[PATCH 1/3] move iova from drivers/pci/ to lib/

FUJITA Tomonori
2007-11-02T17:11:00Z

iova could be used by several IOMMUs. This patch just moves iova from
drivers/pci/ to lib/ and fixes the appropriate Makefile and Kconfig
files.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
---
arch/x86/Kconfig.x86_64 | 1 +
drivers/pci/Makefile | 2 +-
drivers/pci/intel-iommu.c | 1 -
drivers/pci/intel-iommu.h | 2 +-
drivers/pci/iova.c | 394 ---------------------------------------------
drivers/pci/iova.h | 51 ------
include/linux/iova.h | 51 ++++++
lib/Kconfig | 3 +
lib/Makefile | 2 +
lib/iova.c | 394 +++++++++++++++++++++++++++++++++++++++++++++
10 files changed, 453 insertions(+), 448 deletions(-)
delete mode 100644 drivers/pci/iova.c
delete mode 100644 drivers/pci/iova.h
create mode 100644 include/linux/iova.h
create mode 100644 lib/iova.c

diff --git a/arch/x86/Kconfig.x86_64 b/arch/x86/Kconfig.x86_64
index cc468ea..c10d3f0 100644
--- a/arch/x86/Kconfig.x86_64
+++ b/arch/x86/Kconfig.x86_64
@@ -749,6 +749,7 @@ config PCI_DOMAINS
config DMAR
bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
depends on PCI_MSI && ACPI && EXPERIMENTAL
+ select IOVA
help
DMA remapping (DMAR) devices support enables independent address
translations for Direct Memory Access (DMA) from devices.
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 5550556..00c3428 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -21,7 +21,7 @@ obj-$(CONFIG_PCI_MSI) += msi.o
obj-$(CONFIG_HT_IRQ) += htirq.o

# Build Intel IOMMU support
-obj-$(CONFIG_DMAR) += dmar.o iova.o intel-iommu.o
+obj-$(CONFIG_DMAR) += dmar.o intel-iommu.o

#
# Some architectures use the generic PCI setup functions
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index dc1edbd..1a23b4c 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -30,7 +30,6 @@
#include <linux/dmar.h>
#include <linux/dma-mapping.h>
#include <linux/mempool.h>
-#include "iova.h"
#include "intel-iommu.h"
#include <asm/proto.h> /* force_iommu in this header in x86-64*/
#include <asm/cacheflush.h>
diff --git a/drivers/pci/intel-iommu.h b/drivers/pci/intel-iommu.h
index f54efd1..750e1b5 100644
--- a/drivers/pci/intel-iommu.h
+++ b/drivers/pci/intel-iommu.h
@@ -23,7 +23,7 @@

#include <linux/types.h>
#include <linux/msi.h>
-#include "iova.h"
+#include <linux/iova.h>
#include <linux/io.h>

/*
diff --git a/drivers/pci/iova.c b/drivers/pci/iova.c
deleted file mode 100644
index 8de7ab6..0000000
--- a/drivers/pci/iova.c
+++ /dev/null
@@ -1,394 +0,0 @@
-/*
- * Copyright (c) 2006, Intel Corporation.
- *
- * This file is released under the GPLv2.
- *
- * Copyright (C) 2006 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
- */
-
-#include "iova.h"
-
-void
-init_iova_domain(struct iova_domain *iovad, unsigned long pfn_32bit)
-{
- spin_lock_init(&iovad->iova_alloc_lock);
- spin_lock_init(&iovad->iova_rbtree_lock);
- iovad->rbroot = RB_ROOT;
- iovad->cached32_node = NULL;
- iovad->dma_32bit_pfn = pfn_32bit;
-}
-
-static struct rb_node *
-__get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn)
-{
- if ((*limit_pfn != iovad->dma_32bit_pfn) ||
- (iovad->cached32_node == NULL))
- return rb_last(&iovad->rbroot);
- else {
- struct rb_node *prev_node = rb_prev(iovad->cached32_node);
- struct iova *curr_iova =
- container_of(iovad->cached32_node, struct iova, node);
- *limit_pfn = curr_iova->pfn_lo - 1;
- return prev_node;
- }
-}
-
-static void
-__cached_rbnode_insert_update(struct iova_domain *iovad,
- unsigned long limit_pfn, struct iova *new)
-{
- if (limit_pfn != iovad->dma_32bit_pfn)
- return;
- iovad->cached32_node = &new->node;
-}
-
-static void
-__cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
-{
- struct iova *cached_iova;
- struct rb_node *curr;
-
- if (!iovad->cached32_node)
- return;
- curr = iovad->cached32_node;
- cached_iova = container_of(curr, struct iova, node);
-
- if (free->pfn_lo >= cached_iova->pfn_lo)
- iovad->cached32_node = rb_next(&free->node);
-}
-
-/* Computes the padding size required, to make the
- * the start address naturally aligned on its size
- */
-static int
-iova_get_pad_size(int size, unsigned int limit_pfn)
-{
- unsigned int pad_size = 0;
- unsigned int order = ilog2(size);
-
- if (order)
- pad_size = (limit_pfn + 1) % (1 << order);
-
- return pad_size;
-}
-
-static int __alloc_iova_range(struct iova_domain *iovad, unsigned long size,
- unsigned long limit_pfn, struct iova *new, bool size_aligned)
-{
- struct rb_node *curr = NULL;
- unsigned long flags;
- unsigned long saved_pfn;
- unsigned int pad_size = 0;
-
- /* Walk the tree backwards */
- spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
- saved_pfn = limit_pfn;
- curr = __get_cached_rbnode(iovad, &limit_pfn);
- while (curr) {
- struct iova *curr_iova = container_of(curr, struct iova, node);
- if (limit_pfn < curr_iova->pfn_lo)
- goto move_left;
- else if (limit_pfn < curr_iova->pfn_hi)
- goto adjust_limit_pfn;
- else {
- if (size_aligned)
- pad_size = iova_get_pad_size(size, limit_pfn);
- if ((curr_iova->pfn_hi + size + pad_size) <= limit_pfn)
- break; /* found a free slot */
- }
-adjust_limit_pfn:
- limit_pfn = curr_iova->pfn_lo - 1;
-move_left:
- curr = rb_prev(curr);
- }
-
- if (!curr) {
- if (size_aligned)
- pad_size = iova_get_pad_size(size, limit_pfn);
- if ((IOVA_START_PFN + size + pad_size) > limit_pfn) {
- spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
- return -ENOMEM;
- }
- }
-
- /* pfn_lo will point to size aligned address if size_aligned is set */
- new->pfn_lo = limit_pfn - (size + pad_size) + 1;
- new->pfn_hi = new->pfn_lo + size - 1;
-
- spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
- return 0;
-}
-
-static void
-iova_insert_rbtree(struct rb_root *root, struct iova *iova)
-{
- struct rb_node **new = &(root->rb_node), *parent = NULL;
- /* Figure out where to put new node */
- while (*new) {
- struct iova *this = container_of(*new, struct iova, node);
- parent = *new;
-
- if (iova->pfn_lo < this->pfn_lo)
- new = &((*new)->rb_left);
- else if (iova->pfn_lo > this->pfn_lo)
- new = &((*new)->rb_right);
- else
- BUG(); /* this should not happen */
- }
- /* Add new node and rebalance tree. */
- rb_link_node(&iova->node, parent, new);
- rb_insert_color(&iova->node, root);
-}
-
-/**
- * alloc_iova - allocates an iova
- * @iovad - iova domain in question
- * @size - size of page frames to allocate
- * @limit_pfn - max limit address
- * @size_aligned - set if size_aligned address range is required
- * This function allocates an iova in the range limit_pfn to IOVA_START_PFN
- * looking from limit_pfn instead from IOVA_START_PFN. If the size_aligned
- * flag is set then the allocated address iova->pfn_lo will be naturally
- * aligned on roundup_power_of_two(size).
- */
-struct iova *
-alloc_iova(struct iova_domain *iovad, unsigned long size,
- unsigned long limit_pfn,
- bool size_aligned)
-{
- unsigned long flags;
- struct iova *new_iova;
- int ret;
-
- new_iova = alloc_iova_mem();
- if (!new_iova)
- return NULL;
-
- /* If size aligned is set then round the size to
- * to next power of two.
- */
- if (size_aligned)
- size = __roundup_pow_of_two(size);
-
- spin_lock_irqsave(&iovad->iova_alloc_lock, flags);
- ret = __alloc_iova_range(iovad, size, limit_pfn, new_iova,
- size_aligned);
-
- if (ret) {
- spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags);
- free_iova_mem(new_iova);
- return NULL;
- }
-
- /* Insert the new_iova into domain rbtree by holding writer lock */
- spin_lock(&iovad->iova_rbtree_lock);
- iova_insert_rbtree(&iovad->rbroot, new_iova);
- __cached_rbnode_insert_update(iovad, limit_pfn, new_iova);
- spin_unlock(&iovad->iova_rbtree_lock);
-
- spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags);
-
- return new_iova;
-}
-
-/**
- * find_iova - find's an iova for a given pfn
- * @iovad - iova domain in question.
- * pfn - page frame number
- * This function finds and returns an iova belonging to the
- * given doamin which matches the given pfn.
- */
-struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
-{
- unsigned long flags;
- struct rb_node *node;
-
- /* Take the lock so that no other thread is manipulating the rbtree */
- spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
- node = iovad->rbroot.rb_node;
- while (node) {
- struct iova *iova = container_of(node, struct iova, node);
-
- /* If pfn falls within iova's range, return iova */
- if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) {
- spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
- /* We are not holding the lock while this iova
- * is referenced by the caller as the same thread
- * which called this function also calls __free_iova()
- * and it is by desing that only one thread can possibly
- * reference a particular iova and hence no conflict.
- */
- return iova;
- }
-
- if (pfn < iova->pfn_lo)
- node = node->rb_left;
- else if (pfn > iova->pfn_lo)
- node = node->rb_right;
- }
-
- spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
- return NULL;
-}
-
-/**
- * __free_iova - frees the given iova
- * @iovad: iova domain in question.
- * @iova: iova in question.
- * Frees the given iova belonging to the giving domain
- */
-void
-__free_iova(struct iova_domain *iovad, struct iova *iova)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
- __cached_rbnode_delete_update(iovad, iova);
- rb_erase(&iova->node, &iovad->rbroot);
- spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
- free_iova_mem(iova);
-}
-
-/**
- * free_iova - finds and frees the iova for a given pfn
- * @iovad: - iova domain in question.
- * @pfn: - pfn that is allocated previously
- * This functions finds an iova for a given pfn and then
- * frees the iova from that domain.
- */
-void
-free_iova(struct iova_domain *iovad, unsigned long pfn)
-{
- struct iova *iova = find_iova(iovad, pfn);
- if (iova)
- __free_iova(iovad, iova);
-
-}
-
-/**
- * put_iova_domain - destroys the iova doamin
- * @iovad: - iova domain in question.
- * All the iova's in that domain are destroyed.
- */
-void put_iova_domain(struct iova_domain *iovad)
-{
- struct rb_node *node;
- unsigned long flags;
-
- spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
- node = rb_first(&iovad->rbroot);
- while (node) {
- struct iova *iova = container_of(node, struct iova, node);
- rb_erase(node, &iovad->rbroot);
- free_iova_mem(iova);
- node = rb_first(&iovad->rbroot);
- }
- spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
-}
-
-static int
-__is_range_overlap(struct rb_node *node,
- unsigned long pfn_lo, unsigned long pfn_hi)
-{
- struct iova *iova = container_of(node, struct iova, node);
-
- if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo))
- return 1;
- return 0;
-}
-
-static struct iova *
-__insert_new_range(struct iova_domain *iovad,
- unsigned long pfn_lo, unsigned long pfn_hi)
-{
- struct iova *iova;
-
- iova = alloc_iova_mem();
- if (!iova)
- return iova;
-
- iova->pfn_hi = pfn_hi;
- iova->pfn_lo = pfn_lo;
- iova_insert_rbtree(&iovad->rbroot, iova);
- return iova;
-}
-
-static void
-__adjust_overlap_range(struct iova *iova,
- unsigned long *pfn_lo, unsigned long *pfn_hi)
-{
- if (*pfn_lo < iova->pfn_lo)
- iova->pfn_lo = *pfn_lo;
- if (*pfn_hi > iova->pfn_hi)
- *pfn_lo = iova->pfn_hi + 1;
-}
-
-/**
- * reserve_iova - reserves an iova in the given range
- * @iovad: - iova domain pointer
- * @pfn_lo: - lower page frame address
- * @pfn_hi:- higher pfn adderss
- * This function allocates reserves the address range from pfn_lo to pfn_hi so
- * that this address is not dished out as part of alloc_iova.
- */
-struct iova *
-reserve_iova(struct iova_domain *iovad,
- unsigned long pfn_lo, unsigned long pfn_hi)
-{
- struct rb_node *node;
- unsigned long flags;
- struct iova *iova;
- unsigned int overlap = 0;
-
- spin_lock_irqsave(&iovad->iova_alloc_lock, flags);
- spin_lock(&iovad->iova_rbtree_lock);
- for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) {
- if (__is_range_overlap(node, pfn_lo, pfn_hi)) {
- iova = container_of(node, struct iova, node);
- __adjust_overlap_range(iova, &pfn_lo, &pfn_hi);
- if ((pfn_lo >= iova->pfn_lo) &&
- (pfn_hi <= iova->pfn_hi))
- goto finish;
- overlap = 1;
-
- } else if (overlap)
- break;
- }
-
- /* We are here either becasue this is the first reserver node
- * or need to insert remaining non overlap addr range
- */
- iova = __insert_new_range(iovad, pfn_lo, pfn_hi);
-finish:
-
- spin_unlock(&iovad->iova_rbtree_lock);
- spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags);
- return iova;
-}
-
-/**
- * copy_reserved_iova - copies the reserved between domains
- * @from: - source doamin from where to copy
- * @to: - destination domin where to copy
- * This function copies reserved iova's from one doamin to
- * other.
- */
-void
-copy_reserved_iova(struct iova_domain *from, struct iova_domain *to)
-{
- unsigned long flags;
- struct rb_node *node;
-
- spin_lock_irqsave(&from->iova_alloc_lock, flags);
- spin_lock(&from->iova_rbtree_lock);
- for (node = rb_first(&from->rbroot); node; node = rb_next(node)) {
- struct iova *iova = container_of(node, struct iova, node);
- struct iova *new_iova;
- new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi);
- if (!new_iova)
- printk(KERN_ERR "Reserve iova range %lx@%lx failed\n",
- iova->pfn_lo, iova->pfn_lo);
- }
- spin_unlock(&from->iova_rbtree_lock);
- spin_unlock_irqrestore(&from->iova_alloc_lock, flags);
-}
diff --git a/drivers/pci/iova.h b/drivers/pci/iova.h
deleted file mode 100644
index d521b5b..0000000
--- a/drivers/pci/iova.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * Copyright (c) 2006, Intel Corporation.
- *
- * This file is released under the GPLv2.
- *
- * Copyright (C) 2006 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
- *
- */
-
-#ifndef _IOVA_H_
-#define _IOVA_H_
-
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <linux/rbtree.h>
-#include <linux/dma-mapping.h>
-
-/* IO virtual address start page frame number */
-#define IOVA_START_PFN (1)
-
-/* iova structure */
-struct iova {
- struct rb_node node;
- unsigned long pfn_hi; /* IOMMU dish out addr hi */
- unsigned long pfn_lo; /* IOMMU dish out addr lo */
-};
-
-/* holds all the iova translations for a domain */
-struct iova_domain {
- spinlock_t iova_alloc_lock;/* Lock to protect iova allocation */
- spinlock_t iova_rbtree_lock; /* Lock to protect update of rbtree */
- struct rb_root rbroot; /* iova domain rbtree root */
- struct rb_node *cached32_node; /* Save last alloced node */
- unsigned long dma_32bit_pfn;
-};
-
-struct iova *alloc_iova_mem(void);
-void free_iova_mem(struct iova *iova);
-void free_iova(struct iova_domain *iovad, unsigned long pfn);
-void __free_iova(struct iova_domain *iovad, struct iova *iova);
-struct iova *alloc_iova(struct iova_domain *iovad, unsigned long size,
- unsigned long limit_pfn,
- bool size_aligned);
-struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
- unsigned long pfn_hi);
-void copy_reserved_iova(struct iova_domain *from, struct iova_domain *to);
-void init_iova_domain(struct iova_domain *iovad, unsigned long pfn_32bit);
-struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn);
-void put_iova_domain(struct iova_domain *iovad);
-
-#endif
diff --git a/include/linux/iova.h b/include/linux/iova.h
new file mode 100644
index 0000000..d521b5b
--- /dev/null
+++ b/include/linux/iova.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2006, Intel Corporation.
+ *
+ * This file is released under the GPLv2.
+ *
+ * Copyright (C) 2006 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
+ *
+ */
+
+#ifndef _IOVA_H_
+#define _IOVA_H_
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/rbtree.h>
+#include <linux/dma-mapping.h>
+
+/* IO virtual address start page frame number */
+#define IOVA_START_PFN (1)
+
+/* iova structure */
+struct iova {
+ struct rb_node node;
+ unsigned long pfn_hi; /* IOMMU dish out addr hi */
+ unsigned long pfn_lo; /* IOMMU dish out addr lo */
+};
+
+/* holds all the iova translations for a domain */
+struct iova_domain {
+ spinlock_t iova_alloc_lock;/* Lock to protect iova allocation */
+ spinlock_t iova_rbtree_lock; /* Lock to protect update of rbtree */
+ struct rb_root rbroot; /* iova domain rbtree root */
+ struct rb_node *cached32_node; /* Save last alloced node */
+ unsigned long dma_32bit_pfn;
+};
+
+struct iova *alloc_iova_mem(void);
+void free_iova_mem(struct iova *iova);
+void free_iova(struct iova_domain *iovad, unsigned long pfn);
+void __free_iova(struct iova_domain *iovad, struct iova *iova);
+struct iova *alloc_iova(struct iova_domain *iovad, unsigned long size,
+ unsigned long limit_pfn,
+ bool size_aligned);
+struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
+ unsigned long pfn_hi);
+void copy_reserved_iova(struct iova_domain *from, struct iova_domain *to);
+void init_iova_domain(struct iova_domain *iovad, unsigned long pfn_32bit);
+struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn);
+void put_iova_domain(struct iova_domain *iovad);
+
+#endif
diff --git a/lib/Kconfig b/lib/Kconfig
index ba3d104..4107547 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -141,4 +141,7 @@ config HAS_DMA
config CHECK_SIGNATURE
bool

+config IOVA
+ boolean
+
endmenu
diff --git a/lib/Makefile b/lib/Makefile
index 3a0983b..7de33cc 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -66,6 +66,8 @@ obj-$(CONFIG_AUDIT_GENERIC) += audit.o
obj-$(CONFIG_SWIOTLB) += swiotlb.o
obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o

+obj-$(CONFIG_IOVA) += iova.o
+
lib-$(CONFIG_GENERIC_BUG) += bug.o

hostprogs-y := gen_crc32table
diff --git a/lib/iova.c b/lib/iova.c
new file mode 100644
index 0000000..6e14a3f
--- /dev/null
+++ b/lib/iova.c
@@ -0,0 +1,394 @@
+/*
+ * Copyright (c) 2006, Intel Corporation.
+ *
+ * This file is released under the GPLv2.
+ *
+ * Copyright (C) 2006 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
+ */
+
+#include <linux/iova.h>
+
+void
+init_iova_domain(struct iova_domain *iovad, unsigned long pfn_32bit)
+{
+ spin_lock_init(&iovad->iova_alloc_lock);
+ spin_lock_init(&iovad->iova_rbtree_lock);
+ iovad->rbroot = RB_ROOT;
+ iovad->cached32_node = NULL;
+ iovad->dma_32bit_pfn = pfn_32bit;
+}
+
+static struct rb_node *
+__get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn)
+{
+ if ((*limit_pfn != iovad->dma_32bit_pfn) ||
+ (iovad->cached32_node == NULL))
+ return rb_last(&iovad->rbroot);
+ else {
+ struct rb_node *prev_node = rb_prev(iovad->cached32_node);
+ struct iova *curr_iova =
+ container_of(iovad->cached32_node, struct iova, node);
+ *limit_pfn = curr_iova->pfn_lo - 1;
+ return prev_node;
+ }
+}
+
+static void
+__cached_rbnode_insert_update(struct iova_domain *iovad,
+ unsigned long limit_pfn, struct iova *new)
+{
+ if (limit_pfn != iovad->dma_32bit_pfn)
+ return;
+ iovad->cached32_node = &new->node;
+}
+
+static void
+__cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
+{
+ struct iova *cached_iova;
+ struct rb_node *curr;
+
+ if (!iovad->cached32_node)
+ return;
+ curr = iovad->cached32_node;
+ cached_iova = container_of(curr, struct iova, node);
+
+ if (free->pfn_lo >= cached_iova->pfn_lo)
+ iovad->cached32_node = rb_next(&free->node);
+}
+
+/* Computes the padding size required, to make the
+ * the start address naturally aligned on its size
+ */
+static int
+iova_get_pad_size(int size, unsigned int limit_pfn)
+{
+ unsigned int pad_size = 0;
+ unsigned int order = ilog2(size);
+
+ if (order)
+ pad_size = (limit_pfn + 1) % (1 << order);
+
+ return pad_size;
+}
+
+static int __alloc_iova_range(struct iova_domain *iovad, unsigned long size,
+ unsigned long limit_pfn, struct iova *new, bool size_aligned)
+{
+ struct rb_node *curr = NULL;
+ unsigned long flags;
+ unsigned long saved_pfn;
+ unsigned int pad_size = 0;
+
+ /* Walk the tree backwards */
+ spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+ saved_pfn = limit_pfn;
+ curr = __get_cached_rbnode(iovad, &limit_pfn);
+ while (curr) {
+ struct iova *curr_iova = container_of(curr, struct iova, node);
+ if (limit_pfn < curr_iova->pfn_lo)
+ goto move_left;
+ else if (limit_pfn < curr_iova->pfn_hi)
+ goto adjust_limit_pfn;
+ else {
+ if (size_aligned)
+ pad_size = iova_get_pad_size(size, limit_pfn);
+ if ((curr_iova->pfn_hi + size + pad_size) <= limit_pfn)
+ break; /* found a free slot */
+ }
+adjust_limit_pfn:
+ limit_pfn = curr_iova->pfn_lo - 1;
+move_left:
+ curr = rb_prev(curr);
+ }
+
+ if (!curr) {
+ if (size_aligned)
+ pad_size = iova_get_pad_size(size, limit_pfn);
+ if ((IOVA_START_PFN + size + pad_size) > limit_pfn) {
+ spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+ return -ENOMEM;
+ }
+ }
+
+ /* pfn_lo will point to size aligned address if size_aligned is set */
+ new->pfn_lo = limit_pfn - (size + pad_size) + 1;
+ new->pfn_hi = new->pfn_lo + size - 1;
+
+ spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+ return 0;
+}
+
+static void
+iova_insert_rbtree(struct rb_root *root, struct iova *iova)
+{
+ struct rb_node **new = &(root->rb_node), *parent = NULL;
+ /* Figure out where to put new node */
+ while (*new) {
+ struct iova *this = container_of(*new, struct iova, node);
+ parent = *new;
+
+ if (iova->pfn_lo < this->pfn_lo)
+ new = &((*new)->rb_left);
+ else if (iova->pfn_lo > this->pfn_lo)
+ new = &((*new)->rb_right);
+ else
+ BUG(); /* this should not happen */
+ }
+ /* Add new node and rebalance tree. */
+ rb_link_node(&iova->node, parent, new);
+ rb_insert_color(&iova->node, root);
+}
+
+/**
+ * alloc_iova - allocates an iova
+ * @iovad - iova domain in question
+ * @size - size of page frames to allocate
+ * @limit_pfn - max limit address
+ * @size_aligned - set if size_aligned address range is required
+ * This function allocates an iova in the range limit_pfn to IOVA_START_PFN
+ * looking from limit_pfn instead from IOVA_START_PFN. If the size_aligned
+ * flag is set then the allocated address iova->pfn_lo will be naturally
+ * aligned on roundup_power_of_two(size).
+ */
+struct iova *
+alloc_iova(struct iova_domain *iovad, unsigned long size,
+ unsigned long limit_pfn,
+ bool size_aligned)
+{
+ unsigned long flags;
+ struct iova *new_iova;
+ int ret;
+
+ new_iova = alloc_iova_mem();
+ if (!new_iova)
+ return NULL;
+
+ /* If size aligned is set then round the size to
+ * to next power of two.
+ */
+ if (size_aligned)
+ size = __roundup_pow_of_two(size);
+
+ spin_lock_irqsave(&iovad->iova_alloc_lock, flags);
+ ret = __alloc_iova_range(iovad, size, limit_pfn, new_iova,
+ size_aligned);
+
+ if (ret) {
+ spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags);
+ free_iova_mem(new_iova);
+ return NULL;
+ }
+
+ /* Insert the new_iova into domain rbtree by holding writer lock */
+ spin_lock(&iovad->iova_rbtree_lock);
+ iova_insert_rbtree(&iovad->rbroot, new_iova);
+ __cached_rbnode_insert_update(iovad, limit_pfn, new_iova);
+ spin_unlock(&iovad->iova_rbtree_lock);
+
+ spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags);
+
+ return new_iova;
+}
+
+/**
+ * find_iova - find's an iova for a given pfn
+ * @iovad - iova domain in question.
+ * pfn - page frame number
+ * This function finds and returns an iova belonging to the
+ * given doamin which matches the given pfn.
+ */
+struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
+{
+ unsigned long flags;
+ struct rb_node *node;
+
+ /* Take the lock so that no other thread is manipulating the rbtree */
+ spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+ node = iovad->rbroot.rb_node;
+ while (node) {
+ struct iova *iova = container_of(node, struct iova, node);
+
+ /* If pfn falls within iova's range, return iova */
+ if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) {
+ spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+ /* We are not holding the lock while this iova
+ * is referenced by the caller as the same thread
+ * which called this function also calls __free_iova()
+ * and it is by desing that only one thread can possibly
+ * reference a particular iova and hence no conflict.
+ */
+ return iova;
+ }
+
+ if (pfn < iova->pfn_lo)
+ node = node->rb_left;
+ else if (pfn > iova->pfn_lo)
+ node = node->rb_right;
+ }
+
+ spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+ return NULL;
+}
+
+/**
+ * __free_iova - frees the given iova
+ * @iovad: iova domain in question.
+ * @iova: iova in question.
+ * Frees the given iova belonging to the giving domain
+ */
+void
+__free_iova(struct iova_domain *iovad, struct iova *iova)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+ __cached_rbnode_delete_update(iovad, iova);
+ rb_erase(&iova->node, &iovad->rbroot);
+ spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+ free_iova_mem(iova);
+}
+
+/**
+ * free_iova - finds and frees the iova for a given pfn
+ * @iovad: - iova domain in question.
+ * @pfn: - pfn that is allocated previously
+ * This functions finds an iova for a given pfn and then
+ * frees the iova from that domain.
+ */
+void
+free_iova(struct iova_domain *iovad, unsigned long pfn)
+{
+ struct iova *iova = find_iova(iovad, pfn);
+ if (iova)
+ __free_iova(iovad, iova);
+
+}
+
+/**
+ * put_iova_domain - destroys the iova doamin
+ * @iovad: - iova domain in question.
+ * All the iova's in that domain are destroyed.
+ */
+void put_iova_domain(struct iova_domain *iovad)
+{
+ struct rb_node *node;
+ unsigned long flags;
+
+ spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
+ node = rb_first(&iovad->rbroot);
+ while (node) {
+ struct iova *iova = container_of(node, struct iova, node);
+ rb_erase(node, &iovad->rbroot);
+ free_iova_mem(iova);
+ node = rb_first(&iovad->rbroot);
+ }
+ spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
+}
+
+static int
+__is_range_overlap(struct rb_node *node,
+ unsigned long pfn_lo, unsigned long pfn_hi)
+{
+ struct iova *iova = container_of(node, struct iova, node);
+
+ if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo))
+ return 1;
+ return 0;
+}
+
+static struct iova *
+__insert_new_range(struct iova_domain *iovad,
+ unsigned long pfn_lo, unsigned long pfn_hi)
+{
+ struct iova *iova;
+
+ iova = alloc_iova_mem();
+ if (!iova)
+ return iova;
+
+ iova->pfn_hi = pfn_hi;
+ iova->pfn_lo = pfn_lo;
+ iova_insert_rbtree(&iovad->rbroot, iova);
+ return iova;
+}
+
+static void
+__adjust_overlap_range(struct iova *iova,
+ unsigned long *pfn_lo, unsigned long *pfn_hi)
+{
+ if (*pfn_lo < iova->pfn_lo)
+ iova->pfn_lo = *pfn_lo;
+ if (*pfn_hi > iova->pfn_hi)
+ *pfn_lo = iova->pfn_hi + 1;
+}
+
+/**
+ * reserve_iova - reserves an iova in the given range
+ * @iovad: - iova domain pointer
+ * @pfn_lo: - lower page frame address
+ * @pfn_hi:- higher pfn adderss
+ * This function allocates reserves the address range from pfn_lo to pfn_hi so
+ * that this address is not dished out as part of alloc_iova.
+ */
+struct iova *
+reserve_iova(struct iova_domain *iovad,
+ unsigned long pfn_lo, unsigned long pfn_hi)
+{
+ struct rb_node *node;
+ unsigned long flags;
+ struct iova *iova;
+ unsigned int overlap = 0;
+
+ spin_lock_irqsave(&iovad->iova_alloc_lock, flags);
+ spin_lock(&iovad->iova_rbtree_lock);
+ for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) {
+ if (__is_range_overlap(node, pfn_lo, pfn_hi)) {
+ iova = container_of(node, struct iova, node);
+ __adjust_overlap_range(iova, &pfn_lo, &pfn_hi);
+ if ((pfn_lo >= iova->pfn_lo) &&
+ (pfn_hi <= iova->pfn_hi))
+ goto finish;
+ overlap = 1;
+
+ } else if (overlap)
+ break;
+ }
+
+ /* We are here either becasue this is the first reserver node
+ * or need to insert remaining non overlap addr range
+ */
+ iova = __insert_new_range(iovad, pfn_lo, pfn_hi);
+finish:
+
+ spin_unlock(&iovad->iova_rbtree_lock);
+ spin_unlock_irqrestore(&iovad->iova_alloc_lock, flags);
+ return iova;
+}
+
+/**
+ * copy_reserved_iova - copies the reserved between domains
+ * @from: - source doamin from where to copy
+ * @to: - destination domin where to copy
+ * This function copies reserved iova's from one doamin to
+ * other.
+ */
+void
+copy_reserved_iova(struct iova_domain *from, struct iova_domain *to)
+{
+ unsigned long flags;
+ struct rb_node *node;
+
+ spin_lock_irqsave(&from->iova_alloc_lock, flags);
+ spin_lock(&from->iova_rbtree_lock);
+ for (node = rb_first(&from->rbroot); node; node = rb_next(node)) {
+ struct iova *iova = container_of(node, struct iova, node);
+ struct iova *new_iova;
+ new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi);
+ if (!new_iova)
+ printk(KERN_ERR "Reserve iova range %lx@%lx failed\n",
+ iova->pfn_lo, iova->pfn_lo);
+ }
+ spin_unlock(&from->iova_rbtree_lock);
+ spin_unlock_irqrestore(&from->iova_alloc_lock, flags);
+}
--
1.5.2.4