From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 42E98FF8850 for ; Sat, 25 Apr 2026 00:16:55 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E442910E070; Sat, 25 Apr 2026 00:16:54 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="D4NKZstO"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) by gabe.freedesktop.org (Postfix) with ESMTPS id A81ED10E070 for ; Sat, 25 Apr 2026 00:16:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1777076214; x=1808612214; h=date:message-id:from:to:cc:subject:in-reply-to: references:mime-version:content-transfer-encoding; bh=ctfMHRI61IV6v5VxMtYl/SFOcLbJiBWR8udaqFSRXKw=; b=D4NKZstOkecZH+56eGeYaMqEYckXY75eYpxupSq2s/b6RDe6YCoyqwZq InSy5MxR20Vh91CzFuU7qdmu7zxpxZSwIqoHgNzbWkfDqsE6nM12j+SdY XfWuTT1OyXJcZPZB72CmdIpHaPix0k4mfRM0DxmORQjI6fBOY81FnWt0y a82Prm91/Dg0MDbta+1tBej2lnGlcqw9VzVs39r4H03g7GejWOFwKLWry GbkeIijci/kMRCKgbRChhbwVmqcbNJZdo4gM22eTlAEBuGESg3jKuoyxE 7hzozQetppJ1V0vUGsXsNB4d76AgFxfGM/+aHyzxKDWEwOZKRqIOdWrd3 g==; X-CSE-ConnectionGUID: lnymz+jkTi+b34VZY6YH7A== X-CSE-MsgGUID: sZ7eTff8R3yW0WQle0K8cA== X-IronPort-AV: E=McAfee;i="6800,10657,11766"; a="88761671" X-IronPort-AV: E=Sophos;i="6.23,197,1770624000"; d="scan'208";a="88761671" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Apr 2026 17:16:53 -0700 X-CSE-ConnectionGUID: +R7Z8/+xQIWWN8anCaSvKA== X-CSE-MsgGUID: Uu70lEzZT0eYuPSht53D+w== X-ExtLoop1: 1 Received: from orsosgc001.jf.intel.com (HELO orsosgc001.intel.com) ([10.88.27.185]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Apr 2026 17:16:54 -0700 Date: Fri, 24 Apr 2026 17:16:48 -0700 Message-ID: <85tssznbbj.wl-ashutosh.dixit@intel.com> From: "Dixit, Ashutosh" To: Umesh Nerlige Ramappa Cc: Subject: Re: [PATCH 1/3] drm/xe/oa: Use xe_map layer In-Reply-To: <87jytvud4b.wl-ashutosh.dixit@intel.com> References: <20260415020342.782987-1-ashutosh.dixit@intel.com> <20260415020342.782987-2-ashutosh.dixit@intel.com> <87jytvud4b.wl-ashutosh.dixit@intel.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?ISO-8859-4?Q?Goj=F2?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/30.2 (x86_64-redhat-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On Fri, 24 Apr 2026 16:56:04 -0700, Dixit, Ashutosh wrote: > > On Fri, 24 Apr 2026 14:05:16 -0700, Umesh Nerlige Ramappa wrote: > > > > Hi Umesh, > > > On Tue, Apr 14, 2026 at 07:03:40PM -0700, Ashutosh Dixit wrote: > > > OA code should have used xe_map layer to begin with. In CRI, the OA b= uffer > > > can be located both in system and device memory. For these reasons, m= ove OA > > > code to use the xe_map layer when accessing the OA buffer. > > > > > > v2: Use xe_map layer and put_user in xe_oa_copy_to_user (Umesh) > > > v3: To avoid performance impact in v2, revert to v1 but move > > > xe_map_copy_to_user() to xe_map.h > > > v4: Use bounce buffer and copy_to_user in xe_oa_copy_to_user > > > > > > Signed-off-by: Ashutosh Dixit > > > --- > > > drivers/gpu/drm/xe/xe_oa.c | 95 +++++++++++++++++++------------- > > > drivers/gpu/drm/xe/xe_oa_types.h | 4 +- > > > 2 files changed, 58 insertions(+), 41 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/xe/xe_oa.c b/drivers/gpu/drm/xe/xe_oa.c > > > index 6337e671c97ae..4d13d8ef8103f 100644 > > > --- a/drivers/gpu/drm/xe/xe_oa.c > > > +++ b/drivers/gpu/drm/xe/xe_oa.c > > > @@ -213,32 +213,40 @@ static u32 xe_oa_hw_tail_read(struct xe_oa_stre= am *stream) > > > #define oa_report_header_64bit(__s) \ > > > ((__s)->oa_buffer.format->header =3D=3D HDR_64_BIT) > > > > > > -static u64 oa_report_id(struct xe_oa_stream *stream, void *report) > > > +static u64 oa_report_id(struct xe_oa_stream *stream, u32 tail) > > > { > > > - return oa_report_header_64bit(stream) ? *(u64 *)report : *(u32 *)re= port; > > > + struct iosys_map *map =3D &stream->oa_buffer.bo->vmap; > > > + > > > + return oa_report_header_64bit(stream) ? > > > + xe_map_rd(stream->oa->xe, map, tail, u64) : > > > + xe_map_rd(stream->oa->xe, map, tail, u32); > > > } > > > > (1) The helper is just returning the report id for a report passed. In = this > > case it is tail, but the code would work for any report. I would keep t= he > > name as report or report_offset. Let the caller use specific names like > > tail. > > > > > > > > -static void oa_report_id_clear(struct xe_oa_stream *stream, u32 *rep= ort) > > > +static void oa_report_id_clear(struct xe_oa_stream *stream, u32 head) > > > { > > > - if (oa_report_header_64bit(stream)) > > > - *(u64 *)report =3D 0; > > > - else > > > - *report =3D 0; > > > + struct iosys_map *map =3D &stream->oa_buffer.bo->vmap; > > > + > > > + oa_report_header_64bit(stream) ? > > > + xe_map_wr(stream->oa->xe, map, head, u64, 0) : > > > + xe_map_wr(stream->oa->xe, map, head, u32, 0); > > > } > > > > > > -static u64 oa_timestamp(struct xe_oa_stream *stream, void *report) > > > +static u64 oa_timestamp(struct xe_oa_stream *stream, u32 tail) > > > { > > > + struct iosys_map *map =3D &stream->oa_buffer.bo->vmap; > > > + > > > return oa_report_header_64bit(stream) ? > > > - *((u64 *)report + 1) : > > > - *((u32 *)report + 1); > > > + xe_map_rd(stream->oa->xe, map, tail + 2, u64) : > > > + xe_map_rd(stream->oa->xe, map, tail + 1, u32); > > > > (2) I think this should be tail + 8 and tail + 4. Can you please double > > check? The u32/u64 is only being used to access the data at the offset > > rather than determine how to calculate the actual offset. > > Hmm, you are right!!! I don't believe I made such a basic mistake :/ And > all the xe_oa tests work fine even with this. > > Anyway thanks for catching this, I'm fixing this in the next rev. > > > > > > } > > > > > > -static void oa_timestamp_clear(struct xe_oa_stream *stream, u32 *rep= ort) > > > +static void oa_timestamp_clear(struct xe_oa_stream *stream, u32 head) > > > { > > > - if (oa_report_header_64bit(stream)) > > > - *(u64 *)&report[2] =3D 0; > > > - else > > > - report[1] =3D 0; > > > + struct iosys_map *map =3D &stream->oa_buffer.bo->vmap; > > > + > > > + oa_report_header_64bit(stream) ? > > > + xe_map_wr(stream->oa->xe, map, head + 2, u64, 0) : > > > + xe_map_wr(stream->oa->xe, map, head + 1, u32, 0); > > > > Same here - comment (2) > > > > > } > > > > Same comment (1) for all the above helpers - the name can be generic - > > report_offset. I see similar change in other functions below as well. If > > you think it is necessary, I suggest trying to move it to a separate pa= tch > > with commit message explaining why you want to rename them. That would = also > > help review this patch easily. > > So, as we know HW writes to tail and SW reads from head. So the helpers > with head as the arg are invoked from the read side only and the helpers > with tail as the arg are invoked from the write side only. That was the > reason for naming the arg as head/tail, rather than just "offset". I > thought it will make the code easier to understand and also maybe prevent > mistakes in the future. > > So anyway, let me ask once again if you think I should change it. Of > course, there's no problem changing the arg name in the helpers. > > I'll also see if it's possible to split the patch some way to make the > review a bit easier. I just sent out v5 in which I have let all this stay as is. Anyway, please let me know what you prefer. Thanks. > > Thanks. > -- > Ashutosh > > > > > > > > > > static bool xe_oa_buffer_check_unlocked(struct xe_oa_stream *stream) > > > @@ -275,9 +283,7 @@ static bool xe_oa_buffer_check_unlocked(struct xe= _oa_stream *stream) > > > * they were written. If not : (=E2=95=AF=C2=B0=E2=96=A1=C2=B0=EF=BC= =89=E2=95=AF=EF=B8=B5 =E2=94=BB=E2=94=81=E2=94=BB > > > */ > > > while (xe_oa_circ_diff(stream, tail, stream->oa_buffer.tail) >=3D rep= ort_size) { > > > - void *report =3D stream->oa_buffer.vaddr + tail; > > > - > > > - if (oa_report_id(stream, report) || oa_timestamp(stream, report)) > > > + if (oa_report_id(stream, tail) || oa_timestamp(stream, tail)) > > > break; > > > > > > tail =3D xe_oa_circ_diff(stream, tail, report_size); > > > @@ -311,30 +317,35 @@ static enum hrtimer_restart xe_oa_poll_check_ti= mer_cb(struct hrtimer *hrtimer) > > > return HRTIMER_RESTART; > > > } > > > > > > +static unsigned long > > > +xe_oa_copy_to_user(struct xe_oa_stream *stream, void __user *dst, u3= 2 head, u32 len) > > > +{ > > > + xe_map_memcpy_from(stream->oa->xe, stream->oa_buffer.bounce, > > > + &stream->oa_buffer.bo->vmap, head, len); > > > + return copy_to_user(dst, stream->oa_buffer.bounce, len); > > > +} > > > + > > > > Still need to look at the patch below this point. Will send that out ne= xt > > week... > > > > Regards, > > Umesh > > > > > static int xe_oa_append_report(struct xe_oa_stream *stream, char __us= er *buf, > > > - size_t count, size_t *offset, const u8 *report) > > > + size_t count, size_t *offset, u32 head) > > > { > > > int report_size =3D stream->oa_buffer.format->size; > > > int report_size_partial; > > > - u8 *oa_buf_end; > > > > > > if ((count - *offset) < report_size) > > > return -ENOSPC; > > > > > > buf +=3D *offset; > > > > > > - oa_buf_end =3D stream->oa_buffer.vaddr + stream->oa_buffer.circ_siz= e; > > > - report_size_partial =3D oa_buf_end - report; > > > + report_size_partial =3D stream->oa_buffer.circ_size - head; > > > > > > if (report_size_partial < report_size) { > > > - if (copy_to_user(buf, report, report_size_partial)) > > > + if (xe_oa_copy_to_user(stream, buf, head, report_size_partial)) > > > return -EFAULT; > > > buf +=3D report_size_partial; > > > > > > - if (copy_to_user(buf, stream->oa_buffer.vaddr, > > > - report_size - report_size_partial)) > > > + if (xe_oa_copy_to_user(stream, buf, 0, report_size - report_size_p= artial)) > > > return -EFAULT; > > > - } else if (copy_to_user(buf, report, report_size)) { > > > + } else if (xe_oa_copy_to_user(stream, buf, head, report_size)) { > > > return -EFAULT; > > > } > > > > > > @@ -347,7 +358,6 @@ static int xe_oa_append_reports(struct xe_oa_stre= am *stream, char __user *buf, > > > size_t count, size_t *offset) > > > { > > > int report_size =3D stream->oa_buffer.format->size; > > > - u8 *oa_buf_base =3D stream->oa_buffer.vaddr; > > > u32 gtt_offset =3D xe_bo_ggtt_addr(stream->oa_buffer.bo); > > > size_t start_offset =3D *offset; > > > unsigned long flags; > > > @@ -364,26 +374,24 @@ static int xe_oa_append_reports(struct xe_oa_st= ream *stream, char __user *buf, > > > > > > for (; xe_oa_circ_diff(stream, tail, head); > > > head =3D xe_oa_circ_incr(stream, head, report_size)) { > > > - u8 *report =3D oa_buf_base + head; > > > - > > > - ret =3D xe_oa_append_report(stream, buf, count, offset, report); > > > + ret =3D xe_oa_append_report(stream, buf, count, offset, head); > > > if (ret) > > > break; > > > > > > if (!(stream->oa_buffer.circ_size % report_size)) { > > > /* Clear out report id and timestamp to detect unlanded reports */ > > > - oa_report_id_clear(stream, (void *)report); > > > - oa_timestamp_clear(stream, (void *)report); > > > + oa_report_id_clear(stream, head); > > > + oa_timestamp_clear(stream, head); > > > } else { > > > - u8 *oa_buf_end =3D stream->oa_buffer.vaddr + stream->oa_buffer.ci= rc_size; > > > - u32 part =3D oa_buf_end - report; > > > + struct iosys_map *map =3D &stream->oa_buffer.bo->vmap; > > > + u32 part =3D stream->oa_buffer.circ_size - head; > > > > > > /* Zero out the entire report */ > > > if (report_size <=3D part) { > > > - memset(report, 0, report_size); > > > + xe_map_memset(stream->oa->xe, map, head, 0, report_size); > > > } else { > > > - memset(report, 0, part); > > > - memset(oa_buf_base, 0, report_size - part); > > > + xe_map_memset(stream->oa->xe, map, head, 0, part); > > > + xe_map_memset(stream->oa->xe, map, 0, 0, report_size - part); > > > } > > > } > > > } > > > @@ -436,7 +444,8 @@ static void xe_oa_init_oa_buffer(struct xe_oa_str= eam *stream) > > > spin_unlock_irqrestore(&stream->oa_buffer.ptr_lock, flags); > > > > > > /* Zero out the OA buffer since we rely on zero report id and timesta= mp fields */ > > > - memset(stream->oa_buffer.vaddr, 0, xe_bo_size(stream->oa_buffer.bo)= ); > > > + xe_map_memset(stream->oa->xe, &stream->oa_buffer.bo->vmap, 0, 0, > > > + xe_bo_size(stream->oa_buffer.bo)); > > > } > > > > > > static u32 __format_to_oactrl(const struct xe_oa_format *format, int = counter_sel_mask) > > > @@ -699,6 +708,7 @@ static int num_lri_dwords(int num_regs) > > > static void xe_oa_free_oa_buffer(struct xe_oa_stream *stream) > > > { > > > xe_bo_unpin_map_no_vm(stream->oa_buffer.bo); > > > + kfree(stream->oa_buffer.bounce); > > > } > > > > > > static void xe_oa_free_configs(struct xe_oa_stream *stream) > > > @@ -889,9 +899,16 @@ static int xe_oa_alloc_oa_buffer(struct xe_oa_st= ream *stream, size_t size) > > > return PTR_ERR(bo); > > > > > > stream->oa_buffer.bo =3D bo; > > > + > > > /* mmap implementation requires OA buffer to be in system memory */ > > > xe_assert(stream->oa->xe, bo->vmap.is_iomem =3D=3D 0); > > > - stream->oa_buffer.vaddr =3D bo->vmap.vaddr; > > > + > > > + stream->oa_buffer.bounce =3D kmalloc(stream->oa_buffer.format->size= , GFP_KERNEL); > > > + if (!stream->oa_buffer.bounce) { > > > + xe_bo_unpin_map_no_vm(stream->oa_buffer.bo); > > > + return -ENOMEM; > > > + } > > > + > > > return 0; > > > } > > > > > > diff --git a/drivers/gpu/drm/xe/xe_oa_types.h b/drivers/gpu/drm/xe/xe= _oa_types.h > > > index b03ffd5134834..99a04b8d586b5 100644 > > > --- a/drivers/gpu/drm/xe/xe_oa_types.h > > > +++ b/drivers/gpu/drm/xe/xe_oa_types.h > > > @@ -162,8 +162,8 @@ struct xe_oa_buffer { > > > /** @format: xe_bo backing the OA buffer */ > > > struct xe_bo *bo; > > > > > > - /** @vaddr: mapped vaddr of the OA buffer */ > > > - u8 *vaddr; > > > + /** @bounce: bounce buffer used with xe_map layer */ > > > + void *bounce; > > > > > > /** @ptr_lock: Lock protecting reads/writes to head/tail pointers */ > > > spinlock_t ptr_lock; > > > -- > > > 2.48.1 > > >