diff options
Diffstat (limited to 'arch/arm/xen/p2m.c')
| -rw-r--r-- | arch/arm/xen/p2m.c | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c new file mode 100644 index 000000000..309648c17 --- /dev/null +++ b/arch/arm/xen/p2m.c @@ -0,0 +1,210 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/memblock.h> +#include <linux/gfp.h> +#include <linux/export.h> +#include <linux/spinlock.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/dma-mapping.h> +#include <linux/vmalloc.h> +#include <linux/swiotlb.h> + +#include <xen/xen.h> +#include <xen/interface/memory.h> +#include <xen/grant_table.h> +#include <xen/page.h> +#include <xen/swiotlb-xen.h> + +#include <asm/cacheflush.h> +#include <asm/xen/hypercall.h> +#include <asm/xen/interface.h> + +struct xen_p2m_entry { + unsigned long pfn; + unsigned long mfn; + unsigned long nr_pages; + 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 int xen_add_phys_to_mach_entry(struct xen_p2m_entry *new) +{ + struct rb_node **link = &phys_to_mach.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_phys); + + if (new->pfn == entry->pfn) + goto err_out; + + if (new->pfn < entry->pfn) + link = &(*link)->rb_left; + else + link = &(*link)->rb_right; + } + rb_link_node(&new->rbnode_phys, parent, link); + rb_insert_color(&new->rbnode_phys, &phys_to_mach); + 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 __pfn_to_mfn(unsigned long pfn) +{ + struct rb_node *n; + struct xen_p2m_entry *entry; + unsigned long irqflags; + + read_lock_irqsave(&p2m_lock, irqflags); + n = phys_to_mach.rb_node; + while (n) { + entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys); + if (entry->pfn <= pfn && + entry->pfn + entry->nr_pages > pfn) { + unsigned long mfn = entry->mfn + (pfn - entry->pfn); + read_unlock_irqrestore(&p2m_lock, irqflags); + return mfn; + } + if (pfn < entry->pfn) + n = n->rb_left; + else + n = n->rb_right; + } + read_unlock_irqrestore(&p2m_lock, irqflags); + + return INVALID_P2M_ENTRY; +} +EXPORT_SYMBOL_GPL(__pfn_to_mfn); + +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) +{ + int i; + + for (i = 0; i < count; i++) { + struct gnttab_unmap_grant_ref unmap; + int rc; + + if (map_ops[i].status) + continue; + if (likely(set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT, + map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT))) + continue; + + /* + * Signal an error for this slot. This in turn requires + * immediate unmapping. + */ + map_ops[i].status = GNTST_general_error; + unmap.host_addr = map_ops[i].host_addr, + unmap.handle = map_ops[i].handle; + map_ops[i].handle = INVALID_GRANT_HANDLE; + if (map_ops[i].flags & GNTMAP_device_map) + unmap.dev_bus_addr = map_ops[i].dev_bus_addr; + else + unmap.dev_bus_addr = 0; + + /* + * Pre-populate the status field, to be recognizable in + * the log message below. + */ + unmap.status = 1; + + rc = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, + &unmap, 1); + if (rc || unmap.status != GNTST_okay) + pr_err_once("gnttab unmap failed: rc=%d st=%d\n", + rc, unmap.status); + } + + return 0; +} + +int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, + struct gnttab_unmap_grant_ref *kunmap_ops, + struct page **pages, unsigned int count) +{ + int i; + + for (i = 0; i < count; i++) { + set_phys_to_machine(unmap_ops[i].host_addr >> XEN_PAGE_SHIFT, + INVALID_P2M_ENTRY); + } + + return 0; +} + +bool __set_phys_to_machine_multi(unsigned long pfn, + unsigned long mfn, unsigned long nr_pages) +{ + int rc; + unsigned long irqflags; + struct xen_p2m_entry *p2m_entry; + struct rb_node *n; + + if (mfn == INVALID_P2M_ENTRY) { + write_lock_irqsave(&p2m_lock, irqflags); + n = phys_to_mach.rb_node; + while (n) { + 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_phys, &phys_to_mach); + write_unlock_irqrestore(&p2m_lock, irqflags); + kfree(p2m_entry); + return true; + } + if (pfn < p2m_entry->pfn) + n = n->rb_left; + else + n = n->rb_right; + } + write_unlock_irqrestore(&p2m_lock, irqflags); + return true; + } + + p2m_entry = kzalloc(sizeof(*p2m_entry), GFP_NOWAIT); + if (!p2m_entry) + return false; + + p2m_entry->pfn = pfn; + p2m_entry->nr_pages = nr_pages; + p2m_entry->mfn = mfn; + + write_lock_irqsave(&p2m_lock, irqflags); + rc = xen_add_phys_to_mach_entry(p2m_entry); + if (rc < 0) { + write_unlock_irqrestore(&p2m_lock, irqflags); + kfree(p2m_entry); + return false; + } + write_unlock_irqrestore(&p2m_lock, irqflags); + return true; +} +EXPORT_SYMBOL_GPL(__set_phys_to_machine_multi); + +bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn) +{ + return __set_phys_to_machine_multi(pfn, mfn, 1); +} +EXPORT_SYMBOL_GPL(__set_phys_to_machine); + +static int p2m_init(void) +{ + rwlock_init(&p2m_lock); + return 0; +} +arch_initcall(p2m_init); |