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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-05 14:50:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-05 14:50:51 -0700
commit41844e36206be90cd4d962ea49b0abc3612a99d0 (patch)
treece0b3a3403bc6abdb28f52779d0d7b57a51a5c86 /drivers/staging/greybus/manifest.c
parent5691f0e9a3e7855832d5fd094801bf600347c2d0 (diff)
parentfc1e2c8ea85e109acf09e74789e9b852f6eed251 (diff)
downloadop-kernel-dev-41844e36206be90cd4d962ea49b0abc3612a99d0.zip
op-kernel-dev-41844e36206be90cd4d962ea49b0abc3612a99d0.tar.gz
Merge tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging and IIO updates from Greg KH: "Here is the big staging and IIO driver pull request for 4.9-rc1. There are a lot of patches in here, the majority due to the drivers/staging/greybus/ subsystem being merged in with full development history that went back a few years, in order to preserve the work that those developers did over time. Lots and lots of tiny cleanups happened in the tree as well, due to the Outreachy application process and lots of other developers showing up for the first time to clean code up. Along with those changes, we deleted a wireless driver, and added a raspberrypi driver (currently marked broken), and lots of new iio drivers. Overall the tree still shrunk with more lines removed than added, about 10 thousand lines removed in total. Full details are in the very long shortlog below. All of this has been in the linux-next tree with no issues. There will be some merge problems with other subsystem trees, but those are all minor problems and shouldn't be hard to work out when they happen (MAINTAINERS and some lustre build problems with the IB tree)" And furter from me asking for clarification about greybus: "Right now there is a phone from Motorola shipping with this code (a slightly older version, but the same tree), so even though Ara is not alive in the same form, the functionality is happening. We are working with the developers of that phone to merge the newer stuff in with their fork so they can use the upstream version in future versions of their phone product line. Toshiba has at least one chip shipping in their catalog that needs/uses this protocol over a Unipro link, and rumor has it that there might be more in the future. There are also other users of the greybus protocols, there is a talk next week at ELC that shows how it is being used across a network connection to control a device, and previous ELC talks have showed the protocol stack being used over USB to drive embedded Linux boards. I've also talked to some people who are starting to work to add a host controller driver to control arduinos as the greybus PHY protocols are very useful to control a serial/i2c/spio/whatever device across a random physical link, as it is a way to have a self-describing device be attached to a host without needing manual configuration. So yes, people are using it, and there is still the chance that it will show up in a phone/laptop/tablet/whatever from Google in the future as well, the tech isn't dead, even if the original large phone project happens to be" * tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (3703 commits) Staging: fbtft: Fix bug in fbtft-core staging: rtl8188eu: fix double unlock error in rtw_resume_process() staging:r8188eu: remove GEN_MLME_EXT_HANDLER macro staging:r8188eu: remove GEN_DRV_CMD_HANDLER macro staging:r8188eu: remove GEN_EVT_CODE macro staging:r8188eu: remove GEN_CMD_CODE macro staging:r8188eu: remove pkt_newalloc member of the recv_buf structure staging:r8188eu: remove rtw_handle_dualmac declaration staging:r8188eu: remove (RGTRY|BSSID)_(OFT|SZ) macros staging:r8188eu: change rtl8188e_process_phy_info function argument type Staging: fsl-mc: Remove blank lines Staging: fsl-mc: Fix unaligned * in block comments Staging: comedi: Align the * in block comments Staging : ks7010 : Fix block comments warninig Staging: vt6655: Remove explicit NULL comparison using Coccinelle staging: rtl8188eu: core: rtw_xmit: Use macros instead of constants staging: rtl8188eu: core: rtw_xmit: Move constant of the right side staging: dgnc: Fix lines longer than 80 characters Staging: dgnc: constify attribute_group structures Staging: most: hdm-dim2: constify attribute_group structures ...
Diffstat (limited to 'drivers/staging/greybus/manifest.c')
-rw-r--r--drivers/staging/greybus/manifest.c535
1 files changed, 535 insertions, 0 deletions
diff --git a/drivers/staging/greybus/manifest.c b/drivers/staging/greybus/manifest.c
new file mode 100644
index 0000000..7b90377
--- /dev/null
+++ b/drivers/staging/greybus/manifest.c
@@ -0,0 +1,535 @@
+/*
+ * Greybus manifest parsing
+ *
+ * Copyright 2014-2015 Google Inc.
+ * Copyright 2014-2015 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include "greybus.h"
+
+static const char *get_descriptor_type_string(u8 type)
+{
+ switch (type) {
+ case GREYBUS_TYPE_INVALID:
+ return "invalid";
+ case GREYBUS_TYPE_STRING:
+ return "string";
+ case GREYBUS_TYPE_INTERFACE:
+ return "interface";
+ case GREYBUS_TYPE_CPORT:
+ return "cport";
+ case GREYBUS_TYPE_BUNDLE:
+ return "bundle";
+ default:
+ WARN_ON(1);
+ return "unknown";
+ }
+}
+
+/*
+ * We scan the manifest once to identify where all the descriptors
+ * are. The result is a list of these manifest_desc structures. We
+ * then pick through them for what we're looking for (starting with
+ * the interface descriptor). As each is processed we remove it from
+ * the list. When we're done the list should (probably) be empty.
+ */
+struct manifest_desc {
+ struct list_head links;
+
+ size_t size;
+ void *data;
+ enum greybus_descriptor_type type;
+};
+
+static void release_manifest_descriptor(struct manifest_desc *descriptor)
+{
+ list_del(&descriptor->links);
+ kfree(descriptor);
+}
+
+static void release_manifest_descriptors(struct gb_interface *intf)
+{
+ struct manifest_desc *descriptor;
+ struct manifest_desc *next;
+
+ list_for_each_entry_safe(descriptor, next, &intf->manifest_descs, links)
+ release_manifest_descriptor(descriptor);
+}
+
+static void release_cport_descriptors(struct list_head *head, u8 bundle_id)
+{
+ struct manifest_desc *desc, *tmp;
+ struct greybus_descriptor_cport *desc_cport;
+
+ list_for_each_entry_safe(desc, tmp, head, links) {
+ desc_cport = desc->data;
+
+ if (desc->type != GREYBUS_TYPE_CPORT)
+ continue;
+
+ if (desc_cport->bundle == bundle_id)
+ release_manifest_descriptor(desc);
+ }
+}
+
+static struct manifest_desc *get_next_bundle_desc(struct gb_interface *intf)
+{
+ struct manifest_desc *descriptor;
+ struct manifest_desc *next;
+
+ list_for_each_entry_safe(descriptor, next, &intf->manifest_descs, links)
+ if (descriptor->type == GREYBUS_TYPE_BUNDLE)
+ return descriptor;
+
+ return NULL;
+}
+
+/*
+ * Validate the given descriptor. Its reported size must fit within
+ * the number of bytes remaining, and it must have a recognized
+ * type. Check that the reported size is at least as big as what
+ * we expect to see. (It could be bigger, perhaps for a new version
+ * of the format.)
+ *
+ * Returns the (non-zero) number of bytes consumed by the descriptor,
+ * or a negative errno.
+ */
+static int identify_descriptor(struct gb_interface *intf,
+ struct greybus_descriptor *desc, size_t size)
+{
+ struct greybus_descriptor_header *desc_header = &desc->header;
+ struct manifest_desc *descriptor;
+ size_t desc_size;
+ size_t expected_size;
+
+ if (size < sizeof(*desc_header)) {
+ dev_err(&intf->dev, "manifest too small (%zu < %zu)\n",
+ size, sizeof(*desc_header));
+ return -EINVAL; /* Must at least have header */
+ }
+
+ desc_size = le16_to_cpu(desc_header->size);
+ if (desc_size > size) {
+ dev_err(&intf->dev, "descriptor too big (%zu > %zu)\n",
+ desc_size, size);
+ return -EINVAL;
+ }
+
+ /* Descriptor needs to at least have a header */
+ expected_size = sizeof(*desc_header);
+
+ switch (desc_header->type) {
+ case GREYBUS_TYPE_STRING:
+ expected_size += sizeof(struct greybus_descriptor_string);
+ expected_size += desc->string.length;
+
+ /* String descriptors are padded to 4 byte boundaries */
+ expected_size = ALIGN(expected_size, 4);
+ break;
+ case GREYBUS_TYPE_INTERFACE:
+ expected_size += sizeof(struct greybus_descriptor_interface);
+ break;
+ case GREYBUS_TYPE_BUNDLE:
+ expected_size += sizeof(struct greybus_descriptor_bundle);
+ break;
+ case GREYBUS_TYPE_CPORT:
+ expected_size += sizeof(struct greybus_descriptor_cport);
+ break;
+ case GREYBUS_TYPE_INVALID:
+ default:
+ dev_err(&intf->dev, "invalid descriptor type (%u)\n",
+ desc_header->type);
+ return -EINVAL;
+ }
+
+ if (desc_size < expected_size) {
+ dev_err(&intf->dev, "%s descriptor too small (%zu < %zu)\n",
+ get_descriptor_type_string(desc_header->type),
+ desc_size, expected_size);
+ return -EINVAL;
+ }
+
+ /* Descriptor bigger than what we expect */
+ if (desc_size > expected_size) {
+ dev_warn(&intf->dev, "%s descriptor size mismatch (want %zu got %zu)\n",
+ get_descriptor_type_string(desc_header->type),
+ expected_size, desc_size);
+ }
+
+ descriptor = kzalloc(sizeof(*descriptor), GFP_KERNEL);
+ if (!descriptor)
+ return -ENOMEM;
+
+ descriptor->size = desc_size;
+ descriptor->data = (char *)desc + sizeof(*desc_header);
+ descriptor->type = desc_header->type;
+ list_add_tail(&descriptor->links, &intf->manifest_descs);
+
+ /* desc_size is positive and is known to fit in a signed int */
+
+ return desc_size;
+}
+
+/*
+ * Find the string descriptor having the given id, validate it, and
+ * allocate a duplicate copy of it. The duplicate has an extra byte
+ * which guarantees the returned string is NUL-terminated.
+ *
+ * String index 0 is valid (it represents "no string"), and for
+ * that a null pointer is returned.
+ *
+ * Otherwise returns a pointer to a newly-allocated copy of the
+ * descriptor string, or an error-coded pointer on failure.
+ */
+static char *gb_string_get(struct gb_interface *intf, u8 string_id)
+{
+ struct greybus_descriptor_string *desc_string;
+ struct manifest_desc *descriptor;
+ bool found = false;
+ char *string;
+
+ /* A zero string id means no string (but no error) */
+ if (!string_id)
+ return NULL;
+
+ list_for_each_entry(descriptor, &intf->manifest_descs, links) {
+ if (descriptor->type != GREYBUS_TYPE_STRING)
+ continue;
+
+ desc_string = descriptor->data;
+ if (desc_string->id == string_id) {
+ found = true;
+ break;
+ }
+ }
+ if (!found)
+ return ERR_PTR(-ENOENT);
+
+ /* Allocate an extra byte so we can guarantee it's NUL-terminated */
+ string = kmemdup(&desc_string->string, desc_string->length + 1,
+ GFP_KERNEL);
+ if (!string)
+ return ERR_PTR(-ENOMEM);
+ string[desc_string->length] = '\0';
+
+ /* Ok we've used this string, so we're done with it */
+ release_manifest_descriptor(descriptor);
+
+ return string;
+}
+
+/*
+ * Find cport descriptors in the manifest associated with the given
+ * bundle, and set up data structures for the functions that use
+ * them. Returns the number of cports set up for the bundle, or 0
+ * if there is an error.
+ */
+static u32 gb_manifest_parse_cports(struct gb_bundle *bundle)
+{
+ struct gb_interface *intf = bundle->intf;
+ struct greybus_descriptor_cport *desc_cport;
+ struct manifest_desc *desc, *next, *tmp;
+ LIST_HEAD(list);
+ u8 bundle_id = bundle->id;
+ u16 cport_id;
+ u32 count = 0;
+ int i;
+
+ /* Set up all cport descriptors associated with this bundle */
+ list_for_each_entry_safe(desc, next, &intf->manifest_descs, links) {
+ if (desc->type != GREYBUS_TYPE_CPORT)
+ continue;
+
+ desc_cport = desc->data;
+ if (desc_cport->bundle != bundle_id)
+ continue;
+
+ cport_id = le16_to_cpu(desc_cport->id);
+ if (cport_id > CPORT_ID_MAX)
+ goto exit;
+
+ /* Nothing else should have its cport_id as control cport id */
+ if (cport_id == GB_CONTROL_CPORT_ID) {
+ dev_err(&bundle->dev, "invalid cport id found (%02u)\n",
+ cport_id);
+ goto exit;
+ }
+
+ /*
+ * Found one, move it to our temporary list after checking for
+ * duplicates.
+ */
+ list_for_each_entry(tmp, &list, links) {
+ desc_cport = tmp->data;
+ if (cport_id == le16_to_cpu(desc_cport->id)) {
+ dev_err(&bundle->dev,
+ "duplicate CPort %u found\n",
+ cport_id);
+ goto exit;
+ }
+ }
+ list_move_tail(&desc->links, &list);
+ count++;
+ }
+
+ if (!count)
+ return 0;
+
+ bundle->cport_desc = kcalloc(count, sizeof(*bundle->cport_desc),
+ GFP_KERNEL);
+ if (!bundle->cport_desc)
+ goto exit;
+
+ bundle->num_cports = count;
+
+ i = 0;
+ list_for_each_entry_safe(desc, next, &list, links) {
+ desc_cport = desc->data;
+ memcpy(&bundle->cport_desc[i++], desc_cport,
+ sizeof(*desc_cport));
+
+ /* Release the cport descriptor */
+ release_manifest_descriptor(desc);
+ }
+
+ return count;
+exit:
+ release_cport_descriptors(&list, bundle_id);
+ /*
+ * Free all cports for this bundle to avoid 'excess descriptors'
+ * warnings.
+ */
+ release_cport_descriptors(&intf->manifest_descs, bundle_id);
+
+ return 0; /* Error; count should also be 0 */
+}
+
+/*
+ * Find bundle descriptors in the manifest and set up their data
+ * structures. Returns the number of bundles set up for the
+ * given interface.
+ */
+static u32 gb_manifest_parse_bundles(struct gb_interface *intf)
+{
+ struct manifest_desc *desc;
+ struct gb_bundle *bundle;
+ struct gb_bundle *bundle_next;
+ u32 count = 0;
+ u8 bundle_id;
+ u8 class;
+
+ while ((desc = get_next_bundle_desc(intf))) {
+ struct greybus_descriptor_bundle *desc_bundle;
+
+ /* Found one. Set up its bundle structure*/
+ desc_bundle = desc->data;
+ bundle_id = desc_bundle->id;
+ class = desc_bundle->class;
+
+ /* Done with this bundle descriptor */
+ release_manifest_descriptor(desc);
+
+ /* Ignore any legacy control bundles */
+ if (bundle_id == GB_CONTROL_BUNDLE_ID) {
+ dev_dbg(&intf->dev, "%s - ignoring control bundle\n",
+ __func__);
+ release_cport_descriptors(&intf->manifest_descs,
+ bundle_id);
+ continue;
+ }
+
+ /* Nothing else should have its class set to control class */
+ if (class == GREYBUS_CLASS_CONTROL) {
+ dev_err(&intf->dev,
+ "bundle %u cannot use control class\n",
+ bundle_id);
+ goto cleanup;
+ }
+
+ bundle = gb_bundle_create(intf, bundle_id, class);
+ if (!bundle)
+ goto cleanup;
+
+ /*
+ * Now go set up this bundle's functions and cports.
+ *
+ * A 'bundle' represents a device in greybus. It may require
+ * multiple cports for its functioning. If we fail to setup any
+ * cport of a bundle, we better reject the complete bundle as
+ * the device may not be able to function properly then.
+ *
+ * But, failing to setup a cport of bundle X doesn't mean that
+ * the device corresponding to bundle Y will not work properly.
+ * Bundles should be treated as separate independent devices.
+ *
+ * While parsing manifest for an interface, treat bundles as
+ * separate entities and don't reject entire interface and its
+ * bundles on failing to initialize a cport. But make sure the
+ * bundle which needs the cport, gets destroyed properly.
+ */
+ if (!gb_manifest_parse_cports(bundle)) {
+ gb_bundle_destroy(bundle);
+ continue;
+ }
+
+ count++;
+ }
+
+ return count;
+cleanup:
+ /* An error occurred; undo any changes we've made */
+ list_for_each_entry_safe(bundle, bundle_next, &intf->bundles, links) {
+ gb_bundle_destroy(bundle);
+ count--;
+ }
+ return 0; /* Error; count should also be 0 */
+}
+
+static bool gb_manifest_parse_interface(struct gb_interface *intf,
+ struct manifest_desc *interface_desc)
+{
+ struct greybus_descriptor_interface *desc_intf = interface_desc->data;
+ struct gb_control *control = intf->control;
+ char *str;
+
+ /* Handle the strings first--they can fail */
+ str = gb_string_get(intf, desc_intf->vendor_stringid);
+ if (IS_ERR(str))
+ return false;
+ control->vendor_string = str;
+
+ str = gb_string_get(intf, desc_intf->product_stringid);
+ if (IS_ERR(str))
+ goto out_free_vendor_string;
+ control->product_string = str;
+
+ /* Assign feature flags communicated via manifest */
+ intf->features = desc_intf->features;
+
+ /* Release the interface descriptor, now that we're done with it */
+ release_manifest_descriptor(interface_desc);
+
+ /* An interface must have at least one bundle descriptor */
+ if (!gb_manifest_parse_bundles(intf)) {
+ dev_err(&intf->dev, "manifest bundle descriptors not valid\n");
+ goto out_err;
+ }
+
+ return true;
+out_err:
+ kfree(control->product_string);
+ control->product_string = NULL;
+out_free_vendor_string:
+ kfree(control->vendor_string);
+ control->vendor_string = NULL;
+
+ return false;
+}
+
+/*
+ * Parse a buffer containing an interface manifest.
+ *
+ * If we find anything wrong with the content/format of the buffer
+ * we reject it.
+ *
+ * The first requirement is that the manifest's version is
+ * one we can parse.
+ *
+ * We make an initial pass through the buffer and identify all of
+ * the descriptors it contains, keeping track for each its type
+ * and the location size of its data in the buffer.
+ *
+ * Next we scan the descriptors, looking for an interface descriptor;
+ * there must be exactly one of those. When found, we record the
+ * information it contains, and then remove that descriptor (and any
+ * string descriptors it refers to) from further consideration.
+ *
+ * After that we look for the interface's bundles--there must be at
+ * least one of those.
+ *
+ * Returns true if parsing was successful, false otherwise.
+ */
+bool gb_manifest_parse(struct gb_interface *intf, void *data, size_t size)
+{
+ struct greybus_manifest *manifest;
+ struct greybus_manifest_header *header;
+ struct greybus_descriptor *desc;
+ struct manifest_desc *descriptor;
+ struct manifest_desc *interface_desc = NULL;
+ u16 manifest_size;
+ u32 found = 0;
+ bool result;
+
+ /* Manifest descriptor list should be empty here */
+ if (WARN_ON(!list_empty(&intf->manifest_descs)))
+ return false;
+
+ /* we have to have at _least_ the manifest header */
+ if (size < sizeof(*header)) {
+ dev_err(&intf->dev, "short manifest (%zu < %zu)\n",
+ size, sizeof(*header));
+ return false;
+ }
+
+ /* Make sure the size is right */
+ manifest = data;
+ header = &manifest->header;
+ manifest_size = le16_to_cpu(header->size);
+ if (manifest_size != size) {
+ dev_err(&intf->dev, "manifest size mismatch (%zu != %u)\n",
+ size, manifest_size);
+ return false;
+ }
+
+ /* Validate major/minor number */
+ if (header->version_major > GREYBUS_VERSION_MAJOR) {
+ dev_err(&intf->dev, "manifest version too new (%u.%u > %u.%u)\n",
+ header->version_major, header->version_minor,
+ GREYBUS_VERSION_MAJOR, GREYBUS_VERSION_MINOR);
+ return false;
+ }
+
+ /* OK, find all the descriptors */
+ desc = manifest->descriptors;
+ size -= sizeof(*header);
+ while (size) {
+ int desc_size;
+
+ desc_size = identify_descriptor(intf, desc, size);
+ if (desc_size < 0) {
+ result = false;
+ goto out;
+ }
+ desc = (struct greybus_descriptor *)((char *)desc + desc_size);
+ size -= desc_size;
+ }
+
+ /* There must be a single interface descriptor */
+ list_for_each_entry(descriptor, &intf->manifest_descs, links) {
+ if (descriptor->type == GREYBUS_TYPE_INTERFACE)
+ if (!found++)
+ interface_desc = descriptor;
+ }
+ if (found != 1) {
+ dev_err(&intf->dev, "manifest must have 1 interface descriptor (%u found)\n",
+ found);
+ result = false;
+ goto out;
+ }
+
+ /* Parse the manifest, starting with the interface descriptor */
+ result = gb_manifest_parse_interface(intf, interface_desc);
+
+ /*
+ * We really should have no remaining descriptors, but we
+ * don't know what newer format manifests might leave.
+ */
+ if (result && !list_empty(&intf->manifest_descs))
+ dev_info(&intf->dev, "excess descriptors in interface manifest\n");
+out:
+ release_manifest_descriptors(intf);
+
+ return result;
+}
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