[PATCH v7 2/2] iommu/exynos: Add iommu driver for Exynos Platforms
KyongHo Cho
pullip.cho at samsung.com
Tue Dec 6 07:20:31 EST 2011
On Tue, Dec 6, 2011 at 8:48 PM, Marek Szyprowski
<m.szyprowski at samsung.com> wrote:
> Hello,
>
> I'm trying to integrate your SYSMMU driver with my DMA-mapping & IOMMU
> API integration patches. I've noticed some issues, please see my comments below.
>
Thank you!
> On Friday, November 18, 2011 10:48 AM KyongHo Cho wrote:
>
>> +
>> +static int exynos_sysmmu_probe(struct platform_device *pdev)
>> +{
>> + struct resource *res, *ioarea;
>> + int ret;
>> + int irq;
>> + struct device *dev;
>> + void *sfr;
>> + struct sysmmu_drvdata *data;
>> + char *emsg;
>> +
>> + dev = &pdev->dev;
>> +
>> + if (dev_get_platdata(dev) == NULL) {
>> + pr_debug("%s: No System MMU is assigned for %s.%d.\n", __func__,
>> + pdev->name, pdev->id);
>> + return -ENODEV;
>> + }
>> +
>> + data = kzalloc(sizeof(*data), GFP_KERNEL);
>> + if (!data) {
>> + emsg = "Not enough memory";
>> + ret = -ENOMEM;
>> + goto err_alloc;
>> + }
>> +
>> + data->owner = dev_get_platdata(dev);
>> +
>> + ret = dev_set_drvdata(dev, data);
>> + if (ret) {
>> + emsg = "Unable to set driver data.";
>> + goto err_init;
>> + }
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + if (!res) {
>> + emsg = "Failed probing system MMU: failed to get resource.";
>> + goto err_init;
>> + }
>> +
>> + ioarea = request_mem_region(res->start, resource_size(res),
>> + dev_name(dev));
>> + if (ioarea == NULL) {
>> + emsg = "failed to request memory region.";
>> + ret = -ENOMEM;
>> + goto err_init;
>> + }
>> +
>> + sfr = ioremap(res->start, resource_size(res));
>> + if (!sfr) {
>> + emsg = "failed to call ioremap().";
>> + ret = -ENOENT;
>> + goto err_ioremap;
>> + }
>> +
>> + irq = platform_get_irq(pdev, 0);
>> + if (irq <= 0) {
>> + emsg = "failed to get irq resource.";
>> + ret = irq;
>> + goto err_irq;
>> + }
>> +
>> + ret = request_irq(irq, exynos_sysmmu_irq, 0, dev_name(dev), data);
>> + if (ret) {
>> + emsg = "failed to request irq.";
>> + goto err_irq;
>> + }
>> +
>> + data->clk = clk_get(dev, "sysmmu");
>> + if (IS_ERR(data->clk)) {
>> + emsg = "failed to get clock descriptor";
>> + ret = PTR_ERR(data->clk);
>> + goto err_clk;
>> + }
>> +
>> + data->dev = dev;
>> + data->sfrbase = sfr;
>> + __set_fault_handler(data, &default_fault_handler);
>> + rwlock_init(&data->lock);
>
> Here is a serious problem: __set_fault_handler takes data->lock which is initialized after calling
> this function.
>
Yeah, you're right. Thank you. I didn't notice it.
I will fix it.
>> +
>> +static unsigned long *alloc_lv2entry(unsigned long *sent, unsigned long iova,
>> + short *pgcounter)
>> +{
>> + if (lv1ent_fault(sent)) {
>> + unsigned long *pent;
>> +
>> + pent = kzalloc(1024, GFP_KERNEL);
>
> I would use GFP_ATOMIC here. iommu_map() function might be called in atomic context, and
> GFP_KERNEL here causes kernel ops/warning.
>
I wanted to avoid to allocate memory from emergency pool.
Do you think that it needs to allocate memory with GFP_ATOMIC flag?
Thanks.
KyongHo.
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