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[103.229.16.4]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2c164f6ce98sm243670335ad.10.2026.06.10.21.57.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 10 Jun 2026 21:57:36 -0700 (PDT) Message-ID: <3328efab-f835-46e4-b83b-71bf103f6f4c@oss.qualcomm.com> Date: Thu, 11 Jun 2026 12:57:29 +0800 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v18 6/7] coresight: ctcu: enable byte-cntr for TMC ETR devices To: Suzuki K Poulose , Mike Leach , James Clark , Alexander Shishkin , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Tingwei Zhang , Bjorn Andersson , Konrad Dybcio Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org References: <20260507-enable-byte-cntr-for-ctcu-v18-0-2b2d590463a3@oss.qualcomm.com> <20260507-enable-byte-cntr-for-ctcu-v18-6-2b2d590463a3@oss.qualcomm.com> Content-Language: en-US From: Jie Gan In-Reply-To: <20260507-enable-byte-cntr-for-ctcu-v18-6-2b2d590463a3@oss.qualcomm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Proofpoint-GUID: 2iX_lZBqbE45ffolzenlxozvVdwhKIQJ X-Proofpoint-Spam-Info: AW1haW4tMjYwNjExMDA0NSBTYWx0ZWRfXx6qJ+P04fdwW KW7sbZNoWH9tnAyKPgStKA33Md9hsqa5thV7YyDUjH87iLQxznNnHFvjB906D2x8otzGsjlIqVA zhsmMpLULBhAZYFXgA4LFGdhSrp77CE= X-Proofpoint-ORIG-GUID: 2iX_lZBqbE45ffolzenlxozvVdwhKIQJ X-Authority-Analysis: v=2.4 cv=Kux9H2WN c=1 sm=1 tr=0 ts=6a2a4043 cx=c_pps a=JL+w9abYAAE89/QcEU+0QA==:117 a=nuhDOHQX5FNHPW3J6Bj6AA==:17 a=IkcTkHD0fZMA:10 a=FelO9ux0wxsA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=rJkE3RaqiGZ5pbrm-msn:22 a=EUspDBNiAAAA:8 a=anFEHkTd4I48GMdGUucA:9 a=QEXdDO2ut3YA:10 a=324X-CrmTo6CU4MGRt3R:22 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNjExMDA0NSBTYWx0ZWRfX1HFTzz9h4JB3 PI3nTXTyHcLcb68t1XqJMGEqUTH8PBMhB9RftqRpprqQvbEQT0StJ4j4FFbXROv8Ulx5wR6R2LE hG4s2SZxAeG7rNbkhsLiUBy6rWR+jxgLhqzLPc5VL07ARF2DiNA45bUsERJWyMZbJIcsg0pBKju thEIljhOA9LBXb8YDD2cQBXnEuegMKnfqFt7wHP9BM+sX/bdzr0R66wHUFl32PbuZgZddYkboGe EoNpQLQDFVUViQQKr+6ep2BTcFJDbY0vUAkuaAW/kLDunvAYwoJGU+fAqjLFgYtZVVVJYF0NuqW mj5TRlTDkQrt6Xb6+rdmD5jC8EQZAEkROinRSYPiv9xi9T0VrycRvEqvbh1yS7SicAE++Qf4AZk I81Sugjdd3qttU0GvM2tQMPbMU039pjZUZ75Ap2D2pU3RoU8uqd7YenXqL3oOtsz/VvpEB7Bh6S y+ibAbY9XLVGZypTSJA== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.125,FMLib:17.12.100.49 definitions=2026-06-11_01,2026-06-09_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 malwarescore=0 phishscore=0 spamscore=0 bulkscore=0 clxscore=1015 suspectscore=0 lowpriorityscore=0 priorityscore=1501 impostorscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606040000 definitions=main-2606110045 On 5/7/2026 10:12 PM, Jie Gan wrote: > The byte-cntr function provided by the CTCU device is used to transfer data > from the ETR buffer to the userspace. An interrupt is triggered if the data > size exceeds the threshold set in the BYTECNTRVAL register. The interrupt > handler counts the number of triggered interruptions and the read function > will read the data from the synced ETR buffer. > > Switching the sysfs_buf when current buffer is full or the timeout is > triggered and resets rrp and rwp registers after switched the buffer. > The synced buffer will become available for reading after the switch. > > Byte-cntr workflow: > start -> ctcu_enable(ctcu_byte_cntr_start) -> tmc_enable_etr_sink -> > tmc_read_prepare_etr(jump to tmc_read_prepare_byte_cntr) -> > tmc_etr_get_sysfs_trace(jump to tmc_byte_cntr_get_data) -> > tmc_disable_etr_sink -> ctcu_disable(ctcu_byte_cntr_stop) -> > tmc_read_unprepare_etr(jump to tmc_read_unprepare_byte_cntr) -> finish > > Signed-off-by: Jie Gan > --- > .../ABI/testing/sysfs-bus-coresight-devices-ctcu | 9 + > drivers/hwtracing/coresight/Makefile | 2 +- > .../hwtracing/coresight/coresight-ctcu-byte-cntr.c | 304 +++++++++++++++++++++ > drivers/hwtracing/coresight/coresight-ctcu-core.c | 127 ++++++++- > drivers/hwtracing/coresight/coresight-ctcu.h | 79 +++++- > drivers/hwtracing/coresight/coresight-tmc-core.c | 3 +- > drivers/hwtracing/coresight/coresight-tmc-etr.c | 114 +++++++- > drivers/hwtracing/coresight/coresight-tmc.h | 9 + > 8 files changed, 622 insertions(+), 25 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-ctcu b/Documentation/ABI/testing/sysfs-bus-coresight-devices-ctcu > new file mode 100644 > index 000000000000..6e53a5197e53 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-ctcu > @@ -0,0 +1,9 @@ > +What: /sys/bus/coresight/devices//irq_enabled[0:1] > +Date: May 2026 > +KernelVersion: 7.2 > +Contact: Tingwei Zhang ; Jinlong Mao ; Jie Gan > +Description: > + (RW) Configure the flag to enable interrupt to count data during CTCU enablement. > + An interrupt is generated when the data size exceeds the value set in the IRQ register. > + 0 : disable > + 1 : enable > diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile > index ab16d06783a5..821a1b06b20c 100644 > --- a/drivers/hwtracing/coresight/Makefile > +++ b/drivers/hwtracing/coresight/Makefile > @@ -55,5 +55,5 @@ coresight-cti-y := coresight-cti-core.o coresight-cti-platform.o \ > obj-$(CONFIG_ULTRASOC_SMB) += ultrasoc-smb.o > obj-$(CONFIG_CORESIGHT_DUMMY) += coresight-dummy.o > obj-$(CONFIG_CORESIGHT_CTCU) += coresight-ctcu.o > -coresight-ctcu-y := coresight-ctcu-core.o > +coresight-ctcu-y := coresight-ctcu-core.o coresight-ctcu-byte-cntr.o > obj-$(CONFIG_CORESIGHT_KUNIT_TESTS) += coresight-kunit-tests.o > diff --git a/drivers/hwtracing/coresight/coresight-ctcu-byte-cntr.c b/drivers/hwtracing/coresight/coresight-ctcu-byte-cntr.c > new file mode 100644 > index 000000000000..268194f35fd3 > --- /dev/null > +++ b/drivers/hwtracing/coresight/coresight-ctcu-byte-cntr.c > @@ -0,0 +1,304 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "coresight-ctcu.h" > +#include "coresight-priv.h" > +#include "coresight-tmc.h" > + > +static irqreturn_t byte_cntr_handler(int irq, void *data) > +{ > + struct ctcu_byte_cntr *byte_cntr_data = data; > + > + atomic_inc(&byte_cntr_data->irq_cnt); > + wake_up(&byte_cntr_data->wq); > + > + return IRQ_HANDLED; > +} > + > +static void ctcu_cfg_byte_cntr_reg(struct ctcu_drvdata *drvdata, u32 val, > + u32 offset) > +{ > + /* A one value for IRQCTRL register represents 8 bytes */ > + ctcu_program_register(drvdata, val / 8, offset); > +} > + > +static struct ctcu_byte_cntr *ctcu_get_byte_cntr(struct coresight_device *ctcu, > + struct coresight_device *etr) > +{ > + struct ctcu_drvdata *drvdata = dev_get_drvdata(ctcu->dev.parent); > + int port; > + > + port = coresight_get_in_port(etr, ctcu); > + if (port < 0 || port > 1) > + return NULL; > + > + return &drvdata->byte_cntr_data[port]; > +} > + > +static bool ctcu_byte_cntr_switch_buffer(struct tmc_drvdata *etr_drvdata, > + struct ctcu_byte_cntr *byte_cntr_data) > +{ > + struct etr_buf_node *nd, *next, *curr_node = NULL, *picked_node = NULL; > + struct etr_buf *curr_buf = etr_drvdata->sysfs_buf; > + bool found_free_buf = false; > + > + if (WARN_ON(!etr_drvdata || !byte_cntr_data)) > + return false; > + > + /* Stop the ETR before initiating the switch */ > + if (coresight_get_mode(etr_drvdata->csdev) != CS_MODE_DISABLED) > + tmc_etr_enable_disable_hw(etr_drvdata, false); > + > + list_for_each_entry_safe(nd, next, &etr_drvdata->etr_buf_list, link) { > + /* curr_buf is free for next round */ > + if (nd->sysfs_buf == curr_buf) { > + nd->is_free = true; > + curr_node = nd; > + } else if (!found_free_buf && nd->is_free) { > + picked_node = nd; > + found_free_buf = true; > + } > + } > + > + if (found_free_buf) { > + curr_node->pos = 0; > + curr_node->reading = true; > + byte_cntr_data->buf_node = curr_node; > + etr_drvdata->sysfs_buf = picked_node->sysfs_buf; > + etr_drvdata->etr_buf = picked_node->sysfs_buf; > + picked_node->is_free = false; > + /* Reset irq_cnt for next etr_buf */ > + atomic_set(&byte_cntr_data->irq_cnt, 0); > + /* Restart the ETR once a free buffer is available */ > + if (coresight_get_mode(etr_drvdata->csdev) != CS_MODE_DISABLED) > + tmc_etr_enable_disable_hw(etr_drvdata, true); > + } > + > + return found_free_buf; > +} > + > +/* > + * ctcu_byte_cntr_get_data() - reads data from the deactivated and filled buffer. > + * The byte-cntr reading work reads data from the deactivated and filled buffer. > + * The read operation waits for a buffer to become available, either filled or > + * upon timeout, and then reads trace data from the synced buffer. > + */ > +static ssize_t tmc_byte_cntr_get_data(struct tmc_drvdata *etr_drvdata, loff_t pos, > + size_t len, char **bufpp) > +{ > + struct coresight_device *ctcu = tmc_etr_get_ctcu_device(etr_drvdata); > + struct device *dev = &etr_drvdata->csdev->dev; > + struct ctcu_byte_cntr *byte_cntr_data; > + struct etr_buf *sysfs_buf; > + atomic_t *irq_cnt; > + ssize_t actual; > + int ret; > + > + byte_cntr_data = ctcu_get_byte_cntr(ctcu, etr_drvdata->csdev); > + if (!byte_cntr_data || !byte_cntr_data->irq_enabled) > + return -EINVAL; > + > + irq_cnt = &byte_cntr_data->irq_cnt; > + > +wait_buffer: > + if (!byte_cntr_data->buf_node) { > + ret = wait_event_interruptible_timeout(byte_cntr_data->wq, > + (atomic_read(irq_cnt) >= MAX_IRQ_CNT - 1) || > + !byte_cntr_data->enable, > + BYTE_CNTR_TIMEOUT); > + if (ret < 0) > + return ret; > + /* > + * The current etr_buf is almost full or timeout is triggered, > + * so switch the buffer and mark the switched buffer as reading. > + */ > + if (byte_cntr_data->enable) { > + if (!ctcu_byte_cntr_switch_buffer(etr_drvdata, byte_cntr_data)) { > + dev_err(dev, "Switch buffer failed for the byte-cntr\n"); > + return -ENOMEM; > + } > + } else { > + /* Exit byte-cntr reading */ > + return 0; > + } > + } > + > + /* Check the status of current etr_buf */ > + if (atomic_read(irq_cnt) >= MAX_IRQ_CNT) > + dev_warn(dev, "Data overwrite happened\n"); > + > + pos = byte_cntr_data->buf_node->pos; > + sysfs_buf = byte_cntr_data->buf_node->sysfs_buf; > + actual = tmc_etr_read_sysfs_buf(sysfs_buf, pos, len, bufpp); > + if (actual <= 0) { > + /* Reset buf_node upon reading is finished or failed */ > + byte_cntr_data->buf_node->reading = false; > + byte_cntr_data->buf_node = NULL; > + > + /* > + * Nothing in the buffer, waiting for the next buffer > + * to be filled. > + */ > + if (actual == 0) > + goto wait_buffer; > + } > + > + return actual; > +} > + > +static int tmc_read_prepare_byte_cntr(struct tmc_drvdata *etr_drvdata) > +{ > + struct coresight_device *ctcu = tmc_etr_get_ctcu_device(etr_drvdata); > + struct ctcu_byte_cntr *byte_cntr_data; > + unsigned long flags; > + int ret = 0; > + > + /* byte-cntr is operating with SYSFS mode being enabled only */ > + if (coresight_get_mode(etr_drvdata->csdev) != CS_MODE_SYSFS) > + return -EINVAL; > + > + byte_cntr_data = ctcu_get_byte_cntr(ctcu, etr_drvdata->csdev); > + if (!byte_cntr_data || !byte_cntr_data->irq_enabled) > + return -EINVAL; > + > + raw_spin_lock_irqsave(&byte_cntr_data->spin_lock, flags); > + if (byte_cntr_data->reading) { > + raw_spin_unlock_irqrestore(&byte_cntr_data->spin_lock, flags); > + return -EBUSY; > + } > + > + /* byte_cntr_data->enable may race with ctcu_platform_remove() */ > + if (!byte_cntr_data->enable) { > + raw_spin_unlock_irqrestore(&byte_cntr_data->spin_lock, flags); > + return -ENODEV; > + } > + > + byte_cntr_data->reading = true; > + raw_spin_unlock_irqrestore(&byte_cntr_data->spin_lock, flags); > + /* Setup an available etr_buf_list for byte-cntr */ > + ret = tmc_create_etr_buf_list(etr_drvdata, 2); > + if (ret) { > + byte_cntr_data->reading = false; > + return ret; > + } > + > + guard(raw_spinlock_irqsave)(&byte_cntr_data->spin_lock); > + atomic_set(&byte_cntr_data->irq_cnt, 0); > + /* > + * Configure the byte-cntr register to enable IRQ. The configured > + * size is 5% of the buffer_size. > + */ > + ctcu_cfg_byte_cntr_reg(byte_cntr_data->ctcu_drvdata, > + etr_drvdata->size / MAX_IRQ_CNT, > + byte_cntr_data->irq_ctrl_offset); > + enable_irq_wake(byte_cntr_data->irq); > + byte_cntr_data->buf_node = NULL; > + > + return 0; > +} > + > +static int tmc_read_unprepare_byte_cntr(struct tmc_drvdata *etr_drvdata) > +{ > + struct coresight_device *ctcu = tmc_etr_get_ctcu_device(etr_drvdata); > + struct ctcu_byte_cntr *byte_cntr_data; > + > + byte_cntr_data = ctcu_get_byte_cntr(ctcu, etr_drvdata->csdev); > + if (!byte_cntr_data || !byte_cntr_data->irq_enabled) Found an issue here. Need add one more condition to address the issue: if (!byte_cntr_data || !byte_cntr_data->irq_enabled || !byte_cntr_data->reading) In tmc_read_prepare_etr(), when byte_cntr_sysfs_ops is set but tmc_read_prepare_byte_cntr() returns an error, the code falls through to the normal prepare path and sets drvdata->reading = true. In the paired tmc_read_unprepare_etr(), if byte_cntr_ops is still set and tmc_read_unprepare_byte_cntr() returns 0 (because irq_enabled=true, even though byte_cntr_data->reading was never set), the function returns early without clearing drvdata->reading. Thanks, Jie > + return -EINVAL; > + > + tmc_clean_etr_buf_list(etr_drvdata); > + scoped_guard(raw_spinlock_irqsave, &byte_cntr_data->spin_lock) { > + /* Configure the byte-cntr register to disable IRQ */ > + ctcu_cfg_byte_cntr_reg(byte_cntr_data->ctcu_drvdata, 0, > + byte_cntr_data->irq_ctrl_offset); > + disable_irq_wake(byte_cntr_data->irq); > + byte_cntr_data->buf_node = NULL; > + byte_cntr_data->reading = false; > + } > + wake_up(&byte_cntr_data->wq); > + > + return 0; > +} > + > +const struct tmc_sysfs_ops byte_cntr_sysfs_ops = { > + .read_prepare = tmc_read_prepare_byte_cntr, > + .read_unprepare = tmc_read_unprepare_byte_cntr, > + .get_trace_data = tmc_byte_cntr_get_data, > +}; > + > +/* Start the byte-cntr function when the path is enabled. */ > +void ctcu_byte_cntr_start(struct coresight_device *csdev, struct coresight_path *path) > +{ > + struct coresight_device *sink = coresight_get_sink(path); > + struct ctcu_byte_cntr *byte_cntr_data; > + > + byte_cntr_data = ctcu_get_byte_cntr(csdev, sink); > + if (!byte_cntr_data) > + return; > + > + /* Don't start byte-cntr function when irq_enabled is not set. */ > + if (!byte_cntr_data->irq_enabled || byte_cntr_data->enable) > + return; > + > + guard(raw_spinlock_irqsave)(&byte_cntr_data->spin_lock); > + byte_cntr_data->enable = true; > +} > + > +/* Stop the byte-cntr function when the path is disabled. */ > +void ctcu_byte_cntr_stop(struct coresight_device *csdev, struct coresight_path *path) > +{ > + struct coresight_device *sink = coresight_get_sink(path); > + struct ctcu_byte_cntr *byte_cntr_data; > + > + if (coresight_get_mode(sink) == CS_MODE_SYSFS) > + return; > + > + byte_cntr_data = ctcu_get_byte_cntr(csdev, sink); > + if (!byte_cntr_data) > + return; > + > + guard(raw_spinlock_irqsave)(&byte_cntr_data->spin_lock); > + byte_cntr_data->enable = false; > +} > + > +void ctcu_byte_cntr_init(struct device *dev, struct ctcu_drvdata *drvdata, int etr_num) > +{ > + struct ctcu_byte_cntr *byte_cntr_data; > + struct device_node *nd = dev->of_node; > + int irq_num, ret, i, irq_registered = 0; > + > + for (i = 0; i < etr_num; i++) { > + byte_cntr_data = &drvdata->byte_cntr_data[i]; > + irq_num = of_irq_get(nd, i); > + if (irq_num < 0) { > + dev_err(dev, "Failed to get IRQ from DT for port%d\n", i); > + continue; > + } > + > + ret = devm_request_irq(dev, irq_num, byte_cntr_handler, > + IRQF_TRIGGER_RISING | IRQF_SHARED, > + dev_name(dev), byte_cntr_data); > + if (ret) { > + dev_err(dev, "Failed to register IRQ for port%d\n", i); > + continue; > + } > + > + byte_cntr_data->irq = irq_num; > + byte_cntr_data->ctcu_drvdata = drvdata; > + init_waitqueue_head(&byte_cntr_data->wq); > + raw_spin_lock_init(&byte_cntr_data->spin_lock); > + irq_registered++; > + } > + > + if (irq_registered) > + tmc_etr_set_byte_cntr_sysfs_ops(&byte_cntr_sysfs_ops); > +} > diff --git a/drivers/hwtracing/coresight/coresight-ctcu-core.c b/drivers/hwtracing/coresight/coresight-ctcu-core.c > index e8720026c9e3..2da1a6f3d29f 100644 > --- a/drivers/hwtracing/coresight/coresight-ctcu-core.c > +++ b/drivers/hwtracing/coresight/coresight-ctcu-core.c > @@ -1,6 +1,7 @@ > // SPDX-License-Identifier: GPL-2.0-only > /* > - * Copyright (c) 2024-2025 Qualcomm Innovation Center, Inc. All rights reserved. > + * Copyright (c) 2024-2026 Qualcomm Innovation Center, Inc. All rights reserved. > + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. > */ > > #include > @@ -18,6 +19,7 @@ > > #include "coresight-ctcu.h" > #include "coresight-priv.h" > +#include "coresight-tmc.h" > > #define ctcu_writel(drvdata, val, offset) __raw_writel((val), drvdata->base + offset) > #define ctcu_readl(drvdata, offset) __raw_readl(drvdata->base + offset) > @@ -43,17 +45,21 @@ > > #define CTCU_ATID_REG_BIT(traceid) (traceid % 32) > #define CTCU_ATID_REG_SIZE 0x10 > +#define CTCU_ETR0_IRQCTRL 0x6c > +#define CTCU_ETR1_IRQCTRL 0x70 > #define CTCU_ETR0_ATID0 0xf8 > #define CTCU_ETR1_ATID0 0x108 > > static const struct ctcu_etr_config sa8775p_etr_cfgs[] = { > { > - .atid_offset = CTCU_ETR0_ATID0, > - .port_num = 0, > + .atid_offset = CTCU_ETR0_ATID0, > + .irq_ctrl_offset = CTCU_ETR0_IRQCTRL, > + .port_num = 0, > }, > { > - .atid_offset = CTCU_ETR1_ATID0, > - .port_num = 1, > + .atid_offset = CTCU_ETR1_ATID0, > + .irq_ctrl_offset = CTCU_ETR1_IRQCTRL, > + .port_num = 1, > }, > }; > > @@ -62,6 +68,85 @@ static const struct ctcu_config sa8775p_cfgs = { > .num_etr_config = ARRAY_SIZE(sa8775p_etr_cfgs), > }; > > +void ctcu_program_register(struct ctcu_drvdata *drvdata, u32 val, u32 offset) > +{ > + CS_UNLOCK(drvdata->base); > + ctcu_writel(drvdata, val, offset); > + CS_LOCK(drvdata->base); > +} > + > +static ssize_t irq_enabled_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + struct ctcu_byte_cntr_irq_attribute *irq_attr = > + container_of(attr, struct ctcu_byte_cntr_irq_attribute, attr); > + struct ctcu_drvdata *drvdata = dev_get_drvdata(dev->parent); > + u8 port = irq_attr->port; > + > + if (!drvdata->byte_cntr_data[port].irq_ctrl_offset) > + return -EINVAL; > + > + return sysfs_emit(buf, "%u\n", > + (unsigned int)drvdata->byte_cntr_data[port].irq_enabled); > +} > + > +static ssize_t irq_enabled_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, > + size_t size) > +{ > + struct ctcu_byte_cntr_irq_attribute *irq_attr = > + container_of(attr, struct ctcu_byte_cntr_irq_attribute, attr); > + struct ctcu_drvdata *drvdata = dev_get_drvdata(dev->parent); > + u8 port = irq_attr->port; > + unsigned long val; > + > + if (kstrtoul(buf, 0, &val)) > + return -EINVAL; > + > + guard(raw_spinlock_irqsave)(&drvdata->byte_cntr_data[port].spin_lock); > + if (drvdata->byte_cntr_data[port].reading) > + return -EBUSY; > + else if (drvdata->byte_cntr_data[port].irq_ctrl_offset) > + drvdata->byte_cntr_data[port].irq_enabled = !!val; > + > + return size; > +} > + > +static umode_t irq_enabled_is_visible(struct kobject *kobj, > + struct attribute *attr, int n) > +{ > + struct device_attribute *dev_attr = > + container_of(attr, struct device_attribute, attr); > + struct ctcu_byte_cntr_irq_attribute *irq_attr = > + container_of(dev_attr, struct ctcu_byte_cntr_irq_attribute, attr); > + struct device *dev = kobj_to_dev(kobj); > + struct ctcu_drvdata *drvdata = dev_get_drvdata(dev->parent); > + u8 port = irq_attr->port; > + > + if (drvdata && drvdata->byte_cntr_data[port].irq_ctrl_offset) > + return attr->mode; > + > + return 0; > +} > + > +static struct attribute *ctcu_attrs[] = { > + ctcu_byte_cntr_irq_rw(0), > + ctcu_byte_cntr_irq_rw(1), > + NULL, > +}; > + > +static struct attribute_group ctcu_attr_grp = { > + .attrs = ctcu_attrs, > + .is_visible = irq_enabled_is_visible, > +}; > + > +static const struct attribute_group *ctcu_attr_grps[] = { > + &ctcu_attr_grp, > + NULL, > +}; > + > static void ctcu_program_atid_register(struct ctcu_drvdata *drvdata, u32 reg_offset, > u8 bit, bool enable) > { > @@ -140,11 +225,15 @@ static int ctcu_set_etr_traceid(struct coresight_device *csdev, struct coresight > static int ctcu_enable(struct coresight_device *csdev, enum cs_mode mode, > struct coresight_path *path) > { > + ctcu_byte_cntr_start(csdev, path); > + > return ctcu_set_etr_traceid(csdev, path, true); > } > > static int ctcu_disable(struct coresight_device *csdev, struct coresight_path *path) > { > + ctcu_byte_cntr_stop(csdev, path); > + > return ctcu_set_etr_traceid(csdev, path, false); > } > > @@ -195,7 +284,10 @@ static int ctcu_probe(struct platform_device *pdev) > for (i = 0; i < cfgs->num_etr_config; i++) { > etr_cfg = &cfgs->etr_cfgs[i]; > drvdata->atid_offset[i] = etr_cfg->atid_offset; > + drvdata->byte_cntr_data[i].irq_ctrl_offset = > + etr_cfg->irq_ctrl_offset; > } > + ctcu_byte_cntr_init(dev, drvdata, cfgs->num_etr_config); > } > } > > @@ -209,6 +301,7 @@ static int ctcu_probe(struct platform_device *pdev) > desc.dev = dev; > desc.ops = &ctcu_ops; > desc.access = CSDEV_ACCESS_IOMEM(base); > + desc.groups = ctcu_attr_grps; > raw_spin_lock_init(&drvdata->spin_lock); > > drvdata->csdev = coresight_register(&desc); > @@ -244,10 +337,34 @@ static int ctcu_platform_probe(struct platform_device *pdev) > static void ctcu_platform_remove(struct platform_device *pdev) > { > struct ctcu_drvdata *drvdata = platform_get_drvdata(pdev); > + struct ctcu_byte_cntr *byte_cntr_data; > + unsigned long flags; > + int i; > > if (WARN_ON(!drvdata)) > return; > > + /* > + * Signal all active byte-cntr readers to exit, then wait for them to > + * finish before resetting the ops pointer and freeing driver data. > + * Without this, a reader blocked in wait_event_interruptible_timeout() > + * would access the freed ctcu_drvdata wait-queue head (use-after-free). > + */ > + for (i = 0; i < ETR_MAX_NUM; i++) { > + byte_cntr_data = &drvdata->byte_cntr_data[i]; > + raw_spin_lock_irqsave(&byte_cntr_data->spin_lock, flags); > + /* Set enable=false for all ports to signal teardown to racing readers */ > + byte_cntr_data->enable = false; > + if (!byte_cntr_data->reading) { > + raw_spin_unlock_irqrestore(&byte_cntr_data->spin_lock, flags); > + continue; > + } > + raw_spin_unlock_irqrestore(&byte_cntr_data->spin_lock, flags); > + wake_up_all(&byte_cntr_data->wq); > + wait_event(byte_cntr_data->wq, !byte_cntr_data->reading); > + } > + > + tmc_etr_reset_byte_cntr_sysfs_ops(); > ctcu_remove(pdev); > pm_runtime_disable(&pdev->dev); > } > diff --git a/drivers/hwtracing/coresight/coresight-ctcu.h b/drivers/hwtracing/coresight/coresight-ctcu.h > index e9594c38dd91..a2ae0a0d91d0 100644 > --- a/drivers/hwtracing/coresight/coresight-ctcu.h > +++ b/drivers/hwtracing/coresight/coresight-ctcu.h > @@ -1,23 +1,31 @@ > /* SPDX-License-Identifier: GPL-2.0-only */ > /* > - * Copyright (c) 2024-2025 Qualcomm Innovation Center, Inc. All rights reserved. > + * Copyright (c) 2024-2026 Qualcomm Innovation Center, Inc. All rights reserved. > + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. > */ > > #ifndef _CORESIGHT_CTCU_H > #define _CORESIGHT_CTCU_H > + > +#include > #include "coresight-trace-id.h" > > /* Maximum number of supported ETR devices for a single CTCU. */ > #define ETR_MAX_NUM 2 > > +#define BYTE_CNTR_TIMEOUT (3 * HZ) > +#define MAX_IRQ_CNT 20 > + > /** > * struct ctcu_etr_config > * @atid_offset: offset to the ATID0 Register. > - * @port_num: in-port number of CTCU device that connected to ETR. > + * @port_num: in-port number of the CTCU device that connected to ETR. > + * @irq_ctrl_offset: offset to the BYTECNTRVAL register. > */ > struct ctcu_etr_config { > const u32 atid_offset; > const u32 port_num; > + const u32 irq_ctrl_offset; > }; > > struct ctcu_config { > @@ -25,15 +33,68 @@ struct ctcu_config { > int num_etr_config; > }; > > -struct ctcu_drvdata { > - void __iomem *base; > - struct clk *apb_clk; > - struct device *dev; > - struct coresight_device *csdev; > +/** > + * struct ctcu_byte_cntr > + * @enable: indicates that byte_cntr function is enabled or not. > + * @irq_enabled: indicates that the interruption is enabled. > + * @reading: indicates that byte_cntr is reading. > + * @irq: allocated number of the IRQ. > + * @irq_cnt: IRQ count number of the triggered interruptions. > + * @wq: waitqueue for reading data from ETR buffer. > + * @spin_lock: spinlock of the byte_cntr_data. > + * @irq_ctrl_offset: offset to the BYTECNTVAL Register. > + * @ctcu_drvdata: drvdata of the CTCU device. > + * @buf_node: etr_buf_node for reading. > + */ > +struct ctcu_byte_cntr { > + bool enable; > + bool irq_enabled; > + bool reading; > + int irq; > + atomic_t irq_cnt; > + wait_queue_head_t wq; > raw_spinlock_t spin_lock; > - u32 atid_offset[ETR_MAX_NUM]; > + u32 irq_ctrl_offset; > + struct ctcu_drvdata *ctcu_drvdata; > + struct etr_buf_node *buf_node; > +}; > + > +struct ctcu_drvdata { > + void __iomem *base; > + struct clk *apb_clk; > + struct device *dev; > + struct coresight_device *csdev; > + struct ctcu_byte_cntr byte_cntr_data[ETR_MAX_NUM]; > + raw_spinlock_t spin_lock; > + u32 atid_offset[ETR_MAX_NUM]; > /* refcnt for each traceid of each sink */ > - u8 traceid_refcnt[ETR_MAX_NUM][CORESIGHT_TRACE_ID_RES_TOP]; > + u8 traceid_refcnt[ETR_MAX_NUM][CORESIGHT_TRACE_ID_RES_TOP]; > }; > > +/** > + * struct ctcu_byte_cntr_irq_attribute > + * @attr: The device attribute. > + * @port: port number. > + */ > +struct ctcu_byte_cntr_irq_attribute { > + struct device_attribute attr; > + u8 port; > +}; > + > +#define ctcu_byte_cntr_irq_rw(port) \ > + (&((struct ctcu_byte_cntr_irq_attribute[]) { \ > + { \ > + __ATTR(irq_enabled##port, 0644, irq_enabled_show, \ > + irq_enabled_store), \ > + port, \ > + } \ > + })[0].attr.attr) > + > +void ctcu_program_register(struct ctcu_drvdata *drvdata, u32 val, u32 offset); > + > +/* Byte-cntr functions */ > +void ctcu_byte_cntr_start(struct coresight_device *csdev, struct coresight_path *path); > +void ctcu_byte_cntr_stop(struct coresight_device *csdev, struct coresight_path *path); > +void ctcu_byte_cntr_init(struct device *dev, struct ctcu_drvdata *drvdata, int port_num); > + > #endif > diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c > index 110eedde077f..9f4fd86e8c32 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-core.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c > @@ -293,7 +293,8 @@ static ssize_t tmc_read(struct file *file, char __user *data, size_t len, > return -EFAULT; > } > > - *ppos += actual; > + if (!tmc_etr_update_buf_node_pos(drvdata, actual)) > + *ppos += actual; > dev_dbg(&drvdata->csdev->dev, "%zu bytes copied\n", actual); > > return actual; > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c > index b0c5f3559085..54ca9616fa66 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c > @@ -1168,6 +1168,8 @@ static int tmc_etr_enable_hw(struct tmc_drvdata *drvdata, > return rc; > } > > +static const struct tmc_sysfs_ops *byte_cntr_sysfs_ops; > + > /* > * Return the available trace data in the buffer (starts at etr_buf->offset, > * limited by etr_buf->len) from @pos, with a maximum limit of @len, > @@ -1178,23 +1180,39 @@ static int tmc_etr_enable_hw(struct tmc_drvdata *drvdata, > * We are protected here by drvdata->reading != 0, which ensures the > * sysfs_buf stays alive. > */ > -ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata, > - loff_t pos, size_t len, char **bufpp) > +ssize_t tmc_etr_read_sysfs_buf(struct etr_buf *sysfs_buf, loff_t pos, > + size_t len, char **bufpp) > { > s64 offset; > ssize_t actual = len; > - struct etr_buf *etr_buf = drvdata->sysfs_buf; > > - if (pos + actual > etr_buf->len) > - actual = etr_buf->len - pos; > + if (pos + actual > sysfs_buf->len) > + actual = sysfs_buf->len - pos; > if (actual <= 0) > return actual; > > /* Compute the offset from which we read the data */ > - offset = etr_buf->offset + pos; > - if (offset >= etr_buf->size) > - offset -= etr_buf->size; > - return tmc_etr_buf_get_data(etr_buf, offset, actual, bufpp); > + offset = sysfs_buf->offset + pos; > + if (offset >= sysfs_buf->size) > + offset -= sysfs_buf->size; > + return tmc_etr_buf_get_data(sysfs_buf, offset, actual, bufpp); > +} > +EXPORT_SYMBOL_GPL(tmc_etr_read_sysfs_buf); > + > +ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata, > + loff_t pos, size_t len, char **bufpp) > +{ > + ssize_t ret; > + const struct tmc_sysfs_ops *byte_cntr_ops = READ_ONCE(byte_cntr_sysfs_ops); > + > + if (byte_cntr_ops) { > + ret = byte_cntr_ops->get_trace_data(drvdata, pos, len, bufpp); > + /* Return the filled buffer */ > + if (ret > 0 || ret == -ENOMEM) > + return ret; > + } > + > + return tmc_etr_read_sysfs_buf(drvdata->sysfs_buf, pos, len, bufpp); > } > > static struct etr_buf * > @@ -1248,6 +1266,39 @@ static void __tmc_etr_disable_hw(struct tmc_drvdata *drvdata) > > } > > +static void tmc_etr_reset_sysfs_buf(struct tmc_drvdata *drvdata) > +{ > + u32 sts; > + > + CS_UNLOCK(drvdata->base); > + tmc_write_rrp(drvdata, drvdata->sysfs_buf->hwaddr); > + tmc_write_rwp(drvdata, drvdata->sysfs_buf->hwaddr); > + sts = readl_relaxed(drvdata->base + TMC_STS) & ~TMC_STS_FULL; > + writel_relaxed(sts, drvdata->base + TMC_STS); > + CS_LOCK(drvdata->base); > +} > + > +/** > + * tmc_etr_enable_disable_hw - enable/disable the ETR hw. > + * @drvdata: drvdata of the TMC device. > + * @enable: indicates enable/disable. > + */ > +void tmc_etr_enable_disable_hw(struct tmc_drvdata *drvdata, bool enable) > +{ > + unsigned long flags; > + > + raw_spin_lock_irqsave(&drvdata->spinlock, flags); > + if (enable) { > + tmc_etr_reset_sysfs_buf(drvdata); > + __tmc_etr_enable_hw(drvdata); > + } else { > + __tmc_etr_disable_hw(drvdata); > + } > + > + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); > +} > +EXPORT_SYMBOL_GPL(tmc_etr_enable_disable_hw); > + > void tmc_etr_disable_hw(struct tmc_drvdata *drvdata) > { > __tmc_etr_disable_hw(drvdata); > @@ -2047,15 +2098,54 @@ int tmc_create_etr_buf_list(struct tmc_drvdata *drvdata, int num_nodes) > } > EXPORT_SYMBOL_GPL(tmc_create_etr_buf_list); > > +void tmc_etr_set_byte_cntr_sysfs_ops(const struct tmc_sysfs_ops *sysfs_ops) > +{ > + WRITE_ONCE(byte_cntr_sysfs_ops, sysfs_ops); > +} > +EXPORT_SYMBOL_GPL(tmc_etr_set_byte_cntr_sysfs_ops); > + > +void tmc_etr_reset_byte_cntr_sysfs_ops(void) > +{ > + WRITE_ONCE(byte_cntr_sysfs_ops, NULL); > +} > +EXPORT_SYMBOL_GPL(tmc_etr_reset_byte_cntr_sysfs_ops); > + > +bool tmc_etr_update_buf_node_pos(struct tmc_drvdata *drvdata, ssize_t size) > +{ > + struct etr_buf_node *nd, *next; > + > + if (drvdata->config_type != TMC_CONFIG_TYPE_ETR) > + return false; > + > + list_for_each_entry_safe(nd, next, &drvdata->etr_buf_list, link) { > + if (nd && nd->reading) { > + nd->pos += size; > + return true; > + } > + } > + > + return false; > +} > + > int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) > { > int ret = 0; > unsigned long flags; > + const struct tmc_sysfs_ops *byte_cntr_ops; > > /* config types are set a boot time and never change */ > if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR)) > return -EINVAL; > > + byte_cntr_ops = READ_ONCE(byte_cntr_sysfs_ops); > + if (byte_cntr_ops) { > + ret = byte_cntr_ops->read_prepare(drvdata); > + if (!ret || ret == -EBUSY) > + return ret; > + > + ret = 0; > + } > + > raw_spin_lock_irqsave(&drvdata->spinlock, flags); > if (drvdata->reading) { > ret = -EBUSY; > @@ -2087,11 +2177,17 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata) > { > unsigned long flags; > struct etr_buf *sysfs_buf = NULL; > + const struct tmc_sysfs_ops *byte_cntr_ops; > > /* config types are set a boot time and never change */ > if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETR)) > return -EINVAL; > > + byte_cntr_ops = READ_ONCE(byte_cntr_sysfs_ops); > + if (byte_cntr_ops) > + if (!byte_cntr_ops->read_unprepare(drvdata)) > + return 0; > + > raw_spin_lock_irqsave(&drvdata->spinlock, flags); > > /* RE-enable the TMC if need be */ > diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h > index fbb015079872..a15e2f93f16a 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc.h > +++ b/drivers/hwtracing/coresight/coresight-tmc.h > @@ -211,12 +211,15 @@ struct tmc_resrv_buf { > /** > * @sysfs_buf: Allocated sysfs_buf. > * @is_free: Indicates whether the buffer is free to choose. > + * @reading: Indicates byte_cntr is reading the buffer attached to > + * the node. > * @pos: Offset to the start of the buffer. > * @link: list_head of the node. > */ > struct etr_buf_node { > struct etr_buf *sysfs_buf; > bool is_free; > + bool reading; > loff_t pos; > struct list_head link; > }; > @@ -480,5 +483,11 @@ struct etr_buf *tmc_etr_get_buffer(struct coresight_device *csdev, > extern const struct attribute_group coresight_etr_group; > void tmc_clean_etr_buf_list(struct tmc_drvdata *drvdata); > int tmc_create_etr_buf_list(struct tmc_drvdata *drvdata, int num_nodes); > +void tmc_etr_set_byte_cntr_sysfs_ops(const struct tmc_sysfs_ops *sysfs_ops); > +void tmc_etr_reset_byte_cntr_sysfs_ops(void); > +void tmc_etr_enable_disable_hw(struct tmc_drvdata *drvdata, bool enable); > +bool tmc_etr_update_buf_node_pos(struct tmc_drvdata *drvdata, ssize_t size); > +ssize_t tmc_etr_read_sysfs_buf(struct etr_buf *sysfs_buf, loff_t pos, > + size_t len, char **bufpp); > > #endif >