On 07/10, Rob Clark wrote:
> So, in it's current form, this is superficially a copy of msm_iommu
> plus DT conversion. But the pre-DT IOMMU driver had fairly different
> structure.. ie. psuedo root device, with IOMMU devices hanging off
> that, and context devices hanging off that. The context devices were
> what the client device would attach (which was also somewhat non-
> standard.. see msm_iommu_get_ctx()).
>
> I couldn't really think of some sane way to refactor this and add DT
> while at the same time keeping compatibility with the old pre-DT msm
> stuff. So I copied to a new driver.
>
> It was pointed out that nothing upstream actually *used* the msm_iommu
> driver. So if no one objects to dropping pre-DT support, then I could
> do some patch rejuggling + sed to make this replace the old driver
> instead.
+1
> +
> +// TODO any good reason for global lock vs per-iommu lock?
> +DEFINE_SPINLOCK(qcom_iommu_lock);
static?
> +static LIST_HEAD(qcom_iommu_devices);
> +
> +/* Note that a single iommu_domain can, for devices sitting behind
> + * more than one IOMMU (ie. one per AXI interface) will have more
> + * than one iommu in the iommu_list. But all are programmed to
> + * point at the same pagetables so from client device perspective
> + * they act as a single IOMMU.
> + */
> +struct qcom_domain_priv {
> + unsigned long *pgtable;
> + struct list_head iommu_list; /* list of attached 'struct qcom_iommu' */
> +};
> +
> +static int __enable_clocks(struct qcom_iommu *iommu)
> +{
> + int ret;
> +
> + ret = clk_prepare_enable(iommu->pclk);
Looks like __enable_clocks() is called from within a spinlock
sometimes. Please move the prepare call outside of any atomic
sections and also enable CONFIG_PROVE_LOCKING and/or
CONFIG_DEBUG_ATOMIC_SLEEP to find such problems.
> + if (ret)
> + goto fail;
> +
> + if (iommu->clk) {
> + ret = clk_prepare_enable(iommu->clk);
> + if (ret)
> + clk_disable_unprepare(iommu->pclk);
> + }
> +fail:
> + return ret;
> +}
> +
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