diff options
author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-22 14:46:24 -0800 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-02-22 14:46:24 -0800 |
commit | bb27d4998a9e8767674e8eda225c82cc149e5bc8 (patch) | |
tree | dcabb8b8cc510003637323b30ed414b1a1ec86f6 /drivers/hwtracing/coresight/coresight-etb10.c | |
parent | 9676e84dfd641e3366a41f2c45ac5c55dbac820f (diff) | |
parent | 35bf7692e765c2275bf93fe573f7ca868ab73453 (diff) | |
download | linux-bb27d4998a9e8767674e8eda225c82cc149e5bc8.tar.bz2 |
Merge char-misc-next into staging-next
This resolves the merge issues and confusions people were having with
the goldfish drivers due to changes for them showing up in two different
trees.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing/coresight/coresight-etb10.c')
-rw-r--r-- | drivers/hwtracing/coresight/coresight-etb10.c | 293 |
1 files changed, 264 insertions, 29 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c index 77d0f9c1118d..acbce79934d6 100644 --- a/drivers/hwtracing/coresight/coresight-etb10.c +++ b/drivers/hwtracing/coresight/coresight-etb10.c @@ -1,5 +1,7 @@ /* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved. * + * Description: CoreSight Embedded Trace Buffer driver + * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and * only version 2 as published by the Free Software Foundation. @@ -10,8 +12,8 @@ * GNU General Public License for more details. */ +#include <asm/local.h> #include <linux/kernel.h> -#include <linux/module.h> #include <linux/init.h> #include <linux/types.h> #include <linux/device.h> @@ -27,6 +29,11 @@ #include <linux/coresight.h> #include <linux/amba/bus.h> #include <linux/clk.h> +#include <linux/circ_buf.h> +#include <linux/mm.h> +#include <linux/perf_event.h> + +#include <asm/local.h> #include "coresight-priv.h" @@ -64,6 +71,26 @@ #define ETB_FRAME_SIZE_WORDS 4 /** + * struct cs_buffer - keep track of a recording session' specifics + * @cur: index of the current buffer + * @nr_pages: max number of pages granted to us + * @offset: offset within the current buffer + * @data_size: how much we collected in this run + * @lost: other than zero if we had a HW buffer wrap around + * @snapshot: is this run in snapshot mode + * @data_pages: a handle the ring buffer + */ +struct cs_buffers { + unsigned int cur; + unsigned int nr_pages; + unsigned long offset; + local_t data_size; + local_t lost; + bool snapshot; + void **data_pages; +}; + +/** * struct etb_drvdata - specifics associated to an ETB component * @base: memory mapped base address for this component. * @dev: the device entity associated to this component. @@ -71,10 +98,10 @@ * @csdev: component vitals needed by the framework. * @miscdev: specifics to handle "/dev/xyz.etb" entry. * @spinlock: only one at a time pls. - * @in_use: synchronise user space access to etb buffer. + * @reading: synchronise user space access to etb buffer. + * @mode: this ETB is being used. * @buf: area of memory where ETB buffer content gets sent. * @buffer_depth: size of @buf. - * @enable: this ETB is being used. * @trigger_cntr: amount of words to store after a trigger. */ struct etb_drvdata { @@ -84,10 +111,10 @@ struct etb_drvdata { struct coresight_device *csdev; struct miscdevice miscdev; spinlock_t spinlock; - atomic_t in_use; + local_t reading; + local_t mode; u8 *buf; u32 buffer_depth; - bool enable; u32 trigger_cntr; }; @@ -132,18 +159,31 @@ static void etb_enable_hw(struct etb_drvdata *drvdata) CS_LOCK(drvdata->base); } -static int etb_enable(struct coresight_device *csdev) +static int etb_enable(struct coresight_device *csdev, u32 mode) { - struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + u32 val; unsigned long flags; + struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); - pm_runtime_get_sync(drvdata->dev); + val = local_cmpxchg(&drvdata->mode, + CS_MODE_DISABLED, mode); + /* + * When accessing from Perf, a HW buffer can be handled + * by a single trace entity. In sysFS mode many tracers + * can be logging to the same HW buffer. + */ + if (val == CS_MODE_PERF) + return -EBUSY; + + /* Nothing to do, the tracer is already enabled. */ + if (val == CS_MODE_SYSFS) + goto out; spin_lock_irqsave(&drvdata->spinlock, flags); etb_enable_hw(drvdata); - drvdata->enable = true; spin_unlock_irqrestore(&drvdata->spinlock, flags); +out: dev_info(drvdata->dev, "ETB enabled\n"); return 0; } @@ -244,17 +284,225 @@ static void etb_disable(struct coresight_device *csdev) spin_lock_irqsave(&drvdata->spinlock, flags); etb_disable_hw(drvdata); etb_dump_hw(drvdata); - drvdata->enable = false; spin_unlock_irqrestore(&drvdata->spinlock, flags); - pm_runtime_put(drvdata->dev); + local_set(&drvdata->mode, CS_MODE_DISABLED); dev_info(drvdata->dev, "ETB disabled\n"); } +static void *etb_alloc_buffer(struct coresight_device *csdev, int cpu, + void **pages, int nr_pages, bool overwrite) +{ + int node; + struct cs_buffers *buf; + + if (cpu == -1) + cpu = smp_processor_id(); + node = cpu_to_node(cpu); + + buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node); + if (!buf) + return NULL; + + buf->snapshot = overwrite; + buf->nr_pages = nr_pages; + buf->data_pages = pages; + + return buf; +} + +static void etb_free_buffer(void *config) +{ + struct cs_buffers *buf = config; + + kfree(buf); +} + +static int etb_set_buffer(struct coresight_device *csdev, + struct perf_output_handle *handle, + void *sink_config) +{ + int ret = 0; + unsigned long head; + struct cs_buffers *buf = sink_config; + + /* wrap head around to the amount of space we have */ + head = handle->head & ((buf->nr_pages << PAGE_SHIFT) - 1); + + /* find the page to write to */ + buf->cur = head / PAGE_SIZE; + + /* and offset within that page */ + buf->offset = head % PAGE_SIZE; + + local_set(&buf->data_size, 0); + + return ret; +} + +static unsigned long etb_reset_buffer(struct coresight_device *csdev, + struct perf_output_handle *handle, + void *sink_config, bool *lost) +{ + unsigned long size = 0; + struct cs_buffers *buf = sink_config; + + if (buf) { + /* + * In snapshot mode ->data_size holds the new address of the + * ring buffer's head. The size itself is the whole address + * range since we want the latest information. + */ + if (buf->snapshot) + handle->head = local_xchg(&buf->data_size, + buf->nr_pages << PAGE_SHIFT); + + /* + * Tell the tracer PMU how much we got in this run and if + * something went wrong along the way. Nobody else can use + * this cs_buffers instance until we are done. As such + * resetting parameters here and squaring off with the ring + * buffer API in the tracer PMU is fine. + */ + *lost = !!local_xchg(&buf->lost, 0); + size = local_xchg(&buf->data_size, 0); + } + + return size; +} + +static void etb_update_buffer(struct coresight_device *csdev, + struct perf_output_handle *handle, + void *sink_config) +{ + int i, cur; + u8 *buf_ptr; + u32 read_ptr, write_ptr, capacity; + u32 status, read_data, to_read; + unsigned long offset; + struct cs_buffers *buf = sink_config; + struct etb_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); + + if (!buf) + return; + + capacity = drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS; + + CS_UNLOCK(drvdata->base); + etb_disable_hw(drvdata); + + /* unit is in words, not bytes */ + read_ptr = readl_relaxed(drvdata->base + ETB_RAM_READ_POINTER); + write_ptr = readl_relaxed(drvdata->base + ETB_RAM_WRITE_POINTER); + + /* + * Entries should be aligned to the frame size. If they are not + * go back to the last alignement point to give decoding tools a + * chance to fix things. + */ + if (write_ptr % ETB_FRAME_SIZE_WORDS) { + dev_err(drvdata->dev, + "write_ptr: %lu not aligned to formatter frame size\n", + (unsigned long)write_ptr); + + write_ptr &= ~(ETB_FRAME_SIZE_WORDS - 1); + local_inc(&buf->lost); + } + + /* + * Get a hold of the status register and see if a wrap around + * has occurred. If so adjust things accordingly. Otherwise + * start at the beginning and go until the write pointer has + * been reached. + */ + status = readl_relaxed(drvdata->base + ETB_STATUS_REG); + if (status & ETB_STATUS_RAM_FULL) { + local_inc(&buf->lost); + to_read = capacity; + read_ptr = write_ptr; + } else { + to_read = CIRC_CNT(write_ptr, read_ptr, drvdata->buffer_depth); + to_read *= ETB_FRAME_SIZE_WORDS; + } + + /* + * Make sure we don't overwrite data that hasn't been consumed yet. + * It is entirely possible that the HW buffer has more data than the + * ring buffer can currently handle. If so adjust the start address + * to take only the last traces. + * + * In snapshot mode we are looking to get the latest traces only and as + * such, we don't care about not overwriting data that hasn't been + * processed by user space. + */ + if (!buf->snapshot && to_read > handle->size) { + u32 mask = ~(ETB_FRAME_SIZE_WORDS - 1); + + /* The new read pointer must be frame size aligned */ + to_read -= handle->size & mask; + /* + * Move the RAM read pointer up, keeping in mind that + * everything is in frame size units. + */ + read_ptr = (write_ptr + drvdata->buffer_depth) - + to_read / ETB_FRAME_SIZE_WORDS; + /* Wrap around if need be*/ + read_ptr &= ~(drvdata->buffer_depth - 1); + /* let the decoder know we've skipped ahead */ + local_inc(&buf->lost); + } + + /* finally tell HW where we want to start reading from */ + writel_relaxed(read_ptr, drvdata->base + ETB_RAM_READ_POINTER); + + cur = buf->cur; + offset = buf->offset; + for (i = 0; i < to_read; i += 4) { + buf_ptr = buf->data_pages[cur] + offset; + read_data = readl_relaxed(drvdata->base + + ETB_RAM_READ_DATA_REG); + *buf_ptr++ = read_data >> 0; + *buf_ptr++ = read_data >> 8; + *buf_ptr++ = read_data >> 16; + *buf_ptr++ = read_data >> 24; + + offset += 4; + if (offset >= PAGE_SIZE) { + offset = 0; + cur++; + /* wrap around at the end of the buffer */ + cur &= buf->nr_pages - 1; + } + } + + /* reset ETB buffer for next run */ + writel_relaxed(0x0, drvdata->base + ETB_RAM_READ_POINTER); + writel_relaxed(0x0, drvdata->base + ETB_RAM_WRITE_POINTER); + + /* + * In snapshot mode all we have to do is communicate to + * perf_aux_output_end() the address of the current head. In full + * trace mode the same function expects a size to move rb->aux_head + * forward. + */ + if (buf->snapshot) + local_set(&buf->data_size, (cur * PAGE_SIZE) + offset); + else + local_add(to_read, &buf->data_size); + + etb_enable_hw(drvdata); + CS_LOCK(drvdata->base); +} + static const struct coresight_ops_sink etb_sink_ops = { .enable = etb_enable, .disable = etb_disable, + .alloc_buffer = etb_alloc_buffer, + .free_buffer = etb_free_buffer, + .set_buffer = etb_set_buffer, + .reset_buffer = etb_reset_buffer, + .update_buffer = etb_update_buffer, }; static const struct coresight_ops etb_cs_ops = { @@ -266,7 +514,7 @@ static void etb_dump(struct etb_drvdata *drvdata) unsigned long flags; spin_lock_irqsave(&drvdata->spinlock, flags); - if (drvdata->enable) { + if (local_read(&drvdata->mode) == CS_MODE_SYSFS) { etb_disable_hw(drvdata); etb_dump_hw(drvdata); etb_enable_hw(drvdata); @@ -281,7 +529,7 @@ static int etb_open(struct inode *inode, struct file *file) struct etb_drvdata *drvdata = container_of(file->private_data, struct etb_drvdata, miscdev); - if (atomic_cmpxchg(&drvdata->in_use, 0, 1)) + if (local_cmpxchg(&drvdata->reading, 0, 1)) return -EBUSY; dev_dbg(drvdata->dev, "%s: successfully opened\n", __func__); @@ -317,7 +565,7 @@ static int etb_release(struct inode *inode, struct file *file) { struct etb_drvdata *drvdata = container_of(file->private_data, struct etb_drvdata, miscdev); - atomic_set(&drvdata->in_use, 0); + local_set(&drvdata->reading, 0); dev_dbg(drvdata->dev, "%s: released\n", __func__); return 0; @@ -489,15 +737,6 @@ err_misc_register: return ret; } -static int etb_remove(struct amba_device *adev) -{ - struct etb_drvdata *drvdata = amba_get_drvdata(adev); - - misc_deregister(&drvdata->miscdev); - coresight_unregister(drvdata->csdev); - return 0; -} - #ifdef CONFIG_PM static int etb_runtime_suspend(struct device *dev) { @@ -537,14 +776,10 @@ static struct amba_driver etb_driver = { .name = "coresight-etb10", .owner = THIS_MODULE, .pm = &etb_dev_pm_ops, + .suppress_bind_attrs = true, }, .probe = etb_probe, - .remove = etb_remove, .id_table = etb_ids, }; - -module_amba_driver(etb_driver); - -MODULE_LICENSE("GPL v2"); -MODULE_DESCRIPTION("CoreSight Embedded Trace Buffer driver"); +builtin_amba_driver(etb_driver); |