[PATCH v2 5/8] iommu/vt-d: Add first level page table interfaces

[Lu Baolu <baolu.lu@linux.intel.com>]

This adds functions to manipulate first level page tables
which could be used by a scalale mode capable IOMMU unit.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Liu Yi L <yi.l.liu@intel.com>
Cc: Yi Sun <yi.y.sun@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/Makefile             |   2 +-
 drivers/iommu/intel-iommu.c        |  33 +++
 drivers/iommu/intel-pgtable.c      | 376 +++++++++++++++++++++++++++++
 include/linux/intel-iommu.h        |  33 ++-
 include/trace/events/intel_iommu.h |  60 +++++
 5 files changed, 502 insertions(+), 2 deletions(-)
 create mode 100644 drivers/iommu/intel-pgtable.c

diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 35d17094fe3b..aa04f4c3ae26 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -18,7 +18,7 @@ obj-$(CONFIG_ARM_SMMU) += arm-smmu.o arm-smmu-impl.o
 obj-$(CONFIG_ARM_SMMU_V3) += arm-smmu-v3.o
 obj-$(CONFIG_DMAR_TABLE) += dmar.o
 obj-$(CONFIG_INTEL_IOMMU) += intel-iommu.o intel-pasid.o
-obj-$(CONFIG_INTEL_IOMMU) += intel-trace.o
+obj-$(CONFIG_INTEL_IOMMU) += intel-trace.o intel-pgtable.o
 obj-$(CONFIG_INTEL_IOMMU_DEBUGFS) += intel-iommu-debugfs.o
 obj-$(CONFIG_INTEL_IOMMU_SVM) += intel-svm.o
 obj-$(CONFIG_IPMMU_VMSA) += ipmmu-vmsa.o
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 66f76f6df2c2..a314892ee72b 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1670,6 +1670,37 @@ static void free_dmar_iommu(struct intel_iommu *iommu)
 #endif
 }
 
+/* First level 5-level paging support */
+static bool first_lvl_5lp_support(void)
+{
+	struct dmar_drhd_unit *drhd;
+	struct intel_iommu *iommu;
+	static int first_level_5lp_supported = -1;
+
+	if (likely(first_level_5lp_supported != -1))
+		return first_level_5lp_supported;
+
+	first_level_5lp_supported = 1;
+#ifdef CONFIG_X86
+	/* Match IOMMU first level and CPU paging mode */
+	if (!cpu_feature_enabled(X86_FEATURE_LA57)) {
+		first_level_5lp_supported = 0;
+		return first_level_5lp_supported;
+	}
+#endif /* #ifdef CONFIG_X86 */
+
+	rcu_read_lock();
+	for_each_active_iommu(iommu, drhd) {
+		if (!cap_5lp_support(iommu->cap)) {
+			first_level_5lp_supported = 0;
+			break;
+		}
+	}
+	rcu_read_unlock();
+
+	return first_level_5lp_supported;
+}
+
 static struct dmar_domain *alloc_domain(int flags)
 {
 	struct dmar_domain *domain;
@@ -1683,6 +1714,8 @@ static struct dmar_domain *alloc_domain(int flags)
 	domain->flags = flags;
 	domain->has_iotlb_device = false;
 	domain->ops = &second_lvl_pgtable_ops;
+	domain->first_lvl_5lp = first_lvl_5lp_support();
+	spin_lock_init(&domain->page_table_lock);
 	INIT_LIST_HEAD(&domain->devices);
 
 	return domain;
diff --git a/drivers/iommu/intel-pgtable.c b/drivers/iommu/intel-pgtable.c
new file mode 100644
index 000000000000..4a26d08a7570
--- /dev/null
+++ b/drivers/iommu/intel-pgtable.c
@@ -0,0 +1,376 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * intel-pgtable.c - Intel IOMMU page table manipulation library
+ *
+ * Copyright (C) 2019 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ */
+
+#define pr_fmt(fmt)     "DMAR: " fmt
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/io.h>
+#include <linux/export.h>
+#include <linux/intel-iommu.h>
+#include <asm/cacheflush.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <trace/events/intel_iommu.h>
+
+/*
+ * first_lvl_map: Map a range of IO virtual address to physical addresses.
+ */
+#ifdef CONFIG_X86
+#define pgtable_populate(domain, nm)					\
+do {									\
+	void *__new = alloc_pgtable_page(domain->nid);			\
+	if (!__new)							\
+		return -ENOMEM;						\
+	smp_wmb();							\
+	spin_lock(&(domain)->page_table_lock);				\
+	if (nm ## _present(*nm)) {					\
+		free_pgtable_page(__new);				\
+	} else {							\
+		set_##nm(nm, __##nm(__pa(__new) | _PAGE_TABLE));	\
+		domain_flush_cache(domain, nm, sizeof(nm##_t));		\
+	}								\
+	spin_unlock(&(domain)->page_table_lock);			\
+} while (0)
+
+static int
+first_lvl_map_pte_range(struct dmar_domain *domain, pmd_t *pmd,
+			unsigned long addr, unsigned long end,
+			phys_addr_t phys_addr, pgprot_t prot)
+{
+	pte_t *pte, *first_pte;
+	u64 pfn;
+
+	pfn = phys_addr >> PAGE_SHIFT;
+	if (unlikely(pmd_none(*pmd)))
+		pgtable_populate(domain, pmd);
+
+	first_pte = pte = pte_offset_kernel(pmd, addr);
+
+	do {
+		if (pte_present(*pte))
+			pr_crit("ERROR: PTE for vPFN 0x%llx already set to 0x%llx\n",
+				pfn, (unsigned long long)pte_val(*pte));
+		set_pte(pte, pfn_pte(pfn, prot));
+		pfn++;
+	} while (pte++, addr += PAGE_SIZE, addr != end);
+
+	domain_flush_cache(domain, first_pte, (void *)pte - (void *)first_pte);
+
+	return 0;
+}
+
+static int
+first_lvl_map_pmd_range(struct dmar_domain *domain, pud_t *pud,
+			unsigned long addr, unsigned long end,
+			phys_addr_t phys_addr, pgprot_t prot)
+{
+	unsigned long next;
+	pmd_t *pmd;
+
+	if (unlikely(pud_none(*pud)))
+		pgtable_populate(domain, pud);
+	pmd = pmd_offset(pud, addr);
+
+	phys_addr -= addr;
+	do {
+		next = pmd_addr_end(addr, end);
+		if (first_lvl_map_pte_range(domain, pmd, addr, next,
+					    phys_addr + addr, prot))
+			return -ENOMEM;
+	} while (pmd++, addr = next, addr != end);
+
+	return 0;
+}
+
+static int
+first_lvl_map_pud_range(struct dmar_domain *domain, p4d_t *p4d,
+			unsigned long addr, unsigned long end,
+			phys_addr_t phys_addr, pgprot_t prot)
+{
+	unsigned long next;
+	pud_t *pud;
+
+	if (unlikely(p4d_none(*p4d)))
+		pgtable_populate(domain, p4d);
+
+	pud = pud_offset(p4d, addr);
+
+	phys_addr -= addr;
+	do {
+		next = pud_addr_end(addr, end);
+		if (first_lvl_map_pmd_range(domain, pud, addr, next,
+					    phys_addr + addr, prot))
+			return -ENOMEM;
+	} while (pud++, addr = next, addr != end);
+
+	return 0;
+}
+
+static int
+first_lvl_map_p4d_range(struct dmar_domain *domain, pgd_t *pgd,
+			unsigned long addr, unsigned long end,
+			phys_addr_t phys_addr, pgprot_t prot)
+{
+	unsigned long next;
+	p4d_t *p4d;
+
+	if (domain->first_lvl_5lp && unlikely(pgd_none(*pgd)))
+		pgtable_populate(domain, pgd);
+
+	p4d = p4d_offset(pgd, addr);
+
+	phys_addr -= addr;
+	do {
+		next = p4d_addr_end(addr, end);
+		if (first_lvl_map_pud_range(domain, p4d, addr, next,
+					    phys_addr + addr, prot))
+			return -ENOMEM;
+	} while (p4d++, addr = next, addr != end);
+
+	return 0;
+}
+
+int first_lvl_map_range(struct dmar_domain *domain, unsigned long addr,
+			unsigned long end, phys_addr_t phys_addr, int dma_prot)
+{
+	unsigned long next;
+	pgprot_t prot;
+	pgd_t *pgd;
+
+	trace_domain_mm_map(domain, addr, end, phys_addr);
+
+	/*
+	 * There is no PAGE_KERNEL_WO for a pte entry, so let's use RW
+	 * for a pte that requires write operation.
+	 */
+	prot = dma_prot & DMA_PTE_WRITE ? PAGE_KERNEL : PAGE_KERNEL_RO;
+	if (WARN_ON(addr >= end))
+		return -EINVAL;
+
+	phys_addr -= addr;
+	pgd = pgd_offset_pgd(domain->pgd, addr);
+	do {
+		next = pgd_addr_end(addr, end);
+		if (first_lvl_map_p4d_range(domain, pgd, addr, next,
+					    phys_addr + addr, prot))
+			return -ENOMEM;
+	} while (pgd++, addr = next, addr != end);
+
+	return 0;
+}
+
+/*
+ * first_lvl_unmap: Unmap an existing mapping between a range of IO virtual
+ *		    address and physical addresses.
+ */
+static struct page *
+first_lvl_unmap_pte_range(struct dmar_domain *domain, pmd_t *pmd,
+			  unsigned long addr, unsigned long end,
+			  struct page *freelist)
+{
+	unsigned long start;
+	pte_t *pte, *first_pte;
+
+	start = addr;
+	pte = pte_offset_kernel(pmd, addr);
+	first_pte = pte;
+	do {
+		set_pte(pte, __pte(0));
+	} while (pte++, addr += PAGE_SIZE, addr != end);
+
+	domain_flush_cache(domain, first_pte, (void *)pte - (void *)first_pte);
+
+	/*
+	 * Reclaim pmd page, lock is unnecessary here if it owns
+	 * the whole range.
+	 */
+	if (start != end && IS_ALIGNED(start | end, PMD_SIZE)) {
+		struct page *pte_page;
+
+		pte_page = pmd_page(*pmd);
+		pte_page->freelist = freelist;
+		freelist = pte_page;
+		pmd_clear(pmd);
+		domain_flush_cache(domain, pmd, sizeof(pmd_t));
+	}
+
+	return freelist;
+}
+
+static struct page *
+first_lvl_unmap_pmd_range(struct dmar_domain *domain, pud_t *pud,
+			  unsigned long addr, unsigned long end,
+			  struct page *freelist)
+{
+	pmd_t *pmd;
+	unsigned long start, next;
+
+	start = addr;
+	pmd = pmd_offset(pud, addr);
+	do {
+		next = pmd_addr_end(addr, end);
+		if (pmd_none_or_clear_bad(pmd))
+			continue;
+		freelist = first_lvl_unmap_pte_range(domain, pmd,
+						     addr, next, freelist);
+	} while (pmd++, addr = next, addr != end);
+
+	/*
+	 * Reclaim pud page, lock is unnecessary here if it owns
+	 * the whole range.
+	 */
+	if (start != end && IS_ALIGNED(start | end, PUD_SIZE)) {
+		struct page *pmd_page;
+
+		pmd_page = pud_page(*pud);
+		pmd_page->freelist = freelist;
+		freelist = pmd_page;
+		pud_clear(pud);
+		domain_flush_cache(domain, pud, sizeof(pud_t));
+	}
+
+	return freelist;
+}
+
+static struct page *
+first_lvl_unmap_pud_range(struct dmar_domain *domain, p4d_t *p4d,
+			  unsigned long addr, unsigned long end,
+			  struct page *freelist)
+{
+	pud_t *pud;
+	unsigned long start, next;
+
+	start = addr;
+	pud = pud_offset(p4d, addr);
+	do {
+		next = pud_addr_end(addr, end);
+		if (pud_none_or_clear_bad(pud))
+			continue;
+		freelist = first_lvl_unmap_pmd_range(domain, pud,
+						     addr, next, freelist);
+	} while (pud++, addr = next, addr != end);
+
+	/*
+	 * Reclaim p4d page, lock is unnecessary here if it owns
+	 * the whole range.
+	 */
+	if (start != end && IS_ALIGNED(start | end, P4D_SIZE)) {
+		struct page *pud_page;
+
+		pud_page = p4d_page(*p4d);
+		pud_page->freelist = freelist;
+		freelist = pud_page;
+		p4d_clear(p4d);
+		domain_flush_cache(domain, p4d, sizeof(p4d_t));
+	}
+
+	return freelist;
+}
+
+static struct page *
+first_lvl_unmap_p4d_range(struct dmar_domain *domain, pgd_t *pgd,
+			  unsigned long addr, unsigned long end,
+			  struct page *freelist)
+{
+	p4d_t *p4d;
+	unsigned long start, next;
+
+	start = addr;
+	p4d = p4d_offset(pgd, addr);
+	do {
+		next = p4d_addr_end(addr, end);
+		if (p4d_none_or_clear_bad(p4d))
+			continue;
+		freelist = first_lvl_unmap_pud_range(domain, p4d,
+						     addr, next, freelist);
+	} while (p4d++, addr = next, addr != end);
+
+	/*
+	 * Reclaim pgd page, lock is unnecessary here if it owns
+	 * the whole range.
+	 */
+	if (domain->first_lvl_5lp && start != end &&
+	    IS_ALIGNED(start | end, PGDIR_SIZE)) {
+		struct page *p4d_page;
+
+		p4d_page = pgd_page(*pgd);
+		p4d_page->freelist = freelist;
+		freelist = p4d_page;
+		pgd_clear(pgd);
+		domain_flush_cache(domain, pgd, sizeof(pgd_t));
+	}
+
+	return freelist;
+}
+
+struct page *first_lvl_unmap_range(struct dmar_domain *domain,
+				   unsigned long addr, unsigned long end)
+{
+	pgd_t *pgd;
+	unsigned long next;
+	struct page *freelist = NULL;
+
+	trace_domain_mm_unmap(domain, addr, end);
+
+	if (WARN_ON(addr >= end))
+		return NULL;
+
+	pgd = pgd_offset_pgd(domain->pgd, addr);
+	do {
+		next = pgd_addr_end(addr, end);
+		if (pgd_none_or_clear_bad(pgd))
+			continue;
+		freelist = first_lvl_unmap_p4d_range(domain, pgd,
+						     addr, next, freelist);
+	} while (pgd++, addr = next, addr != end);
+
+	return freelist;
+}
+
+static pte_t *iova_to_pte(struct dmar_domain *domain, unsigned long iova)
+{
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+
+	if (WARN_ON_ONCE(!IS_ALIGNED(iova, PAGE_SIZE)))
+		return NULL;
+
+	pgd = pgd_offset_pgd(domain->pgd, iova);
+	if (pgd_none_or_clear_bad(pgd))
+		return NULL;
+
+	p4d = p4d_offset(pgd, iova);
+	if (p4d_none_or_clear_bad(p4d))
+		return NULL;
+
+	pud = pud_offset(p4d, iova);
+	if (pud_none_or_clear_bad(pud))
+		return NULL;
+
+	pmd = pmd_offset(pud, iova);
+	if (pmd_none_or_clear_bad(pmd))
+		return NULL;
+
+	return pte_offset_kernel(pmd, iova);
+}
+
+phys_addr_t
+first_lvl_iova_to_phys(struct dmar_domain *domain, unsigned long iova)
+{
+	pte_t *pte = iova_to_pte(domain, PAGE_ALIGN(iova));
+
+	if (!pte || !pte_present(*pte))
+		return 0;
+
+	return (pte_val(*pte) & PTE_PFN_MASK) | (iova & ~PAGE_MASK);
+}
+#endif /* CONFIG_X86 */
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 9b259756057b..9273e3f59078 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -540,9 +540,11 @@ struct dmar_domain {
 	struct iova_domain iovad;	/* iova's that belong to this domain */
 
 	/* page table used by this domain */
-	struct dma_pte	*pgd;		/* virtual address */
+	void		*pgd;		/* virtual address */
+	spinlock_t page_table_lock;	/* Protects page tables */
 	int		gaw;		/* max guest address width */
 	const struct pgtable_ops *ops;	/* page table ops */
+	bool		first_lvl_5lp;	/* First level 5-level paging support */
 
 	/* adjusted guest address width, 0 is level 2 30-bit */
 	int		agaw;
@@ -708,6 +710,35 @@ int for_each_device_domain(int (*fn)(struct device_domain_info *info,
 void iommu_flush_write_buffer(struct intel_iommu *iommu);
 int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev);
 
+#ifdef CONFIG_X86
+int first_lvl_map_range(struct dmar_domain *domain, unsigned long addr,
+			unsigned long end, phys_addr_t phys_addr, int dma_prot);
+struct page *first_lvl_unmap_range(struct dmar_domain *domain,
+				   unsigned long addr, unsigned long end);
+phys_addr_t first_lvl_iova_to_phys(struct dmar_domain *domain,
+				   unsigned long iova);
+#else
+static inline int
+first_lvl_map_range(struct dmar_domain *domain, unsigned long addr,
+		    unsigned long end, phys_addr_t phys_addr, int dma_prot)
+{
+	return -ENODEV;
+}
+
+static inline struct page *
+first_lvl_unmap_range(struct dmar_domain *domain,
+		      unsigned long addr, unsigned long end)
+{
+	return NULL;
+}
+
+static inline phys_addr_t
+first_lvl_iova_to_phys(struct dmar_domain *domain, unsigned long iova)
+{
+	return 0;
+}
+#endif /* CONFIG_X86 */
+
 #ifdef CONFIG_INTEL_IOMMU_SVM
 extern void intel_svm_check(struct intel_iommu *iommu);
 extern int intel_svm_enable_prq(struct intel_iommu *iommu);
diff --git a/include/trace/events/intel_iommu.h b/include/trace/events/intel_iommu.h
index 54e61d456cdf..e8c95290fd13 100644
--- a/include/trace/events/intel_iommu.h
+++ b/include/trace/events/intel_iommu.h
@@ -99,6 +99,66 @@ DEFINE_EVENT(dma_unmap, bounce_unmap_single,
 	TP_ARGS(dev, dev_addr, size)
 );
 
+DECLARE_EVENT_CLASS(domain_map,
+	TP_PROTO(struct dmar_domain *domain, unsigned long addr,
+		 unsigned long end, phys_addr_t phys_addr),
+
+	TP_ARGS(domain, addr, end, phys_addr),
+
+	TP_STRUCT__entry(
+		__field(struct dmar_domain *, domain)
+		__field(unsigned long, addr)
+		__field(unsigned long, end)
+		__field(phys_addr_t, phys_addr)
+	),
+
+	TP_fast_assign(
+		__entry->domain = domain;
+		__entry->addr = addr;
+		__entry->end = end;
+		__entry->phys_addr = phys_addr;
+	),
+
+	TP_printk("domain=%p addr=0x%lx end=0x%lx phys_addr=0x%llx",
+		  __entry->domain, __entry->addr, __entry->end,
+		  (unsigned long long)__entry->phys_addr)
+);
+
+DEFINE_EVENT(domain_map, domain_mm_map,
+	TP_PROTO(struct dmar_domain *domain, unsigned long addr,
+		 unsigned long end, phys_addr_t phys_addr),
+
+	TP_ARGS(domain, addr, end, phys_addr)
+);
+
+DECLARE_EVENT_CLASS(domain_unmap,
+	TP_PROTO(struct dmar_domain *domain, unsigned long addr,
+		 unsigned long end),
+
+	TP_ARGS(domain, addr, end),
+
+	TP_STRUCT__entry(
+		__field(struct dmar_domain *, domain)
+		__field(unsigned long, addr)
+		__field(unsigned long, end)
+	),
+
+	TP_fast_assign(
+		__entry->domain = domain;
+		__entry->addr = addr;
+		__entry->end = end;
+	),
+
+	TP_printk("domain=%p addr=0x%lx end=0x%lx",
+		  __entry->domain, __entry->addr, __entry->end)
+);
+
+DEFINE_EVENT(domain_unmap, domain_mm_unmap,
+	TP_PROTO(struct dmar_domain *domain, unsigned long addr,
+		 unsigned long end),
+
+	TP_ARGS(domain, addr, end)
+);
 #endif /* _TRACE_INTEL_IOMMU_H */
 
 /* This part must be outside protection */
-- 
2.17.1

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