diff options
| -rw-r--r-- | Documentation/ABI/testing/configfs-stp-policy | 48 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-stm | 14 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-stm_source | 11 | ||||
| -rw-r--r-- | Documentation/ioctl/ioctl-number.txt | 3 | ||||
| -rw-r--r-- | Documentation/trace/stm.txt | 80 | ||||
| -rw-r--r-- | drivers/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/Makefile | 1 | ||||
| -rw-r--r-- | drivers/hwtracing/stm/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/hwtracing/stm/Makefile | 3 | ||||
| -rw-r--r-- | drivers/hwtracing/stm/core.c | 1029 | ||||
| -rw-r--r-- | drivers/hwtracing/stm/policy.c | 529 | ||||
| -rw-r--r-- | drivers/hwtracing/stm/stm.h | 87 | ||||
| -rw-r--r-- | include/linux/stm.h | 126 | ||||
| -rw-r--r-- | include/uapi/linux/stm.h | 50 |
14 files changed, 1991 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/configfs-stp-policy b/Documentation/ABI/testing/configfs-stp-policy new file mode 100644 index 0000000..421ce68 --- /dev/null +++ b/Documentation/ABI/testing/configfs-stp-policy @@ -0,0 +1,48 @@ +What: /config/stp-policy +Date: June 2015 +KernelVersion: 4.3 +Description: + This group contains policies mandating Master/Channel allocation + for software sources wishing to send trace data over an STM + device. + +What: /config/stp-policy/<device>.<policy> +Date: June 2015 +KernelVersion: 4.3 +Description: + This group is the root of a policy; its name is a concatenation + of an stm device name to which this policy applies and an + arbitrary string. If <device> part doesn't match an existing + stm device, mkdir will fail with ENODEV; if that device already + has a policy assigned to it, mkdir will fail with EBUSY. + +What: /config/stp-policy/<device>.<policy>/device +Date: June 2015 +KernelVersion: 4.3 +Description: + STM device to which this policy applies, read only. Same as the + <device> component of its parent directory. + +What: /config/stp-policy/<device>.<policy>/<node> +Date: June 2015 +KernelVersion: 4.3 +Description: + Policy node is a string identifier that software clients will + use to request a master/channel to be allocated and assigned to + them. + +What: /config/stp-policy/<device>.<policy>/<node>/masters +Date: June 2015 +KernelVersion: 4.3 +Description: + Range of masters from which to allocate for users of this node. + Write two numbers: the first master and the last master number. + +What: /config/stp-policy/<device>.<policy>/<node>/channels +Date: June 2015 +KernelVersion: 4.3 +Description: + Range of channels from which to allocate for users of this node. + Write two numbers: the first channel and the last channel + number. + diff --git a/Documentation/ABI/testing/sysfs-class-stm b/Documentation/ABI/testing/sysfs-class-stm new file mode 100644 index 0000000..c9aa4f3 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-stm @@ -0,0 +1,14 @@ +What: /sys/class/stm/<stm>/masters +Date: June 2015 +KernelVersion: 4.3 +Contact: Alexander Shishkin <alexander.shishkin@linux.intel.com> +Description: + Shows first and last available to software master numbers on + this STM device. + +What: /sys/class/stm/<stm>/channels +Date: June 2015 +KernelVersion: 4.3 +Contact: Alexander Shishkin <alexander.shishkin@linux.intel.com> +Description: + Shows the number of channels per master on this STM device. diff --git a/Documentation/ABI/testing/sysfs-class-stm_source b/Documentation/ABI/testing/sysfs-class-stm_source new file mode 100644 index 0000000..57b8dd3 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-stm_source @@ -0,0 +1,11 @@ +What: /sys/class/stm_source/<stm_source>/stm_source_link +Date: June 2015 +KernelVersion: 4.3 +Contact: Alexander Shishkin <alexander.shishkin@linux.intel.com> +Description: + stm_source device linkage to stm device, where its tracing data + is directed. Reads return an existing connection or "<none>" if + this stm_source is not connected to any stm device yet. + Write an existing (registered) stm device's name here to + connect that device. If a device is already connected to this + stm_source, it will first be disconnected. diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index df1b25e..3785b7e 100644 --- a/Documentation/ioctl/ioctl-number.txt +++ b/Documentation/ioctl/ioctl-number.txt @@ -81,6 +81,9 @@ Code Seq#(hex) Include File Comments 0x22 all scsi/sg.h '#' 00-3F IEEE 1394 Subsystem Block for the entire subsystem '$' 00-0F linux/perf_counter.h, linux/perf_event.h +'%' 00-0F include/uapi/linux/stm.h + System Trace Module subsystem + <mailto:alexander.shishkin@linux.intel.com> '&' 00-07 drivers/firewire/nosy-user.h '1' 00-1F <linux/timepps.h> PPS kit from Ulrich Windl <ftp://ftp.de.kernel.org/pub/linux/daemons/ntp/PPS/> diff --git a/Documentation/trace/stm.txt b/Documentation/trace/stm.txt new file mode 100644 index 0000000..ea035f9 --- /dev/null +++ b/Documentation/trace/stm.txt @@ -0,0 +1,80 @@ +System Trace Module +=================== + +System Trace Module (STM) is a device described in MIPI STP specs as +STP trace stream generator. STP (System Trace Protocol) is a trace +protocol multiplexing data from multiple trace sources, each one of +which is assigned a unique pair of master and channel. While some of +these masters and channels are statically allocated to certain +hardware trace sources, others are available to software. Software +trace sources are usually free to pick for themselves any +master/channel combination from this pool. + +On the receiving end of this STP stream (the decoder side), trace +sources can only be identified by master/channel combination, so in +order for the decoder to be able to make sense of the trace that +involves multiple trace sources, it needs to be able to map those +master/channel pairs to the trace sources that it understands. + +For instance, it is helpful to know that syslog messages come on +master 7 channel 15, while arbitrary user applications can use masters +48 to 63 and channels 0 to 127. + +To solve this mapping problem, stm class provides a policy management +mechanism via configfs, that allows defining rules that map string +identifiers to ranges of masters and channels. If these rules (policy) +are consistent with what decoder expects, it will be able to properly +process the trace data. + +This policy is a tree structure containing rules (policy_node) that +have a name (string identifier) and a range of masters and channels +associated with it, located in "stp-policy" subsystem directory in +configfs. The topmost directory's name (the policy) is formatted as +the STM device name to which this policy applies and and arbitrary +string identifier separated by a stop. From the examle above, a rule +may look like this: + +$ ls /config/stp-policy/dummy_stm.my-policy/user +channels masters +$ cat /config/stp-policy/dummy_stm.my-policy/user/masters +48 63 +$ cat /config/stp-policy/dummy_stm.my-policy/user/channels +0 127 + +which means that the master allocation pool for this rule consists of +masters 48 through 63 and channel allocation pool has channels 0 +through 127 in it. Now, any producer (trace source) identifying itself +with "user" identification string will be allocated a master and +channel from within these ranges. + +These rules can be nested, for example, one can define a rule "dummy" +under "user" directory from the example above and this new rule will +be used for trace sources with the id string of "user/dummy". + +Trace sources have to open the stm class device's node and write their +trace data into its file descriptor. In order to identify themselves +to the policy, they need to do a STP_POLICY_ID_SET ioctl on this file +descriptor providing their id string. Otherwise, they will be +automatically allocated a master/channel pair upon first write to this +file descriptor according to the "default" rule of the policy, if such +exists. + +Some STM devices may allow direct mapping of the channel mmio regions +to userspace for zero-copy writing. One mappable page (in terms of +mmu) will usually contain multiple channels' mmios, so the user will +need to allocate that many channels to themselves (via the +aforementioned ioctl() call) to be able to do this. That is, if your +stm device's channel mmio region is 64 bytes and hardware page size is +4096 bytes, after a successful STP_POLICY_ID_SET ioctl() call with +width==64, you should be able to mmap() one page on this file +descriptor and obtain direct access to an mmio region for 64 channels. + +For kernel-based trace sources, there is "stm_source" device +class. Devices of this class can be connected and disconnected to/from +stm devices at runtime via a sysfs attribute. + +Examples of STM devices are Intel(R) Trace Hub [1] and Coresight STM +[2]. + +[1] https://software.intel.com/sites/default/files/managed/d3/3c/intel-th-developer-manual.pdf +[2] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0444b/index.html diff --git a/drivers/Kconfig b/drivers/Kconfig index 46b4a8e..b6e1cea6 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -188,4 +188,6 @@ source "drivers/nvdimm/Kconfig" source "drivers/nvmem/Kconfig" +source "drivers/hwtracing/stm/Kconfig" + endmenu diff --git a/drivers/Makefile b/drivers/Makefile index b250b36..e71b5e2 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -165,5 +165,6 @@ obj-$(CONFIG_PERF_EVENTS) += perf/ obj-$(CONFIG_RAS) += ras/ obj-$(CONFIG_THUNDERBOLT) += thunderbolt/ obj-$(CONFIG_CORESIGHT) += hwtracing/coresight/ +obj-$(CONFIG_STM) += hwtracing/stm/ obj-$(CONFIG_ANDROID) += android/ obj-$(CONFIG_NVMEM) += nvmem/ diff --git a/drivers/hwtracing/stm/Kconfig b/drivers/hwtracing/stm/Kconfig new file mode 100644 index 0000000..e101cb4 --- /dev/null +++ b/drivers/hwtracing/stm/Kconfig @@ -0,0 +1,8 @@ +config STM + tristate "System Trace Module devices" + help + A System Trace Module (STM) is a device exporting data in System + Trace Protocol (STP) format as defined by MIPI STP standards. + Examples of such devices are Intel(R) Trace Hub and Coresight STM. + + Say Y here to enable System Trace Module device support. diff --git a/drivers/hwtracing/stm/Makefile b/drivers/hwtracing/stm/Makefile new file mode 100644 index 0000000..adec701 --- /dev/null +++ b/drivers/hwtracing/stm/Makefile @@ -0,0 +1,3 @@ +obj-$(CONFIG_STM) += stm_core.o + +stm_core-y := core.o policy.o diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c new file mode 100644 index 0000000..b79c42c --- /dev/null +++ b/drivers/hwtracing/stm/core.c @@ -0,0 +1,1029 @@ +/* + * System Trace Module (STM) infrastructure + * Copyright (c) 2014, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + * + * STM class implements generic infrastructure for System Trace Module devices + * as defined in MIPI STPv2 specification. + */ + +#include <linux/uaccess.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/compat.h> +#include <linux/kdev_t.h> +#include <linux/srcu.h> +#include <linux/slab.h> +#include <linux/stm.h> +#include <linux/fs.h> +#include <linux/mm.h> +#include "stm.h" + +#include <uapi/linux/stm.h> + +static unsigned int stm_core_up; + +/* + * The SRCU here makes sure that STM device doesn't disappear from under a + * stm_source_write() caller, which may want to have as little overhead as + * possible. + */ +static struct srcu_struct stm_source_srcu; + +static ssize_t masters_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct stm_device *stm = to_stm_device(dev); + int ret; + + ret = sprintf(buf, "%u %u\n", stm->data->sw_start, stm->data->sw_end); + + return ret; +} + +static DEVICE_ATTR_RO(masters); + +static ssize_t channels_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct stm_device *stm = to_stm_device(dev); + int ret; + + ret = sprintf(buf, "%u\n", stm->data->sw_nchannels); + + return ret; +} + +static DEVICE_ATTR_RO(channels); + +static struct attribute *stm_attrs[] = { + &dev_attr_masters.attr, + &dev_attr_channels.attr, + NULL, +}; + +ATTRIBUTE_GROUPS(stm); + +static struct class stm_class = { + .name = "stm", + .dev_groups = stm_groups, +}; + +static int stm_dev_match(struct device *dev, const void *data) +{ + const char *name = data; + + return sysfs_streq(name, dev_name(dev)); +} + +/** + * stm_find_device() - find stm device by name + * @buf: character buffer containing the name + * + * This is called when either policy gets assigned to an stm device or an + * stm_source device gets linked to an stm device. + * + * This grabs device's reference (get_device()) and module reference, both + * of which the calling path needs to make sure to drop with stm_put_device(). + * + * Return: stm device pointer or null if lookup failed. + */ +struct stm_device *stm_find_device(const char *buf) +{ + struct stm_device *stm; + struct device *dev; + + if (!stm_core_up) + return NULL; + + dev = class_find_device(&stm_class, NULL, buf, stm_dev_match); + if (!dev) + return NULL; + + stm = to_stm_device(dev); + if (!try_module_get(stm->owner)) { + put_device(dev); + return NULL; + } + + return stm; +} + +/** + * stm_put_device() - drop references on the stm device + * @stm: stm device, previously acquired by stm_find_device() + * + * This drops the module reference and device reference taken by + * stm_find_device(). + */ +void stm_put_device(struct stm_device *stm) +{ + module_put(stm->owner); + put_device(&stm->dev); +} + +/* + * Internally we only care about software-writable masters here, that is the + * ones in the range [stm_data->sw_start..stm_data..sw_end], however we need + * original master numbers to be visible externally, since they are the ones + * that will appear in the STP stream. Thus, the internal bookkeeping uses + * $master - stm_data->sw_start to reference master descriptors and such. + */ + +#define __stm_master(_s, _m) \ + ((_s)->masters[(_m) - (_s)->data->sw_start]) + +static inline struct stp_master * +stm_master(struct stm_device *stm, unsigned int idx) +{ + if (idx < stm->data->sw_start || idx > stm->data->sw_end) + return NULL; + + return __stm_master(stm, idx); +} + +static int stp_master_alloc(struct stm_device *stm, unsigned int idx) +{ + struct stp_master *master; + size_t size; + + size = ALIGN(stm->data->sw_nchannels, 8) / 8; + size += sizeof(struct stp_master); + master = kzalloc(size, GFP_ATOMIC); + if (!master) + return -ENOMEM; + + master->nr_free = stm->data->sw_nchannels; + __stm_master(stm, idx) = master; + + return 0; +} + +static void stp_master_free(struct stm_device *stm, unsigned int idx) +{ + struct stp_master *master = stm_master(stm, idx); + + if (!master) + return; + + __stm_master(stm, idx) = NULL; + kfree(master); +} + +static void stm_output_claim(struct stm_device *stm, struct stm_output *output) +{ + struct stp_master *master = stm_master(stm, output->master); + + if (WARN_ON_ONCE(master->nr_free < output->nr_chans)) + return; + + bitmap_allocate_region(&master->chan_map[0], output->channel, + ilog2(output->nr_chans)); + + master->nr_free -= output->nr_chans; +} + +static void +stm_output_disclaim(struct stm_device *stm, struct stm_output *output) +{ + struct stp_master *master = stm_master(stm, output->master); + + bitmap_release_region(&master->chan_map[0], output->channel, + ilog2(output->nr_chans)); + + output->nr_chans = 0; + master->nr_free += output->nr_chans; +} + +/* + * This is like bitmap_find_free_region(), except it can ignore @start bits + * at the beginning. + */ +static int find_free_channels(unsigned long *bitmap, unsigned int start, + unsigned int end, unsigned int width) +{ + unsigned int pos; + int i; + + for (pos = start; pos < end + 1; pos = ALIGN(pos, width)) { + pos = find_next_zero_bit(bitmap, end + 1, pos); + if (pos + width > end + 1) + break; + + if (pos & (width - 1)) + continue; + + for (i = 1; i < width && !test_bit(pos + i, bitmap); i++) + ; + if (i == width) + return pos; + } + + return -1; +} + +static unsigned int +stm_find_master_chan(struct stm_device *stm, unsigned int width, + unsigned int *mstart, unsigned int mend, + unsigned int *cstart, unsigned int cend) +{ + struct stp_master *master; + unsigned int midx; + int pos, err; + + for (midx = *mstart; midx <= mend; midx++) { + if (!stm_master(stm, midx)) { + err = stp_master_alloc(stm, midx); + if (err) + return err; + } + + master = stm_master(stm, midx); + + if (!master->nr_free) + continue; + + pos = find_free_channels(master->chan_map, *cstart, cend, + width); + if (pos < 0) + continue; + + *mstart = midx; + *cstart = pos; + return 0; + } + + return -ENOSPC; +} + +static int stm_output_assign(struct stm_device *stm, unsigned int width, + struct stp_policy_node *policy_node, + struct stm_output *output) +{ + unsigned int midx, cidx, mend, cend; + int ret = -EINVAL; + + if (width > stm->data->sw_nchannels) + return -EINVAL; + + if (policy_node) { + stp_policy_node_get_ranges(policy_node, + &midx, &mend, &cidx, &cend); + } else { + midx = stm->data->sw_start; + cidx = 0; + mend = stm->data->sw_end; + cend = stm->data->sw_nchannels - 1; + } + + spin_lock(&stm->mc_lock); + /* output is already assigned -- shouldn't happen */ + if (WARN_ON_ONCE(output->nr_chans)) + goto unlock; + + ret = stm_find_master_chan(stm, width, &midx, mend, &cidx, cend); + if (ret) + goto unlock; + + output->master = midx; + output->channel = cidx; + output->nr_chans = width; + stm_output_claim(stm, output); + dev_dbg(&stm->dev, "assigned %u:%u (+%u)\n", midx, cidx, width); + + ret = 0; +unlock: + spin_unlock(&stm->mc_lock); + + return ret; +} + +static void stm_output_free(struct stm_device *stm, struct stm_output *output) +{ + spin_lock(&stm->mc_lock); + if (output->nr_chans) + stm_output_disclaim(stm, output); + spin_unlock(&stm->mc_lock); +} + +static int major_match(struct device *dev, const void *data) +{ + unsigned int major = *(unsigned int *)data; + + return MAJOR(dev->devt) == major; +} + +static int stm_char_open(struct inode *inode, struct file *file) +{ + struct stm_file *stmf; + struct device *dev; + unsigned int major = imajor(inode); + int err = -ENODEV; + + dev = class_find_device(&stm_class, NULL, &major, major_match); + if (!dev) + return -ENODEV; + + stmf = kzalloc(sizeof(*stmf), GFP_KERNEL); + if (!stmf) + return -ENOMEM; + + stmf->stm = to_stm_device(dev); + + if (!try_module_get(stmf->stm->owner)) + goto err_free; + + file->private_data = stmf; + + return nonseekable_open(inode, file); + +err_free: + kfree(stmf); + + return err; +} + +static int stm_char_release(struct inode *inode, struct file *file) +{ + struct stm_file *stmf = file->private_data; + + stm_output_free(stmf->stm, &stmf->output); + stm_put_device(stmf->stm); + kfree(stmf); + + return 0; +} + +static int stm_file_assign(struct stm_file *stmf, char *id, unsigned int width) +{ + struct stm_device *stm = stmf->stm; + int ret; + + stmf->policy_node = stp_policy_node_lookup(stm, id); + + ret = stm_output_assign(stm, width, stmf->policy_node, &stmf->output); + + if (stmf->policy_node) + stp_policy_node_put(stmf->policy_node); + + return ret; +} + +static void stm_write(struct stm_data *data, unsigned int master, + unsigned int channel, const char *buf, size_t count) +{ + unsigned int flags = STP_PACKET_TIMESTAMPED; + const unsigned char *p = buf, nil = 0; + size_t pos; + ssize_t sz; + + for (pos = 0, p = buf; count > pos; pos += sz, p += sz) { + sz = min_t(unsigned int, count - pos, 8); + sz = data->packet(data, master, channel, STP_PACKET_DATA, flags, + sz, p); + flags = 0; + } + + data->packet(data, master, channel, STP_PACKET_FLAG, 0, 0, &nil); +} + +static ssize_t stm_char_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct stm_file *stmf = file->private_data; + struct stm_device *stm = stmf->stm; + char *kbuf; + int err; + + /* + * if no m/c have been assigned to this writer up to this + * point, use "default" policy entry + */ + if (!stmf->output.nr_chans) { + err = stm_file_assign(stmf, "default", 1); + /* + * EBUSY means that somebody else just assigned this + * output, which is just fine for write() + */ + if (err && err != -EBUSY) + return err; + } + + kbuf = kmalloc(count + 1, GFP_KERNEL); + if (!kbuf) + return -ENOMEM; + + err = copy_from_user(kbuf, buf, count); + if (err) { + kfree(kbuf); + return -EFAULT; + } + + stm_write(stm->data, stmf->output.master, stmf->output.channel, kbuf, + count); + + kfree(kbuf); + + return count; +} + +static int stm_char_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct stm_file *stmf = file->private_data; + struct stm_device *stm = stmf->stm; + unsigned long size, phys; + + if (!stm->data->mmio_addr) + return -EOPNOTSUPP; + + if (vma->vm_pgoff) + return -EINVAL; + + size = vma->vm_end - vma->vm_start; + + if (stmf->output.nr_chans * stm->data->sw_mmiosz != size) + return -EINVAL; + + phys = stm->data->mmio_addr(stm->data, stmf->output.master, + stmf->output.channel, + stmf->output.nr_chans); + + if (!phys) + return -EINVAL; + + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP; + vm_iomap_memory(vma, phys, size); + + return 0; +} + +static int stm_char_policy_set_ioctl(struct stm_file *stmf, void __user *arg) +{ + struct stm_device *stm = stmf->stm; + struct stp_policy_id *id; + int ret = -EINVAL; + u32 size; + + if (stmf->output.nr_chans) + return -EBUSY; + + if (copy_from_user(&size, arg, sizeof(size))) + return -EFAULT; + + if (size >= PATH_MAX + sizeof(*id)) + return -EINVAL; + + /* + * size + 1 to make sure the .id string at the bottom is terminated, + * which is also why memdup_user() is not useful here + */ + id = kzalloc(size + 1, GFP_KERNEL); + if (!id) + return -ENOMEM; + + if (copy_from_user(id, arg, size)) { + ret = -EFAULT; + goto err_free; + } + + if (id->__reserved_0 || id->__reserved_1) + goto err_free; + + if (id->width < 1 || + id->width > PAGE_SIZE / stm->data->sw_mmiosz) + goto err_free; + + ret = stm_file_assign(stmf, id->id, id->width); + if (ret) + goto err_free; + + ret = 0; + + if (stm->data->link) + ret = stm->data->link(stm->data, stmf->output.master, + stmf->output.channel); + + if (ret) { + stm_output_free(stmf->stm, &stmf->output); + stm_put_device(stmf->stm); + } + +err_free: + kfree(id); + + return ret; +} + +static int stm_char_policy_get_ioctl(struct stm_file *stmf, void __user *arg) +{ + struct stp_policy_id id = { + .size = sizeof(id), + .master = stmf->output.master, + .channel = stmf->output.channel, + .width = stmf->output.nr_chans, + .__reserved_0 = 0, + .__reserved_1 = 0, + }; + + return copy_to_user(arg, &id, id.size) ? -EFAULT : 0; +} + +static long +stm_char_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct stm_file *stmf = file->private_data; + struct stm_data *stm_data = stmf->stm->data; + int err = -ENOTTY; + u64 options; + + switch (cmd) { + case STP_POLICY_ID_SET: + err = stm_char_policy_set_ioctl(stmf, (void __user *)arg); + if (err) + return err; + + return stm_char_policy_get_ioctl(stmf, (void __user *)arg); + + case STP_POLICY_ID_GET: + return stm_char_policy_get_ioctl(stmf, (void __user *)arg); + + case STP_SET_OPTIONS: + if (copy_from_user(&options, (u64 __user *)arg, sizeof(u64))) + return -EFAULT; + + if (stm_data->set_options) + err = stm_data->set_options(stm_data, + stmf->output.master, + stmf->output.channel, + stmf->output.nr_chans, + options); + + break; + default: + break; + } + + return err; +} + +#ifdef CONFIG_COMPAT +static long +stm_char_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + return stm_char_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); +} +#else +#define stm_char_compat_ioctl NULL +#endif + +static const struct file_operations stm_fops = { + .open = stm_char_open, + .release = stm_char_release, + .write = stm_char_write, + .mmap = stm_char_mmap, + .unlocked_ioctl = stm_char_ioctl, + .compat_ioctl = stm_char_compat_ioctl, + .llseek = no_llseek, +}; + +static void stm_device_release(struct device *dev) +{ + struct stm_device *stm = to_stm_device(dev); + + kfree(stm); +} + +int stm_register_device(struct device *parent, struct stm_data *stm_data, + struct module *owner) +{ + struct stm_device *stm; + unsigned int nmasters; + int err = -ENOMEM; + + if (!stm_core_up) + return -EPROBE_DEFER; + + if (!stm_data->packet || !stm_data->sw_nchannels) + return -EINVAL; + + nmasters = stm_data->sw_end - stm_data->sw_start; + stm = kzalloc(sizeof(*stm) + nmasters * sizeof(void *), GFP_KERNEL); + if (!stm) + return -ENOMEM; + + stm->major = register_chrdev(0, stm_data->name, &stm_fops); + if (stm->major < 0) + goto err_free; + + device_initialize(&stm->dev); + stm->dev.devt = MKDEV(stm->major, 0); + stm->dev.class = &stm_class; + stm->dev.parent = parent; + stm->dev.release = stm_device_release; + + err = kobject_set_name(&stm->dev.kobj, "%s", stm_data->name); + if (err) + goto err_device; + + err = device_add(&stm->dev); + if (err) + goto err_device; + + spin_lock_init(&stm->link_lock); + INIT_LIST_HEAD(&stm->link_list); + + spin_lock_init(&stm->mc_lock); + mutex_init(&stm->policy_mutex); + stm->sw_nmasters = nmasters; + stm->owner = owner; + stm->data = stm_data; + stm_data->stm = stm; + + return 0; + +err_device: + put_device(&stm->dev); +err_free: + kfree(stm); + + return err; +} +EXPORT_SYMBOL_GPL(stm_register_device); + +static void __stm_source_link_drop(struct stm_source_device *src, + struct stm_device *stm); + +void stm_unregister_device(struct stm_data *stm_data) +{ + struct stm_device *stm = stm_data->stm; + struct stm_source_device *src, *iter; + int i; + + spin_lock(&stm->link_lock); + list_for_each_entry_safe(src, iter, &stm->link_list, link_entry) { + __stm_source_link_drop(src, stm); + } + spin_unlock(&stm->link_lock); + + synchronize_srcu(&stm_source_srcu); + + unregister_chrdev(stm->major, stm_data->name); + + mutex_lock(&stm->policy_mutex); + if (stm->policy) + stp_policy_unbind(stm->policy); + mutex_unlock(&stm->policy_mutex); + + for (i = 0; i < stm->sw_nmasters; i++) + stp_master_free(stm, i); + + device_unregister(&stm->dev); + stm_data->stm = NULL; +} +EXPORT_SYMBOL_GPL(stm_unregister_device); + +/** + * stm_source_link_add() - connect an stm_source device to an stm device + * @src: stm_source device + * @stm: stm device + * + * This function establishes a link from stm_source to an stm device so that + * the former can send out trace data to the latter. + * + * Return: 0 on success, -errno otherwise. + */ +static int stm_source_link_add(struct stm_source_device *src, + struct stm_device *stm) +{ + char *id; + int err; + + spin_lock(&stm->link_lock); + spin_lock(&src->link_lock); + + /* src->link is dereferenced under stm_source_srcu but not the list */ + rcu_assign_pointer(src->link, stm); + list_add_tail(&src->link_entry, &stm->link_list); + + spin_unlock(&src->link_lock); + spin_unlock(&stm->link_lock); + + id = kstrdup(src->data->name, GFP_KERNEL); + if (id) { + src->policy_node = + stp_policy_node_lookup(stm, id); + + kfree(id); + } + + err = stm_output_assign(stm, src->data->nr_chans, + src->policy_node, &src->output); + + if (src->policy_node) + stp_policy_node_put(src->policy_node); + + if (err) + goto fail_detach; + + /* this is to notify the STM device that a new link has been made */ + if (stm->data->link) + err = stm->data->link(stm->data, src->output.master, + src->output.channel); + + if (err) + goto fail_free_output; + + /* this is to let the source carry out all necessary preparations */ + if (src->data->link) + src->data->link(src->data); + + return 0; + +fail_free_output: + stm_output_free(stm, &src->output); + stm_put_device(stm); + +fail_detach: + spin_lock(&stm->link_lock); + spin_lock(&src->link_lock); + + rcu_assign_pointer(src->link, NULL); + list_del_init(&src->link_entry); + + spin_unlock(&src->link_lock); + spin_unlock(&stm->link_lock); + + return err; +} + +/** + * __stm_source_link_drop() - detach stm_source from an stm device + * @src: stm_source device + * @stm: stm device + * + * If @stm is @src::link, disconnect them from one another and put the + * reference on the @stm device. + * + * Caller must hold stm::link_lock. + */ +static void __stm_source_link_drop(struct stm_source_device *src, + struct stm_device *stm) +{ + spin_lock(&src->link_lock); + if (WARN_ON_ONCE(src->link != stm)) { + spin_unlock(&src->link_lock); + return; + } + + stm_output_free(src->link, &src->output); + /* caller must hold stm::link_lock */ + list_del_init(&src->link_entry); + /* matches stm_find_device() from stm_source_link_store() */ + stm_put_device(src->link); + rcu_assign_pointer(src->link, NULL); + + spin_unlock(&src->link_lock); +} + +/** + * stm_source_link_drop() - detach stm_source from its stm device + * @src: stm_source device + * + * Unlinking means disconnecting from source's STM device; after this + * writes will be unsuccessful until it is linked to a new STM device. + * + * This will happen on "stm_source_link" sysfs attribute write to undo + * the existing link (if any), or on linked STM device's de-registration. + */ +static void stm_source_link_drop(struct stm_source_device *src) +{ + struct stm_device *stm; + int idx; + + idx = srcu_read_lock(&stm_source_srcu); + stm = srcu_dereference(src->link, &stm_source_srcu); + + if (stm) { + if (src->data->unlink) + src->data->unlink(src->data); + + spin_lock(&stm->link_lock); + __stm_source_link_drop(src, stm); + spin_unlock(&stm->link_lock); + } + + srcu_read_unlock(&stm_source_srcu, idx); +} + +static ssize_t stm_source_link_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct stm_source_device *src = to_stm_source_device(dev); + struct stm_device *stm; + int idx, ret; + + idx = srcu_read_lock(&stm_source_srcu); + stm = srcu_dereference(src->link, &stm_source_srcu); + ret = sprintf(buf, "%s\n", + stm ? dev_name(&stm->dev) : "<none>"); + srcu_read_unlock(&stm_source_srcu, idx); + + return ret; +} + +static ssize_t stm_source_link_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct stm_source_device *src = to_stm_source_device(dev); + struct stm_device *link; + int err; + + stm_source_link_drop(src); + + link = stm_find_device(buf); + if (!link) + return -EINVAL; + + err = stm_source_link_add(src, link); + if (err) + stm_put_device(link); + + return err ? : count; +} + +static DEVICE_ATTR_RW(stm_source_link); + +static struct attribute *stm_source_attrs[] = { + &dev_attr_stm_source_link.attr, + NULL, +}; + +ATTRIBUTE_GROUPS(stm_source); + +static struct class stm_source_class = { + .name = "stm_source", + .dev_groups = stm_source_groups, +}; + +static void stm_source_device_release(struct device *dev) +{ + struct stm_source_device *src = to_stm_source_device(dev); + + kfree(src); +} + +/** + * stm_source_register_device() - register an stm_source device + * @parent: parent device + * @data: device description structure + * + * This will create a device of stm_source class that can write + * data to an stm device once linked. + * + * Return: 0 on success, -errno otherwise. + */ +int stm_source_register_device(struct device *parent, + struct stm_source_data *data) +{ + struct stm_source_device *src; + int err; + + if (!stm_core_up) + return -EPROBE_DEFER; + + src = kzalloc(sizeof(*src), GFP_KERNEL); + if (!src) + return -ENOMEM; + + device_initialize(&src->dev); + src->dev.class = &stm_source_class; + src->dev.parent = parent; + src->dev.release = stm_source_device_release; + + err = kobject_set_name(&src->dev.kobj, "%s", data->name); + if (err) + goto err; + + err = device_add(&src->dev); + if (err) + goto err; + + spin_lock_init(&src->link_lock); + INIT_LIST_HEAD(&src->link_entry); + src->data = data; + data->src = src; + + return 0; + +err: + put_device(&src->dev); + kfree(src); + + return err; +} +EXPORT_SYMBOL_GPL(stm_source_register_device); + +/** + * stm_source_unregister_device() - unregister an stm_source device + * @data: device description that was used to register the device + * + * This will remove a previously created stm_source device from the system. + */ +void stm_source_unregister_device(struct stm_source_data *data) +{ + struct stm_source_device *src = data->src; + + stm_source_link_drop(src); + + device_destroy(&stm_source_class, src->dev.devt); +} +EXPORT_SYMBOL_GPL(stm_source_unregister_device); + +int stm_source_write(struct stm_source_data *data, unsigned int chan, + const char *buf, size_t count) +{ + struct stm_source_device *src = data->src; + struct stm_device *stm; + int idx; + + if (!src->output.nr_chans) + return -ENODEV; + + if (chan >= src->output.nr_chans) + return -EINVAL; + + idx = srcu_read_lock(&stm_source_srcu); + + stm = srcu_dereference(src->link, &stm_source_srcu); + if (stm) + stm_write(stm->data, src->output.master, + src->output.channel + chan, + buf, count); + else + count = -ENODEV; + + srcu_read_unlock(&stm_source_srcu, idx); + + return count; +} +EXPORT_SYMBOL_GPL(stm_source_write); + +static int __init stm_core_init(void) +{ + int err; + + err = class_register(&stm_class); + if (err) + return err; + + err = class_register(&stm_source_class); + if (err) + goto err_stm; + + err = stp_configfs_init(); + if (err) + goto err_src; + + init_srcu_struct(&stm_source_srcu); + + stm_core_up++; + + return 0; + +err_src: + class_unregister(&stm_source_class); +err_stm: + class_unregister(&stm_class); + + return err; +} + +module_init(stm_core_init); + +static void __exit stm_core_exit(void) +{ + cleanup_srcu_struct(&stm_source_srcu); + class_unregister(&stm_source_class); + class_unregister(&stm_class); + stp_configfs_exit(); +} + +module_exit(stm_core_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("System Trace Module device class"); +MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>"); diff --git a/drivers/hwtracing/stm/policy.c b/drivers/hwtracing/stm/policy.c new file mode 100644 index 0000000..6498a9d --- /dev/null +++ b/drivers/hwtracing/stm/policy.c @@ -0,0 +1,529 @@ +/* + * System Trace Module (STM) master/channel allocation policy management + * Copyright (c) 2014, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + * + * A master/channel allocation policy allows mapping string identifiers to + * master and channel ranges, where allocation can be done. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/types.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/configfs.h> +#include <linux/slab.h> +#include <linux/stm.h> +#include "stm.h" + +/* + * STP Master/Channel allocation policy configfs layout. + */ + +struct stp_policy { + struct config_group group; + struct stm_device *stm; +}; + +struct stp_policy_node { + struct config_group group; + struct stp_policy *policy; + unsigned int first_master; + unsigned int last_master; + unsigned int first_channel; + unsigned int last_channel; +}; + +static struct configfs_subsystem stp_policy_subsys; + +void stp_policy_node_get_ranges(struct stp_policy_node *policy_node, + unsigned int *mstart, unsigned int *mend, + unsigned int *cstart, unsigned int *cend) +{ + *mstart = policy_node->first_master; + *mend = policy_node->last_master; + *cstart = policy_node->first_channel; + *cend = policy_node->last_channel; +} + +static inline char *stp_policy_node_name(struct stp_policy_node *policy_node) +{ + return policy_node->group.cg_item.ci_name ? : "<none>"; +} + +static inline struct stp_policy *to_stp_policy(struct config_item *item) +{ + return item ? + container_of(to_config_group(item), struct stp_policy, group) : + NULL; +} + +static inline struct stp_policy_node * +to_stp_policy_node(struct config_item *item) +{ + return item ? + container_of(to_config_group(item), struct stp_policy_node, + group) : + NULL; +} + +static ssize_t stp_policy_node_masters_show(struct stp_policy_node *policy_node, + char *page) +{ + ssize_t count; + + count = sprintf(page, "%u %u\n", policy_node->first_master, + policy_node->last_master); + + return count; +} + +static ssize_t +stp_policy_node_masters_store(struct stp_policy_node *policy_node, + const char *page, size_t count) +{ + unsigned int first, last; + struct stm_device *stm; + char *p = (char *)page; + ssize_t ret = -ENODEV; + + if (sscanf(p, "%u %u", &first, &last) != 2) + return -EINVAL; + + mutex_lock(&stp_policy_subsys.su_mutex); + stm = policy_node->policy->stm; + if (!stm) + goto unlock; + + /* must be within [sw_start..sw_end], which is an inclusive range */ + if (first > INT_MAX || last > INT_MAX || first > last || + first < stm->data->sw_start || + last > stm->data->sw_end) { + ret = -ERANGE; + goto unlock; + } + + ret = count; + policy_node->first_master = first; + policy_node->last_master = last; + +unlock: + mutex_unlock(&stp_policy_subsys.su_mutex); + + return ret; +} + +static ssize_t +stp_policy_node_channels_show(struct stp_policy_node *policy_node, char *page) +{ + ssize_t count; + + count = sprintf(page, "%u %u\n", policy_node->first_channel, + policy_node->last_channel); + + return count; +} + +static ssize_t +stp_policy_node_channels_store(struct stp_policy_node *policy_node, + const char *page, size_t count) +{ + unsigned int first, last; + struct stm_device *stm; + char *p = (char *)page; + ssize_t ret = -ENODEV; + + if (sscanf(p, "%u %u", &first, &last) != 2) + return -EINVAL; + + mutex_lock(&stp_policy_subsys.su_mutex); + stm = policy_node->policy->stm; + if (!stm) + goto unlock; + + if (first > INT_MAX || last > INT_MAX || first > last || + last >= stm->data->sw_nchannels) { + ret = -ERANGE; + goto unlock; + } + + ret = count; + policy_node->first_channel = first; + policy_node->last_channel = last; + +unlock: + mutex_unlock(&stp_policy_subsys.su_mutex); + + return ret; +} + +static void stp_policy_node_release(struct config_item *item) +{ + kfree(to_stp_policy_node(item)); +} + +struct stp_policy_node_attribute { + struct configfs_attribute attr; + ssize_t (*show)(struct stp_policy_node *, char *); + ssize_t (*store)(struct stp_policy_node *, const char *, size_t); +}; + +static ssize_t stp_policy_node_attr_show(struct config_item *item, + struct configfs_attribute *attr, + char *page) +{ + struct stp_policy_node *policy_node = to_stp_policy_node(item); + struct stp_policy_node_attribute *pn_attr = + container_of(attr, struct stp_policy_node_attribute, attr); + ssize_t count = 0; + + if (pn_attr->show) + count = pn_attr->show(policy_node, page); + + return count; +} + +static ssize_t stp_policy_node_attr_store(struct config_item *item, + struct configfs_attribute *attr, + const char *page, size_t len) +{ + struct stp_policy_node *policy_node = to_stp_policy_node(item); + struct stp_policy_node_attribute *pn_attr = + container_of(attr, struct stp_policy_node_attribute, attr); + ssize_t count = -EINVAL; + + if (pn_attr->store) + count = pn_attr->store(policy_node, page, len); + + return count; +} + +static struct configfs_item_operations stp_policy_node_item_ops = { + .release = stp_policy_node_release, + .show_attribute = stp_policy_node_attr_show, + .store_attribute = stp_policy_node_attr_store, +}; + +static struct stp_policy_node_attribute stp_policy_node_attr_range = { + .attr = { + .ca_owner = THIS_MODULE, + .ca_name = "masters", + .ca_mode = S_IRUGO | S_IWUSR, + }, + .show = stp_policy_node_masters_show, + .store = stp_policy_node_masters_store, +}; + +static struct stp_policy_node_attribute stp_policy_node_attr_channels = { + .attr = { + .ca_owner = THIS_MODULE, + .ca_name = "channels", + .ca_mode = S_IRUGO | S_IWUSR, + }, + .show = stp_policy_node_channels_show, + .store = stp_policy_node_channels_store, +}; + +static struct configfs_attribute *stp_policy_node_attrs[] = { + &stp_policy_node_attr_range.attr, + &stp_policy_node_attr_channels.attr, + NULL, +}; + +static struct config_item_type stp_policy_type; +static struct config_item_type stp_policy_node_type; + +static struct config_group * +stp_policy_node_make(struct config_group *group, const char *name) +{ + struct stp_policy_node *policy_node, *parent_node; + struct stp_policy *policy; + + if (group->cg_item.ci_type == &stp_policy_type) { + policy = container_of(group, struct stp_policy, group); + } else { + parent_node = container_of(group, struct stp_policy_node, + group); + policy = parent_node->policy; + } + + if (!policy->stm) + return ERR_PTR(-ENODEV); + + policy_node = kzalloc(sizeof(struct stp_policy_node), GFP_KERNEL); + if (!policy_node) + return ERR_PTR(-ENOMEM); + + config_group_init_type_name(&policy_node->group, name, + &stp_policy_node_type); + + policy_node->policy = policy; + + /* default values for the attributes */ + policy_node->first_master = policy->stm->data->sw_start; + policy_node->last_master = policy->stm->data->sw_end; + policy_node->first_channel = 0; + policy_node->last_channel = policy->stm->data->sw_nchannels - 1; + + return &policy_node->group; +} + +static void +stp_policy_node_drop(struct config_group *group, struct config_item *item) +{ + config_item_put(item); +} + +static struct configfs_group_operations stp_policy_node_group_ops = { + .make_group = stp_policy_node_make, + .drop_item = stp_policy_node_drop, +}; + +static struct config_item_type stp_policy_node_type = { + .ct_item_ops = &stp_policy_node_item_ops, + .ct_group_ops = &stp_policy_node_group_ops, + .ct_attrs = stp_policy_node_attrs, + .ct_owner = THIS_MODULE, +}; + +/* + * Root group: policies. + */ +static struct configfs_attribute stp_policy_attr_device = { + .ca_owner = THIS_MODULE, + .ca_name = "device", + .ca_mode = S_IRUGO, +}; + +static struct configfs_attribute *stp_policy_attrs[] = { + &stp_policy_attr_device, + NULL, +}; + +static ssize_t stp_policy_attr_show(struct config_item *item, + struct configfs_attribute *attr, + char *page) +{ + struct stp_policy *policy = to_stp_policy(item); + ssize_t count; + + count = sprintf(page, "%s\n", + (policy && policy->stm) ? + policy->stm->data->name : + "<none>"); + + return count; +} + +void stp_policy_unbind(struct stp_policy *policy) +{ + struct stm_device *stm = policy->stm; + + if (WARN_ON_ONCE(!policy->stm)) + return; + + mutex_lock(&stm->policy_mutex); + stm->policy = NULL; + mutex_unlock(&stm->policy_mutex); + + policy->stm = NULL; + + stm_put_device(stm); +} + +static void stp_policy_release(struct config_item *item) +{ + struct stp_policy *policy = to_stp_policy(item); + + stp_policy_unbind(policy); + kfree(policy); +} + +static struct configfs_item_operations stp_policy_item_ops = { + .release = stp_policy_release, + .show_attribute = stp_policy_attr_show, +}; + +static struct configfs_group_operations stp_policy_group_ops = { + .make_group = stp_policy_node_make, +}; + +static struct config_item_type stp_policy_type = { + .ct_item_ops = &stp_policy_item_ops, + .ct_group_ops = &stp_policy_group_ops, + .ct_attrs = stp_policy_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct config_group * +stp_policies_make(struct config_group *group, const char *name) +{ + struct config_group *ret; + struct stm_device *stm; + char *devname, *p; + + devname = kasprintf(GFP_KERNEL, "%s", name); + if (!devname) + return ERR_PTR(-ENOMEM); + + /* + * node must look like <device_name>.<policy_name>, where + * <device_name> is the name of an existing stm device and + * <policy_name> is an arbitrary string + */ + p = strchr(devname, '.'); + if (!p) { + kfree(devname); + return ERR_PTR(-EINVAL); + } + + *p++ = '\0'; + + stm = stm_find_device(devname); + kfree(devname); + + if (!stm) + return ERR_PTR(-ENODEV); + + mutex_lock(&stm->policy_mutex); + if (stm->policy) { + ret = ERR_PTR(-EBUSY); + goto unlock_policy; + } + + stm->policy = kzalloc(sizeof(*stm->policy), GFP_KERNEL); + if (!stm->policy) { + ret = ERR_PTR(-ENOMEM); + goto unlock_policy; + } + + config_group_init_type_name(&stm->policy->group, name, + &stp_policy_type); + stm->policy->stm = stm; + + ret = &stm->policy->group; + +unlock_policy: + mutex_unlock(&stm->policy_mutex); + + if (IS_ERR(ret)) + stm_put_device(stm); + + return ret; +} + +static struct configfs_group_operations stp_policies_group_ops = { + .make_group = stp_policies_make, +}; + +static struct config_item_type stp_policies_type = { + .ct_group_ops = &stp_policies_group_ops, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem stp_policy_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "stp-policy", + .ci_type = &stp_policies_type, + }, + }, +}; + +/* + * Lock the policy mutex from the outside + */ +static struct stp_policy_node * +__stp_policy_node_lookup(struct stp_policy *policy, char *s) +{ + struct stp_policy_node *policy_node, *ret; + struct list_head *head = &policy->group.cg_children; + struct config_item *item; + char *start, *end = s; + + if (list_empty(head)) + return NULL; + + /* return the first entry if everything else fails */ + item = list_entry(head->next, struct config_item, ci_entry); + ret = to_stp_policy_node(item); + +next: + for (;;) { + start = strsep(&end, "/"); + if (!start) + break; + + if (!*start) + continue; + + list_for_each_entry(item, head, ci_entry) { + policy_node = to_stp_policy_node(item); + + if (!strcmp(start, + policy_node->group.cg_item.ci_name)) { + ret = policy_node; + + if (!end) + goto out; + + head = &policy_node->group.cg_children; + goto next; + } + } + break; + } + +out: + return ret; +} + + +struct stp_policy_node * +stp_policy_node_lookup(struct stm_device *stm, char *s) +{ + struct stp_policy_node *policy_node = NULL; + + mutex_lock(&stp_policy_subsys.su_mutex); + + mutex_lock(&stm->policy_mutex); + if (stm->policy) + policy_node = __stp_policy_node_lookup(stm->policy, s); + mutex_unlock(&stm->policy_mutex); + + if (policy_node) + config_item_get(&policy_node->group.cg_item); + mutex_unlock(&stp_policy_subsys.su_mutex); + + return policy_node; +} + +void stp_policy_node_put(struct stp_policy_node *policy_node) +{ + config_item_put(&policy_node->group.cg_item); +} + +int __init stp_configfs_init(void) +{ + int err; + + config_group_init(&stp_policy_subsys.su_group); + mutex_init(&stp_policy_subsys.su_mutex); + err = configfs_register_subsystem(&stp_policy_subsys); + + return err; +} + +void __exit stp_configfs_exit(void) +{ + configfs_unregister_subsystem(&stp_policy_subsys); +} diff --git a/drivers/hwtracing/stm/stm.h b/drivers/hwtracing/stm/stm.h new file mode 100644 index 0000000..cf33bf9 --- /dev/null +++ b/drivers/hwtracing/stm/stm.h @@ -0,0 +1,87 @@ +/* + * System Trace Module (STM) infrastructure + * Copyright (c) 2014, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + * + * STM class implements generic infrastructure for System Trace Module devices + * as defined in MIPI STPv2 specification. + */ + +#ifndef _STM_STM_H_ +#define _STM_STM_H_ + +struct stp_policy; +struct stp_policy_node; + +struct stp_policy_node * +stp_policy_node_lookup(struct stm_device *stm, char *s); +void stp_policy_node_put(struct stp_policy_node *policy_node); +void stp_policy_unbind(struct stp_policy *policy); + +void stp_policy_node_get_ranges(struct stp_policy_node *policy_node, + unsigned int *mstart, unsigned int *mend, + unsigned int *cstart, unsigned int *cend); +int stp_configfs_init(void); +void stp_configfs_exit(void); + +struct stp_master { + unsigned int nr_free; + unsigned long chan_map[0]; +}; + +struct stm_device { + struct device dev; + struct module *owner; + struct stp_policy *policy; + struct mutex policy_mutex; + int major; + unsigned int sw_nmasters; + struct stm_data *data; + spinlock_t link_lock; + struct list_head link_list; + /* master allocation */ + spinlock_t mc_lock; + struct stp_master *masters[0]; +}; + +#define to_stm_device(_d) \ + container_of((_d), struct stm_device, dev) + +struct stm_output { + unsigned int master; + unsigned int channel; + unsigned int nr_chans; +}; + +struct stm_file { + struct stm_device *stm; + struct stp_policy_node *policy_node; + struct stm_output output; +}; + +struct stm_device *stm_find_device(const char *name); +void stm_put_device(struct stm_device *stm); + +struct stm_source_device { + struct device dev; + struct stm_source_data *data; + spinlock_t link_lock; + struct stm_device *link; + struct list_head link_entry; + /* one output per stm_source device */ + struct stp_policy_node *policy_node; + struct stm_output output; +}; + +#define to_stm_source_device(_d) \ + container_of((_d), struct stm_source_device, dev) + +#endif /* _STM_STM_H_ */ diff --git a/include/linux/stm.h b/include/linux/stm.h new file mode 100644 index 0000000..9d0083d --- /dev/null +++ b/include/linux/stm.h @@ -0,0 +1,126 @@ +/* + * System Trace Module (STM) infrastructure apis + * Copyright (C) 2014 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + */ + +#ifndef _STM_H_ +#define _STM_H_ + +#include <linux/device.h> + +/** + * enum stp_packet_type - STP packets that an STM driver sends + */ +enum stp_packet_type { + STP_PACKET_DATA = 0, + STP_PACKET_FLAG, + STP_PACKET_USER, + STP_PACKET_MERR, + STP_PACKET_GERR, + STP_PACKET_TRIG, + STP_PACKET_XSYNC, +}; + +/** + * enum stp_packet_flags - STP packet modifiers + */ +enum stp_packet_flags { + STP_PACKET_MARKED = 0x1, + STP_PACKET_TIMESTAMPED = 0x2, +}; + +struct stp_policy; + +struct stm_device; + +/** + * struct stm_data - STM device description and callbacks + * @name: device name + * @stm: internal structure, only used by stm class code + * @sw_start: first STP master available to software + * @sw_end: last STP master available to software + * @sw_nchannels: number of STP channels per master + * @sw_mmiosz: size of one channel's IO space, for mmap, optional + * @packet: callback that sends an STP packet + * @mmio_addr: mmap callback, optional + * @link: called when a new stm_source gets linked to us, optional + * @unlink: likewise for unlinking, again optional + * @set_options: set device-specific options on a channel + * + * Fill out this structure before calling stm_register_device() to create + * an STM device and stm_unregister_device() to destroy it. It will also be + * passed back to @packet(), @mmio_addr(), @link(), @unlink() and @set_options() + * callbacks. + * + * Normally, an STM device will have a range of masters available to software + * and the rest being statically assigned to various hardware trace sources. + * The former is defined by the the range [@sw_start..@sw_end] of the device + * description. That is, the lowest master that can be allocated to software + * writers is @sw_start and data from this writer will appear is @sw_start + * master in the STP stream. + */ +struct stm_data { + const char *name; + struct stm_device *stm; + unsigned int sw_start; + unsigned int sw_end; + unsigned int sw_nchannels; + unsigned int sw_mmiosz; + ssize_t (*packet)(struct stm_data *, unsigned int, + unsigned int, unsigned int, + unsigned int, unsigned int, + const unsigned char *); + phys_addr_t (*mmio_addr)(struct stm_data *, unsigned int, + unsigned int, unsigned int); + int (*link)(struct stm_data *, unsigned int, + unsigned int); + void (*unlink)(struct stm_data *, unsigned int, + unsigned int); + long (*set_options)(struct stm_data *, unsigned int, + unsigned int, unsigned int, + unsigned long); +}; + +int stm_register_device(struct device *parent, struct stm_data *stm_data, + struct module *owner); +void stm_unregister_device(struct stm_data *stm_data); + +struct stm_source_device; + +/** + * struct stm_source_data - STM source device description and callbacks + * @name: device name, will be used for policy lookup + * @src: internal structure, only used by stm class code + * @nr_chans: number of channels to allocate + * @link: called when this source gets linked to an STM device + * @unlink: called when this source is about to get unlinked from its STM + * + * Fill in this structure before calling stm_source_register_device() to + * register a source device. Also pass it to unregister and write calls. + */ +struct stm_source_data { + const char *name; + struct stm_source_device *src; + unsigned int percpu; + unsigned int nr_chans; + int (*link)(struct stm_source_data *data); + void (*unlink)(struct stm_source_data *data); +}; + +int stm_source_register_device(struct device *parent, + struct stm_source_data *data); +void stm_source_unregister_device(struct stm_source_data *data); + +int stm_source_write(struct stm_source_data *data, unsigned int chan, + const char *buf, size_t count); + +#endif /* _STM_H_ */ diff --git a/include/uapi/linux/stm.h b/include/uapi/linux/stm.h new file mode 100644 index 0000000..626a8d3 --- /dev/null +++ b/include/uapi/linux/stm.h @@ -0,0 +1,50 @@ +/* + * System Trace Module (STM) userspace interfaces + * Copyright (c) 2014, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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. + * + * STM class implements generic infrastructure for System Trace Module devices + * as defined in MIPI STPv2 specification. + */ + +#ifndef _UAPI_LINUX_STM_H +#define _UAPI_LINUX_STM_H + +#include <linux/types.h> + +/** + * struct stp_policy_id - identification for the STP policy + * @size: size of the structure including real id[] length + * @master: assigned master + * @channel: first assigned channel + * @width: number of requested channels + * @id: identification string + * + * User must calculate the total size of the structure and put it into + * @size field, fill out the @id and desired @width. In return, kernel + * fills out @master, @channel and @width. + */ +struct stp_policy_id { + __u32 size; + __u16 master; + __u16 channel; + __u16 width; + /* padding */ + __u16 __reserved_0; + __u32 __reserved_1; + char id[0]; +}; + +#define STP_POLICY_ID_SET _IOWR('%', 0, struct stp_policy_id) +#define STP_POLICY_ID_GET _IOR('%', 1, struct stp_policy_id) +#define STP_SET_OPTIONS _IOW('%', 2, __u64) + +#endif /* _UAPI_LINUX_STM_H */ |
