From d50582e06fd5a58281151e097ff68b02ca65cf2d Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Wed, 10 Sep 2014 22:49:48 +0000 Subject: [PATCH] xen/arm: remove mach_to_phys rbtree 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 Tested-by: Denis Schneider --- 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 ded062f9b358..135c24a5ba26 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 97baf4427817..054857776254 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; } -- 2.34.1