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authordfr <dfr@FreeBSD.org>2008-11-22 16:14:52 +0000
committerdfr <dfr@FreeBSD.org>2008-11-22 16:14:52 +0000
commit19b6af98ec71398e77874582eb84ec5310c7156f (patch)
tree61eebb1b357f3edaa339d295e26a47a74534ac23 /sys/xen/gnttab.c
parent83299de5870b2dc099c17aec548d3502821bc29b (diff)
downloadFreeBSD-src-19b6af98ec71398e77874582eb84ec5310c7156f.zip
FreeBSD-src-19b6af98ec71398e77874582eb84ec5310c7156f.tar.gz
Clone Kip's Xen on stable/6 tree so that I can work on improving FreeBSD/amd64
performance in Xen's HVM mode.
Diffstat (limited to 'sys/xen/gnttab.c')
-rw-r--r--sys/xen/gnttab.c591
1 files changed, 0 insertions, 591 deletions
diff --git a/sys/xen/gnttab.c b/sys/xen/gnttab.c
deleted file mode 100644
index 5fd51aa..0000000
--- a/sys/xen/gnttab.c
+++ /dev/null
@@ -1,591 +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_global.h"
-#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 <machine/xen/hypervisor.h>
-#include <machine/xen/synch_bitops.h>
-#include <xen/gnttab.h>
-
-#define cmpxchg(a, b, c) atomic_cmpset_int((volatile u_int *)(a),(b),(c))
-
-#if 1
-#define ASSERT(_p) \
- if ( !(_p) ) { printk("Assertion '%s': line %d, file %s\n", \
- #_p , __LINE__, __FILE__); *(int*)0=0; }
-#else
-#define ASSERT(_p) ((void)0)
-#endif
-
-#define WPRINTK(fmt, args...) \
- printk("xen_grant: " fmt, ##args)
-
-/* External tools reserve first few grant table entries. */
-#define NR_RESERVED_ENTRIES 8
-#define GNTTAB_LIST_END 0xffffffff
-#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;
-
-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 ref, rc;
- grant_ref_t head;
-
- mtx_lock(&gnttab_list_lock);
- if ((gnttab_free_count < count) &&
- ((rc = gnttab_expand(count - gnttab_free_count)) < 0)) {
- mtx_unlock(&gnttab_list_lock);
- return (rc);
- }
- 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);
- return (ref);
-}
-
-#define get_free_entry() get_free_entries(1)
-
-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 (unlikely(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)
-{
- int ref;
-
- if (unlikely((ref = get_free_entry()) == -1))
- return -ENOSPC;
-
- shared[ref].frame = frame;
- shared[ref].domid = domid;
- wmb();
- shared[ref].flags = GTF_permit_access | (readonly ? GTF_readonly : 0);
-
- return ref;
-}
-
-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("WARNING: g.e. still in use!\n");
- 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("WARNING: leaking g.e. and page still in use!\n");
- }
-}
-
-int
-gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn)
-{
- int ref;
-
- if (unlikely((ref = get_free_entry()) == -1))
- return -ENOSPC;
-
- gnttab_grant_foreign_transfer_ref(ref, domid, pfn);
-
- return (ref);
-}
-
-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;
- PANIC_IF(frame == 0);
-
- 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;
-
- mtx_lock(&gnttab_list_lock);
- ref = head;
- while (gnttab_entry(ref) != GNTTAB_LIST_END) {
- ref = gnttab_entry(ref);
- count++;
- }
- 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 h = get_free_entries(count);
-
- if (h == -1)
- return -ENOSPC;
-
- *head = h;
-
- 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 (unlikely(g == GNTTAB_LIST_END))
- return -ENOSPC;
- *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
-
-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;
- }
- PANIC_IF(rc || setup.status);
-
- if (shared == NULL) {
- vm_offset_t area;
-
- area = kmem_alloc_nofault(kernel_map,
- PAGE_SIZE * max_nr_grant_frames());
- PANIC_IF(area == 0);
- 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(void)
-{
- if (max_nr_grant_frames() < nr_grant_frames)
- return -ENOSYS;
- return gnttab_map(0, nr_grant_frames - 1);
-}
-
-int
-gnttab_suspend(void)
-{
- int i, pages;
-
- pages = (PAGE_SIZE*nr_grant_frames) >> PAGE_SHIFT;
-
- for (i = 0; i < pages; i++)
- PT_SET_MA(shared + (i*PAGE_SIZE), (vm_paddr_t)0);
-
- return (0);
-}
-
-static int
-gnttab_expand(unsigned int req_entries)
-{
- int rc;
- 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;
-
- if ((rc = gnttab_map(cur, cur + extra - 1)) == 0)
- rc = grow_gnttab_list(extra);
-
- return rc;
-}
-
-static int
-gnttab_init(void *unused)
-{
- 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() < 0)
- 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;
-
- printk("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);
-SYSINIT(gnttab, SI_SUB_PSEUDO, SI_ORDER_FIRST, gnttab_init, NULL);
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