--- /dev/null
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Copyright (C) IBM Corp. 2006
+ *
+ * Authors: Hollis Blanchard <hollisb@us.ibm.com>
+ */
+
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <asm/page.h>
+#include <xen/xencomm.h>
+#include <xen/interface/xen.h>
+
+static int xencomm_init(struct xencomm_desc *desc,
+ void *buffer, unsigned long bytes)
+{
+ unsigned long recorded = 0;
+ int i = 0;
+
+ while ((recorded < bytes) && (i < desc->nr_addrs)) {
+ unsigned long vaddr = (unsigned long)buffer + recorded;
+ unsigned long paddr;
+ int offset;
+ int chunksz;
+
+ offset = vaddr % PAGE_SIZE; /* handle partial pages */
+ chunksz = min(PAGE_SIZE - offset, bytes - recorded);
+
+ paddr = xencomm_vtop(vaddr);
+ if (paddr == ~0UL) {
+ printk("%s: couldn't translate vaddr %lx\n",
+ __func__, vaddr);
+ return -EINVAL;
+ }
+
+ desc->address[i++] = paddr;
+ recorded += chunksz;
+ }
+
+ if (recorded < bytes) {
+ printk("%s: could only translate %ld of %ld bytes\n",
+ __func__, recorded, bytes);
+ return -ENOSPC;
+ }
+
+ /* mark remaining addresses invalid (just for safety) */
+ while (i < desc->nr_addrs)
+ desc->address[i++] = XENCOMM_INVALID;
+
+ desc->magic = XENCOMM_MAGIC;
+
+ return 0;
+}
+
+/* XXX use slab allocator */
+static struct xencomm_desc *xencomm_alloc(gfp_t gfp_mask)
+{
+ struct xencomm_desc *desc;
+
+ desc = (struct xencomm_desc *)__get_free_page(gfp_mask);
+ if (desc == NULL)
+ return NULL;
+
+ desc->nr_addrs = (PAGE_SIZE - sizeof(struct xencomm_desc)) /
+ sizeof(*desc->address);
+
+ return desc;
+}
+
+void xencomm_free(void *desc)
+{
+ if (desc && !((ulong)desc & XENCOMM_INLINE_FLAG))
+ free_page((unsigned long)__va(desc));
+}
+
+static int xencomm_create(void *buffer, unsigned long bytes, struct xencomm_desc **ret, gfp_t gfp_mask)
+{
+ struct xencomm_desc *desc;
+ int rc;
+
+ pr_debug("%s: %p[%ld]\n", __func__, buffer, bytes);
+
+ if (bytes == 0) {
+ /* don't create a descriptor; Xen recognizes NULL. */
+ BUG_ON(buffer != NULL);
+ *ret = NULL;
+ return 0;
+ }
+
+ BUG_ON(buffer == NULL); /* 'bytes' is non-zero */
+
+ desc = xencomm_alloc(gfp_mask);
+ if (!desc) {
+ printk("%s failure\n", "xencomm_alloc");
+ return -ENOMEM;
+ }
+
+ rc = xencomm_init(desc, buffer, bytes);
+ if (rc) {
+ printk("%s failure: %d\n", "xencomm_init", rc);
+ xencomm_free(desc);
+ return rc;
+ }
+
+ *ret = desc;
+ return 0;
+}
+
+/* check if memory address is within VMALLOC region */
+static int is_phys_contiguous(unsigned long addr)
+{
+ if (!is_kernel_addr(addr))
+ return 0;
+
+ return (addr < VMALLOC_START) || (addr >= VMALLOC_END);
+}
+
+static void *xencomm_create_inline(void *ptr)
+{
+ unsigned long paddr;
+
+ BUG_ON(!is_phys_contiguous((unsigned long)ptr));
+
+ paddr = (unsigned long)xencomm_pa(ptr);
+ BUG_ON(paddr & XENCOMM_INLINE_FLAG);
+ return (void *)(paddr | XENCOMM_INLINE_FLAG);
+}
+
+/* "mini" routine, for stack-based communications: */
+static int xencomm_create_mini(void *buffer,
+ unsigned long bytes, struct xencomm_mini *xc_desc,
+ struct xencomm_desc **ret)
+{
+ int rc = 0;
+ struct xencomm_desc *desc;
+
+ desc = (void *)xc_desc;
+
+ desc->nr_addrs = XENCOMM_MINI_ADDRS;
+
+ if (!(rc = xencomm_init(desc, buffer, bytes)))
+ *ret = desc;
+
+ return rc;
+}
+
+void *xencomm_map(void *ptr, unsigned long bytes)
+{
+ int rc;
+ struct xencomm_desc *desc;
+
+ if (is_phys_contiguous((unsigned long)ptr))
+ return xencomm_create_inline(ptr);
+
+ rc = xencomm_create(ptr, bytes, &desc, GFP_KERNEL);
+
+ if (rc || desc == NULL)
+ return NULL;
+
+ return (void *)__pa(desc);
+}
+
+void *__xencomm_map_no_alloc(void *ptr, unsigned long bytes,
+ struct xencomm_mini *xc_desc)
+{
+ int rc;
+ struct xencomm_desc *desc = NULL;
+
+ if (is_phys_contiguous((unsigned long)ptr))
+ return xencomm_create_inline(ptr);
+
+ rc = xencomm_create_mini(ptr, bytes, xc_desc,
+ &desc);
+
+ if (rc)
+ return NULL;
+
+ return (void *)__pa(desc);
+}
--- /dev/null
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Copyright (C) IBM Corp. 2006
+ *
+ * Authors: Hollis Blanchard <hollisb@us.ibm.com>
+ * Jerone Young <jyoung5@us.ibm.com>
+ */
+
+#ifndef _LINUX_XENCOMM_H_
+#define _LINUX_XENCOMM_H_
+
+#include <xen/interface/xencomm.h>
+
+#define XENCOMM_MINI_ADDRS 3
+struct xencomm_mini {
+ struct xencomm_desc _desc;
+ uint64_t address[XENCOMM_MINI_ADDRS];
+};
+
+extern void xencomm_free(void *desc);
+extern void *xencomm_map(void *ptr, unsigned long bytes);
+extern void *__xencomm_map_no_alloc(void *ptr, unsigned long bytes,
+ struct xencomm_mini *xc_area);
+
+#define xencomm_map_no_alloc(ptr, bytes) \
+ ({struct xencomm_mini xc_desc\
+ __attribute__((__aligned__(sizeof(struct xencomm_mini))));\
+ __xencomm_map_no_alloc(ptr, bytes, &xc_desc);})
+
+/* provided by architecture code: */
+extern unsigned long xencomm_vtop(unsigned long vaddr);
+
+static inline void *xencomm_pa(void *ptr)
+{
+ return (void *)xencomm_vtop((unsigned long)ptr);
+}
+
+#endif /* _LINUX_XENCOMM_H_ */
projects / legacy / linux-2.6.18-xen.git / commitdiff