Messages in this thread | | | Date | Tue, 19 Aug 2014 15:51:54 -0500 | From | German Rivera <> | Subject | Re: [RFC PATCH 2/4] drivers/bus: Freescale Management Complex (fsl-mc) bus driver |
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Hi Arnd,
Thanks for your comments. My replies inline below. Please let me know if there is anything else, before post a respin of the patch series that addresses your comments.
Thanks,
German
On 08/16/2014 09:12 AM, Arnd Bergmann wrote: > On Friday 15 August 2014 17:13:12 J. German Rivera wrote: >> +struct fsl_mc_bus *fsl_mc_bus; >> +EXPORT_SYMBOL(fsl_mc_bus); > > This does not look like something that should be exported. > Or even better, kill this structure entirely and just pass around > pointers to the fsl_mc_device so you can deal with multiple root > instances. > Ok. I'll remove this global structure.
>> +static struct kmem_cache *mc_dev_cache; >> + >> +/** >> + * fsl_mc_bus_match - device to driver matching callback >> + * @dev: the MC object device structure to match against >> + * @drv: the device driver to search for matching MC object device id >> + * structures >> + * >> + * Returns 1 on success, 0 otherwise. >> + */ >> +static int fsl_mc_bus_match(struct device *dev, struct device_driver *drv) >> +{ >> + const struct fsl_mc_device_match_id *id; >> + struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev); >> + struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(drv); >> + bool found = false; >> + >> + if (WARN_ON(mc_dev->magic != FSL_MC_DEVICE_MAGIC)) >> + goto out; >> + if (WARN_ON(mc_drv->magic != FSL_MC_DRIVER_MAGIC)) >> + goto out; > > We normally don't do this magic number matching, just remove these > and rely on the compile-time checks. Ok. I'll remove all the magic fields and their checking.
>> +struct bus_type fsl_mc_bus_type = { >> + .name = "fsl-mc", >> + .match = fsl_mc_bus_match, >> + .uevent = fsl_mc_bus_uevent, >> + .drv_groups = NULL, >> + .dev_groups = NULL, >> + .bus_groups = NULL, >> + .pm = NULL, >> +}; >> +EXPORT_SYMBOL(fsl_mc_bus_type); > > No need to assign NULL members. > Ok. I'll removed them.
> Does it need to be exported to drivers? How about making it > EXPORT_SYMBOL_GPL if it does? > Yes it needs to be accessed by another driver that will come in a later patch series. I'll change it to EXPORT_SYMBOL_GPL()
>> +static int dprc_parse_dt_node(struct platform_device *pdev, >> + phys_addr_t *mc_portal_phys_addr, >> + uint32_t *mc_portal_size) >> +{ >> + struct resource res; >> + struct device_node *pdev_of_node = pdev->dev.of_node; >> + int error = -EINVAL; >> + >> + error = of_address_to_resource(pdev_of_node, 0, &res); >> + if (error < 0) { >> + FSL_MC_ERROR(&pdev->dev, >> + "of_address_to_resource() failed for %s\n", >> + pdev_of_node->full_name); >> + goto out; >> + } >> + >> + *mc_portal_phys_addr = res.start; >> + *mc_portal_size = resource_size(&res); >> + error = 0; >> +out: >> + return error; >> +} > > Why not just call of_address_to_resource in the caller? > Done.
>> +/** >> + * __fsl_mc_driver_register - registers a child device driver with the >> + * MC bus >> + * >> + * This function is implicitly invoked from the registration function of >> + * fsl_mc device drivers, which is generated by the >> + * module_fsl_mc_driver() macro. >> + */ >> +int __fsl_mc_driver_register(struct fsl_mc_driver *mc_driver, >> + struct module *owner) >> +{ >> + struct fsl_mc_device *root_mc_dev; > > Here the root_mc_dev variable isn't really used for much. > Removed.
>> +static int fsl_mc_device_get_mmio_regions(struct fsl_mc_device *mc_dev, >> + struct fsl_mc_device *container_dev) >> +{ >> + int i; >> + int error; >> + struct fsl_mc_device_region *regions; >> + struct dprc_obj_desc *obj_desc = &mc_dev->obj_desc; >> + struct device *parent_dev = mc_dev->dev.parent; >> + >> + regions = kmalloc_array(obj_desc->region_count, >> + sizeof(regions[0]), GFP_KERNEL); > > Better use 'struct resource' for the resources than make your own type. > Ok, I will remove struct fsl_mc_device_region and use struct resource instead.
>> + mc_dev->icid = container_dev->icid; >> + mc_dev->dma_mask = 0xffffffff; /* 32bit */ >> + mc_dev->dev.dma_mask = &mc_dev->dma_mask; > > Is 32-bit DMA a fundamental limit of the bus? > No, there is not 32-bit DMA limitation for this bus. Also,this dma_mask field is not currently being used. So, I'll remove it.
>> + >> +static const struct of_device_id fsl_mc_bus_match_table[] = { >> + {.compatible = "fsl,qoriq-mc",}, >> + {}, >> +}; > > Please add a binding documentation for this device in Documentation/device-tree/ > Yes, this is being added in the 'ARM64: Add support for FSL's LS2085A SoC' patch series, already posted for review.
>> +#define FSL_MC_MAGIC(_a, _b, _c, _d) \ >> + (((uint32_t)(_a) << 24) | \ >> + ((uint32_t)(_b) << 16) | \ >> + ((uint32_t)(_c) << 8) | \ >> + (uint32_t)(_d)) > > Can be dropped once you remove all the magic number matching > Done.
>> +/** >> + * struct fsl_mc_device_region - MC object device MMIO region >> + * @addr: base physical address >> + * @size: size of the region in bytes >> + */ >> +struct fsl_mc_device_region { >> + phys_addr_t paddr; >> + uint32_t size; >> +}; > > Can be removed when you move to 'struct resource' > Done.
>> +/** >> + * struct fsl_mc_device - MC object device object >> + * @magic: marker to verify identity of this structure > > remove > Removed all 'magic' fields
>> + * @flags: MC object device flags >> + * @icid: Isolation context ID for the device >> + * @mc_handle: MC handle for the corresponding MC object opened >> + * @mc_io: Pointer to MC IO object assigned to this device or >> + * NULL if none. >> + * @driver: Pointer to the MC object device driver for this device > > Use container_of(&this->dev.driver, ...) instead > Removed redundant driver field.
>> + * @container: Pointer to the DPRC device that contains this MC object device > > Why are there two devices for this? Should this just use dev->parent instead? > You are right. Removed the container field. We can get the parent DPRC of a given dev, from its dev.parent field.
>> + * @dev_node: Node in the container's child list > > Same here: just use the device model's list management instead if you can, > or explain why this is needed. > We still need to keep a per-bus list of child devices (devices contained in a given DPRC object). Unless I'm missing something, I think the device model's list management links together all the devices of the same bus type. We are trying to follow a similar approach to the pci_dev/pci_bus structs.
>> + * @obj_desc: MC description of the DPAA device >> + * @num_regions: Number of MMIO regions for this MC object device > > Doesn't actually exist? > No. Removed.
>> +#define FSL_MC_ERROR(_dev, _fmt, ...) \ >> + do { \ >> + if ((_dev) != NULL) \ >> + dev_err(_dev, "%s:" __stringify(__LINE__) " " \ >> + _fmt, __func__, ##__VA_ARGS__); \ >> + else \ >> + pr_err("%s:" __stringify(__LINE__) " " _fmt, \ >> + __func__, ##__VA_ARGS__); \ >> + } while (0) > > just use dev_err() directly, it handles the !_dev case already > Done.
>> +/** >> + * struct fsl_mc_bus - Management Complex (MC) bus object >> + * @magic: marker to verify identity of this structure >> + * @pdev: platform device for this MC bus object >> + * @root_mc_dev: pointer to root MC object device for this MC bus. >> + */ >> +struct fsl_mc_bus { >> +# define FSL_MC_BUS_MAGIC FSL_MC_MAGIC('L', 'B', 'U', 'S') >> + uint32_t magic; >> + struct platform_device *pdev; >> + struct fsl_mc_device *root_mc_dev; >> +}; > > pdev should be root_mc_dev->dev->parent, and magic seems pointless, so > no need for this structure at all. > Agreed. This is redundant. Removed.
>> +/** >> + * struct fsl_mc_dprc - Data Path Resource Container (DPRC) object >> + * @magic: marker to verify identity of this structure >> + * @mc_dev: pointer to MC object device object for this DPRC >> + * @mutex: mutex to serialize access to the container. >> + * @child_device_count: have the count of devices in this DPRC >> + * @child_list: anchor node of list of child devices on this DPRC >> + */ >> +struct fsl_mc_dprc { >> +# define FSL_MC_DPRC_MAGIC FSL_MC_MAGIC('D', 'P', 'R', 'C') >> + uint32_t magic; >> + struct fsl_mc_device *mc_dev; >> + struct mutex mutex; /* serializes access to fields below */ >> + uint16_t child_device_count; /* Count of devices in this DPRC */ >> + struct list_head child_list; >> +}; > > It's not clear what this represents to me. mc_dev presumably already > has a list of children, so why not just use a pointer to mc_dev > and remove this structure entirely? > This structure represents the per-bus (per DPRC object) information. It is kind of the equivalent to 'struct pci_bus' in the PCI world. I have renamed this struct to 'struct fsl_mc_bus'.
> Arnd >
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