/*
* Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* 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.
*/
#include <linux/device.h>
#include <linux/ndctl.h>
#include <linux/io.h>
#include <linux/nd.h>
#include "nd-core.h"
#include "label.h"
#include "nd.h"
static u32 best_seq(u32 a, u32 b)
{
a &= NSINDEX_SEQ_MASK;
b &= NSINDEX_SEQ_MASK;
if (a == 0 || a == b)
return b;
else if (b == 0)
return a;
else if (nd_inc_seq(a) == b)
return b;
else
return a;
}
size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd)
{
u32 index_span;
if (ndd->nsindex_size)
return ndd->nsindex_size;
/*
* The minimum index space is 512 bytes, with that amount of
* index we can describe ~1400 labels which is less than a byte
* of overhead per label. Round up to a byte of overhead per
* label and determine the size of the index region. Yes, this
* starts to waste space at larger config_sizes, but it's
* unlikely we'll ever see anything but 128K.
*/
index_span = ndd->nsarea.config_size / 129;
index_span /= NSINDEX_ALIGN * 2;
ndd->nsindex_size = index_span * NSINDEX_ALIGN;
return ndd->nsindex_size;
}
int nd_label_validate(struct nvdimm_drvdata *ndd)
{
/*
* On media label format consists of two index blocks followed
* by an array of labels. None of these structures are ever
* updated in place. A sequence number tracks the current
* active index and the next one to write, while labels are
* written to free slots.
*
* +------------+
* | |
* | nsindex0 |
* | |
* +------------+
* | |
* | nsindex1 |
* | |
* +------------+
* | label0 |
* +------------+
* | label1 |
* +------------+
* | |
* ....nslot...
* | |
* +------------+
* | labelN |
* +------------+
*/
struct nd_namespace_index *nsindex[] = {
to_namespace_index(ndd, 0),
to_namespace_index(ndd, 1),
};
const int num_index = ARRAY_SIZE(nsindex);
struct device *dev = ndd->dev;
bool valid[2] = { 0 };
int i, num_valid = 0;
u32 seq;
for (i = 0; i < num_index; i++) {
u32 nslot;
u8 sig[NSINDEX_SIG_LEN];
u64 sum_save, sum, size;
memcpy(sig, nsindex[i]->sig, NSINDEX_SIG_LEN);
if (memcmp(sig, NSINDEX_SIGNATURE, NSINDEX_SIG_LEN) != 0) {
dev_dbg(dev, "%s: nsindex%d signature invalid\n",
__func__, i);
continue;
}
sum_save = __le64_to_cpu(nsindex[i]->checksum);
nsindex[i]->checksum = __cpu_to_le64(0);
sum = nd_fletcher64(nsindex[i], sizeof_namespace_index(ndd), 1);
nsindex[i]->checksum = __cpu_to_le64(sum_save);
if (sum != sum_save) {
dev_dbg(dev, "%s: nsindex%d checksum invalid\n",
__func__, i);
continue;
}
seq = __le32_to_cpu(nsindex[i]->seq);
if ((seq & NSINDEX_SEQ_MASK) == 0) {
dev_dbg(dev, "%s: nsindex%d sequence: %#x invalid\n",
__func__, i, seq);
continue;
}
/* sanity check the index against expected values */
if (__le64_to_cpu(nsindex[i]->myoff)
!= i * sizeof_namespace_index(ndd)) {
dev_dbg(dev, "%s: nsindex%d myoff: %#llx invalid\n",
__func__, i, (unsigned long long)
__le64_to_cpu(nsindex[i]->myoff));
continue;
}
if (__le64_to_cpu(nsindex[i]->otheroff)
!= (!i) * sizeof_namespace_index(ndd)) {
dev_dbg(dev, "%s: nsindex%d otheroff: %#llx invalid\n",
__func__, i, (unsigned long long)
__le64_to_cpu(nsindex[i]->otheroff));
continue;
}
size = __le64_to_cpu(nsindex[i]->mysize);
if (size > sizeof_namespace_index(ndd)
|| size < sizeof(struct nd_namespace_index)) {
dev_dbg(dev, "%s: nsindex%d mysize: %#llx invalid\n",
__func__, i, size);
continue;
}
nslot = __le32_to_cpu(nsindex[i]->nslot);
if (nslot * sizeof(struct nd_namespace_label)
+ 2 * sizeof_namespace_index(ndd)
> ndd->nsarea.config_size) {
dev_dbg(dev, "%s: nsindex%d nslot: %u invalid, config_size: %#x\n",
__func__, i, nslot,
ndd->nsarea.config_size);
continue;
}
valid[i] = true;
num_valid++;
}
switch (num_valid) {
case 0:
break;
case 1:
for (i = 0; i < num_index; i++)
if (valid[i])
return i;
/* can't have num_valid > 0 but valid[] = { false, false } */
WARN_ON(1);
break;
default:
/* pick the best index... */
seq = best_seq(__le32_to_cpu(nsindex[0]->seq),
__le32_to_cpu(nsindex[1]->seq));
if (seq == (__le32_to_cpu(nsindex[1]->seq) & NSINDEX_SEQ_MASK))
return 1;
else
return 0;
break;
}
return -1;
}
void nd_label_copy(struct nvdimm_drvdata *ndd, struct nd_namespace_index *dst,
struct nd_namespace_index *src)
{
if (dst && src)
/* pass */;
else
return;
memcpy(dst, src, sizeof_namespace_index(ndd));
}
static struct nd_namespace_label *nd_label_base(struct nvdimm_drvdata *ndd)
{
void *base = to_namespace_index(ndd, 0);
return base + 2 * sizeof_namespace_index(ndd);
}
#define for_each_clear_bit_le(bit, addr, size) \
for ((bit) = find_next_zero_bit_le((addr), (size), 0); \
(bit) < (size); \
(bit) = find_next_zero_bit_le((addr), (size), (bit) + 1))
/**
* preamble_current - common variable initialization for nd_label_* routines
* @ndd: dimm container for the relevant label set
* @nsindex_out: on return set to the currently active namespace index
* @free: on return set to the free label bitmap in the index
* @nslot: on return set to the number of slots in the label space
*/
static bool preamble_current(struct nvdimm_drvdata *ndd,
struct nd_namespace_index **nsindex_out,
unsigned long **free, u32 *nslot)
{
struct nd_namespace_index *nsindex;
nsindex = to_current_namespace_index(ndd);
if (nsindex == NULL)
return false;
*free = (unsigned long *) nsindex->free;
*nslot = __le32_to_cpu(nsindex->nslot);
*nsindex_out = nsindex;
return true;
}
static char *nd_label_gen_id(struct nd_label_id *label_id, u8 *uuid, u32 flags)
{
if (!label_id || !uuid)
return NULL;
snprintf(label_id->id, ND_LABEL_ID_SIZE, "%s-%pUb",
flags & NSLABEL_FLAG_LOCAL ? "blk" : "pmem", uuid);
return label_id->id;
}
static bool slot_valid(struct nd_namespace_label *nd_label, u32 slot)
{
/* check that we are written where we expect to be written */
if (slot != __le32_to_cpu(nd_label->slot))
return false;
/* check that DPA allocations are page aligned */
if ((__le64_to_cpu(nd_label->dpa)
| __le64_to_cpu(nd_label->rawsize)) % SZ_4K)
return false;
return true;
}
int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd)
{
struct nd_namespace_index *nsindex;
unsigned long *free;
u32 nslot, slot;
if (!preamble_current(ndd, &nsindex, &free, &nslot))
return 0; /* no label, nothing to reserve */
for_each_clear_bit_le(slot, free, nslot) {
struct nd_namespace_label *nd_label;
struct nd_region *nd_region = NULL;
u8 label_uuid[NSLABEL_UUID_LEN];
struct nd_label_id label_id;
struct resource *res;
u32 flags;
nd_label = nd_label_base(ndd) + slot;
if (!slot_valid(nd_label, slot))
continue;
memcpy(label_uuid, nd_label->uuid, NSLABEL_UUID_LEN);
flags = __le32_to_cpu(nd_label->flags);
nd_label_gen_id(&label_id, label_uuid, flags);
res = nvdimm_allocate_dpa(ndd, &label_id,
__le64_to_cpu(nd_label->dpa),
__le64_to_cpu(nd_label->rawsize));
nd_dbg_dpa(nd_region, ndd, res, "reserve\n");
if (!res)
return -EBUSY;
}
return 0;
}
