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Message-ID: <1eeed328-fd6c-4740-b1f5-339aad559997@linux.intel.com>
Date: Thu, 2 May 2024 11:51:22 +0800
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Cc: baolu.lu@linux.intel.com, Palmer Dabbelt <palmer@dabbelt.com>,
 Albert Ou <aou@eecs.berkeley.edu>, Anup Patel <apatel@ventanamicro.com>,
 Sunil V L <sunilvl@ventanamicro.com>, Nick Kossifidis <mick@ics.forth.gr>,
 Sebastien Boeuf <seb@rivosinc.com>, Rob Herring <robh+dt@kernel.org>,
 Krzysztof Kozlowski <krzk+dt@kernel.org>, Conor Dooley
 <conor+dt@kernel.org>, devicetree@vger.kernel.org, iommu@lists.linux.dev,
 linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
 linux@rivosinc.com
Subject: Re: [PATCH v3 6/7] iommu/riscv: Command and fault queue support
To: Tomasz Jeznach <tjeznach@rivosinc.com>, Joerg Roedel <joro@8bytes.org>,
 Will Deacon <will@kernel.org>, Robin Murphy <robin.murphy@arm.com>,
 Paul Walmsley <paul.walmsley@sifive.com>
References: <cover.1714494653.git.tjeznach@rivosinc.com>
 <fbf49cba213b03d42aae398c1b48da06e3f6e1b7.1714494653.git.tjeznach@rivosinc.com>
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From: Baolu Lu <baolu.lu@linux.intel.com>
In-Reply-To: <fbf49cba213b03d42aae398c1b48da06e3f6e1b7.1714494653.git.tjeznach@rivosinc.com>
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On 5/1/24 4:01 AM, Tomasz Jeznach wrote:
> Introduce device command submission and fault reporting queues,
> as described in Chapter 3.1 and 3.2 of the RISC-V IOMMU Architecture
> Specification.
> 
> Command and fault queues are instantiated in contiguous system memory
> local to IOMMU device domain, or mapped from fixed I/O space provided
> by the hardware implementation. Detection of the location and maximum
> allowed size of the queue utilize WARL properties of queue base control
> register. Driver implementation will try to allocate up to 128KB of
> system memory, while respecting hardware supported maximum queue size.
> 
> Interrupts allocation is based on interrupt vectors availability and
> distributed to all queues in simple round-robin fashion. For hardware
> Implementation with fixed event type to interrupt vector assignment
> IVEC WARL property is used to discover such mappings.
> 
> Address translation, command and queue fault handling in this change
> is limited to simple fault reporting without taking any action.
> 
> Signed-off-by: Tomasz Jeznach<tjeznach@rivosinc.com>

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>

Best regards,
baolu