xen: move grant table code

Mave the grant table code into the dev/xen folder in preparation for turning
it into a device using the newbus interface. This is just code motion, no
functional changes.

Sponsored by: Citrix Systems R&D

1 files changed, 0 insertions, 720 deletions

diff --git a/sys/xen/gnttab.c b/sys/xen/gnttab.c
deleted file mode 100644
index 9ab3145..0000000
--- a/sys/xen/gnttab.c
+++ /dev/null
@@ -1,720 +0,0 @@
-/******************************************************************************
- * gnttab.c
- * 
- * Two sets of functionality:
- * 1. Granting foreign access to our memory reservation.
- * 2. Accessing others' memory reservations via grant references.
- * (i.e., mechanisms for both sender and recipient of grant references)
- * 
- * Copyright (c) 2005, Christopher Clark
- * Copyright (c) 2004, K A Fraser
- */
-
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-
-#include "opt_pmap.h"
-
-#include <sys/param.h>
-#include <sys/systm.h>
-#include <sys/bus.h>
-#include <sys/conf.h>
-#include <sys/module.h>
-#include <sys/kernel.h>
-#include <sys/lock.h>
-#include <sys/malloc.h>
-#include <sys/mman.h>
-#include <sys/limits.h>
-#include <sys/rman.h>
-#include <machine/resource.h>
-
-#include <xen/xen-os.h>
-#include <xen/hypervisor.h>
-#include <machine/xen/synch_bitops.h>
-
-#include <xen/hypervisor.h>
-#include <xen/gnttab.h>
-
-#include <vm/vm.h>
-#include <vm/vm_kern.h>
-#include <vm/vm_extern.h>
-#include <vm/pmap.h>
-
-#define cmpxchg(a, b, c) atomic_cmpset_int((volatile u_int *)(a),(b),(c))
-
-/* External tools reserve first few grant table entries. */
-#define NR_RESERVED_ENTRIES 8
-#define GREFS_PER_GRANT_FRAME (PAGE_SIZE / sizeof(grant_entry_t))
-
-static grant_ref_t **gnttab_list;
-static unsigned int nr_grant_frames;
-static unsigned int boot_max_nr_grant_frames;
-static int gnttab_free_count;
-static grant_ref_t gnttab_free_head;
-static struct mtx gnttab_list_lock;
-
-#ifdef XENHVM
-/*
- * Resource representing allocated physical address space
- * for the grant table metainfo
- */
-static struct resource *gnttab_pseudo_phys_res;
-
-/* Resource id for allocated physical address space. */
-static int gnttab_pseudo_phys_res_id;
-#endif
-
-static grant_entry_t *shared;
-
-static struct gnttab_free_callback *gnttab_free_callback_list = NULL;
-
-static int gnttab_expand(unsigned int req_entries);
-
-#define RPP (PAGE_SIZE / sizeof(grant_ref_t))
-#define gnttab_entry(entry) (gnttab_list[(entry) / RPP][(entry) % RPP])
-
-static int
-get_free_entries(int count, int *entries)
-{
-	int ref, error;
-	grant_ref_t head;
-
-	mtx_lock(&gnttab_list_lock);
-	if ((gnttab_free_count < count) &&
-	    ((error = gnttab_expand(count - gnttab_free_count)) != 0)) {
-		mtx_unlock(&gnttab_list_lock);
-		return (error);
-	}
-	ref = head = gnttab_free_head;
-	gnttab_free_count -= count;
-	while (count-- > 1)
-		head = gnttab_entry(head);
-	gnttab_free_head = gnttab_entry(head);
-	gnttab_entry(head) = GNTTAB_LIST_END;
-	mtx_unlock(&gnttab_list_lock);
-
-	*entries = ref;
-	return (0);
-}
-
-static void
-do_free_callbacks(void)
-{
-	struct gnttab_free_callback *callback, *next;
-
-	callback = gnttab_free_callback_list;
-	gnttab_free_callback_list = NULL;
-
-	while (callback != NULL) {
-		next = callback->next;
-		if (gnttab_free_count >= callback->count) {
-			callback->next = NULL;
-			callback->fn(callback->arg);
-		} else {
-			callback->next = gnttab_free_callback_list;
-			gnttab_free_callback_list = callback;
-		}
-		callback = next;
-	}
-}
-
-static inline void
-check_free_callbacks(void)
-{
-	if (__predict_false(gnttab_free_callback_list != NULL))
-		do_free_callbacks();
-}
-
-static void
-put_free_entry(grant_ref_t ref)
-{
-
-	mtx_lock(&gnttab_list_lock);
-	gnttab_entry(ref) = gnttab_free_head;
-	gnttab_free_head = ref;
-	gnttab_free_count++;
-	check_free_callbacks();
-	mtx_unlock(&gnttab_list_lock);
-}
-
-/*
- * Public grant-issuing interface functions
- */
-
-int
-gnttab_grant_foreign_access(domid_t domid, unsigned long frame, int readonly,
-	grant_ref_t *result)
-{
-	int error, ref;
-
-	error = get_free_entries(1, &ref);
-
-	if (__predict_false(error))
-		return (error);
-
-	shared[ref].frame = frame;
-	shared[ref].domid = domid;
-	wmb();
-	shared[ref].flags = GTF_permit_access | (readonly ? GTF_readonly : 0);
-
-	if (result)
-		*result = ref;
-
-	return (0);
-}
-
-void
-gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
-				unsigned long frame, int readonly)
-{
-
-	shared[ref].frame = frame;
-	shared[ref].domid = domid;
-	wmb();
-	shared[ref].flags = GTF_permit_access | (readonly ? GTF_readonly : 0);
-}
-
-int
-gnttab_query_foreign_access(grant_ref_t ref)
-{
-	uint16_t nflags;
-
-	nflags = shared[ref].flags;
-
-	return (nflags & (GTF_reading|GTF_writing));
-}
-
-int
-gnttab_end_foreign_access_ref(grant_ref_t ref)
-{
-	uint16_t flags, nflags;
-
-	nflags = shared[ref].flags;
-	do {
-		if ( (flags = nflags) & (GTF_reading|GTF_writing) ) {
-			printf("%s: WARNING: g.e. still in use!\n", __func__);
-			return (0);
-		}
-	} while ((nflags = synch_cmpxchg(&shared[ref].flags, flags, 0)) !=
-	       flags);
-
-	return (1);
-}
-
-void
-gnttab_end_foreign_access(grant_ref_t ref, void *page)
-{
-	if (gnttab_end_foreign_access_ref(ref)) {
-		put_free_entry(ref);
-		if (page != NULL) {
-			free(page, M_DEVBUF);
-		}
-	}
-	else {
-		/* XXX This needs to be fixed so that the ref and page are
-		   placed on a list to be freed up later. */
-		printf("%s: WARNING: leaking g.e. and page still in use!\n",
-		       __func__);
-	}
-}
-
-void
-gnttab_end_foreign_access_references(u_int count, grant_ref_t *refs)
-{
-	grant_ref_t *last_ref;
-	grant_ref_t  head;
-	grant_ref_t  tail;
-
-	head = GNTTAB_LIST_END;
-	tail = *refs;
-	last_ref = refs + count;
-	while (refs != last_ref) {
-
-		if (gnttab_end_foreign_access_ref(*refs)) {
-			gnttab_entry(*refs) = head;
-			head = *refs;
-		} else {
-			/*
-			 * XXX This needs to be fixed so that the ref 
-			 * is placed on a list to be freed up later.
-			 */
-			printf("%s: WARNING: leaking g.e. still in use!\n",
-			       __func__);
-			count--;
-		}
-		refs++;
-	}
-
-	if (count != 0) {
-		mtx_lock(&gnttab_list_lock);
-		gnttab_free_count += count;
-		gnttab_entry(tail) = gnttab_free_head;
-		gnttab_free_head = head;
-		mtx_unlock(&gnttab_list_lock);
-	}
-}
-
-int
-gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn,
-    grant_ref_t *result)
-{
-	int error, ref;
-
-	error = get_free_entries(1, &ref);
-	if (__predict_false(error))
-		return (error);
-
-	gnttab_grant_foreign_transfer_ref(ref, domid, pfn);
-
-	*result = ref;
-	return (0);
-}
-
-void
-gnttab_grant_foreign_transfer_ref(grant_ref_t ref, domid_t domid,
-	unsigned long pfn)
-{
-	shared[ref].frame = pfn;
-	shared[ref].domid = domid;
-	wmb();
-	shared[ref].flags = GTF_accept_transfer;
-}
-
-unsigned long
-gnttab_end_foreign_transfer_ref(grant_ref_t ref)
-{
-	unsigned long frame;
-	uint16_t      flags;
-
-	/*
-         * If a transfer is not even yet started, try to reclaim the grant
-         * reference and return failure (== 0).
-         */
-	while (!((flags = shared[ref].flags) & GTF_transfer_committed)) {
-		if ( synch_cmpxchg(&shared[ref].flags, flags, 0) == flags )
-			return (0);
-		cpu_relax();
-	}
-
-	/* If a transfer is in progress then wait until it is completed. */
-	while (!(flags & GTF_transfer_completed)) {
-		flags = shared[ref].flags;
-		cpu_relax();
-	}
-
-	/* Read the frame number /after/ reading completion status. */
-	rmb();
-	frame = shared[ref].frame;
-	KASSERT(frame != 0, ("grant table inconsistent"));
-
-	return (frame);
-}
-
-unsigned long
-gnttab_end_foreign_transfer(grant_ref_t ref)
-{
-	unsigned long frame = gnttab_end_foreign_transfer_ref(ref);
-
-	put_free_entry(ref);
-	return (frame);
-}
-
-void
-gnttab_free_grant_reference(grant_ref_t ref)
-{
-
-	put_free_entry(ref);
-}
-
-void
-gnttab_free_grant_references(grant_ref_t head)
-{
-	grant_ref_t ref;
-	int count = 1;
-
-	if (head == GNTTAB_LIST_END)
-		return;
-
-	ref = head;
-	while (gnttab_entry(ref) != GNTTAB_LIST_END) {
-		ref = gnttab_entry(ref);
-		count++;
-	}
-	mtx_lock(&gnttab_list_lock);
-	gnttab_entry(ref) = gnttab_free_head;
-	gnttab_free_head = head;
-	gnttab_free_count += count;
-	check_free_callbacks();
-	mtx_unlock(&gnttab_list_lock);
-}
-
-int
-gnttab_alloc_grant_references(uint16_t count, grant_ref_t *head)
-{
-	int ref, error;
-
-	error = get_free_entries(count, &ref);
-	if (__predict_false(error))
-		return (error);
-
-	*head = ref;
-	return (0);
-}
-
-int
-gnttab_empty_grant_references(const grant_ref_t *private_head)
-{
-
-	return (*private_head == GNTTAB_LIST_END);
-}
-
-int
-gnttab_claim_grant_reference(grant_ref_t *private_head)
-{
-	grant_ref_t g = *private_head;
-
-	if (__predict_false(g == GNTTAB_LIST_END))
-		return (g);
-	*private_head = gnttab_entry(g);
-	return (g);
-}
-
-void
-gnttab_release_grant_reference(grant_ref_t *private_head, grant_ref_t  release)
-{
-
-	gnttab_entry(release) = *private_head;
-	*private_head = release;
-}
-
-void
-gnttab_request_free_callback(struct gnttab_free_callback *callback,
-    void (*fn)(void *), void *arg, uint16_t count)
-{
-
-	mtx_lock(&gnttab_list_lock);
-	if (callback->next)
-		goto out;
-	callback->fn = fn;
-	callback->arg = arg;
-	callback->count = count;
-	callback->next = gnttab_free_callback_list;
-	gnttab_free_callback_list = callback;
-	check_free_callbacks();
- out:
-	mtx_unlock(&gnttab_list_lock);
-
-}
-
-void
-gnttab_cancel_free_callback(struct gnttab_free_callback *callback)
-{
-	struct gnttab_free_callback **pcb;
-
-	mtx_lock(&gnttab_list_lock);
-	for (pcb = &gnttab_free_callback_list; *pcb; pcb = &(*pcb)->next) {
-		if (*pcb == callback) {
-			*pcb = callback->next;
-			break;
-		}
-	}
-	mtx_unlock(&gnttab_list_lock);
-}
-
-
-static int
-grow_gnttab_list(unsigned int more_frames)
-{
-	unsigned int new_nr_grant_frames, extra_entries, i;
-
-	new_nr_grant_frames = nr_grant_frames + more_frames;
-	extra_entries       = more_frames * GREFS_PER_GRANT_FRAME;
-
-	for (i = nr_grant_frames; i < new_nr_grant_frames; i++)
-	{
-		gnttab_list[i] = (grant_ref_t *)
-			malloc(PAGE_SIZE, M_DEVBUF, M_NOWAIT);
-
-		if (!gnttab_list[i])
-			goto grow_nomem;
-	}
-
-	for (i = GREFS_PER_GRANT_FRAME * nr_grant_frames;
-	     i < GREFS_PER_GRANT_FRAME * new_nr_grant_frames - 1; i++)
-		gnttab_entry(i) = i + 1;
-
-	gnttab_entry(i) = gnttab_free_head;
-	gnttab_free_head = GREFS_PER_GRANT_FRAME * nr_grant_frames;
-	gnttab_free_count += extra_entries;
-
-	nr_grant_frames = new_nr_grant_frames;
-
-	check_free_callbacks();
-
-	return (0);
-
-grow_nomem:
-	for ( ; i >= nr_grant_frames; i--)
-		free(gnttab_list[i], M_DEVBUF);
-	return (ENOMEM);
-}
-
-static unsigned int
-__max_nr_grant_frames(void)
-{
-	struct gnttab_query_size query;
-	int rc;
-
-	query.dom = DOMID_SELF;
-
-	rc = HYPERVISOR_grant_table_op(GNTTABOP_query_size, &query, 1);
-	if ((rc < 0) || (query.status != GNTST_okay))
-		return (4); /* Legacy max supported number of frames */
-
-	return (query.max_nr_frames);
-}
-
-static inline
-unsigned int max_nr_grant_frames(void)
-{
-	unsigned int xen_max = __max_nr_grant_frames();
-
-	if (xen_max > boot_max_nr_grant_frames)
-		return (boot_max_nr_grant_frames);
-	return (xen_max);
-}
-
-#ifdef notyet
-/*
- * XXX needed for backend support
- *
- */
-static int
-map_pte_fn(pte_t *pte, struct page *pmd_page,
-		      unsigned long addr, void *data)
-{
-	unsigned long **frames = (unsigned long **)data;
-
-	set_pte_at(&init_mm, addr, pte, pfn_pte_ma((*frames)[0], PAGE_KERNEL));
-	(*frames)++;
-	return 0;
-}
-
-static int
-unmap_pte_fn(pte_t *pte, struct page *pmd_page,
-			unsigned long addr, void *data)
-{
-
-	set_pte_at(&init_mm, addr, pte, __pte(0));
-	return 0;
-}
-#endif
-
-#ifndef XENHVM
-
-static int
-gnttab_map(unsigned int start_idx, unsigned int end_idx)
-{
-	struct gnttab_setup_table setup;
-	u_long *frames;
-
-	unsigned int nr_gframes = end_idx + 1;
-	int i, rc;
-
-	frames = malloc(nr_gframes * sizeof(unsigned long), M_DEVBUF, M_NOWAIT);
-	if (!frames)
-		return (ENOMEM);
-
-	setup.dom        = DOMID_SELF;
-	setup.nr_frames  = nr_gframes;
-	set_xen_guest_handle(setup.frame_list, frames);
-
-	rc = HYPERVISOR_grant_table_op(GNTTABOP_setup_table, &setup, 1);
-	if (rc == -ENOSYS) {
-		free(frames, M_DEVBUF);
-		return (ENOSYS);
-	}
-	KASSERT(!(rc || setup.status),
-	    ("unexpected result from grant_table_op"));
-
-	if (shared == NULL) {
-		vm_offset_t area;
-
-		area = kva_alloc(PAGE_SIZE * max_nr_grant_frames());
-		KASSERT(area, ("can't allocate VM space for grant table"));
-		shared = (grant_entry_t *)area;
-	}
-
-	for (i = 0; i < nr_gframes; i++)
-		PT_SET_MA(((caddr_t)shared) + i*PAGE_SIZE, 
-		    ((vm_paddr_t)frames[i]) << PAGE_SHIFT | PG_RW | PG_V);
-
-	free(frames, M_DEVBUF);
-
-	return (0);
-}
-
-int
-gnttab_resume(device_t dev)
-{
-
-	if (max_nr_grant_frames() < nr_grant_frames)
-		return (ENOSYS);
-	return (gnttab_map(0, nr_grant_frames - 1));
-}
-
-int
-gnttab_suspend(void)
-{
-	int i;
-
-	for (i = 0; i < nr_grant_frames; i++)
-		pmap_kremove((vm_offset_t) shared + i * PAGE_SIZE);
-
-	return (0);
-}
-
-#else /* XENHVM */
-
-static vm_paddr_t resume_frames;
-
-static int
-gnttab_map(unsigned int start_idx, unsigned int end_idx)
-{
-	struct xen_add_to_physmap xatp;
-	unsigned int i = end_idx;
-
-	/*
-	 * Loop backwards, so that the first hypercall has the largest index,
-	 * ensuring that the table will grow only once.
-	 */
-	do {
-		xatp.domid = DOMID_SELF;
-		xatp.idx = i;
-		xatp.space = XENMAPSPACE_grant_table;
-		xatp.gpfn = (resume_frames >> PAGE_SHIFT) + i;
-		if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
-			panic("HYPERVISOR_memory_op failed to map gnttab");
-	} while (i-- > start_idx);
-
-	if (shared == NULL) {
-		vm_offset_t area;
-
-		area = kva_alloc(PAGE_SIZE * max_nr_grant_frames());
-		KASSERT(area, ("can't allocate VM space for grant table"));
-		shared = (grant_entry_t *)area;
-	}
-
-	for (i = start_idx; i <= end_idx; i++) {
-		pmap_kenter((vm_offset_t) shared + i * PAGE_SIZE,
-		    resume_frames + i * PAGE_SIZE);
-	}
-
-	return (0);
-}
-
-int
-gnttab_resume(device_t dev)
-{
-	unsigned int max_nr_gframes, nr_gframes;
-
-	nr_gframes = nr_grant_frames;
-	max_nr_gframes = max_nr_grant_frames();
-	if (max_nr_gframes < nr_gframes)
-		return (ENOSYS);
-
-	if (!resume_frames) {
-		KASSERT(dev != NULL,
-		    ("No resume frames and no device provided"));
-
-		gnttab_pseudo_phys_res = bus_alloc_resource(dev,
-		    SYS_RES_MEMORY, &gnttab_pseudo_phys_res_id, 0, ~0,
-		    PAGE_SIZE * max_nr_gframes, RF_ACTIVE);
-		if (gnttab_pseudo_phys_res == NULL)
-			panic("Unable to reserve physical memory for gnttab");
-		resume_frames = rman_get_start(gnttab_pseudo_phys_res);
-	}
-
-	return (gnttab_map(0, nr_gframes - 1));
-}
-
-#endif
-
-static int
-gnttab_expand(unsigned int req_entries)
-{
-	int error;
-	unsigned int cur, extra;
-
-	cur = nr_grant_frames;
-	extra = ((req_entries + (GREFS_PER_GRANT_FRAME-1)) /
-		 GREFS_PER_GRANT_FRAME);
-	if (cur + extra > max_nr_grant_frames())
-		return (ENOSPC);
-
-	error = gnttab_map(cur, cur + extra - 1);
-	if (!error)
-		error = grow_gnttab_list(extra);
-
-	return (error);
-}
-
-int 
-gnttab_init(device_t dev)
-{
-	int i;
-	unsigned int max_nr_glist_frames;
-	unsigned int nr_init_grefs;
-
-	if (!is_running_on_xen())
-		return (ENODEV);
-
-	nr_grant_frames = 1;
-	boot_max_nr_grant_frames = __max_nr_grant_frames();
-
-	/* Determine the maximum number of frames required for the
-	 * grant reference free list on the current hypervisor.
-	 */
-	max_nr_glist_frames = (boot_max_nr_grant_frames *
-			       GREFS_PER_GRANT_FRAME /
-			       (PAGE_SIZE / sizeof(grant_ref_t)));
-
-	gnttab_list = malloc(max_nr_glist_frames * sizeof(grant_ref_t *),
-	    M_DEVBUF, M_NOWAIT);
-
-	if (gnttab_list == NULL)
-		return (ENOMEM);
-
-	for (i = 0; i < nr_grant_frames; i++) {
-		gnttab_list[i] = (grant_ref_t *)
-			malloc(PAGE_SIZE, M_DEVBUF, M_NOWAIT);
-		if (gnttab_list[i] == NULL)
-			goto ini_nomem;
-	}
-
-	if (gnttab_resume(dev))
-		return (ENODEV);
-
-	nr_init_grefs = nr_grant_frames * GREFS_PER_GRANT_FRAME;
-
-	for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++)
-		gnttab_entry(i) = i + 1;
-
-	gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END;
-	gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES;
-	gnttab_free_head  = NR_RESERVED_ENTRIES;
-
-	if (bootverbose)
-		printf("Grant table initialized\n");
-
-	return (0);
-
-ini_nomem:
-	for (i--; i >= 0; i--)
-		free(gnttab_list[i], M_DEVBUF);
-	free(gnttab_list, M_DEVBUF);
-	return (ENOMEM);
-
-}
-
-MTX_SYSINIT(gnttab, &gnttab_list_lock, "GNTTAB LOCK", MTX_DEF);