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Message-ID: <tkrat.033aeb4c3d7dc6d0@s5r6.in-berlin.de>
Date: Sat, 26 Dec 2009 01:42:28 +0100 (CET)
From: Stefan Richter <stefanr@...6.in-berlin.de>
To: linux-kernel@...r.kernel.org
cc: linux1394-devel@...ts.sourceforge.net,
Clemens Ladisch <cladisch@...tmail.net>
Subject: [PATCH 1/3 resend] firewire: add fw_csr_string() helper function
Date: Thu, 24 Dec 2009 11:59:57 +0100
From: Clemens Ladisch <clemens@...isch.de>
The core (sysfs attributes), the firedtv driver, and possible future
drivers all read strings from some configuration ROM directory. Factor
out the generic code from show_text_leaf() into a new helper function,
modified slightly to handle arbitrary buffer sizes.
Signed-off-by: Clemens Ladisch <clemens@...isch.de>
Signed-off-by: Stefan Richter <stefanr@...6.in-berlin.de>
---
drivers/firewire/core-device.c | 110 +++++++++++++++++-------
drivers/media/dvb/firewire/firedtv-fw.c | 39 +--------
include/linux/firewire.h | 2 +
3 files changed, 84 insertions(+), 67 deletions(-)
Index: linux-2.6.33-rc2/include/linux/firewire.h
===================================================================
--- linux-2.6.33-rc2.orig/include/linux/firewire.h
+++ linux-2.6.33-rc2/include/linux/firewire.h
@@ -72,6 +72,8 @@ struct fw_csr_iterator {
void fw_csr_iterator_init(struct fw_csr_iterator *ci, u32 *p);
int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value);
+int fw_csr_string(u32 *directory, int key, char *buf, size_t size);
+
extern struct bus_type fw_bus_type;
struct fw_card_driver;
Index: linux-2.6.33-rc2/drivers/firewire/core-device.c
===================================================================
--- linux-2.6.33-rc2.orig/drivers/firewire/core-device.c
+++ linux-2.6.33-rc2/drivers/firewire/core-device.c
@@ -59,6 +59,67 @@ int fw_csr_iterator_next(struct fw_csr_i
}
EXPORT_SYMBOL(fw_csr_iterator_next);
+static u32 *search_leaf(u32 *directory, int search_key)
+{
+ struct fw_csr_iterator ci;
+ int last_key = 0, key, value;
+
+ fw_csr_iterator_init(&ci, directory);
+ while (fw_csr_iterator_next(&ci, &key, &value)) {
+ if (last_key == search_key &&
+ key == (CSR_DESCRIPTOR | CSR_LEAF))
+ return ci.p - 1 + value;
+ last_key = key;
+ }
+ return NULL;
+}
+
+static int textual_leaf_to_string(u32 *block, char *buf, size_t size)
+{
+ unsigned int quadlets, length;
+
+ if (!size || !buf)
+ return -EINVAL;
+
+ quadlets = min(block[0] >> 16, 256u);
+ if (quadlets < 2)
+ return -ENODATA;
+
+ if (block[1] != 0 || block[2] != 0)
+ /* unknown language/character set */
+ return -ENODATA;
+
+ block += 3;
+ quadlets -= 2;
+ for (length = 0; length < quadlets * 4 && length + 1 < size; length++) {
+ char c = block[length / 4] >> (24 - 8 * (length % 4));
+ if (c == '\0')
+ break;
+ buf[length] = c;
+ }
+ buf[length] = '\0';
+ return length;
+}
+
+/**
+ * fw_csr_string - reads a string from the configuration ROM
+ * @directory: device or unit directory;
+ * fw_device->config_rom+5 or fw_unit->directory
+ * @key: the key of the preceding directory entry
+ * @buf: where to put the string
+ * @size: size of @buf, in bytes
+ *
+ * Returns string length (>= 0) or error code (< 0).
+ */
+int fw_csr_string(u32 *directory, int key, char *buf, size_t size)
+{
+ u32 *leaf = search_leaf(directory, key);
+ if (!leaf)
+ return -ENOENT;
+ return textual_leaf_to_string(leaf, buf, size);
+}
+EXPORT_SYMBOL(fw_csr_string);
+
static bool is_fw_unit(struct device *dev);
static int match_unit_directory(u32 *directory, u32 match_flags,
@@ -226,10 +287,10 @@ static ssize_t show_text_leaf(struct dev
{
struct config_rom_attribute *attr =
container_of(dattr, struct config_rom_attribute, attr);
- struct fw_csr_iterator ci;
- u32 *dir, *block = NULL, *p, *end;
- int length, key, value, last_key = 0, ret = -ENOENT;
- char *b;
+ u32 *dir;
+ size_t bufsize;
+ char dummy_buf[2];
+ int ret;
down_read(&fw_device_rwsem);
@@ -238,40 +299,23 @@ static ssize_t show_text_leaf(struct dev
else
dir = fw_device(dev)->config_rom + 5;
- fw_csr_iterator_init(&ci, dir);
- while (fw_csr_iterator_next(&ci, &key, &value)) {
- if (attr->key == last_key &&
- key == (CSR_DESCRIPTOR | CSR_LEAF))
- block = ci.p - 1 + value;
- last_key = key;
+ if (buf) {
+ bufsize = PAGE_SIZE - 1;
+ } else {
+ buf = dummy_buf;
+ bufsize = 1;
}
- if (block == NULL)
- goto out;
-
- length = min(block[0] >> 16, 256U);
- if (length < 3)
- goto out;
-
- if (block[1] != 0 || block[2] != 0)
- /* Unknown encoding. */
- goto out;
+ ret = fw_csr_string(dir, attr->key, buf, bufsize);
- if (buf == NULL) {
- ret = length * 4;
- goto out;
+ if (ret >= 0) {
+ /* Strip trailing whitespace and add newline. */
+ while (ret > 0 && isspace(buf[ret - 1]))
+ ret--;
+ strcpy(buf + ret, "\n");
+ ret++;
}
- b = buf;
- end = &block[length + 1];
- for (p = &block[3]; p < end; p++, b += 4)
- * (u32 *) b = (__force u32) __cpu_to_be32(*p);
-
- /* Strip trailing whitespace and add newline. */
- while (b--, (isspace(*b) || *b == '\0') && b > buf);
- strcpy(b + 1, "\n");
- ret = b + 2 - buf;
- out:
up_read(&fw_device_rwsem);
return ret;
Index: linux-2.6.33-rc2/drivers/media/dvb/firewire/firedtv-fw.c
===================================================================
--- linux-2.6.33-rc2.orig/drivers/media/dvb/firewire/firedtv-fw.c
+++ linux-2.6.33-rc2/drivers/media/dvb/firewire/firedtv-fw.c
@@ -239,47 +239,18 @@ static const struct fw_address_region fc
};
/* Adjust the template string if models with longer names appear. */
-#define MAX_MODEL_NAME_LEN ((int)DIV_ROUND_UP(sizeof("FireDTV ????"), 4))
-
-static size_t model_name(u32 *directory, __be32 *buffer)
-{
- struct fw_csr_iterator ci;
- int i, length, key, value, last_key = 0;
- u32 *block = NULL;
-
- fw_csr_iterator_init(&ci, directory);
- while (fw_csr_iterator_next(&ci, &key, &value)) {
- if (last_key == CSR_MODEL &&
- key == (CSR_DESCRIPTOR | CSR_LEAF))
- block = ci.p - 1 + value;
- last_key = key;
- }
-
- if (block == NULL)
- return 0;
-
- length = min((int)(block[0] >> 16) - 2, MAX_MODEL_NAME_LEN);
- if (length <= 0)
- return 0;
-
- /* fast-forward to text string */
- block += 3;
-
- for (i = 0; i < length; i++)
- buffer[i] = cpu_to_be32(block[i]);
-
- return length * 4;
-}
+#define MAX_MODEL_NAME_LEN sizeof("FireDTV ????")
static int node_probe(struct device *dev)
{
struct firedtv *fdtv;
- __be32 name[MAX_MODEL_NAME_LEN];
+ char name[MAX_MODEL_NAME_LEN];
int name_len, err;
- name_len = model_name(fw_unit(dev)->directory, name);
+ name_len = fw_csr_string(fw_unit(dev)->directory, CSR_MODEL,
+ name, sizeof(name));
- fdtv = fdtv_alloc(dev, &backend, (char *)name, name_len);
+ fdtv = fdtv_alloc(dev, &backend, name, name_len >= 0 ? name_len : 0);
if (!fdtv)
return -ENOMEM;
--
Stefan Richter
-=====-==--= ==-- ==-=-
http://arcgraph.de/sr/
--
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