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freebsd-skq/sys/dev/netmap/netmap_mem2.c

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/*
* Copyright (C) 2012-2013 Matteo Landi, Luigi Rizzo, Giuseppe Lettieri. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* $FreeBSD$
*
* (New) memory allocator for netmap
*/
/*
* This allocator creates three memory pools:
* nm_if_pool for the struct netmap_if
* nm_ring_pool for the struct netmap_ring
* nm_buf_pool for the packet buffers.
*
* that contain netmap objects. Each pool is made of a number of clusters,
* multiple of a page size, each containing an integer number of objects.
* The clusters are contiguous in user space but not in the kernel.
* Only nm_buf_pool needs to be dma-able,
* but for convenience use the same type of allocator for all.
*
* Once mapped, the three pools are exported to userspace
* as a contiguous block, starting from nm_if_pool. Each
* cluster (and pool) is an integral number of pages.
* [ . . . ][ . . . . . .][ . . . . . . . . . .]
* nm_if nm_ring nm_buf
*
* The userspace areas contain offsets of the objects in userspace.
* When (at init time) we write these offsets, we find out the index
* of the object, and from there locate the offset from the beginning
* of the region.
*
* The invididual allocators manage a pool of memory for objects of
* the same size.
* The pool is split into smaller clusters, whose size is a
* multiple of the page size. The cluster size is chosen
* to minimize the waste for a given max cluster size
* (we do it by brute force, as we have relatively few objects
* per cluster).
*
* Objects are aligned to the cache line (64 bytes) rounding up object
* sizes when needed. A bitmap contains the state of each object.
* Allocation scans the bitmap; this is done only on attach, so we are not
* too worried about performance
*
* For each allocator we can define (thorugh sysctl) the size and
* number of each object. Memory is allocated at the first use of a
* netmap file descriptor, and can be freed when all such descriptors
* have been released (including unmapping the memory).
* If memory is scarce, the system tries to get as much as possible
* and the sysctl values reflect the actual allocation.
* Together with desired values, the sysctl export also absolute
* min and maximum values that cannot be overridden.
*
* struct netmap_if:
* variable size, max 16 bytes per ring pair plus some fixed amount.
* 1024 bytes should be large enough in practice.
*
* In the worst case we have one netmap_if per ring in the system.
*
* struct netmap_ring
* variable size, 8 byte per slot plus some fixed amount.
* Rings can be large (e.g. 4k slots, or >32Kbytes).
* We default to 36 KB (9 pages), and a few hundred rings.
*
* struct netmap_buffer
* The more the better, both because fast interfaces tend to have
* many slots, and because we may want to use buffers to store
* packets in userspace avoiding copies.
* Must contain a full frame (eg 1518, or more for vlans, jumbo
* frames etc.) plus be nicely aligned, plus some NICs restrict
* the size to multiple of 1K or so. Default to 2K
*/
#define NETMAP_BUF_MAX_NUM 20*4096*2 /* large machine */
#ifdef linux
// XXX a mtx would suffice here 20130415 lr
// #define NMA_LOCK_T safe_spinlock_t
#define NMA_LOCK_T struct semaphore
#define NMA_LOCK_INIT() sema_init(&nm_mem.nm_mtx, 1)
#define NMA_LOCK_DESTROY()
#define NMA_LOCK() down(&nm_mem.nm_mtx)
#define NMA_UNLOCK() up(&nm_mem.nm_mtx)
#else /* !linux */
#define NMA_LOCK_T struct mtx
#define NMA_LOCK_INIT() mtx_init(&nm_mem.nm_mtx, "netmap memory allocator lock", NULL, MTX_DEF)
#define NMA_LOCK_DESTROY() mtx_destroy(&nm_mem.nm_mtx)
#define NMA_LOCK() mtx_lock(&nm_mem.nm_mtx)
#define NMA_UNLOCK() mtx_unlock(&nm_mem.nm_mtx)
#endif /* linux */
enum {
NETMAP_IF_POOL = 0,
NETMAP_RING_POOL,
NETMAP_BUF_POOL,
NETMAP_POOLS_NR
};
struct netmap_obj_params {
u_int size;
u_int num;
};
struct netmap_obj_params netmap_params[NETMAP_POOLS_NR] = {
[NETMAP_IF_POOL] = {
.size = 1024,
.num = 100,
},
[NETMAP_RING_POOL] = {
.size = 9*PAGE_SIZE,
.num = 200,
},
[NETMAP_BUF_POOL] = {
.size = 2048,
.num = NETMAP_BUF_MAX_NUM,
},
};
struct netmap_obj_pool {
char name[16]; /* name of the allocator */
u_int objtotal; /* actual total number of objects. */
u_int objfree; /* number of free objects. */
u_int clustentries; /* actual objects per cluster */
/* limits */
u_int objminsize; /* minimum object size */
u_int objmaxsize; /* maximum object size */
u_int nummin; /* minimum number of objects */
u_int nummax; /* maximum number of objects */
/* the total memory space is _numclusters*_clustsize */
u_int _numclusters; /* how many clusters */
u_int _clustsize; /* cluster size */
u_int _objsize; /* actual object size */
u_int _memtotal; /* _numclusters*_clustsize */
struct lut_entry *lut; /* virt,phys addresses, objtotal entries */
uint32_t *bitmap; /* one bit per buffer, 1 means free */
uint32_t bitmap_slots; /* number of uint32 entries in bitmap */
};
struct netmap_mem_d {
NMA_LOCK_T nm_mtx; /* protect the allocator */
u_int nm_totalsize; /* shorthand */
int finalized; /* !=0 iff preallocation done */
int lasterr; /* last error for curr config */
int refcount; /* existing priv structures */
/* the three allocators */
struct netmap_obj_pool pools[NETMAP_POOLS_NR];
};
/*
* nm_mem is the memory allocator used for all physical interfaces
* running in netmap mode.
* Virtual (VALE) ports will have each its own allocator.
*/
static struct netmap_mem_d nm_mem = { /* Our memory allocator. */
.pools = {
[NETMAP_IF_POOL] = {
.name = "netmap_if",
.objminsize = sizeof(struct netmap_if),
.objmaxsize = 4096,
.nummin = 10, /* don't be stingy */
.nummax = 10000, /* XXX very large */
},
[NETMAP_RING_POOL] = {
.name = "netmap_ring",
.objminsize = sizeof(struct netmap_ring),
.objmaxsize = 32*PAGE_SIZE,
.nummin = 2,
.nummax = 1024,
},
[NETMAP_BUF_POOL] = {
.name = "netmap_buf",
.objminsize = 64,
.objmaxsize = 65536,
.nummin = 4,
.nummax = 1000000, /* one million! */
},
},
};
// XXX logically belongs to nm_mem
struct lut_entry *netmap_buffer_lut; /* exported */
/* memory allocator related sysctls */
#define STRINGIFY(x) #x
#define DECLARE_SYSCTLS(id, name) \
SYSCTL_INT(_dev_netmap, OID_AUTO, name##_size, \
CTLFLAG_RW, &netmap_params[id].size, 0, "Requested size of netmap " STRINGIFY(name) "s"); \
SYSCTL_INT(_dev_netmap, OID_AUTO, name##_curr_size, \
CTLFLAG_RD, &nm_mem.pools[id]._objsize, 0, "Current size of netmap " STRINGIFY(name) "s"); \
SYSCTL_INT(_dev_netmap, OID_AUTO, name##_num, \
CTLFLAG_RW, &netmap_params[id].num, 0, "Requested number of netmap " STRINGIFY(name) "s"); \
SYSCTL_INT(_dev_netmap, OID_AUTO, name##_curr_num, \
CTLFLAG_RD, &nm_mem.pools[id].objtotal, 0, "Current number of netmap " STRINGIFY(name) "s")
DECLARE_SYSCTLS(NETMAP_IF_POOL, if);
DECLARE_SYSCTLS(NETMAP_RING_POOL, ring);
DECLARE_SYSCTLS(NETMAP_BUF_POOL, buf);
/*
* Convert a userspace offset to a physical address.
* XXX only called in the FreeBSD's netmap_mmap()
* because in linux we map everything at once.
*
* First, find the allocator that contains the requested offset,
* then locate the cluster through a lookup table.
*/
static inline vm_paddr_t
netmap_ofstophys(vm_offset_t offset)
{
int i;
vm_offset_t o = offset;
struct netmap_obj_pool *p = nm_mem.pools;
for (i = 0; i < NETMAP_POOLS_NR; offset -= p[i]._memtotal, i++) {
if (offset >= p[i]._memtotal)
continue;
// now lookup the cluster's address
return p[i].lut[offset / p[i]._objsize].paddr +
offset % p[i]._objsize;
}
/* this is only in case of errors */
D("invalid ofs 0x%x out of 0x%x 0x%x 0x%x", (u_int)o,
p[NETMAP_IF_POOL]._memtotal,
p[NETMAP_IF_POOL]._memtotal
+ p[NETMAP_RING_POOL]._memtotal,
p[NETMAP_IF_POOL]._memtotal
+ p[NETMAP_RING_POOL]._memtotal
+ p[NETMAP_BUF_POOL]._memtotal);
return 0; // XXX bad address
}
/*
* we store objects by kernel address, need to find the offset
* within the pool to export the value to userspace.
* Algorithm: scan until we find the cluster, then add the
* actual offset in the cluster
*/
static ssize_t
netmap_obj_offset(struct netmap_obj_pool *p, const void *vaddr)
{
int i, k = p->clustentries, n = p->objtotal;
ssize_t ofs = 0;
for (i = 0; i < n; i += k, ofs += p->_clustsize) {
const char *base = p->lut[i].vaddr;
ssize_t relofs = (const char *) vaddr - base;
if (relofs < 0 || relofs >= p->_clustsize)
continue;
ofs = ofs + relofs;
ND("%s: return offset %d (cluster %d) for pointer %p",
p->name, ofs, i, vaddr);
return ofs;
}
D("address %p is not contained inside any cluster (%s)",
vaddr, p->name);
return 0; /* An error occurred */
}
/* Helper functions which convert virtual addresses to offsets */
#define netmap_if_offset(v) \
netmap_obj_offset(&nm_mem.pools[NETMAP_IF_POOL], (v))
#define netmap_ring_offset(v) \
(nm_mem.pools[NETMAP_IF_POOL]._memtotal + \
netmap_obj_offset(&nm_mem.pools[NETMAP_RING_POOL], (v)))
#define netmap_buf_offset(v) \
(nm_mem.pools[NETMAP_IF_POOL]._memtotal + \
nm_mem.pools[NETMAP_RING_POOL]._memtotal + \
netmap_obj_offset(&nm_mem.pools[NETMAP_BUF_POOL], (v)))
/*
* report the index, and use start position as a hint,
* otherwise buffer allocation becomes terribly expensive.
*/
static void *
netmap_obj_malloc(struct netmap_obj_pool *p, int len, uint32_t *start, uint32_t *index)
{
uint32_t i = 0; /* index in the bitmap */
uint32_t mask, j; /* slot counter */
void *vaddr = NULL;
if (len > p->_objsize) {
D("%s request size %d too large", p->name, len);
// XXX cannot reduce the size
return NULL;
}
if (p->objfree == 0) {
D("%s allocator: run out of memory", p->name);
return NULL;
}
if (start)
i = *start;
/* termination is guaranteed by p->free, but better check bounds on i */
while (vaddr == NULL && i < p->bitmap_slots) {
uint32_t cur = p->bitmap[i];
if (cur == 0) { /* bitmask is fully used */
i++;
continue;
}
/* locate a slot */
for (j = 0, mask = 1; (cur & mask) == 0; j++, mask <<= 1)
;
p->bitmap[i] &= ~mask; /* mark object as in use */
p->objfree--;
vaddr = p->lut[i * 32 + j].vaddr;
if (index)
*index = i * 32 + j;
}
ND("%s allocator: allocated object @ [%d][%d]: vaddr %p", i, j, vaddr);
if (start)
*start = i;
return vaddr;
}
/*
* free by index, not by address. This is slow, but is only used
* for a small number of objects (rings, nifp)
*/
static void
netmap_obj_free(struct netmap_obj_pool *p, uint32_t j)
{
if (j >= p->objtotal) {
D("invalid index %u, max %u", j, p->objtotal);
return;
}
p->bitmap[j / 32] |= (1 << (j % 32));
p->objfree++;
return;
}
static void
netmap_obj_free_va(struct netmap_obj_pool *p, void *vaddr)
{
int i, j, n = p->_memtotal / p->_clustsize;
for (i = 0, j = 0; i < n; i++, j += p->clustentries) {
void *base = p->lut[i * p->clustentries].vaddr;
ssize_t relofs = (ssize_t) vaddr - (ssize_t) base;
/* Given address, is out of the scope of the current cluster.*/
if (vaddr < base || relofs >= p->_clustsize)
continue;
j = j + relofs / p->_objsize;
KASSERT(j != 0, ("Cannot free object 0"));
netmap_obj_free(p, j);
return;
}
D("address %p is not contained inside any cluster (%s)",
vaddr, p->name);
}
#define netmap_if_malloc(len) netmap_obj_malloc(&nm_mem.pools[NETMAP_IF_POOL], len, NULL, NULL)
#define netmap_if_free(v) netmap_obj_free_va(&nm_mem.pools[NETMAP_IF_POOL], (v))
#define netmap_ring_malloc(len) netmap_obj_malloc(&nm_mem.pools[NETMAP_RING_POOL], len, NULL, NULL)
#define netmap_ring_free(v) netmap_obj_free_va(&nm_mem.pools[NETMAP_RING_POOL], (v))
#define netmap_buf_malloc(_pos, _index) \
netmap_obj_malloc(&nm_mem.pools[NETMAP_BUF_POOL], NETMAP_BUF_SIZE, _pos, _index)
/* Return the index associated to the given packet buffer */
#define netmap_buf_index(v) \
(netmap_obj_offset(&nm_mem.pools[NETMAP_BUF_POOL], (v)) / nm_mem.pools[NETMAP_BUF_POOL]._objsize)
/* Return nonzero on error */
static int
netmap_new_bufs(struct netmap_if *nifp,
struct netmap_slot *slot, u_int n)
{
struct netmap_obj_pool *p = &nm_mem.pools[NETMAP_BUF_POOL];
int i = 0; /* slot counter */
uint32_t pos = 0; /* slot in p->bitmap */
uint32_t index = 0; /* buffer index */
(void)nifp; /* UNUSED */
for (i = 0; i < n; i++) {
void *vaddr = netmap_buf_malloc(&pos, &index);
if (vaddr == NULL) {
D("unable to locate empty packet buffer");
goto cleanup;
}
slot[i].buf_idx = index;
slot[i].len = p->_objsize;
/* XXX setting flags=NS_BUF_CHANGED forces a pointer reload
* in the NIC ring. This is a hack that hides missing
* initializations in the drivers, and should go away.
*/
// slot[i].flags = NS_BUF_CHANGED;
}
ND("allocated %d buffers, %d available, first at %d", n, p->objfree, pos);
return (0);
cleanup:
while (i > 0) {
i--;
netmap_obj_free(p, slot[i].buf_idx);
}
bzero(slot, n * sizeof(slot[0]));
return (ENOMEM);
}
static void
netmap_free_buf(struct netmap_if *nifp, uint32_t i)
{
struct netmap_obj_pool *p = &nm_mem.pools[NETMAP_BUF_POOL];
if (i < 2 || i >= p->objtotal) {
D("Cannot free buf#%d: should be in [2, %d[", i, p->objtotal);
return;
}
netmap_obj_free(p, i);
}
static void
netmap_reset_obj_allocator(struct netmap_obj_pool *p)
{
if (p == NULL)
return;
if (p->bitmap)
free(p->bitmap, M_NETMAP);
p->bitmap = NULL;
if (p->lut) {
int i;
for (i = 0; i < p->objtotal; i += p->clustentries) {
if (p->lut[i].vaddr)
contigfree(p->lut[i].vaddr, p->_clustsize, M_NETMAP);
}
bzero(p->lut, sizeof(struct lut_entry) * p->objtotal);
#ifdef linux
vfree(p->lut);
#else
free(p->lut, M_NETMAP);
#endif
}
p->lut = NULL;
}
/*
* Free all resources related to an allocator.
*/
static void
netmap_destroy_obj_allocator(struct netmap_obj_pool *p)
{
if (p == NULL)
return;
netmap_reset_obj_allocator(p);
}
/*
* We receive a request for objtotal objects, of size objsize each.
* Internally we may round up both numbers, as we allocate objects
* in small clusters multiple of the page size.
* In the allocator we don't need to store the objsize,
* but we do need to keep track of objtotal' and clustentries,
* as they are needed when freeing memory.
*
* XXX note -- userspace needs the buffers to be contiguous,
* so we cannot afford gaps at the end of a cluster.
*/
/* call with NMA_LOCK held */
static int
netmap_config_obj_allocator(struct netmap_obj_pool *p, u_int objtotal, u_int objsize)
{
int i, n;
u_int clustsize; /* the cluster size, multiple of page size */
u_int clustentries; /* how many objects per entry */
#define MAX_CLUSTSIZE (1<<17)
#define LINE_ROUND 64
if (objsize >= MAX_CLUSTSIZE) {
/* we could do it but there is no point */
D("unsupported allocation for %d bytes", objsize);
goto error;
}
/* make sure objsize is a multiple of LINE_ROUND */
i = (objsize & (LINE_ROUND - 1));
if (i) {
D("XXX aligning object by %d bytes", LINE_ROUND - i);
objsize += LINE_ROUND - i;
}
if (objsize < p->objminsize || objsize > p->objmaxsize) {
D("requested objsize %d out of range [%d, %d]",
objsize, p->objminsize, p->objmaxsize);
goto error;
}
if (objtotal < p->nummin || objtotal > p->nummax) {
D("requested objtotal %d out of range [%d, %d]",
objtotal, p->nummin, p->nummax);
goto error;
}
/*
* Compute number of objects using a brute-force approach:
* given a max cluster size,
* we try to fill it with objects keeping track of the
* wasted space to the next page boundary.
*/
for (clustentries = 0, i = 1;; i++) {
u_int delta, used = i * objsize;
if (used > MAX_CLUSTSIZE)
break;
delta = used % PAGE_SIZE;
if (delta == 0) { // exact solution
clustentries = i;
break;
}
if (delta > ( (clustentries*objsize) % PAGE_SIZE) )
clustentries = i;
}
// D("XXX --- ouch, delta %d (bad for buffers)", delta);
/* compute clustsize and round to the next page */
clustsize = clustentries * objsize;
i = (clustsize & (PAGE_SIZE - 1));
if (i)
clustsize += PAGE_SIZE - i;
if (netmap_verbose)
D("objsize %d clustsize %d objects %d",
objsize, clustsize, clustentries);
/*
* The number of clusters is n = ceil(objtotal/clustentries)
* objtotal' = n * clustentries
*/
p->clustentries = clustentries;
p->_clustsize = clustsize;
n = (objtotal + clustentries - 1) / clustentries;
p->_numclusters = n;
p->objtotal = n * clustentries;
p->objfree = p->objtotal - 2; /* obj 0 and 1 are reserved */
p->_memtotal = p->_numclusters * p->_clustsize;
p->_objsize = objsize;
return 0;
error:
p->_objsize = objsize;
p->objtotal = objtotal;
return EINVAL;
}
/* call with NMA_LOCK held */
static int
netmap_finalize_obj_allocator(struct netmap_obj_pool *p)
{
int i, n;
n = sizeof(struct lut_entry) * p->objtotal;
#ifdef linux
p->lut = vmalloc(n);
#else
p->lut = malloc(n, M_NETMAP, M_NOWAIT | M_ZERO);
#endif
if (p->lut == NULL) {
D("Unable to create lookup table (%d bytes) for '%s'", n, p->name);
goto clean;
}
/* Allocate the bitmap */
n = (p->objtotal + 31) / 32;
p->bitmap = malloc(sizeof(uint32_t) * n, M_NETMAP, M_NOWAIT | M_ZERO);
if (p->bitmap == NULL) {
D("Unable to create bitmap (%d entries) for allocator '%s'", n,
p->name);
goto clean;
}
p->bitmap_slots = n;
/*
* Allocate clusters, init pointers and bitmap
*/
for (i = 0; i < p->objtotal;) {
int lim = i + p->clustentries;
char *clust;
clust = contigmalloc(p->_clustsize, M_NETMAP, M_NOWAIT | M_ZERO,
0, -1UL, PAGE_SIZE, 0);
if (clust == NULL) {
/*
* If we get here, there is a severe memory shortage,
* so halve the allocated memory to reclaim some.
* XXX check boundaries
*/
D("Unable to create cluster at %d for '%s' allocator",
i, p->name);
lim = i / 2;
for (i--; i >= lim; i--) {
p->bitmap[ (i>>5) ] &= ~( 1 << (i & 31) );
if (i % p->clustentries == 0 && p->lut[i].vaddr)
contigfree(p->lut[i].vaddr,
p->_clustsize, M_NETMAP);
}
p->objtotal = i;
p->objfree = p->objtotal - 2;
p->_numclusters = i / p->clustentries;
p->_memtotal = p->_numclusters * p->_clustsize;
break;
}
for (; i < lim; i++, clust += p->_objsize) {
p->bitmap[ (i>>5) ] |= ( 1 << (i & 31) );
p->lut[i].vaddr = clust;
p->lut[i].paddr = vtophys(clust);
}
}
p->bitmap[0] = ~3; /* objs 0 and 1 is always busy */
if (netmap_verbose)
D("Pre-allocated %d clusters (%d/%dKB) for '%s'",
p->_numclusters, p->_clustsize >> 10,
p->_memtotal >> 10, p->name);
return 0;
clean:
netmap_reset_obj_allocator(p);
return ENOMEM;
}
/* call with lock held */
static int
netmap_memory_config_changed(void)
{
int i;
for (i = 0; i < NETMAP_POOLS_NR; i++) {
if (nm_mem.pools[i]._objsize != netmap_params[i].size ||
nm_mem.pools[i].objtotal != netmap_params[i].num)
return 1;
}
return 0;
}
/* call with lock held */
static int
netmap_memory_config(void)
{
int i;
if (!netmap_memory_config_changed())
goto out;
D("reconfiguring");
if (nm_mem.finalized) {
/* reset previous allocation */
for (i = 0; i < NETMAP_POOLS_NR; i++) {
netmap_reset_obj_allocator(&nm_mem.pools[i]);
}
nm_mem.finalized = 0;
}
for (i = 0; i < NETMAP_POOLS_NR; i++) {
nm_mem.lasterr = netmap_config_obj_allocator(&nm_mem.pools[i],
netmap_params[i].num, netmap_params[i].size);
if (nm_mem.lasterr)
goto out;
}
D("Have %d KB for interfaces, %d KB for rings and %d MB for buffers",
nm_mem.pools[NETMAP_IF_POOL]._memtotal >> 10,
nm_mem.pools[NETMAP_RING_POOL]._memtotal >> 10,
nm_mem.pools[NETMAP_BUF_POOL]._memtotal >> 20);
out:
return nm_mem.lasterr;
}
/* call with lock held */
static int
netmap_memory_finalize(void)
{
int i;
u_int totalsize = 0;
nm_mem.refcount++;
if (nm_mem.refcount > 1) {
ND("busy (refcount %d)", nm_mem.refcount);
goto out;
}
/* update configuration if changed */
if (netmap_memory_config())
goto out;
if (nm_mem.finalized) {
/* may happen if config is not changed */
ND("nothing to do");
goto out;
}
for (i = 0; i < NETMAP_POOLS_NR; i++) {
nm_mem.lasterr = netmap_finalize_obj_allocator(&nm_mem.pools[i]);
if (nm_mem.lasterr)
goto cleanup;
totalsize += nm_mem.pools[i]._memtotal;
}
nm_mem.nm_totalsize = totalsize;
/* backward compatibility */
netmap_buf_size = nm_mem.pools[NETMAP_BUF_POOL]._objsize;
netmap_total_buffers = nm_mem.pools[NETMAP_BUF_POOL].objtotal;
netmap_buffer_lut = nm_mem.pools[NETMAP_BUF_POOL].lut;
netmap_buffer_base = nm_mem.pools[NETMAP_BUF_POOL].lut[0].vaddr;
nm_mem.finalized = 1;
nm_mem.lasterr = 0;
/* make sysctl values match actual values in the pools */
for (i = 0; i < NETMAP_POOLS_NR; i++) {
netmap_params[i].size = nm_mem.pools[i]._objsize;
netmap_params[i].num = nm_mem.pools[i].objtotal;
}
out:
if (nm_mem.lasterr)
nm_mem.refcount--;
return nm_mem.lasterr;
cleanup:
for (i = 0; i < NETMAP_POOLS_NR; i++) {
netmap_reset_obj_allocator(&nm_mem.pools[i]);
}
nm_mem.refcount--;
return nm_mem.lasterr;
}
static int
netmap_memory_init(void)
{
NMA_LOCK_INIT();
return (0);
}
static void
netmap_memory_fini(void)
{
int i;
for (i = 0; i < NETMAP_POOLS_NR; i++) {
netmap_destroy_obj_allocator(&nm_mem.pools[i]);
}
NMA_LOCK_DESTROY();
}
static void
netmap_free_rings(struct netmap_adapter *na)
{
int i;
if (!na->tx_rings)
return;
for (i = 0; i < na->num_tx_rings + 1; i++) {
netmap_ring_free(na->tx_rings[i].ring);
na->tx_rings[i].ring = NULL;
}
for (i = 0; i < na->num_rx_rings + 1; i++) {
netmap_ring_free(na->rx_rings[i].ring);
na->rx_rings[i].ring = NULL;
}
free(na->tx_rings, M_DEVBUF);
na->tx_rings = na->rx_rings = NULL;
}
/* call with NMA_LOCK held */
/*
* Allocate the per-fd structure netmap_if.
* If this is the first instance, also allocate the krings, rings etc.
*/
static void *
netmap_if_new(const char *ifname, struct netmap_adapter *na)
{
struct netmap_if *nifp;
struct netmap_ring *ring;
ssize_t base; /* handy for relative offsets between rings and nifp */
u_int i, len, ndesc, ntx, nrx;
struct netmap_kring *kring;
if (netmap_update_config(na)) {
/* configuration mismatch, report and fail */
return NULL;
}
ntx = na->num_tx_rings + 1; /* shorthand, include stack ring */
nrx = na->num_rx_rings + 1; /* shorthand, include stack ring */
/*
* the descriptor is followed inline by an array of offsets
* to the tx and rx rings in the shared memory region.
*/
len = sizeof(struct netmap_if) + (nrx + ntx) * sizeof(ssize_t);
nifp = netmap_if_malloc(len);
if (nifp == NULL) {
return NULL;
}
/* initialize base fields -- override const */
*(int *)(uintptr_t)&nifp->ni_tx_rings = na->num_tx_rings;
*(int *)(uintptr_t)&nifp->ni_rx_rings = na->num_rx_rings;
strncpy(nifp->ni_name, ifname, IFNAMSIZ);
(na->refcount)++; /* XXX atomic ? we are under lock */
if (na->refcount > 1) { /* already setup, we are done */
goto final;
}
len = (ntx + nrx) * sizeof(struct netmap_kring);
na->tx_rings = malloc(len, M_DEVBUF, M_NOWAIT | M_ZERO);
if (na->tx_rings == NULL) {
D("Cannot allocate krings for %s", ifname);
goto cleanup;
}
na->rx_rings = na->tx_rings + ntx;
/*
* First instance, allocate netmap rings and buffers for this card
* The rings are contiguous, but have variable size.
*/
for (i = 0; i < ntx; i++) { /* Transmit rings */
kring = &na->tx_rings[i];
ndesc = na->num_tx_desc;
bzero(kring, sizeof(*kring));
len = sizeof(struct netmap_ring) +
ndesc * sizeof(struct netmap_slot);
ring = netmap_ring_malloc(len);
if (ring == NULL) {
D("Cannot allocate tx_ring[%d] for %s", i, ifname);
goto cleanup;
}
ND("txring[%d] at %p ofs %d", i, ring);
kring->na = na;
kring->ring = ring;
*(int *)(uintptr_t)&ring->num_slots = kring->nkr_num_slots = ndesc;
*(ssize_t *)(uintptr_t)&ring->buf_ofs =
(nm_mem.pools[NETMAP_IF_POOL]._memtotal +
nm_mem.pools[NETMAP_RING_POOL]._memtotal) -
netmap_ring_offset(ring);
/*
* IMPORTANT:
* Always keep one slot empty, so we can detect new
* transmissions comparing cur and nr_hwcur (they are
* the same only if there are no new transmissions).
*/
ring->avail = kring->nr_hwavail = ndesc - 1;
ring->cur = kring->nr_hwcur = 0;
*(int *)(uintptr_t)&ring->nr_buf_size = NETMAP_BUF_SIZE;
ND("initializing slots for txring[%d]", i);
if (netmap_new_bufs(nifp, ring->slot, ndesc)) {
D("Cannot allocate buffers for tx_ring[%d] for %s", i, ifname);
goto cleanup;
}
}
for (i = 0; i < nrx; i++) { /* Receive rings */
kring = &na->rx_rings[i];
ndesc = na->num_rx_desc;
bzero(kring, sizeof(*kring));
len = sizeof(struct netmap_ring) +
ndesc * sizeof(struct netmap_slot);
ring = netmap_ring_malloc(len);
if (ring == NULL) {
D("Cannot allocate rx_ring[%d] for %s", i, ifname);
goto cleanup;
}
ND("rxring[%d] at %p ofs %d", i, ring);
kring->na = na;
kring->ring = ring;
*(int *)(uintptr_t)&ring->num_slots = kring->nkr_num_slots = ndesc;
*(ssize_t *)(uintptr_t)&ring->buf_ofs =
(nm_mem.pools[NETMAP_IF_POOL]._memtotal +
nm_mem.pools[NETMAP_RING_POOL]._memtotal) -
netmap_ring_offset(ring);
ring->cur = kring->nr_hwcur = 0;
ring->avail = kring->nr_hwavail = 0; /* empty */
*(int *)(uintptr_t)&ring->nr_buf_size = NETMAP_BUF_SIZE;
ND("initializing slots for rxring[%d]", i);
if (netmap_new_bufs(nifp, ring->slot, ndesc)) {
D("Cannot allocate buffers for rx_ring[%d] for %s", i, ifname);
goto cleanup;
}
}
#ifdef linux
// XXX initialize the selrecord structs.
for (i = 0; i < ntx; i++)
init_waitqueue_head(&na->tx_rings[i].si);
for (i = 0; i < nrx; i++)
init_waitqueue_head(&na->rx_rings[i].si);
init_waitqueue_head(&na->tx_si);
init_waitqueue_head(&na->rx_si);
#endif
final:
/*
* fill the slots for the rx and tx rings. They contain the offset
* between the ring and nifp, so the information is usable in
* userspace to reach the ring from the nifp.
*/
base = netmap_if_offset(nifp);
for (i = 0; i < ntx; i++) {
*(ssize_t *)(uintptr_t)&nifp->ring_ofs[i] =
netmap_ring_offset(na->tx_rings[i].ring) - base;
}
for (i = 0; i < nrx; i++) {
*(ssize_t *)(uintptr_t)&nifp->ring_ofs[i+ntx] =
netmap_ring_offset(na->rx_rings[i].ring) - base;
}
return (nifp);
cleanup:
netmap_free_rings(na);
netmap_if_free(nifp);
(na->refcount)--;
return NULL;
}
/* call with NMA_LOCK held */
static void
netmap_memory_deref(void)
{
nm_mem.refcount--;
if (netmap_verbose)
D("refcount = %d", nm_mem.refcount);
}
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