From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 915B03112D3 for ; Fri, 12 Sep 2025 14:25:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757687133; cv=none; b=Rv5CvBC/KpzlsVhe+83jyveaFDfoD9LWd6Xz8DDn8ps/Ww/PDB76Ne2x1qynOCzWZp2VZJxq0zx/GvlxwafOIw8KnAfKk52E6dMoiVA65xCgVrI88vOQF/98WWyRQNvB9lVr10l3UlVtuvdP3qszcPEqxUAa0P3Kyl7r/ZMliK4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757687133; c=relaxed/simple; bh=8Sei8j+dgGy0eB4klRTxUxVywzuM4/POcKi7ZOuMGRU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GnSPyFJxzHKKWkoJFnVfyqc9MMXBA8LDDfmJB/v4y5006ED3acolXU82KdeBWoPshDRRfuqnbd+Xcun3VhyGORwdLkMcEEGKhc0LIUei6yLwP0Xre7NsEvJQFbnZrWoC00cAT5Dk7Orvr46Iv3PcWuvWqh9bWBMy9vSKl1DoKXI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CD4BB16A3; Fri, 12 Sep 2025 07:25:14 -0700 (PDT) Received: from [10.57.66.149] (unknown [10.57.66.149]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C97EE3F66E; Fri, 12 Sep 2025 07:25:19 -0700 (PDT) Message-ID: Date: Fri, 12 Sep 2025 16:24:57 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 5/7] drm/panthor: Implement the counter sampler and sample handling To: Lukas Zapolskas , dri-devel@lists.freedesktop.org Cc: nd@arm.com, =?UTF-8?Q?Adri=C3=A1n_Larumbe?= , Boris Brezillon , Steven Price , Liviu Dudau , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , linux-kernel@vger.kernel.org References: Content-Language: en-US From: Ketil Johnsen In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 25/07/2025 16:57, Lukas Zapolskas wrote: > From: Adrián Larumbe > > The sampler aggregates counter and set requests coming from userspace > and mediates interactions with the FW interface, to ensure that user > sessions cannot override the global configuration. > > From the top-level interface, the sampler supports two different types > of samples: clearing samples and regular samples. Clearing samples are > a special sample type that allow for the creation of a sampling > baseline, to ensure that a session does not obtain counter data from > before its creation. > > Upon receipt of a relevant interrupt, corresponding to one of the > three relevant bits of the GLB_ACK register, the sampler takes any > samples that occurred, and, based on the insert and extract indices, > accumulates them to an internal storage buffer after zero-extending > the counters from the 32-bit counters emitted by the hardware to > 64-bit counters for internal accumulation. > > When the performance counters are enabled, the FW ensures no counter > data is lost when entering and leaving non-counting regions by > producing automatic samples that do not correspond to a > GLB_REQ.PRFCNT_SAMPLE request. Such regions may be per hardware unit, > such as when a shader core powers down, or global. Most of these > events do not directly correspond to session sample requests, so any > intermediary counter data must be stored into a temporary > accumulation buffer. > > If there are sessions waiting for a sample, this accumulated buffer > will be taken, and emitted for each waiting client. During this phase, > information like the timestamps of sample request and sample emission, > type of the counter block and block index annotations are added to the > sample header and block headers. If no sessions are waiting for > a sample, this accumulation buffer is kept until the next time a > sample is requested. > > Special handling is needed for the PRFCNT_OVERFLOW interrupt, which is > an indication that the internal sample handling rate was insufficient. > > The sampler also maintains a buffer descriptor indicating the > structure of a firmware sample, since neither the firmware nor the > hardware give any indication of the sample structure, only that it > is composed out of three parts: > - the metadata is an optional initial counter block on supporting > firmware versions that contains a single counter, indicating the > reason a sample was taken when entering global non-counting regions. > This is used to provide coarse-grained information about why a > sample was taken to userspace, to help userspace interpret > variations in counter magnitude (the handling for this will be > implemented in another patch series). > - the firmware component of the sample is composed out of a global > firmware counter block on supporting firmware versions. > - the hardware component is the most sizeable of the three and > contains a block of counters for each of the underlying hardware > resources. It has a fixed structure that is described in the > architecture specification, and contains the command stream > hardware block(s), the tiler block(s), the MMU and L2 blocks > (collectively named the memsys blocks) and the shader core blocks, > in that order. > The structure of this buffer changes based on the firmware and > hardware combination, but is constant on a single system. > > This buffer descriptor also handles the sparseness of the shader cores, > wherein the physical core mask contains holes, but the memory allocated > for it is done based on the position of the most significant bit. In > cases with highly sparse core masks, this means that a lot of shader > counter blocks are empty, and must be skipped. > > The number of ring buffer slots is configurable through module param > to allow for a lower memory footprint on memory constrained systems. > > Signed-off-by: Adrián Larumbe > Co-developed-by: Lukas Zapolskas > Signed-off-by: Lukas Zapolskas > --- > drivers/gpu/drm/panthor/panthor_fw.c | 6 + > drivers/gpu/drm/panthor/panthor_fw.h | 6 +- > drivers/gpu/drm/panthor/panthor_perf.c | 1061 +++++++++++++++++++++++- > drivers/gpu/drm/panthor/panthor_perf.h | 2 + > 4 files changed, 1068 insertions(+), 7 deletions(-) > > diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c > index 36f1034839c2..c3e1e5ed4f9c 100644 > --- a/drivers/gpu/drm/panthor/panthor_fw.c > +++ b/drivers/gpu/drm/panthor/panthor_fw.c > @@ -22,6 +22,7 @@ > #include "panthor_gem.h" > #include "panthor_gpu.h" > #include "panthor_mmu.h" > +#include "panthor_perf.h" > #include "panthor_regs.h" > #include "panthor_sched.h" > > @@ -989,9 +990,12 @@ static void panthor_fw_init_global_iface(struct panthor_device *ptdev) > > /* Enable interrupts we care about. */ > glb_iface->input->ack_irq_mask = GLB_CFG_ALLOC_EN | > + GLB_PERFCNT_SAMPLE | > GLB_PING | > GLB_CFG_PROGRESS_TIMER | > GLB_CFG_POWEROFF_TIMER | > + GLB_PERFCNT_THRESHOLD | > + GLB_PERFCNT_OVERFLOW | > GLB_IDLE_EN | > GLB_IDLE; > > @@ -1022,6 +1026,8 @@ static void panthor_job_irq_handler(struct panthor_device *ptdev, u32 status) > return; > > panthor_sched_report_fw_events(ptdev, status); > + > + panthor_perf_report_irq(ptdev, status); > } > PANTHOR_IRQ_HANDLER(job, JOB, panthor_job_irq_handler); > > diff --git a/drivers/gpu/drm/panthor/panthor_fw.h b/drivers/gpu/drm/panthor/panthor_fw.h > index 8bcb933fa790..5a561e72e88b 100644 > --- a/drivers/gpu/drm/panthor/panthor_fw.h > +++ b/drivers/gpu/drm/panthor/panthor_fw.h > @@ -198,6 +198,7 @@ struct panthor_fw_global_control_iface { > u32 group_num; > u32 group_stride; > #define GLB_PERFCNT_FW_SIZE(x) ((((x) >> 16) << 8)) > +#define GLB_PERFCNT_HW_SIZE(x) (((x) & GENMASK(15, 0)) << 8) > u32 perfcnt_size; > u32 instr_features; > #define PERFCNT_FEATURES_MD_SIZE(x) (((x) & GENMASK(3, 0)) << 8) > @@ -210,7 +211,7 @@ struct panthor_fw_global_input_iface { > #define GLB_CFG_ALLOC_EN BIT(2) > #define GLB_CFG_POWEROFF_TIMER BIT(3) > #define GLB_PROTM_ENTER BIT(4) > -#define GLB_PERFCNT_EN BIT(5) > +#define GLB_PERFCNT_ENABLE BIT(5) > #define GLB_PERFCNT_SAMPLE BIT(6) > #define GLB_COUNTER_EN BIT(7) > #define GLB_PING BIT(8) > @@ -243,6 +244,9 @@ struct panthor_fw_global_input_iface { > u64 perfcnt_base; > u32 perfcnt_extract; > u32 reserved3[3]; > +#define GLB_PERFCNT_CONFIG_SIZE(x) ((x) & GENMASK(7, 0)) > +#define GLB_PERFCNT_CONFIG_SET(x) (((x) & GENMASK(1, 0)) << 8) > +#define GLB_PERFCNT_METADATA_ENABLE BIT(10) > u32 perfcnt_config; > u32 perfcnt_csg_select; > u32 perfcnt_fw_enable; > diff --git a/drivers/gpu/drm/panthor/panthor_perf.c b/drivers/gpu/drm/panthor/panthor_perf.c > index d1f984b3302a..fd16039d9244 100644 > --- a/drivers/gpu/drm/panthor/panthor_perf.c > +++ b/drivers/gpu/drm/panthor/panthor_perf.c > @@ -10,6 +10,9 @@ > > #include "panthor_device.h" > #include "panthor_fw.h" > +#include "panthor_gem.h" > +#include "panthor_gpu.h" > +#include "panthor_mmu.h" > #include "panthor_perf.h" > #include "panthor_regs.h" > > @@ -20,6 +23,81 @@ > */ > #define PANTHOR_PERF_EM_BITS (BITS_PER_TYPE(u64) * 2) > > +/** > + * PANTHOR_CTR_TIMESTAMP_LO - The first architecturally mandated counter of every block type > + * contains the low 32-bits of the TIMESTAMP value. > + */ > +#define PANTHOR_CTR_TIMESTAMP_LO (0) > + > +/** > + * PANTHOR_CTR_TIMESTAMP_HI - The register offset containinig the high 32-bits of the TIMESTAMP > + * value. > + */ > +#define PANTHOR_CTR_TIMESTAMP_HI (1) > + > +/** > + * PANTHOR_CTR_PRFCNT_EN - The register offset containing the enable mask for the enabled counters > + * that were written to memory. > + */ > +#define PANTHOR_CTR_PRFCNT_EN (2) > + > +/** > + * PANTHOR_HEADER_COUNTERS - The first four counters of every block type are architecturally > + * defined to be equivalent. The fourth counter is always reserved, > + * and should be zero and as such, does not have a separate define. > + * > + * These are the only four counters that are the same between different > + * blocks and are consistent between different architectures. > + */ > +#define PANTHOR_HEADER_COUNTERS (4) > + > +/** > + * PANTHOR_CTR_SAMPLE_REASON - The metadata block has a single value in position three which > + * indicates the reason a sample was taken. > + */ > +#define PANTHOR_CTR_SAMPLE_REASON (3) > + > +/** > + * PANTHOR_HW_COUNTER_SIZE - The size of a hardware counter in the FW ring buffer. > + */ > +#define PANTHOR_HW_COUNTER_SIZE (sizeof(u32)) > + > +/** > + * PANTHOR_PERF_RINGBUF_SLOTS_MIN - The minimum permitted number of slots in the Panthor perf > + * ring buffer. > + */ > +#define PANTHOR_PERF_RINGBUF_SLOTS_MIN (16) > + > +/** > + * PANTHOR_PERF_RINGBUF_SLOTS_MAX - The maximum permitted number of slots in the Panthor perf > + * ring buffer. > + */ > +#define PANTHOR_PERF_RINGBUF_SLOTS_MAX (256) > + > +static unsigned int perf_ringbuf_slots = 32; > + > +static int perf_ringbuf_slots_set(const char *val, const struct kernel_param *kp) > +{ > + unsigned int slots; > + int ret = kstrtouint(val, 0, &slots); > + > + if (ret) > + return ret; > + > + if (!is_power_of_2(slots)) > + return -EINVAL; > + > + return param_set_uint_minmax(val, kp, 16, 256); > +} > + > +static const struct kernel_param_ops perf_ringbuf_ops = { > + .set = perf_ringbuf_slots_set, > + .get = param_get_uint, > +}; > +module_param_cb(perf_ringbuf_slots, &perf_ringbuf_ops, &perf_ringbuf_slots, 0400); > +MODULE_PARM_DESC(perf_ringbuf_slots, > + "Power of two slots allocated for the Panthor perf kernel-FW ringbuffer"); > + > enum panthor_perf_session_state { > /** @PANTHOR_PERF_SESSION_ACTIVE: The session is active and can be used for sampling. */ > PANTHOR_PERF_SESSION_ACTIVE = 0, > @@ -65,6 +143,116 @@ enum session_sample_type { > SAMPLE_TYPE_REGULAR, > }; > > +struct panthor_perf_buffer_descriptor { > + /** > + * @block_size: The size of a single block in the FW ring buffer, equal to > + * sizeof(u32) * counters_per_block. > + */ > + size_t block_size; > + > + /** > + * @buffer_size: The total size of the buffer, equal to (#hardware blocks + > + * #firmware blocks) * block_size. > + */ > + size_t buffer_size; > + > + /** > + * @available_blocks: Bitmask indicating the blocks supported by the hardware and firmware > + * combination. Note that this can also include blocks that will not > + * be exposed to the user. > + */ > + DECLARE_BITMAP(available_blocks, DRM_PANTHOR_PERF_BLOCK_MAX); > + struct { > + /** @offset: Starting offset of a block of type @type in the FW ringbuffer. */ > + size_t offset; > + > + /** @block_count: Number of blocks of the given @type, starting at @offset. */ > + size_t block_count; > + > + /** @phys_mask: Bitmask of the physically available blocks. */ > + u64 phys_mask; > + } blocks[DRM_PANTHOR_PERF_BLOCK_MAX]; > +}; > + > +/** > + * struct panthor_perf_sampler - Interface to de-multiplex firmware interaction and handle > + * global interactions. > + */ > +struct panthor_perf_sampler { > + /** > + * @enabled_clients: The number of clients concurrently requesting samples. To ensure that > + * one client cannot deny samples to another, we must ensure that clients > + * are effectively reference counted. > + */ > + atomic_t enabled_clients; > + > + /** > + * @sample_handled: Synchronization point between the interrupt bottom half and the > + * main sampler interface. Must be re-armed solely on a new request > + * coming to the sampler. > + */ > + struct completion sample_handled; > + > + /** @rb: Kernel BO in the FW AS containing the sample ringbuffer. */ > + struct panthor_kernel_bo *rb; > + > + /** > + * @sample_slots: Number of slots for samples in the FW ringbuffer. Could be static, > + * but may be useful to customize for low-memory devices. > + */ > + size_t sample_slots; > + > + /** @em: Combined enable mask for all of the active sessions. */ > + struct panthor_perf_enable_masks *em; > + > + /** > + * @desc: Buffer descriptor for a sample in the FW ringbuffer. Note that this buffer > + * at current time does some interesting things with the zeroth block type. On > + * newer FW revisions, the first counter block of the sample is the METADATA block, > + * which contains a single value indicating the reason the sample was taken (if > + * any). This block must not be exposed to userspace, as userspace does not > + * have sufficient context to interpret it. As such, this block type is not > + * added to the uAPI, but we still use it in the kernel. > + */ > + struct panthor_perf_buffer_descriptor desc; > + > + /** > + * @sample: Pointer to an upscaled and annotated sample that may be emitted to userspace. > + * This is used both as an intermediate buffer to do the zero-extension of the > + * 32-bit counters to 64-bits and as a storage buffer in case the sampler > + * requests an additional sample that was not requested by any of the top-level > + * sessions (for instance, when changing the enable masks). > + */ > + u8 *sample; > + > + /** > + * @sampler_lock: Lock used to guard the list of sessions and the sampler configuration. > + * In particular, it guards the @session_list and the @em. > + */ > + struct mutex sampler_lock; > + > + /** @session_list: List of all sessions. */ > + struct list_head session_list; > + > + /** @pend_lock: Lock used to guard the list of sessions with pending samples. */ > + spinlock_t pend_lock; > + > + /** @pending_samples: List of sessions requesting samples. */ > + struct list_head pending_samples; > + > + /** @sample_requested: A sample has been requested. */ > + bool sample_requested; > + > + /** @set_config: The set that will be configured onto the hardware. */ > + u8 set_config; > + > + /** > + * @ptdev: Backpointer to the Panthor device, needed to ring the global doorbell and > + * interface with FW. > + */ > + struct panthor_device *ptdev; > +}; > + > struct panthor_perf_session { > DECLARE_BITMAP(state, PANTHOR_PERF_SESSION_MAX); > > @@ -186,6 +374,9 @@ struct panthor_perf { > * @sessions: Global map of sessions, accessed by their ID. > */ > struct xarray sessions; > + > + /** @sampler: FW control interface. */ > + struct panthor_perf_sampler sampler; > }; > > static size_t get_annotated_block_size(size_t counters_per_block) > @@ -255,6 +446,23 @@ static struct panthor_perf_enable_masks *panthor_perf_create_em(struct drm_panth > return em; > } > > +static void panthor_perf_em_add(struct panthor_perf_enable_masks *const dst_em, > + const struct panthor_perf_enable_masks *const src_em) > +{ > + size_t i = 0; > + > + for (i = DRM_PANTHOR_PERF_BLOCK_FIRST; i <= DRM_PANTHOR_PERF_BLOCK_LAST; i++) > + bitmap_or(dst_em->mask[i], dst_em->mask[i], src_em->mask[i], PANTHOR_PERF_EM_BITS); > +} > + > +static void panthor_perf_em_zero(struct panthor_perf_enable_masks *em) > +{ > + size_t i = 0; > + > + for (i = DRM_PANTHOR_PERF_BLOCK_FIRST; i <= DRM_PANTHOR_PERF_BLOCK_LAST; i++) > + bitmap_zero(em->mask[i], PANTHOR_PERF_EM_BITS); > +} > + > static u64 session_read_extract_idx(struct panthor_perf_session *session) > { > const u64 slots = session->ringbuf_slots; > @@ -265,6 +473,12 @@ static u64 session_read_extract_idx(struct panthor_perf_session *session) > return smp_load_acquire(&session->control->extract_idx) % slots; > } > > +static void session_write_insert_idx(struct panthor_perf_session *session, u64 idx) > +{ > + /* Userspace needs the insert index to know where to look for the sample. */ > + smp_store_release(&session->control->insert_idx, idx); > +} > + > static u64 session_read_insert_idx(struct panthor_perf_session *session) > { > const u64 slots = session->ringbuf_slots; > @@ -352,6 +566,758 @@ static struct panthor_perf_session *session_find(struct panthor_file *pfile, > return session; > } > > +static u32 compress_enable_mask(u32 counters, const unsigned long *const src) > +{ > + size_t i; > + u32 result = 0; > + const unsigned long ctr_per_bit = counters / BITS_PER_TYPE(u32); > + > + for_each_set_bit(i, src, counters) { > + const unsigned long pos = div_u64(i, ctr_per_bit); > + > + result |= BIT(pos); > + } > + > + return result; > +} > + > +static void expand_enable_mask(u32 counters, u32 em, unsigned long *const dst) > +{ > + size_t i; > + const unsigned long ctrs_per_bit = counters / BITS_PER_TYPE(u32); > + DECLARE_BITMAP(emb, BITS_PER_TYPE(u32)); > + > + bitmap_from_arr32(emb, &em, BITS_PER_TYPE(u32)); > + > + for_each_set_bit(i, emb, BITS_PER_TYPE(u32)) > + bitmap_set(dst, i * ctrs_per_bit, ctrs_per_bit); > +} > + > +/** > + * panthor_perf_block_data - Identify the block index and type based on the offset. > + * > + * @desc: FW buffer descriptor. > + * @offset: The current offset being examined. > + * @idx: Pointer to an output index. > + * @type: Pointer to an output block type. > + * > + * To disambiguate different types of blocks as well as different blocks of the same type, > + * the offset into the FW ringbuffer is used to uniquely identify the block being considered. > + * > + * In the future, this is a good time to identify whether a block will be empty, > + * allowing us to short-circuit its processing after emitting header information. > + * > + * Return: True if the current block is available, false otherwise. > + */ > +static bool panthor_perf_block_data(struct panthor_perf_buffer_descriptor *const desc, > + size_t offset, u32 *const idx, > + enum drm_panthor_perf_block_type *type) > +{ > + unsigned long id; > + > + for_each_set_bit(id, desc->available_blocks, DRM_PANTHOR_PERF_BLOCK_LAST) { I think you mean DRM_PANTHOR_PERF_BLOCK_MAX here, otherwise bit for shader block will not be checked. > + const size_t block_start = desc->blocks[id].offset; > + const size_t block_count = desc->blocks[id].block_count; > + const size_t block_end = desc->blocks[id].offset + > + desc->block_size * block_count; > + > + if (!block_count) > + continue; > + > + if (offset >= block_start && offset < block_end) { > + const unsigned long phys_mask[] = { > + BITMAP_FROM_U64(desc->blocks[id].phys_mask), > + }; > + const size_t pos = > + div_u64(offset - desc->blocks[id].offset, desc->block_size); > + > + *type = id; > + > + if (test_bit(pos, phys_mask)) { > + const u64 mask = GENMASK_ULL(pos, 0); > + const u64 zeroes = ~desc->blocks[id].phys_mask & mask; > + > + *idx = pos - hweight64(zeroes); > + return true; > + } > + return false; > + } > + } > + > + return false; > +} > + > +static u32 panthor_perf_handle_sample(struct panthor_device *ptdev, u32 extract_idx, u32 insert_idx) > +{ > + struct panthor_perf *perf = ptdev->perf; > + struct panthor_perf_sampler *sampler = &ptdev->perf->sampler; > + const size_t ann_block_size = > + get_annotated_block_size(ptdev->perf_info.counters_per_block); > + u32 i; > + > + for (i = extract_idx; i != insert_idx; i++) { > + u32 slot = i % sampler->sample_slots; > + u8 *fw_sample = (u8 *)sampler->rb->kmap + slot * sampler->desc.buffer_size; > + > + for (size_t fw_off = 0, ann_off = ptdev->perf_info.sample_header_size; > + fw_off < sampler->desc.buffer_size; > + fw_off += sampler->desc.block_size) > + > + { > + u32 idx = 0; > + enum drm_panthor_perf_block_type type = 0; > + DECLARE_BITMAP(expanded_em, PANTHOR_PERF_EM_BITS); > + struct panthor_perf_counter_block *blk = > + (typeof(blk))(perf->sampler.sample + ann_off); > + u32 *const block = (u32 *)(fw_sample + fw_off); > + const u32 prfcnt_en = block[PANTHOR_CTR_PRFCNT_EN]; > + > + if (!panthor_perf_block_data(&sampler->desc, fw_off, &idx, &type)) > + continue; > + > + /** > + * TODO Data from the metadata block must be used to populate the > + * block state information. > + */ > + if (type == DRM_PANTHOR_PERF_BLOCK_METADATA) { > + /* > + * The host must clear the SAMPLE_REASON to acknowledge it has > + * consumed the sample. > + */ > + block[PANTHOR_CTR_SAMPLE_REASON] = 0; > + continue; > + } > + > + expand_enable_mask(ptdev->perf_info.counters_per_block, > + prfcnt_en, expanded_em); > + > + blk->header = (struct drm_panthor_perf_block_header) { > + .clock = 0, > + .block_idx = idx, > + .block_type = type, > + .block_states = DRM_PANTHOR_PERF_BLOCK_STATE_UNKNOWN > + }; > + bitmap_to_arr64(blk->header.enable_mask, expanded_em, PANTHOR_PERF_EM_BITS); > + > + /* > + * The four header counters must be treated differently, because they are > + * not additive. For the fourth, the assignment does not matter, as it > + * is reserved and should be zero. > + */ > + blk->counters[PANTHOR_CTR_TIMESTAMP_LO] = block[PANTHOR_CTR_TIMESTAMP_LO]; > + blk->counters[PANTHOR_CTR_TIMESTAMP_HI] = block[PANTHOR_CTR_TIMESTAMP_HI]; > + blk->counters[PANTHOR_CTR_PRFCNT_EN] = block[PANTHOR_CTR_PRFCNT_EN]; > + > + /* > + * The host must clear PRFCNT_EN to acknowledge it has consumed the sample. > + */ > + block[PANTHOR_CTR_PRFCNT_EN] = 0; > + > + for (size_t k = PANTHOR_HEADER_COUNTERS; > + k < ptdev->perf_info.counters_per_block; > + k++) > + blk->counters[k] += block[k]; > + > + ann_off += ann_block_size; > + } > + } > + > + return i; > +} > + > +static size_t panthor_perf_get_fw_reported_size(struct panthor_device *ptdev) > +{ > + struct panthor_fw_global_iface *glb_iface = panthor_fw_get_glb_iface(ptdev); > + > + size_t fw_size = GLB_PERFCNT_FW_SIZE(glb_iface->control->perfcnt_size); > + size_t hw_size = GLB_PERFCNT_HW_SIZE(glb_iface->control->perfcnt_size); > + size_t md_size = PERFCNT_FEATURES_MD_SIZE(glb_iface->control->perfcnt_features); > + > + return md_size + fw_size + hw_size; > +} > + > +#define PANTHOR_PERF_SET_BLOCK_DESC_DATA(__desc, __type, __blk_count, __phys_mask, __offset) \ > + ({ \ > + (__desc)->blocks[(__type)].offset = (__offset); \ > + (__desc)->blocks[(__type)].block_count = (__blk_count); \ > + (__desc)->blocks[(__type)].phys_mask = (__phys_mask); \ > + if ((__blk_count)) \ > + set_bit((__type), (__desc)->available_blocks); \ > + (__offset) + ((__desc)->block_size) * (__blk_count); \ > + }) > + > +static size_t get_reserved_sc_blocks(struct panthor_device *ptdev) > +{ > + const u64 sc_mask = ptdev->gpu_info.shader_present; > + > + return fls64(sc_mask); > +} > + > +#define BLK_MASK(x) GENMASK_ULL((x) - 1, 0) > + > +static u64 get_sc_mask(struct panthor_device *ptdev) > +{ > + const u64 sc_mask = ptdev->gpu_info.shader_present; > + > + return BLK_MASK(hweight64(sc_mask)); > +} > + > +static int panthor_perf_setup_fw_buffer_desc(struct panthor_device *ptdev, > + struct panthor_perf_sampler *sampler) > +{ > + const struct drm_panthor_perf_info *const info = &ptdev->perf_info; > + const size_t block_size = info->counters_per_block * PANTHOR_HW_COUNTER_SIZE; > + struct panthor_perf_buffer_descriptor *desc = &sampler->desc; > + const size_t fw_sample_size = panthor_perf_get_fw_reported_size(ptdev); > + size_t offset = 0; > + > + desc->block_size = block_size; > + > + for (enum drm_panthor_perf_block_type type = 0; type < DRM_PANTHOR_PERF_BLOCK_MAX; type++) { > + switch (type) { > + case DRM_PANTHOR_PERF_BLOCK_METADATA: > + if (info->flags & DRM_PANTHOR_PERF_BLOCK_STATES_SUPPORT) > + offset = PANTHOR_PERF_SET_BLOCK_DESC_DATA(desc, type, 1, > + BLK_MASK(1), offset); > + break; > + case DRM_PANTHOR_PERF_BLOCK_FW: > + offset = PANTHOR_PERF_SET_BLOCK_DESC_DATA(desc, type, info->fw_blocks, > + BLK_MASK(info->fw_blocks), > + offset); > + break; > + case DRM_PANTHOR_PERF_BLOCK_CSHW: > + offset = PANTHOR_PERF_SET_BLOCK_DESC_DATA(desc, type, info->cshw_blocks, > + BLK_MASK(info->cshw_blocks), > + offset); > + break; > + case DRM_PANTHOR_PERF_BLOCK_TILER: > + offset = PANTHOR_PERF_SET_BLOCK_DESC_DATA(desc, type, info->tiler_blocks, > + BLK_MASK(info->tiler_blocks), > + offset); > + break; > + case DRM_PANTHOR_PERF_BLOCK_MEMSYS: > + offset = PANTHOR_PERF_SET_BLOCK_DESC_DATA(desc, type, info->memsys_blocks, > + BLK_MASK(info->memsys_blocks), > + offset); > + break; > + case DRM_PANTHOR_PERF_BLOCK_SHADER: > + offset = PANTHOR_PERF_SET_BLOCK_DESC_DATA(desc, type, > + get_reserved_sc_blocks(ptdev), > + get_sc_mask(ptdev), offset); > + break; > + case DRM_PANTHOR_PERF_BLOCK_MAX: > + drm_WARN_ON_ONCE(&ptdev->base, > + "DRM_PANTHOR_PERF_BLOCK_MAX should be unreachable!"); > + break; > + } > + } > + > + /* Computed size is not the same as the reported size, so we should not proceed in > + * initializing the sampling session. > + */ > + if (offset != fw_sample_size) > + return -EINVAL; > + > + desc->buffer_size = offset; > + > + return 0; > +} > + > +static int panthor_perf_fw_stop_sampling(struct panthor_device *ptdev) > +{ > + struct panthor_fw_global_iface *glb_iface = panthor_fw_get_glb_iface(ptdev); > + u32 acked; > + int ret; > + > + if (~READ_ONCE(glb_iface->input->req) & GLB_PERFCNT_ENABLE) > + return 0; > + > + panthor_fw_update_reqs(glb_iface, req, 0, GLB_PERFCNT_ENABLE); > + gpu_write(ptdev, CSF_DOORBELL(CSF_GLB_DOORBELL_ID), 1); > + ret = panthor_fw_glb_wait_acks(ptdev, GLB_PERFCNT_ENABLE, &acked, 100); > + if (ret) > + drm_warn(&ptdev->base, "Could not disable performance counters"); > + > + return ret; > +} > + > +static int panthor_perf_fw_start_sampling(struct panthor_device *ptdev) > +{ > + struct panthor_fw_global_iface *glb_iface = panthor_fw_get_glb_iface(ptdev); > + u32 acked; > + int ret; > + > + if (READ_ONCE(glb_iface->input->req) & GLB_PERFCNT_ENABLE) > + return 0; > + > + /** > + * The spec mandates that the host zero the PRFCNT_EXTRACT register before an enable > + * operation, and each (re-)enable will require an enable-disable pair to program > + * the new changes onto the FW interface. > + */ > + WRITE_ONCE(glb_iface->input->perfcnt_extract, 0); > + > + panthor_fw_update_reqs(glb_iface, req, GLB_PERFCNT_ENABLE, GLB_PERFCNT_ENABLE); > + gpu_write(ptdev, CSF_DOORBELL(CSF_GLB_DOORBELL_ID), 1); > + ret = panthor_fw_glb_wait_acks(ptdev, GLB_PERFCNT_ENABLE, &acked, 100); > + if (ret) > + drm_warn(&ptdev->base, "Could not enable performance counters"); > + > + return ret; > +} > + > +static void panthor_perf_fw_write_sampler_config(struct panthor_perf_sampler *sampler) > +{ > + struct panthor_fw_global_iface *glb_iface = panthor_fw_get_glb_iface(sampler->ptdev); > + const u32 counters = sampler->ptdev->perf_info.counters_per_block; > + const struct panthor_perf_enable_masks *const em = sampler->em; > + u32 perfcnt_config; > + > + glb_iface->input->perfcnt_csf_enable = > + compress_enable_mask(counters, em->mask[DRM_PANTHOR_PERF_BLOCK_CSHW]); > + glb_iface->input->perfcnt_shader_enable = > + compress_enable_mask(counters, em->mask[DRM_PANTHOR_PERF_BLOCK_SHADER]); > + glb_iface->input->perfcnt_mmu_l2_enable = > + compress_enable_mask(counters, em->mask[DRM_PANTHOR_PERF_BLOCK_MEMSYS]); > + glb_iface->input->perfcnt_tiler_enable = > + compress_enable_mask(counters, em->mask[DRM_PANTHOR_PERF_BLOCK_TILER]); > + glb_iface->input->perfcnt_fw_enable = > + compress_enable_mask(counters, em->mask[DRM_PANTHOR_PERF_BLOCK_FW]); > + glb_iface->input->perfcnt_csg_enable = 0; > + > + WRITE_ONCE(glb_iface->input->perfcnt_as, panthor_vm_as(panthor_fw_vm(sampler->ptdev))); > + WRITE_ONCE(glb_iface->input->perfcnt_base, panthor_kernel_bo_gpuva(sampler->rb)); > + > + perfcnt_config = GLB_PERFCNT_CONFIG_SIZE(perf_ringbuf_slots); > + perfcnt_config |= GLB_PERFCNT_CONFIG_SET(sampler->set_config); > + if (sampler->ptdev->perf_info.flags & DRM_PANTHOR_PERF_BLOCK_STATES_SUPPORT) > + perfcnt_config |= GLB_PERFCNT_METADATA_ENABLE; > + > + WRITE_ONCE(glb_iface->input->perfcnt_config, perfcnt_config); > +} > + > +static void session_populate_sample_header(struct panthor_perf_session *session, > + struct drm_panthor_perf_sample_header *hdr, u8 set) > +{ > + *hdr = (struct drm_panthor_perf_sample_header) { > + .block_set = set, > + .user_data = session->user_data, > + .timestamp_start_ns = session->sample_start_ns, > + /** > + * TODO This should be changed to use the GPU clocks and the TIMESTAMP register, > + * when support is added. > + */ > + .timestamp_end_ns = ktime_get_raw_ns(), > + }; > +} > + > +/** > + * session_accumulate_sample - Accumulate the counters that are requested by the session > + * into the target buffer. > + * > + * @ptdev: Panthor device > + * @session: Perf session > + * @session_sample: Starting offset of the sample in the userspace mapping. > + * @sampler_sample: Starting offset of the sample in the sampler intermediate buffer. > + * > + * The hardware supports counter selection at the granularity of 1 bit per 4 counters, and there > + * is a single global FW frontend to program the counter requests from multiple sessions. This may > + * lead to a large disparity between the requested and provided counters for an individual client. > + * To remove this cross-talk, we patch out the counters that have not been requested by this > + * session and update the PRFCNT_EN, the header counter containing a bitmask of enabled counters, > + * accordingly. > + */ > +static void session_accumulate_sample(struct panthor_device *ptdev, > + struct panthor_perf_session *session, > + u8 *session_sample, u8 *sampler_sample) > +{ > + const struct drm_panthor_perf_info *const perf_info = &ptdev->perf_info; > + const u32 counters = perf_info->counters_per_block; > + const size_t block_size = get_annotated_block_size(perf_info->counters_per_block); > + const size_t sample_size = perf_info->sample_size; > + const size_t sample_header_size = perf_info->sample_header_size; > + const size_t data_size = sample_size - sample_header_size; > + struct drm_panthor_perf_sample_header *hdr = (typeof(hdr))session_sample; > + > + hdr->timestamp_end_ns = ktime_get_raw_ns(); > + > + session_sample += sample_header_size; > + sampler_sample += sample_header_size; > + > + for (size_t i = 0; i < data_size; i += block_size) { > + DECLARE_BITMAP(enabled_ctrs, PANTHOR_PERF_EM_BITS); > + struct panthor_perf_counter_block *dst_blk = (typeof(dst_blk))(session_sample + i); > + struct panthor_perf_counter_block *src_blk = (typeof(src_blk))(sampler_sample + i); > + > + bitmap_from_arr64(enabled_ctrs, dst_blk->header.enable_mask, PANTHOR_PERF_EM_BITS); > + bitmap_clear(enabled_ctrs, 0, PANTHOR_HEADER_COUNTERS); > + > + dst_blk->counters[PANTHOR_CTR_TIMESTAMP_HI] = > + src_blk->counters[PANTHOR_CTR_TIMESTAMP_HI]; > + dst_blk->counters[PANTHOR_CTR_TIMESTAMP_LO] = > + src_blk->counters[PANTHOR_CTR_TIMESTAMP_LO]; > + > + for (size_t ctr_idx = PANTHOR_HEADER_COUNTERS; ctr_idx < counters; ctr_idx++) > + if (test_bit(ctr_idx, enabled_ctrs)) > + dst_blk->counters[ctr_idx] += src_blk->counters[ctr_idx]; > + } > + > + hdr->timestamp_end_ns = ktime_get_raw_ns(); > + hdr->user_data = session->user_data; > +} > + > +static void panthor_perf_fw_request_sample(struct panthor_perf_sampler *sampler) > +{ > + struct panthor_fw_global_iface *glb_iface = panthor_fw_get_glb_iface(sampler->ptdev); > + > + panthor_fw_toggle_reqs(glb_iface, req, ack, GLB_PERFCNT_SAMPLE); > + gpu_write(sampler->ptdev, CSF_DOORBELL(CSF_GLB_DOORBELL_ID), 1); > +} > + > +/** > + * session_populate_sample - Write out a new sample into a previously populated slot in the user > + * ringbuffer and update both the header of the block and the PRFCNT_EN > + * counter to contain only the selected subset of counters for that block. > + * > + * @ptdev: Panthor device > + * @session: Perf session > + * @session_sample: Pointer aligned to the start of the data section of the sample in the targeted > + * slot. > + * @sampler_sample: Pointer aligned to the start of the data section of the intermediate sampler > + * buffer. > + * > + * When a new sample slot is targeted, it must be cleared of the data already existing there, > + * enabling a direct copy from the intermediate buffer and then zeroing out any counters > + * that are not required for the current session. > + */ > +static void session_populate_sample(struct panthor_device *ptdev, > + struct panthor_perf_session *session, u8 *session_sample, > + u8 *sampler_sample) > +{ > + const struct drm_panthor_perf_info *const perf_info = &ptdev->perf_info; > + > + const size_t block_size = get_annotated_block_size(perf_info->counters_per_block); > + const size_t sample_size = session_get_user_sample_size(perf_info); > + const size_t sample_header_size = perf_info->sample_header_size; > + const size_t data_size = sample_size - sample_header_size; > + const u32 counters = perf_info->counters_per_block; > + > + session_populate_sample_header(session, > + (struct drm_panthor_perf_sample_header *)session_sample, > + ptdev->perf->sampler.set_config); > + > + session_sample += sample_header_size; > + > + memcpy(session_sample, sampler_sample + sample_header_size, data_size); > + > + for (size_t i = 0; i < data_size; i += block_size) { > + DECLARE_BITMAP(em_diff, PANTHOR_PERF_EM_BITS); > + struct panthor_perf_counter_block *blk = (typeof(blk))(session_sample + i); > + enum drm_panthor_perf_block_type type = blk->header.block_type; > + unsigned long *blk_em = session->enabled_counters->mask[type]; > + > + bitmap_from_arr64(em_diff, blk->header.enable_mask, PANTHOR_PERF_EM_BITS); > + > + bitmap_andnot(em_diff, em_diff, blk_em, PANTHOR_PERF_EM_BITS); > + bitmap_clear(em_diff, 0, PANTHOR_HEADER_COUNTERS); > + > + blk->counters[PANTHOR_CTR_PRFCNT_EN] = compress_enable_mask(counters, blk_em); > + > + for (size_t ctr_idx = PANTHOR_HEADER_COUNTERS; ctr_idx < counters; ctr_idx++) { > + if (test_bit(ctr_idx, em_diff)) > + blk->counters[ctr_idx] = 0; > + } > + > + bitmap_to_arr64(&blk->header.enable_mask, blk_em, PANTHOR_PERF_EM_BITS); > + } > +} > + > +static int session_copy_sample(struct panthor_device *ptdev, struct panthor_perf_session *session) > +{ > + struct panthor_perf *perf = ptdev->perf; > + const size_t sample_size = session_get_user_sample_size(&ptdev->perf_info); > + const u64 insert_idx = session_read_insert_idx(session); > + const u64 extract_idx = session_read_extract_idx(session); > + u8 *new_sample; > + > + if (!CIRC_SPACE(insert_idx, extract_idx, session->ringbuf_slots)) > + return -ENOSPC; > + > + if (READ_ONCE(session->pending_sample_request) == SAMPLE_TYPE_INITIAL) > + return 0; > + > + new_sample = session->samples + insert_idx * sample_size; > + > + if (session->accum_idx != insert_idx) { > + session_populate_sample(ptdev, session, new_sample, perf->sampler.sample); > + session->accum_idx = insert_idx; > + } else { > + session_accumulate_sample(ptdev, session, new_sample, perf->sampler.sample); > + } > + > + return 0; > +} > + > +static void session_emit_sample(struct panthor_perf_session *session) > +{ > + const u64 insert_idx = session_read_insert_idx(session); > + const enum session_sample_type type = READ_ONCE(session->pending_sample_request); > + > + if (type == SAMPLE_TYPE_INITIAL || type == SAMPLE_TYPE_NONE) > + goto reset_sample_request; > + > + session_write_insert_idx(session, (insert_idx + 1) % session->ringbuf_slots); > + > + /* Since we are about to notify userspace, we must ensure that all changes to memory > + * are visible. > + */ > + wmb(); > + > + eventfd_signal(session->eventfd); > + > +reset_sample_request: > + WRITE_ONCE(session->pending_sample_request, SAMPLE_TYPE_NONE); > +} > + > +#define PRFCNT_IRQS (GLB_PERFCNT_OVERFLOW | GLB_PERFCNT_SAMPLE | GLB_PERFCNT_THRESHOLD) > + > +void panthor_perf_report_irq(struct panthor_device *ptdev, u32 status) > +{ > + struct panthor_perf *const perf = ptdev->perf; > + struct panthor_perf_sampler *sampler; > + struct panthor_fw_global_iface *glb_iface = panthor_fw_get_glb_iface(ptdev); > + bool sample_requested; > + > + if (!(status & JOB_INT_GLOBAL_IF)) > + return; > + > + if (!perf) > + return; > + > + sampler = &perf->sampler; > + > + const u32 ack = READ_ONCE(glb_iface->output->ack); > + const u32 req = READ_ONCE(glb_iface->input->req); > + > + scoped_guard(spinlock_irqsave, &sampler->pend_lock) > + sample_requested = sampler->sample_requested; > + > + /* > + * TODO Fix up the error handling for overflow. Currently, the user is unblocked > + * with a completely empty sample, whic is not the intended behaviour. > + */ > + if (drm_WARN_ON_ONCE(&ptdev->base, (req ^ ack) & GLB_PERFCNT_OVERFLOW)) > + goto emit; > + > + if ((sample_requested && (req & GLB_PERFCNT_SAMPLE) == (ack & GLB_PERFCNT_SAMPLE)) || > + ((req ^ ack) & GLB_PERFCNT_THRESHOLD)) { > + const u32 extract_idx = READ_ONCE(glb_iface->input->perfcnt_extract); > + const u32 insert_idx = READ_ONCE(glb_iface->output->perfcnt_insert); > + > + /* If the sample was requested around a reset, some time may be needed > + * for the FW interface to be updated, so we reschedule a sample > + * and return immediately. > + */ > + if (insert_idx == extract_idx) { > + guard(spinlock_irqsave)(&sampler->pend_lock); > + if (sampler->sample_requested) > + panthor_perf_fw_request_sample(sampler); > + > + return; > + } > + > + WRITE_ONCE(glb_iface->input->perfcnt_extract, > + panthor_perf_handle_sample(ptdev, extract_idx, insert_idx)); > + } > + > + scoped_guard(mutex, &sampler->sampler_lock) > + { > + struct list_head *pos; > + > + list_for_each(pos, &sampler->session_list) { > + struct panthor_perf_session *session = list_entry(pos, > + struct panthor_perf_session, sessions); > + > + session_copy_sample(ptdev, session); > + } > + } > + > +emit: > + scoped_guard(spinlock_irqsave, &sampler->pend_lock) { > + struct list_head *pos, *tmp; > + > + list_for_each_safe(pos, tmp, &sampler->pending_samples) { > + struct panthor_perf_session *session = list_entry(pos, > + struct panthor_perf_session, pending); > + > + session_emit_sample(session); > + list_del(pos); > + session_put(session); > + } > + > + sampler->sample_requested = false; > + } > + > + memset(sampler->sample, 0, session_get_user_sample_size(&ptdev->perf_info)); > + complete(&sampler->sample_handled); > +} > + > +static int panthor_perf_sampler_init(struct panthor_perf_sampler *sampler, > + struct panthor_device *ptdev) > +{ > + struct panthor_kernel_bo *bo; > + u8 *sample; > + int ret; > + > + ret = panthor_perf_setup_fw_buffer_desc(ptdev, sampler); > + if (ret) { > + drm_err(&ptdev->base, > + "Failed to setup descriptor for FW ring buffer, err = %d", ret); > + return ret; > + } > + > + bo = panthor_kernel_bo_create(ptdev, panthor_fw_vm(ptdev), > + sampler->desc.buffer_size * perf_ringbuf_slots, > + DRM_PANTHOR_BO_NO_MMAP, > + DRM_PANTHOR_VM_BIND_OP_MAP_NOEXEC | > + DRM_PANTHOR_VM_BIND_OP_MAP_UNCACHED, > + PANTHOR_VM_KERNEL_AUTO_VA, > + "perf_ringbuf"); > + > + if (IS_ERR_OR_NULL(bo)) > + return IS_ERR(bo) ? PTR_ERR(bo) : -ENOMEM; > + > + ret = panthor_kernel_bo_vmap(bo); > + if (ret) > + goto cleanup_bo; > + > + sample = kzalloc(session_get_user_sample_size(&ptdev->perf_info), GFP_KERNEL); > + if (ZERO_OR_NULL_PTR(sample)) { > + ret = -ENOMEM; > + goto cleanup_vmap; > + } > + > + sampler->rb = bo; > + sampler->sample = sample; > + sampler->sample_slots = perf_ringbuf_slots; > + sampler->em = kzalloc(sizeof(*sampler->em), GFP_KERNEL); > + > + mutex_init(&sampler->sampler_lock); > + spin_lock_init(&sampler->pend_lock); > + INIT_LIST_HEAD(&sampler->session_list); > + INIT_LIST_HEAD(&sampler->pending_samples); > + init_completion(&sampler->sample_handled); > + > + sampler->ptdev = ptdev; > + > + return 0; > + > +cleanup_vmap: > + panthor_kernel_bo_vunmap(bo); > + > +cleanup_bo: > + panthor_kernel_bo_destroy(bo); > + > + return ret; > +} > + > +static void panthor_perf_sampler_term(struct panthor_perf_sampler *sampler) > +{ > + int ret; > + bool requested; > + > + scoped_guard(spinlock_irqsave, &sampler->pend_lock) > + requested = sampler->sample_requested; > + > + if (requested) > + wait_for_completion_killable(&sampler->sample_handled); > + > + ret = panthor_perf_fw_stop_sampling(sampler->ptdev); > + if (ret) > + drm_warn_once(&sampler->ptdev->base, "Sampler termination failed, ret = %d", ret); > + > + /* At this point, the sampler enable mask is already zero, so it can be used directly. */ > + panthor_perf_fw_write_sampler_config(sampler); > + > + kfree(sampler->em); > + kfree(sampler->sample); > + > + panthor_kernel_bo_destroy(sampler->rb); > +} > + > +static int panthor_perf_sampler_add(struct panthor_perf_sampler *sampler, > + struct panthor_perf_session *session, u8 set) > +{ > + int ret = 0; > + struct panthor_perf_enable_masks *const session_em = session->enabled_counters; > + > + guard(mutex)(&sampler->sampler_lock); > + > + /* Early check for whether a new set can be configured. */ > + if (!atomic_read(&sampler->enabled_clients)) > + sampler->set_config = set; > + else > + if (sampler->set_config != set) > + return -EBUSY; > + > + panthor_perf_em_add(sampler->em, session_em); > + ret = pm_runtime_resume_and_get(sampler->ptdev->base.dev); > + if (ret) > + return ret; > + > + if (atomic_read(&sampler->enabled_clients)) { > + ret = panthor_perf_fw_stop_sampling(sampler->ptdev); > + if (ret) > + return ret; > + } > + > + panthor_perf_fw_write_sampler_config(sampler); > + > + ret = panthor_perf_fw_start_sampling(sampler->ptdev); > + if (ret) > + return ret; > + > + session_get(session); > + list_add_tail(&session->sessions, &sampler->session_list); > + atomic_inc(&sampler->enabled_clients); > + > + return 0; > +} > + > +static int panthor_perf_sampler_remove_session(struct panthor_perf_sampler *sampler, > + struct panthor_perf_session *session) > +{ > + int ret; > + struct list_head *snode; > + > + guard(mutex)(&sampler->sampler_lock); > + > + list_del_init(&session->sessions); > + session_put(session); > + > + panthor_perf_em_zero(sampler->em); > + list_for_each(snode, &sampler->session_list) > + { > + struct panthor_perf_session *session = > + container_of(snode, typeof(*session), sessions); > + > + panthor_perf_em_add(sampler->em, session->enabled_counters); > + } > + > + ret = panthor_perf_fw_stop_sampling(sampler->ptdev); > + if (ret) > + return ret; > + > + atomic_dec(&sampler->enabled_clients); > + pm_runtime_put_sync(sampler->ptdev->base.dev); > + > + panthor_perf_fw_write_sampler_config(sampler); > + > + if (atomic_read(&sampler->enabled_clients)) > + return panthor_perf_fw_start_sampling(sampler->ptdev); > + return 0; > +} > + > /** > * panthor_perf_init - Initialize the performance counter subsystem. > * @ptdev: Panthor device > @@ -382,6 +1348,10 @@ int panthor_perf_init(struct panthor_device *ptdev) > .max = 1, > }; > > + ret = panthor_perf_sampler_init(&perf->sampler, ptdev); > + if (ret) > + return ret; > + > drm_info(&ptdev->base, "Performance counter subsystem initialized"); > > ptdev->perf = no_free_ptr(perf); > @@ -389,6 +1359,70 @@ int panthor_perf_init(struct panthor_device *ptdev) > return ret; > } > > +static int sampler_request(struct panthor_perf_sampler *sampler, > + struct panthor_perf_session *session, enum session_sample_type type) > +{ > + /* > + * If a previous sample has not been handled yet, the session cannot request another > + * sample. If this happens too often, the requested sample rate is too high. > + */ > + if (READ_ONCE(session->pending_sample_request) != SAMPLE_TYPE_NONE) > + return -EBUSY; > + > + WRITE_ONCE(session->pending_sample_request, type); > + session_get(session); > + > + scoped_guard(spinlock_irqsave, &sampler->pend_lock) { > + list_add_tail(&session->pending, &sampler->pending_samples); > + > + if (!sampler->sample_requested) { > + reinit_completion(&sampler->sample_handled); > + sampler->sample_requested = true; > + panthor_perf_fw_request_sample(sampler); > + } > + } > + > + return 0; > +} > + > +/** > + * panthor_perf_sampler_request_initial - Request an initial sample. > + * @sampler: Panthor sampler > + * @session: Target session > + * > + * Perform a synchronous sample that gets immediately discarded. This sets a baseline at the point > + * of time a new session is started, to avoid having counters from before the session. > + */ > +static int panthor_perf_sampler_request_initial(struct panthor_perf_sampler *sampler, > + struct panthor_perf_session *session) > +{ > + int ret = sampler_request(sampler, session, SAMPLE_TYPE_INITIAL); > + > + if (ret) > + return ret; > + > + return wait_for_completion_timeout(&sampler->sample_handled, > + msecs_to_jiffies(1000)); > +} > + > +/** > + * panthor_perf_sampler_request_sample - Request a counter sample for the userspace client. > + * @sampler: Panthor sampler > + * @session: Target session > + * > + * A session that has already requested a sample cannot request another one until the previous > + * sample has been delivered. > + * > + * Return: > + * * %0 - The sample has been requested successfully. > + * * %-EBUSY - The target session has already requested a sample and has not received it yet. > + */ > +static int panthor_perf_sampler_request_sample(struct panthor_perf_sampler *sampler, > + struct panthor_perf_session *session) > +{ > + return sampler_request(sampler, session, SAMPLE_TYPE_REGULAR); > +} > + > static int session_validate_set(u8 set) > { > if (set > DRM_PANTHOR_PERF_SET_TERTIARY) > @@ -513,6 +1547,10 @@ int panthor_perf_session_setup(struct drm_file *file, struct panthor_perf *perf, > kref_init(&session->ref); > session->enabled_counters = em; > > + ret = panthor_perf_sampler_add(&perf->sampler, session, setup_args->block_set); > + if (ret) > + goto cleanup_xa_alloc; > + > session->sample_freq_ns = setup_args->sample_freq_ns; > session->user_sample_size = user_sample_size; > session->ring_buf = ringbuffer; > @@ -523,6 +1561,9 @@ int panthor_perf_session_setup(struct drm_file *file, struct panthor_perf *perf, > > return session_id; > > +cleanup_xa_alloc: > + xa_store(&perf->sessions, session_id, NULL, GFP_KERNEL); > + > cleanup_em: > kfree(em); > > @@ -550,6 +1591,8 @@ int panthor_perf_session_setup(struct drm_file *file, struct panthor_perf *perf, > static int session_stop(struct panthor_perf *perf, struct panthor_perf_session *session, > u64 user_data) > { > + int ret; > + > if (!test_bit(PANTHOR_PERF_SESSION_ACTIVE, session->state)) > return 0; > > @@ -562,9 +1605,12 @@ static int session_stop(struct panthor_perf *perf, struct panthor_perf_session * > > session->user_data = user_data; > > + ret = panthor_perf_sampler_request_sample(&perf->sampler, session); > + if (ret) > + return ret; > + > clear_bit(PANTHOR_PERF_SESSION_ACTIVE, session->state); > > - /* TODO Calls to the FW interface will go here in later patches. */ > return 0; > } > > @@ -583,8 +1629,7 @@ static int session_start(struct panthor_perf *perf, struct panthor_perf_session > if (session->sample_freq_ns) > session->user_data = user_data; > > - /* TODO Calls to the FW interface will go here in later patches. */ > - return 0; > + return panthor_perf_sampler_request_initial(&perf->sampler, session); > } > > static int session_sample(struct panthor_perf *perf, struct panthor_perf_session *session, > @@ -605,20 +1650,22 @@ static int session_sample(struct panthor_perf *perf, struct panthor_perf_session > * the current sample, and one for a stop sample, since a stop command should > * always be acknowledged by taking a final sample and stopping the session. > */ > - if (CIRC_SPACE_TO_END(insert_idx, extract_idx, session->ringbuf_slots) < 2) > + if (CIRC_SPACE(insert_idx, extract_idx, session->ringbuf_slots) < 2) > return -EBUSY; > > session->sample_start_ns = ktime_get_raw_ns(); > session->user_data = user_data; > > - return 0; > + return panthor_perf_sampler_request_sample(&perf->sampler, session); > } > > static int session_destroy(struct panthor_perf *perf, struct panthor_perf_session *session) > { > + int ret = panthor_perf_sampler_remove_session(&perf->sampler, session); > + > session_put(session); > > - return 0; > + return ret; > } > > static int session_teardown(struct panthor_perf *perf, struct panthor_perf_session *session) > @@ -825,6 +1872,8 @@ void panthor_perf_unplug(struct panthor_device *ptdev) > > xa_destroy(&perf->sessions); > > + panthor_perf_sampler_term(&perf->sampler); > + > kfree(ptdev->perf); > > ptdev->perf = NULL; > diff --git a/drivers/gpu/drm/panthor/panthor_perf.h b/drivers/gpu/drm/panthor/panthor_perf.h > index c46f94ed8a96..5a14854368eb 100644 > --- a/drivers/gpu/drm/panthor/panthor_perf.h > +++ b/drivers/gpu/drm/panthor/panthor_perf.h > @@ -28,5 +28,7 @@ int panthor_perf_session_sample(struct panthor_file *pfile, struct panthor_perf > u32 sid, u64 user_data); > void panthor_perf_session_destroy(struct panthor_file *pfile, struct panthor_perf *perf); > > +void panthor_perf_report_irq(struct panthor_device *ptdev, u32 status); > + > #endif /* __PANTHOR_PERF_H__ */ > -- Cheers, Ketil