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From: Sibi Sankar <>
To: Christoph Hellwig <>
Subject: Re: [PATCH 0/3] Request direct mapping for modem firmware subdevice
Date: Mon, 16 Mar 2020 22:07:04 +0530
Message-ID: <> (raw)
In-Reply-To: <>

Hey Christoph,
Thanks for taking time to review
the series.

On 2020-03-16 21:20, Christoph Hellwig wrote:
> On Mon, Mar 09, 2020 at 11:52:52PM +0530, Sibi Sankar wrote:
>> The Q6 modem sub-system has direct access to DDR through memnoc and
>> an indirect access routed through a SMMU which MSS CE (crypto engine
>> sub-component of MSS) uses during out of reset sequence. Request 
>> direct
>> mapping for the modem-firmware subdevice since smmu is not expected
>> to provide access control/translation for these SIDs (sandboxing of 
>> the
>> modem is achieved through XPUs engaged using SMC calls).
> Please fix your device tree so that the device isn't bound to an

the bindings proposed in the series
would add a sub-device with an iommu

modem_pil: remoteproc@xxxxx {
    modem-firmware {
         iommus = <&apps_smmu 0x460 0x1>;

Remoteproc device will not have a iommu
property but modem-firmware sub-device

we would want to configure the SID either
in direct mapping or bypass (either will
do since protection is achieved through
other means)

Currently the restructuring is trending
towards whats discussed in the ^^ thread.
i.e either direct mapping/bypass will be
done in the SoC specific corner of the
SMMU driver.

Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project.

      reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-09 18:22 Sibi Sankar
2020-03-09 18:22 ` [PATCH 1/3] iommu: Export "iommu_request_dm_for_dev" Sibi Sankar
2020-03-09 18:22 ` [PATCH 2/3] dt-bindings: remoteproc: qcom: Add modem-firmware bindings Sibi Sankar
2020-03-09 18:22 ` [PATCH 3/3] remoteproc: qcom_q6v5_mss: Request direct mapping for firmware subdevice Sibi Sankar
2020-03-10 11:23 ` [PATCH 0/3] Request direct mapping for modem " Joerg Roedel
2020-03-10 14:00   ` Sibi Sankar
2020-03-10 16:23     ` Joerg Roedel
2020-03-10 16:44       ` Robin Murphy
2020-03-12  6:28         ` Sai Prakash Ranjan
2020-03-12 12:05           ` Robin Murphy
2020-03-23  9:43             ` Sai Prakash Ranjan
2020-03-16 15:50 ` Christoph Hellwig
2020-03-16 16:37   ` Sibi Sankar [this message]

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