux/io-pgtable.h>
 #include <asm/irq_remapping.h>
 #include <asm/io_apic.h>
 #include <asm/apic.h>
@@ -1901,7 +1902,7 @@ static void protection_domain_free(struct protection_domain *domain)
 	kfree(domain);
 }
 
-static int protection_domain_init(struct protection_domain *domain, int mode)
+static int protection_domain_init_v1(struct protection_domain *domain, int mode)
 {
 	u64 *pt_root = NULL;
 
@@ -1924,34 +1925,55 @@ static int protection_domain_init(struct protection_domain *domain, int mode)
 	return 0;
 }
 
-static struct protection_domain *protection_domain_alloc(int mode)
+static struct protection_domain *protection_domain_alloc(unsigned int type)
 {
+	struct io_pgtable_ops *pgtbl_ops;
 	struct protection_domain *domain;
+	int pgtable = amd_iommu_pgtable;
+	int mode = DEFAULT_PGTABLE_LEVEL;
+	int ret;
 
 	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 	if (!domain)
 		return NULL;
 
-	if (protection_domain_init(domain, mode))
+	/*
+	 * Force IOMMU v1 page table when iommu=pt and
+	 * when allocating domain for pass-through devices.
+	 */
+	if (type == IOMMU_DOMAIN_IDENTITY) {
+		pgtable = AMD_IOMMU_V1;
+		mode = PAGE_MODE_NONE;
+	} else if (type == IOMMU_DOMAIN_UNMANAGED) {
+		pgtable = AMD_IOMMU_V1;
+	}
+
+	switch (pgtable) {
+	case AMD_IOMMU_V1:
+		ret = protection_domain_init_v1(domain, mode);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	if (ret)
 		goto out_err;
 
-	return domain;
+	pgtbl_ops = alloc_io_pgtable_ops(pgtable, &domain->iop.pgtbl_cfg, domain);
+	if (!pgtbl_ops)
+		goto out_err;
 
+	return domain;
 out_err:
 	kfree(domain);
-
 	return NULL;
 }
 
 static struct iommu_domain *amd_iommu_domain_alloc(unsigned type)
 {
 	struct protection_domain *domain;
-	int mode = DEFAULT_PGTABLE_LEVEL;
-
-	if (type == IOMMU_DOMAIN_IDENTITY)
-		mode = PAGE_MODE_NONE;
 
-	domain = protection_domain_alloc(mode);
+	domain = protection_domain_alloc(type);
 	if (!domain)
 		return NULL;
 
@@ -2070,7 +2092,8 @@ static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova,
 	int prot = 0;
 	int ret = -EINVAL;
 
-	if (domain->iop.mode == PAGE_MODE_NONE)
+	if ((amd_iommu_pgtable == AMD_IOMMU_V1) &&
+	    (domain->iop.mode == PAGE_MODE_NONE))
 		return -EINVAL;
 
 	if (iommu_prot & IOMMU_READ)
@@ -2093,7 +2116,8 @@ static size_t amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova,
 	struct protection_domain *domain = to_pdomain(dom);
 	struct io_pgtable_ops *ops = &domain->iop.iop.ops;
 
-	if (domain->iop.mode == PAGE_MODE_NONE)
+	if ((amd_iommu_pgtable == AMD_IOMMU_V1) &&
+	    (domain->iop.mode == PAGE_MODE_NONE))
 		return 0;
 
 	return (ops->unmap) ? ops->unmap(ops, iova, page_size, gather) : 0;
-- 
2.17.1

