nfp: remove automatic caching of RTsym table

The fact that RTsym table is cached inside nfp_cpp handle is
a relic of old times when nfpcore was a library module.  All
the nfp_cpp "caches" are awkward to deal with because of
concurrency and prone to keeping stale information.  Make
the run time symbol table be an object read out from the device
and managed by whoever requested it.  Since the driver loads
FW at ->probe() and never reloads, we can hold onto the table
for ever.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 43 insertions, 68 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_rtsym.c b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_rtsym.c
index 0e3870ecfb8c..ef3566163cb0 100644
--- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_rtsym.c
+++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_rtsym.c
@@ -65,7 +65,8 @@ struct nfp_rtsym_entry {
 	__le32	size_lo;
 };
 
-struct nfp_rtsym_cache {
+struct nfp_rtsym_table {
+	struct nfp_cpp *cpp;
 	int num;
 	char *strtab;
 	struct nfp_rtsym symtab[];
@@ -78,7 +79,7 @@ static int nfp_meid(u8 island_id, u8 menum)
 }
 
 static void
-nfp_rtsym_sw_entry_init(struct nfp_rtsym_cache *cache, u32 strtab_size,
+nfp_rtsym_sw_entry_init(struct nfp_rtsym_table *cache, u32 strtab_size,
 			struct nfp_rtsym *sw, struct nfp_rtsym_entry *fw)
 {
 	sw->type = fw->type;
@@ -106,26 +107,26 @@ nfp_rtsym_sw_entry_init(struct nfp_rtsym_cache *cache, u32 strtab_size,
 		sw->domain = -1;
 }
 
-static int nfp_rtsymtab_probe(struct nfp_cpp *cpp)
+struct nfp_rtsym_table *nfp_rtsym_table_read(struct nfp_cpp *cpp)
 {
 	const u32 dram = NFP_CPP_ID(NFP_CPP_TARGET_MU, NFP_CPP_ACTION_RW, 0) |
 		NFP_ISL_EMEM0;
 	u32 strtab_addr, symtab_addr, strtab_size, symtab_size;
 	struct nfp_rtsym_entry *rtsymtab;
-	struct nfp_rtsym_cache *cache;
+	struct nfp_rtsym_table *cache;
 	const struct nfp_mip *mip;
 	int err, n, size;
 
 	mip = nfp_mip_open(cpp);
 	if (!mip)
-		return -EIO;
+		return NULL;
 
 	nfp_mip_strtab(mip, &strtab_addr, &strtab_size);
 	nfp_mip_symtab(mip, &symtab_addr, &symtab_size);
 	nfp_mip_close(mip);
 
 	if (!symtab_size || !strtab_size || symtab_size % sizeof(*rtsymtab))
-		return -ENXIO;
+		return NULL;
 
 	/* Align to 64 bits */
 	symtab_size = round_up(symtab_size, 8);
@@ -133,27 +134,26 @@ static int nfp_rtsymtab_probe(struct nfp_cpp *cpp)
 
 	rtsymtab = kmalloc(symtab_size, GFP_KERNEL);
 	if (!rtsymtab)
-		return -ENOMEM;
+		return NULL;
 
 	size = sizeof(*cache);
 	size += symtab_size / sizeof(*rtsymtab) * sizeof(struct nfp_rtsym);
 	size +=	strtab_size + 1;
 	cache = kmalloc(size, GFP_KERNEL);
-	if (!cache) {
-		err = -ENOMEM;
-		goto err_free_rtsym_raw;
-	}
+	if (!cache)
+		goto exit_free_rtsym_raw;
 
+	cache->cpp = cpp;
 	cache->num = symtab_size / sizeof(*rtsymtab);
 	cache->strtab = (void *)&cache->symtab[cache->num];
 
 	err = nfp_cpp_read(cpp, dram, symtab_addr, rtsymtab, symtab_size);
 	if (err != symtab_size)
-		goto err_free_cache;
+		goto exit_free_cache;
 
 	err = nfp_cpp_read(cpp, dram, strtab_addr, cache->strtab, strtab_size);
 	if (err != strtab_size)
-		goto err_free_cache;
+		goto exit_free_cache;
 	cache->strtab[strtab_size] = '\0';
 
 	for (n = 0; n < cache->num; n++)
@@ -161,97 +161,71 @@ static int nfp_rtsymtab_probe(struct nfp_cpp *cpp)
 					&cache->symtab[n], &rtsymtab[n]);
 
 	kfree(rtsymtab);
-	nfp_rtsym_cache_set(cpp, cache);
-	return 0;
 
-err_free_cache:
+	return cache;
+
+exit_free_cache:
 	kfree(cache);
-err_free_rtsym_raw:
+exit_free_rtsym_raw:
 	kfree(rtsymtab);
-	return err;
-}
-
-static struct nfp_rtsym_cache *nfp_rtsym(struct nfp_cpp *cpp)
-{
-	struct nfp_rtsym_cache *cache;
-	int err;
-
-	cache = nfp_rtsym_cache(cpp);
-	if (cache)
-		return cache;
-
-	err = nfp_rtsymtab_probe(cpp);
-	if (err < 0)
-		return ERR_PTR(err);
-
-	return nfp_rtsym_cache(cpp);
+	return NULL;
 }
 
 /**
  * nfp_rtsym_count() - Get the number of RTSYM descriptors
- * @cpp:	NFP CPP handle
+ * @rtbl:	NFP RTsym table
  *
- * Return: Number of RTSYM descriptors, or -ERRNO
+ * Return: Number of RTSYM descriptors
  */
-int nfp_rtsym_count(struct nfp_cpp *cpp)
+int nfp_rtsym_count(struct nfp_rtsym_table *rtbl)
 {
-	struct nfp_rtsym_cache *cache;
-
-	cache = nfp_rtsym(cpp);
-	if (IS_ERR(cache))
-		return PTR_ERR(cache);
-
-	return cache->num;
+	if (!rtbl)
+		return -EINVAL;
+	return rtbl->num;
 }
 
 /**
  * nfp_rtsym_get() - Get the Nth RTSYM descriptor
- * @cpp:	NFP CPP handle
+ * @rtbl:	NFP RTsym table
  * @idx:	Index (0-based) of the RTSYM descriptor
  *
  * Return: const pointer to a struct nfp_rtsym descriptor, or NULL
  */
-const struct nfp_rtsym *nfp_rtsym_get(struct nfp_cpp *cpp, int idx)
+const struct nfp_rtsym *nfp_rtsym_get(struct nfp_rtsym_table *rtbl, int idx)
 {
-	struct nfp_rtsym_cache *cache;
-
-	cache = nfp_rtsym(cpp);
-	if (IS_ERR(cache))
+	if (!rtbl)
 		return NULL;
-
-	if (idx >= cache->num)
+	if (idx >= rtbl->num)
 		return NULL;
 
-	return &cache->symtab[idx];
+	return &rtbl->symtab[idx];
 }
 
 /**
  * nfp_rtsym_lookup() - Return the RTSYM descriptor for a symbol name
- * @cpp:	NFP CPP handle
+ * @rtbl:	NFP RTsym table
  * @name:	Symbol name
  *
  * Return: const pointer to a struct nfp_rtsym descriptor, or NULL
  */
-const struct nfp_rtsym *nfp_rtsym_lookup(struct nfp_cpp *cpp, const char *name)
+const struct nfp_rtsym *
+nfp_rtsym_lookup(struct nfp_rtsym_table *rtbl, const char *name)
 {
-	struct nfp_rtsym_cache *cache;
 	int n;
 
-	cache = nfp_rtsym(cpp);
-	if (IS_ERR(cache))
+	if (!rtbl)
 		return NULL;
 
-	for (n = 0; n < cache->num; n++) {
-		if (strcmp(name, cache->symtab[n].name) == 0)
-			return &cache->symtab[n];
-	}
+	for (n = 0; n < rtbl->num; n++)
+		if (strcmp(name, rtbl->symtab[n].name) == 0)
+			return &rtbl->symtab[n];
 
 	return NULL;
 }
 
 /**
  * nfp_rtsym_read_le() - Read a simple unsigned scalar value from symbol
- * @cpp:	NFP CPP handle
+ * @rtbl:	NFP RTsym table
  * @name:	Symbol name
  * @error:	Poniter to error code (optional)
  *
@@ -261,14 +235,15 @@ const struct nfp_rtsym *nfp_rtsym_lookup(struct nfp_cpp *cpp, const char *name)
  *
  * Return: value read, on error sets the error and returns ~0ULL.
  */
-u64 nfp_rtsym_read_le(struct nfp_cpp *cpp, const char *name, int *error)
+u64 nfp_rtsym_read_le(struct nfp_rtsym_table *rtbl, const char *name,
+		      int *error)
 {
 	const struct nfp_rtsym *sym;
 	u32 val32, id;
 	u64 val;
 	int err;
 
-	sym = nfp_rtsym_lookup(cpp, name);
+	sym = nfp_rtsym_lookup(rtbl, name);
 	if (!sym) {
 		err = -ENOENT;
 		goto exit;
@@ -278,14 +253,14 @@ u64 nfp_rtsym_read_le(struct nfp_cpp *cpp, const char *name, int *error)
 
 	switch (sym->size) {
 	case 4:
-		err = nfp_cpp_readl(cpp, id, sym->addr, &val32);
+		err = nfp_cpp_readl(rtbl->cpp, id, sym->addr, &val32);
 		val = val32;
 		break;
 	case 8:
-		err = nfp_cpp_readq(cpp, id, sym->addr, &val);
+		err = nfp_cpp_readq(rtbl->cpp, id, sym->addr, &val);
 		break;
 	default:
-		nfp_err(cpp,
+		nfp_err(rtbl->cpp,
 			"rtsym '%s' unsupported or non-scalar size: %lld\n",
 			name, sym->size);
 		err = -EINVAL;