From: Dave Jiang <dave.jiang@intel.com>
To: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
Subject: Re: [PATCH] dmaengine: idxd: add module parameter to force disable of SVA
Date: Mon, 18 Jan 2021 10:06:56 -0700 [thread overview]
Message-ID: <a7b50b40-ee4a-24c3-d4ba-40c770c970f1@intel.com> (raw)
In-Reply-To: <20210117065115.GL2771@vkoul-mobl>
On 1/16/2021 11:51 PM, Vinod Koul wrote:
> On 15-01-21, 15:01, Dave Jiang wrote:
>> Add a module parameter that overrides the SVA feature enabling. This keeps
>> the driver in legacy mode even when intel_iommu=sm_on is set. In this mode,
>> the descriptor fields must be programmed with dma_addr_t from the Linux DMA
>> API for source, destination, and completion descriptors.
>>
>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>> ---
>> drivers/dma/idxd/init.c | 8 +++++++-
>> 1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
>> index 25cc947c6179..9687a24ff982 100644
>> --- a/drivers/dma/idxd/init.c
>> +++ b/drivers/dma/idxd/init.c
>> @@ -26,6 +26,10 @@ MODULE_VERSION(IDXD_DRIVER_VERSION);
>> MODULE_LICENSE("GPL v2");
>> MODULE_AUTHOR("Intel Corporation");
>>
>> +static bool sva = true;
>> +module_param(sva, bool, 0644);
>> +MODULE_PARM_DESC(sva, "Toggle SVA support on/off");
> Documentation for this please..
Just comments or is there somewhere specific for driver module parameter
documentations?
>
>> +
>> #define DRV_NAME "idxd"
>>
>> bool support_enqcmd;
>> @@ -338,12 +342,14 @@ static int idxd_probe(struct idxd_device *idxd)
>> idxd_device_init_reset(idxd);
>> dev_dbg(dev, "IDXD reset complete\n");
>>
>> - if (IS_ENABLED(CONFIG_INTEL_IDXD_SVM)) {
>> + if (IS_ENABLED(CONFIG_INTEL_IDXD_SVM) && sva) {
>> rc = idxd_enable_system_pasid(idxd);
>> if (rc < 0)
>> dev_warn(dev, "Failed to enable PASID. No SVA support: %d\n", rc);
>> else
>> set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
>> + } else if (!sva) {
>> + dev_warn(dev, "User forced SVA off via module param.\n");
>> }
>>
>> idxd_read_caps(idxd);
>>
next prev parent reply other threads:[~2021-01-18 17:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-15 22:01 [PATCH] dmaengine: idxd: add module parameter to force disable of SVA Dave Jiang
2021-01-17 6:51 ` Vinod Koul
2021-01-18 17:06 ` Dave Jiang [this message]
2021-01-19 16:38 ` Vinod Koul
2021-01-19 19:44 ` Dave Jiang
2021-01-26 17:02 ` Vinod Koul
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