/* * Xen implementation for transcendent memory (tmem) * * Copyright (C) 2009-2010 Oracle Corp. All rights reserved. * Author: Dan Magenheimer */ #include #include #include #include #include #include #include #include #include #include #define TMEM_CONTROL 0 #define TMEM_NEW_POOL 1 #define TMEM_DESTROY_POOL 2 #define TMEM_NEW_PAGE 3 #define TMEM_PUT_PAGE 4 #define TMEM_GET_PAGE 5 #define TMEM_FLUSH_PAGE 6 #define TMEM_FLUSH_OBJECT 7 #define TMEM_READ 8 #define TMEM_WRITE 9 #define TMEM_XCHG 10 /* Bits for HYPERVISOR_tmem_op(TMEM_NEW_POOL) */ #define TMEM_POOL_PERSIST 1 #define TMEM_POOL_SHARED 2 #define TMEM_POOL_PAGESIZE_SHIFT 4 #define TMEM_VERSION_SHIFT 24 struct tmem_pool_uuid { u64 uuid_lo; u64 uuid_hi; }; struct tmem_oid { u64 oid[3]; }; #define TMEM_POOL_PRIVATE_UUID { 0, 0 } /* flags for tmem_ops.new_pool */ #define TMEM_POOL_PERSIST 1 #define TMEM_POOL_SHARED 2 /* xen tmem foundation ops/hypercalls */ static inline int xen_tmem_op(u32 tmem_cmd, u32 tmem_pool, struct tmem_oid oid, u32 index, unsigned long gmfn, u32 tmem_offset, u32 pfn_offset, u32 len) { struct tmem_op op; int rc = 0; op.cmd = tmem_cmd; op.pool_id = tmem_pool; op.u.gen.oid[0] = oid.oid[0]; op.u.gen.oid[1] = oid.oid[1]; op.u.gen.oid[2] = oid.oid[2]; op.u.gen.index = index; op.u.gen.tmem_offset = tmem_offset; op.u.gen.pfn_offset = pfn_offset; op.u.gen.len = len; set_xen_guest_handle(op.u.gen.gmfn, (void *)gmfn); rc = HYPERVISOR_tmem_op(&op); return rc; } static int xen_tmem_new_pool(struct tmem_pool_uuid uuid, u32 flags, unsigned long pagesize) { struct tmem_op op; int rc = 0, pageshift; for (pageshift = 0; pagesize != 1; pageshift++) pagesize >>= 1; flags |= (pageshift - 12) << TMEM_POOL_PAGESIZE_SHIFT; flags |= TMEM_SPEC_VERSION << TMEM_VERSION_SHIFT; op.cmd = TMEM_NEW_POOL; op.u.new.uuid[0] = uuid.uuid_lo; op.u.new.uuid[1] = uuid.uuid_hi; op.u.new.flags = flags; rc = HYPERVISOR_tmem_op(&op); return rc; } /* xen generic tmem ops */ static int xen_tmem_put_page(u32 pool_id, struct tmem_oid oid, u32 index, unsigned long pfn) { unsigned long gmfn = xen_pv_domain() ? pfn_to_mfn(pfn) : pfn; return xen_tmem_op(TMEM_PUT_PAGE, pool_id, oid, index, gmfn, 0, 0, 0); } static int xen_tmem_get_page(u32 pool_id, struct tmem_oid oid, u32 index, unsigned long pfn) { unsigned long gmfn = xen_pv_domain() ? pfn_to_mfn(pfn) : pfn; return xen_tmem_op(TMEM_GET_PAGE, pool_id, oid, index, gmfn, 0, 0, 0); } static int xen_tmem_flush_page(u32 pool_id, struct tmem_oid oid, u32 index) { return xen_tmem_op(TMEM_FLUSH_PAGE, pool_id, oid, index, 0, 0, 0, 0); } static int xen_tmem_flush_object(u32 pool_id, struct tmem_oid oid) { return xen_tmem_op(TMEM_FLUSH_OBJECT, pool_id, oid, 0, 0, 0, 0, 0); } static int xen_tmem_destroy_pool(u32 pool_id) { struct tmem_oid oid = { { 0 } }; return xen_tmem_op(TMEM_DESTROY_POOL, pool_id, oid, 0, 0, 0, 0, 0); } int tmem_enabled; static int __init enable_tmem(char *s) { tmem_enabled = 1; return 1; } __setup("tmem", enable_tmem); /* cleancache ops */ static void tmem_cleancache_put_page(int pool, struct cleancache_filekey key, pgoff_t index, struct page *page) { u32 ind = (u32) index; struct tmem_oid oid = *(struct tmem_oid *)&key; unsigned long pfn = page_to_pfn(page); if (pool < 0) return; if (ind != index) return; mb(); /* ensure page is quiescent; tmem may address it with an alias */ (void)xen_tmem_put_page((u32)pool, oid, ind, pfn); } static int tmem_cleancache_get_page(int pool, struct cleancache_filekey key, pgoff_t index, struct page *page) { u32 ind = (u32) index; struct tmem_oid oid = *(struct tmem_oid *)&key; unsigned long pfn = page_to_pfn(page); int ret; /* translate return values to linux semantics */ if (pool < 0) return -1; if (ind != index) return -1; ret = xen_tmem_get_page((u32)pool, oid, ind, pfn); if (ret == 1) return 0; else return -1; } static void tmem_cleancache_flush_page(int pool, struct cleancache_filekey key, pgoff_t index) { u32 ind = (u32) index; struct tmem_oid oid = *(struct tmem_oid *)&key; if (pool < 0) return; if (ind != index) return; (void)xen_tmem_flush_page((u32)pool, oid, ind); } static void tmem_cleancache_flush_inode(int pool, struct cleancache_filekey key) { struct tmem_oid oid = *(struct tmem_oid *)&key; if (pool < 0) return; (void)xen_tmem_flush_object((u32)pool, oid); } static void tmem_cleancache_flush_fs(int pool) { if (pool < 0) return; (void)xen_tmem_destroy_pool((u32)pool); } static int tmem_cleancache_init_fs(size_t pagesize) { struct tmem_pool_uuid uuid_private = TMEM_POOL_PRIVATE_UUID; return xen_tmem_new_pool(uuid_private, 0, pagesize); } static int tmem_cleancache_init_shared_fs(char *uuid, size_t pagesize) { struct tmem_pool_uuid shared_uuid; shared_uuid.uuid_lo = *(u64 *)uuid; shared_uuid.uuid_hi = *(u64 *)(&uuid[8]); return xen_tmem_new_pool(shared_uuid, TMEM_POOL_SHARED, pagesize); } static int use_cleancache = 1; static int __init no_cleancache(char *s) { use_cleancache = 0; return 1; } __setup("nocleancache", no_cleancache); static struct cleancache_ops tmem_cleancache_ops = { .put_page = tmem_cleancache_put_page, .get_page = tmem_cleancache_get_page, .flush_page = tmem_cleancache_flush_page, .flush_inode = tmem_cleancache_flush_inode, .flush_fs = tmem_cleancache_flush_fs, .init_shared_fs = tmem_cleancache_init_shared_fs, .init_fs = tmem_cleancache_init_fs }; static int __init xen_tmem_init(void) { struct cleancache_ops old_ops; if (!xen_domain()) return 0; #ifdef CONFIG_CLEANCACHE BUG_ON(sizeof(struct cleancache_filekey) != sizeof(struct tmem_oid)); if (tmem_enabled && use_cleancache) { char *s = ""; old_ops = cleancache_register_ops(&tmem_cleancache_ops); if (old_ops.init_fs != NULL) s = " (WARNING: cleancache_ops overridden)"; printk(KERN_INFO "cleancache enabled, RAM provided by " "Xen Transcendent Memory%s\n", s); } #endif return 0; } module_init(xen_tmem_init)