From: Bagas Sanjaya <bagasdotme@gmail.com>
To: Joel Fernandes <joelagnelf@nvidia.com>,
linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org,
dri-devel@lists.freedesktop.org, dakr@kernel.org,
acourbot@nvidia.com
Cc: Alistair Popple <apopple@nvidia.com>,
Miguel Ojeda <ojeda@kernel.org>,
Alex Gaynor <alex.gaynor@gmail.com>,
Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>,
bjorn3_gh@protonmail.com, Benno Lossin <lossin@kernel.org>,
Andreas Hindborg <a.hindborg@kernel.org>,
Alice Ryhl <aliceryhl@google.com>,
Trevor Gross <tmgross@umich.edu>,
David Airlie <airlied@gmail.com>, Simona Vetter <simona@ffwll.ch>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
John Hubbard <jhubbard@nvidia.com>, Timur Tabi <ttabi@nvidia.com>,
joel@joelfernandes.org, Elle Rhumsaa <elle@weathered-steel.dev>,
Daniel Almeida <daniel.almeida@collabora.com>,
nouveau@lists.freedesktop.org
Subject: Re: [PATCH 4/7] docs: gpu: nova-core: Document the PRAMIN aperture mechanism
Date: Wed, 22 Oct 2025 09:09:06 +0700 [thread overview]
Message-ID: <aPg8wuF5ZodLxOH0@archie.me> (raw)
In-Reply-To: <20251020185539.49986-5-joelagnelf@nvidia.com>
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On Mon, Oct 20, 2025 at 02:55:36PM -0400, Joel Fernandes wrote:
> +The window position is controlled via the PBUS BAR0_WINDOW register::
> +
> + NV_PBUS_BAR0_WINDOW Register
> + +-----+-----+--------------------------------------+
> + |31-26|25-24| 23-0 |
> + | |TARG | BASE_ADDR |
> + | | ET | (bits 39:16 of VRAM address) |
> + +-----+-----+--------------------------------------+
Shouldn't the TARGET field cell above be fitted (extended)?
> +
> + TARGET field values:
> + - 0x0: VID_MEM (Video Memory / VRAM)
> + - 0x1: SYS_MEM_COHERENT (Coherent system memory)
> + - 0x2: SYS_MEM_NONCOHERENT (Non-coherent system memory)
> +
> +64KB Alignment Requirement
> +---------------------------
> +
> +The PRAMIN window must be aligned to 64KB boundaries in VRAM. This is enforced
> +by the BASE_ADDR field representing bits [39:16] of the target address::
> +
> + VRAM Address Calculation:
> + actual_vram_addr = (BASE_ADDR << 16) + pramin_offset
> + Where:
> + - BASE_ADDR: 24-bit value from NV_PBUS_BAR0_WINDOW[23:0]
> + - pramin_offset: 20-bit offset within PRAMIN window [0x00000-0xFFFFF]
> + Example Window Positioning:
Move the supplementary explanation out of respective literal code blocks,
like::
---- >8 ----
diff --git a/Documentation/gpu/nova/core/pramin.rst b/Documentation/gpu/nova/core/pramin.rst
index 19615e504db9d5..47abe539e32a81 100644
--- a/Documentation/gpu/nova/core/pramin.rst
+++ b/Documentation/gpu/nova/core/pramin.rst
@@ -70,23 +70,28 @@ The window position is controlled via the PBUS BAR0_WINDOW register::
| | ET | (bits 39:16 of VRAM address) |
+-----+-----+--------------------------------------+
- TARGET field values:
- - 0x0: VID_MEM (Video Memory / VRAM)
- - 0x1: SYS_MEM_COHERENT (Coherent system memory)
- - 0x2: SYS_MEM_NONCOHERENT (Non-coherent system memory)
+where TARGET field values are:
+
+ - 0x0: VID_MEM (Video Memory / VRAM)
+ - 0x1: SYS_MEM_COHERENT (Coherent system memory)
+ - 0x2: SYS_MEM_NONCOHERENT (Non-coherent system memory)
64KB Alignment Requirement
---------------------------
The PRAMIN window must be aligned to 64KB boundaries in VRAM. This is enforced
-by the BASE_ADDR field representing bits [39:16] of the target address::
+by the BASE_ADDR field representing bits [39:16] of the target address. The
+VRAM address calculation is determined by::
- VRAM Address Calculation:
actual_vram_addr = (BASE_ADDR << 16) + pramin_offset
- Where:
- - BASE_ADDR: 24-bit value from NV_PBUS_BAR0_WINDOW[23:0]
- - pramin_offset: 20-bit offset within PRAMIN window [0x00000-0xFFFFF]
- Example Window Positioning:
+
+where:
+
+ - BASE_ADDR: 24-bit value from NV_PBUS_BAR0_WINDOW[23:0]
+ - pramin_offset: 20-bit offset within PRAMIN window [0x00000-0xFFFFF]
+
+Example window positioning::
+
+---------------------------------------------------------+
| VRAM Space |
| |
Thanks.
--
An old man doll... just what I always wanted! - Clara
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next prev parent reply other threads:[~2025-10-22 2:09 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-20 18:55 [PATCH 0/7] Pre-requisite patches for mm and irq in nova-core Joel Fernandes
2025-10-20 18:55 ` [PATCH 1/7] docs: rust: Fix a few grammatical errors Joel Fernandes
2025-10-20 21:21 ` John Hubbard
2025-10-20 21:33 ` Miguel Ojeda
2025-10-20 23:23 ` Joel Fernandes
2025-10-20 18:55 ` [PATCH 2/7] gpu: nova-core: Add support to convert bitfield to underlying type Joel Fernandes
2025-10-20 21:25 ` John Hubbard
2025-10-22 6:25 ` Alexandre Courbot
2025-10-22 17:51 ` Joel Fernandes
2025-10-20 18:55 ` [PATCH 3/7] docs: gpu: nova-core: Document GSP RPC message queue architecture Joel Fernandes
2025-10-20 21:49 ` John Hubbard
2025-10-22 1:43 ` Bagas Sanjaya
2025-10-22 11:16 ` Alexandre Courbot
2025-10-20 18:55 ` [PATCH 4/7] docs: gpu: nova-core: Document the PRAMIN aperture mechanism Joel Fernandes
2025-10-20 19:36 ` John Hubbard
2025-10-20 19:48 ` Joel Fernandes
2025-10-20 20:42 ` John Hubbard
2025-10-20 20:45 ` Joel Fernandes
2025-10-20 22:08 ` John Hubbard
2025-10-22 2:09 ` Bagas Sanjaya [this message]
2025-10-20 18:55 ` [PATCH 5/7] gpu: nova-core: Add support for managing GSP falcon interrupts Joel Fernandes
2025-10-20 22:35 ` John Hubbard
2025-10-21 18:42 ` Joel Fernandes
2025-10-22 6:48 ` Alexandre Courbot
2025-10-22 21:09 ` Joel Fernandes
2025-10-22 23:16 ` John Hubbard
2025-10-22 6:47 ` Alexandre Courbot
2025-10-22 21:05 ` Joel Fernandes
2025-10-20 18:55 ` [PATCH 6/7] nova-core: mm: Add support to use PRAMIN windows to write to VRAM Joel Fernandes
2025-10-22 2:18 ` John Hubbard
2025-10-22 17:48 ` Joel Fernandes
2025-10-22 20:43 ` Joel Fernandes
2025-10-24 11:31 ` Alexandre Courbot
2025-10-22 10:41 ` Alexandre Courbot
2025-10-22 22:04 ` Joel Fernandes
2025-10-24 11:39 ` Alexandre Courbot
2025-10-20 18:55 ` [PATCH 7/7] nova-core: mm: Add data structures for page table management Joel Fernandes
2025-10-20 20:59 ` John Hubbard
2025-10-21 18:26 ` Joel Fernandes
2025-10-21 20:30 ` John Hubbard
2025-10-21 21:58 ` Joel Fernandes
2025-10-20 21:30 ` Miguel Ojeda
2025-11-03 19:21 ` Joel Fernandes
2025-11-04 17:54 ` Miguel Ojeda
2025-11-04 18:18 ` Danilo Krummrich
2025-11-03 19:29 ` John Hubbard
2025-11-04 17:56 ` Miguel Ojeda
2025-11-05 2:25 ` John Hubbard
2025-10-22 11:21 ` Alexandre Courbot
2025-10-22 19:13 ` Joel Fernandes
2025-10-20 21:20 ` [PATCH 0/7] Pre-requisite patches for mm and irq in nova-core John Hubbard
2025-10-21 18:29 ` Joel Fernandes
2025-10-22 6:57 ` Alexandre Courbot
2025-10-22 21:30 ` Joel Fernandes
2025-10-24 11:51 ` Alexandre Courbot
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