Remove the rbtree used to keep track of machine to physical mappings:
the frontend can grant the same page multiple times, leading to errors
inserting or removing entries from the mach_to_phys tree.
Linux only needed to know the physical address corresponding to a given
machine address in swiotlb-xen. Now that swiotlb-xen can call the
xen_dma_* functions passing the machine address directly, we can remove
it.
Signed-off-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
Tested-by: Denis Schneider <v1ne2go at gmail.com>
---
Changes in v2:
- do not check for mfn in xen_add_phys_to_mach_entry.
---
arch/arm/include/asm/xen/page.h | 9 ------
arch/arm/xen/p2m.c | 66 +--------------------------------------
2 files changed, 1 insertion(+), 74 deletions(-)
diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h
index ded062f..135c24a 100644
--- a/arch/arm/include/asm/xen/page.h
+++ b/arch/arm/include/asm/xen/page.h
@@ -33,7 +33,6 @@ typedef struct xpaddr {
#define INVALID_P2M_ENTRY (~0UL)
unsigned long __pfn_to_mfn(unsigned long pfn);
-unsigned long __mfn_to_pfn(unsigned long mfn);
extern struct rb_root phys_to_mach;
static inline unsigned long pfn_to_mfn(unsigned long pfn)
@@ -51,14 +50,6 @@ static inline unsigned long pfn_to_mfn(unsigned long pfn)
static inline unsigned long mfn_to_pfn(unsigned long mfn)
{
- unsigned long pfn;
-
- if (phys_to_mach.rb_node != NULL) {
- pfn = __mfn_to_pfn(mfn);
- if (pfn != INVALID_P2M_ENTRY)
- return pfn;
- }
-
return mfn;
}
diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c
index 97baf44..0548577 100644
--- a/arch/arm/xen/p2m.c
+++ b/arch/arm/xen/p2m.c
@@ -21,14 +21,12 @@ struct xen_p2m_entry {
unsigned long pfn;
unsigned long mfn;
unsigned long nr_pages;
- struct rb_node rbnode_mach;
struct rb_node rbnode_phys;
};
static rwlock_t p2m_lock;
struct rb_root phys_to_mach = RB_ROOT;
EXPORT_SYMBOL_GPL(phys_to_mach);
-static struct rb_root mach_to_phys = RB_ROOT;
static int xen_add_phys_to_mach_entry(struct xen_p2m_entry *new)
{
@@ -41,8 +39,6 @@ static int xen_add_phys_to_mach_entry(struct xen_p2m_entry *new)
parent = *link;
entry = rb_entry(parent, struct xen_p2m_entry, rbnode_phys);
- if (new->mfn == entry->mfn)
- goto err_out;
if (new->pfn == entry->pfn)
goto err_out;
@@ -88,64 +84,6 @@ unsigned long __pfn_to_mfn(unsigned long pfn)
}
EXPORT_SYMBOL_GPL(__pfn_to_mfn);
-static int xen_add_mach_to_phys_entry(struct xen_p2m_entry *new)
-{
- struct rb_node **link = &mach_to_phys.rb_node;
- struct rb_node *parent = NULL;
- struct xen_p2m_entry *entry;
- int rc = 0;
-
- while (*link) {
- parent = *link;
- entry = rb_entry(parent, struct xen_p2m_entry, rbnode_mach);
-
- if (new->mfn == entry->mfn)
- goto err_out;
- if (new->pfn == entry->pfn)
- goto err_out;
-
- if (new->mfn < entry->mfn)
- link = &(*link)->rb_left;
- else
- link = &(*link)->rb_right;
- }
- rb_link_node(&new->rbnode_mach, parent, link);
- rb_insert_color(&new->rbnode_mach, &mach_to_phys);
- goto out;
-
-err_out:
- rc = -EINVAL;
- pr_warn("%s: cannot add pfn=%pa -> mfn=%pa: pfn=%pa -> mfn=%pa already exists\n",
- __func__, &new->pfn, &new->mfn, &entry->pfn, &entry->mfn);
-out:
- return rc;
-}
-
-unsigned long __mfn_to_pfn(unsigned long mfn)
-{
- struct rb_node *n = mach_to_phys.rb_node;
- struct xen_p2m_entry *entry;
- unsigned long irqflags;
-
- read_lock_irqsave(&p2m_lock, irqflags);
- while (n) {
- entry = rb_entry(n, struct xen_p2m_entry, rbnode_mach);
- if (entry->mfn <= mfn &&
- entry->mfn + entry->nr_pages > mfn) {
- read_unlock_irqrestore(&p2m_lock, irqflags);
- return entry->pfn + (mfn - entry->mfn);
- }
- if (mfn < entry->mfn)
- n = n->rb_left;
- else
- n = n->rb_right;
- }
- read_unlock_irqrestore(&p2m_lock, irqflags);
-
- return INVALID_P2M_ENTRY;
-}
-EXPORT_SYMBOL_GPL(__mfn_to_pfn);
-
int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
struct gnttab_map_grant_ref *kmap_ops,
struct page **pages, unsigned int count)
@@ -192,7 +130,6 @@ bool __set_phys_to_machine_multi(unsigned long pfn,
p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys);
if (p2m_entry->pfn <= pfn &&
p2m_entry->pfn + p2m_entry->nr_pages > pfn) {
- rb_erase(&p2m_entry->rbnode_mach, &mach_to_phys);
rb_erase(&p2m_entry->rbnode_phys, &phys_to_mach);
write_unlock_irqrestore(&p2m_lock, irqflags);
kfree(p2m_entry);
@@ -217,8 +154,7 @@ bool __set_phys_to_machine_multi(unsigned long pfn,
p2m_entry->mfn = mfn;
write_lock_irqsave(&p2m_lock, irqflags);
- if ((rc = xen_add_phys_to_mach_entry(p2m_entry) < 0) ||
- (rc = xen_add_mach_to_phys_entry(p2m_entry) < 0)) {
+ if ((rc = xen_add_phys_to_mach_entry(p2m_entry)) < 0) {
write_unlock_irqrestore(&p2m_lock, irqflags);
return false;
}
--
1.7.10.4