Re: [PATCH v5 1/7] fpga: dfl: parse interrupt info for feature devices on enumeration

Xu Yilun
2020-05-13T09:49:32Z

On Mon, May 11, 2020 at 09:09:07PM -0700, Moritz Fischer wrote:
> On Mon, Apr 20, 2020 at 04:11:37PM +0800, Xu Yilun wrote:
> > DFL based FPGA devices could support interrupts for different purposes,
> > but current DFL framework only supports feature device enumeration with
> > given MMIO resources information via common DFL headers. This patch
> > introduces one new API dfl_fpga_enum_info_add_irq for low level bus
> > drivers (e.g. PCIe device driver) to pass its interrupt resources
> > information to DFL framework for enumeration, and also adds interrupt
> > enumeration code in framework to parse and assign interrupt resources
> > for enumerated feature devices and their own sub features.
> >
> > With this patch, DFL framework enumerates interrupt resources for core
> > features, including PORT Error Reporting, FME (FPGA Management Engine)
> > Error Reporting and also AFU User Interrupts.
> >
> > Signed-off-by: Luwei Kang <luwei.kang@intel.com>
> > Signed-off-by: Wu Hao <hao.wu@intel.com>
> > Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> > Acked-by: Wu Hao <hao.wu@intel.com>
> > ----
> > v2: early validating irq table for each feature in parse_feature_irq().
> > Some code improvement and minor fix for Hao's comments.
> > v3: put parse_feature_irqs() inside create_feature_instance()
> > some minor fixes and more comments
> > v4: no need to include asm/irq.h.
> > fail the dfl enumeration when irq parsing error happens.
> > v5: Some minor fix for Hao's comments
> > ---
> > drivers/fpga/dfl.c | 154 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> > drivers/fpga/dfl.h | 40 ++++++++++++++
> > 2 files changed, 194 insertions(+)
> >
> > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
> > index 9909948..b49fbed 100644
> > --- a/drivers/fpga/dfl.c
> > +++ b/drivers/fpga/dfl.c
> > @@ -421,6 +421,9 @@ EXPORT_SYMBOL_GPL(dfl_fpga_dev_ops_unregister);
> > *
> > * @dev: device to enumerate.
> > * @cdev: the container device for all feature devices.
> > + * @nr_irqs: number of irqs for all feature devices.
> > + * @irq_table: Linux IRQ numbers for all irqs, indexed by local irq index of
> > + * this device.
> > * @feature_dev: current feature device.
> > * @ioaddr: header register region address of feature device in enumeration.
> > * @sub_features: a sub features linked list for feature device in enumeration.
> > @@ -429,6 +432,9 @@ EXPORT_SYMBOL_GPL(dfl_fpga_dev_ops_unregister);
> > struct build_feature_devs_info {
> > struct device *dev;
> > struct dfl_fpga_cdev *cdev;
> > + unsigned int nr_irqs;
> > + int *irq_table;
> > +
> > struct platform_device *feature_dev;
> > void __iomem *ioaddr;
> > struct list_head sub_features;
> > @@ -442,12 +448,16 @@ struct build_feature_devs_info {
> > * @mmio_res: mmio resource of this sub feature.
> > * @ioaddr: mapped base address of mmio resource.
> > * @node: node in sub_features linked list.
> > + * @irq_base: start of irq index in this sub feature.
> > + * @nr_irqs: number of irqs of this sub feature.
> > */
> > struct dfl_feature_info {
> > u64 fid;
> > struct resource mmio_res;
> > void __iomem *ioaddr;
> > struct list_head node;
> > + unsigned int irq_base;
> > + unsigned int nr_irqs;
> > };
> >
> > static void dfl_fpga_cdev_add_port_dev(struct dfl_fpga_cdev *cdev,
> > @@ -520,6 +530,8 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo)
> > /* fill features and resource information for feature dev */
> > list_for_each_entry_safe(finfo, p, &binfo->sub_features, node) {
> > struct dfl_feature *feature = &pdata->features[index];
> > + struct dfl_feature_irq_ctx *ctx;
> > + unsigned int i;
> >
> > /* save resource information for each feature */
> > feature->id = finfo->fid;
> > @@ -527,6 +539,20 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo)
> > feature->ioaddr = finfo->ioaddr;
> > fdev->resource[index++] = finfo->mmio_res;
> >
> > + if (finfo->nr_irqs) {
> > + ctx = devm_kcalloc(binfo->dev, finfo->nr_irqs,
> > + sizeof(*ctx), GFP_KERNEL);
> > + if (!ctx)
> > + return -ENOMEM;
> > +
> > + for (i = 0; i < finfo->nr_irqs; i++)
> > + ctx[i].irq =
> > + binfo->irq_table[finfo->irq_base + i];
> > +
> > + feature->irq_ctx = ctx;
> > + feature->nr_irqs = finfo->nr_irqs;
> > + }
> > +
> > list_del(&finfo->node);
> > kfree(finfo);
> > }
> > @@ -638,6 +664,79 @@ static u64 feature_id(void __iomem *start)
> > return 0;
> > }
> >
> > +static int parse_feature_irqs(struct build_feature_devs_info *binfo,
> > + resource_size_t ofst, u64 fid,
> > + unsigned int *irq_base, unsigned int *nr_irqs)
> > +{
> > + void __iomem *base = binfo->ioaddr + ofst;
> > + unsigned int i, ibase, inr = 0;
> > + int virq;
> > + u64 v;
> > +
> > + /*
> > + * Ideally DFL framework should only read info from DFL header, but
> > + * current version DFL only provides mmio resources information for
> > + * each feature in DFL Header, no field for interrupt resources.
> > + * Interrupt resource information is provided by specific mmio
> > + * registers of each private feature which supports interrupt. So in
> > + * order to parse and assign irq resources, DFL framework has to look
> > + * into specific capability registers of these private features.
> > + *
> > + * Once future DFL version supports generic interrupt resource
> > + * information in common DFL headers, the generic interrupt parsing
> > + * code will be added. But in order to be compatible to old version
> > + * DFL, driver may still fall back to these quirks.
> Nit: *the* driver may still fall ack ...

Thanks for the correction, I'll fix it in next version.

> > + */
> > + switch (fid) {
> > + case PORT_FEATURE_ID_UINT:
> > + v = readq(base + PORT_UINT_CAP);
> > + ibase = FIELD_GET(PORT_UINT_CAP_FST_VECT, v);
> > + inr = FIELD_GET(PORT_UINT_CAP_INT_NUM, v);
> > + break;
> > + case PORT_FEATURE_ID_ERROR:
> > + v = readq(base + PORT_ERROR_CAP);
> > + ibase = FIELD_GET(PORT_ERROR_CAP_INT_VECT, v);
> > + inr = FIELD_GET(PORT_ERROR_CAP_SUPP_INT, v);
> > + break;
> > + case FME_FEATURE_ID_GLOBAL_ERR:
> > + v = readq(base + FME_ERROR_CAP);
> > + ibase = FIELD_GET(FME_ERROR_CAP_INT_VECT, v);
> > + inr = FIELD_GET(FME_ERROR_CAP_SUPP_INT, v);
> > + break;
> > + }
> > +
> > + if (!inr) {
> > + *irq_base = 0;
> > + *nr_irqs = 0;
> > + return 0;
> > + }
> > +
> > + dev_dbg(binfo->dev, "feature: 0x%llx, irq_base: %u, nr_irqs: %u\n",
> > + (unsigned long long)fid, ibase, inr);
> Is that cast required?

I read the printk-formats.txt, the u64 to unsigned long long cast is not
required in kernel since long time ago. I'll fix it.

> > +
> > + if (ibase + inr > binfo->nr_irqs) {
> > + dev_err(binfo->dev,
> > + "Invalid interrupt number in feature 0x%llx\n",
> > + (unsigned long long)fid);
> Same here?

Yes.

> > + return -EINVAL;
> > + }
> > +
> > + for (i = 0; i < inr; i++) {
> > + virq = binfo->irq_table[ibase + i];
> > + if (virq < 0 || virq > NR_IRQS) {
> > + dev_err(binfo->dev,
> > + "Invalid irq table entry for feature 0x%llx\n",
> > + (unsigned long long)fid);
> > + return -EINVAL;
> > + }
> > + }
> > +
> > + *irq_base = (unsigned int)ibase;
> > + *nr_irqs = (unsigned int)inr;
> ibase and nr_iqs are already unsigend int?

Yes, the cast is not needed.

Thanks,
Yilun.

> > +
> > + return 0;
> > +}
> > +
> > /*
> > * when create sub feature instances, for private features, it doesn't need
> > * to provide resource size and feature id as they could be read from DFH
> > @@ -650,7 +749,9 @@ create_feature_instance(struct build_feature_devs_info *binfo,
> > struct dfl_fpga_enum_dfl *dfl, resource_size_t ofst,
> > resource_size_t size, u64 fid)
> > {
> > + unsigned int irq_base, nr_irqs;
> > struct dfl_feature_info *finfo;
> > + int ret;
> >
> > /* read feature size and id if inputs are invalid */
> > size = size ? size : feature_size(dfl->ioaddr + ofst);
> > @@ -659,6 +760,10 @@ create_feature_instance(struct build_feature_devs_info *binfo,
> > if (dfl->len - ofst < size)
> > return -EINVAL;
> >
> > + ret = parse_feature_irqs(binfo, ofst, fid, &irq_base, &nr_irqs);
> > + if (ret)
> > + return ret;
> > +
> > finfo = kzalloc(sizeof(*finfo), GFP_KERNEL);
> > if (!finfo)
> > return -ENOMEM;
> > @@ -667,6 +772,8 @@ create_feature_instance(struct build_feature_devs_info *binfo,
> > finfo->mmio_res.start = dfl->start + ofst;
> > finfo->mmio_res.end = finfo->mmio_res.start + size - 1;
> > finfo->mmio_res.flags = IORESOURCE_MEM;
> > + finfo->irq_base = irq_base;
> > + finfo->nr_irqs = nr_irqs;
> > finfo->ioaddr = dfl->ioaddr + ofst;
> >
> > list_add_tail(&finfo->node, &binfo->sub_features);
> > @@ -853,6 +960,10 @@ void dfl_fpga_enum_info_free(struct dfl_fpga_enum_info *info)
> > devm_kfree(dev, dfl);
> > }
> >
> > + /* remove irq table */
> > + if (info->irq_table)
> > + devm_kfree(dev, info->irq_table);
> > +
> > devm_kfree(dev, info);
> > put_device(dev);
> > }
> > @@ -892,6 +1003,45 @@ int dfl_fpga_enum_info_add_dfl(struct dfl_fpga_enum_info *info,
> > }
> > EXPORT_SYMBOL_GPL(dfl_fpga_enum_info_add_dfl);
> >
> > +/**
> > + * dfl_fpga_enum_info_add_irq - add irq table to enum info
> > + *
> > + * @info: ptr to dfl_fpga_enum_info
> > + * @nr_irqs: number of irqs of the DFL fpga device to be enumerated.
> > + * @irq_table: Linux IRQ numbers for all irqs, indexed by local irq index of
> > + * this device.
> > + *
> > + * One FPGA device may have several interrupts. This function adds irq
> > + * information of the DFL fpga device to enum info for next step enumeration.
> > + * This function should be called before dfl_fpga_feature_devs_enumerate().
> > + * As we only support one irq domain for all DFLs in the same enum info, adding
> > + * irq table a second time for the same enum info will return error.
> > + *
> > + * If we need to enumerate DFLs which belong to different irq domains, we
> > + * should fill more enum info and enumerate them one by one.
> > + *
> > + * Return: 0 on success, negative error code otherwise.
> > + */
> > +int dfl_fpga_enum_info_add_irq(struct dfl_fpga_enum_info *info,
> > + unsigned int nr_irqs, int *irq_table)
> > +{
> > + if (!nr_irqs || !irq_table)
> > + return -EINVAL;
> > +
> > + if (info->irq_table)
> > + return -EEXIST;
> > +
> > + info->irq_table = devm_kmemdup(info->dev, irq_table,
> > + sizeof(int) * nr_irqs, GFP_KERNEL);
> > + if (!info->irq_table)
> > + return -ENOMEM;
> > +
> > + info->nr_irqs = nr_irqs;
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(dfl_fpga_enum_info_add_irq);
> > +
> > static int remove_feature_dev(struct device *dev, void *data)
> > {
> > struct platform_device *pdev = to_platform_device(dev);
> > @@ -959,6 +1109,10 @@ dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info)
> > binfo->dev = info->dev;
> > binfo->cdev = cdev;
> >
> > + binfo->nr_irqs = info->nr_irqs;
> > + if (info->nr_irqs)
> > + binfo->irq_table = info->irq_table;
> > +
> > /*
> > * start enumeration for all feature devices based on Device Feature
> > * Lists.
> > diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
> > index 74784d3..4bc165f 100644
> > --- a/drivers/fpga/dfl.h
> > +++ b/drivers/fpga/dfl.h
> > @@ -112,6 +112,13 @@
> > #define FME_PORT_OFST_ACC_VF 1
> > #define FME_PORT_OFST_IMP BIT_ULL(60)
> >
> > +/* FME Error Capability Register */
> > +#define FME_ERROR_CAP 0x70
> > +
> > +/* FME Error Capability Register Bitfield */
> > +#define FME_ERROR_CAP_SUPP_INT BIT_ULL(0) /* Interrupt Support */
> > +#define FME_ERROR_CAP_INT_VECT GENMASK_ULL(12, 1) /* Interrupt vector */
> > +
> > /* PORT Header Register Set */
> > #define PORT_HDR_DFH DFH
> > #define PORT_HDR_GUID_L GUID_L
> > @@ -145,6 +152,20 @@
> > #define PORT_STS_PWR_STATE_AP2 2 /* 90% throttling */
> > #define PORT_STS_PWR_STATE_AP6 6 /* 100% throttling */
> >
> > +/* Port Error Capability Register */
> > +#define PORT_ERROR_CAP 0x38
> > +
> > +/* Port Error Capability Register Bitfield */
> > +#define PORT_ERROR_CAP_SUPP_INT BIT_ULL(0) /* Interrupt Support */
> > +#define PORT_ERROR_CAP_INT_VECT GENMASK_ULL(12, 1) /* Interrupt vector */
> > +
> > +/* Port Uint Capability Register */
> > +#define PORT_UINT_CAP 0x8
> > +
> > +/* Port Uint Capability Register Bitfield */
> > +#define PORT_UINT_CAP_INT_NUM GENMASK_ULL(11, 0) /* Interrupts num */
> > +#define PORT_UINT_CAP_FST_VECT GENMASK_ULL(23, 12) /* First Vector */
> > +
> > /**
> > * struct dfl_fpga_port_ops - port ops
> > *
> > @@ -189,6 +210,15 @@ struct dfl_feature_driver {
> > };
> >
> > /**
> > + * struct dfl_feature_irq_ctx - dfl private feature interrupt context
> > + *
> > + * @irq: Linux IRQ number of this interrupt.
> > + */
> > +struct dfl_feature_irq_ctx {
> > + int irq;
> > +};
> > +
> > +/**
> > * struct dfl_feature - sub feature of the feature devices
> > *
> > * @id: sub feature id.
> > @@ -196,12 +226,16 @@ struct dfl_feature_driver {
> > * this index is used to find its mmio resource from the
> > * feature dev (platform device)'s reources.
> > * @ioaddr: mapped mmio resource address.
> > + * @irq_ctx: interrupt context list.
> > + * @nr_irqs: number of interrupt contexts.
> > * @ops: ops of this sub feature.
> > */
> > struct dfl_feature {
> > u64 id;
> > int resource_index;
> > void __iomem *ioaddr;
> > + struct dfl_feature_irq_ctx *irq_ctx;
> > + unsigned int nr_irqs;
> > const struct dfl_feature_ops *ops;
> > };
> >
> > @@ -388,10 +422,14 @@ static inline u8 dfl_feature_revision(void __iomem *base)
> > *
> > * @dev: parent device.
> > * @dfls: list of device feature lists.
> > + * @nr_irqs: number of irqs for all feature devices.
> > + * @irq_table: Linux IRQ numbers for all irqs, indexed by hw irq numbers.
> > */
> > struct dfl_fpga_enum_info {
> > struct device *dev;
> > struct list_head dfls;
> > + unsigned int nr_irqs;
> > + int *irq_table;
> > };
> >
> > /**
> > @@ -415,6 +453,8 @@ struct dfl_fpga_enum_info *dfl_fpga_enum_info_alloc(struct device *dev);
> > int dfl_fpga_enum_info_add_dfl(struct dfl_fpga_enum_info *info,
> > resource_size_t start, resource_size_t len,
> > void __iomem *ioaddr);
> > +int dfl_fpga_enum_info_add_irq(struct dfl_fpga_enum_info *info,
> > + unsigned int nr_irqs, int *irq_table);
> > void dfl_fpga_enum_info_free(struct dfl_fpga_enum_info *info);
> >
> > /**
> > --
> > 2.7.4
> >
>
> Thanks,
> Moritz