Re: [PATCH v2 07/22] fpga: intel: pcie: parse feature list and create platform device for features.

[Wu Hao <hao.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

On Thu, Sep 21, 2017 at 02:58:57PM -0500, Alan Tull wrote:
> )On Wed, Sep 20, 2017 at 4:24 PM, Alan Tull <atull-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
> 
> Hi Hao,
> 
> A few more minor things below.

Hi Alan

Thanks for your comments, will fix them in the next version.

Thanks
Hao

> 
> >  a (wh., *()On Sun, Jun 25, 2017 at 8:52 PM, Wu Hao <hao.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> wrote:
> >
> > Hi Hao,
> >
> > I'm done with some board bringup so I have time to look at your patchset again.
> >
> > Something I can't help but notice is that this patchset will be almost
> > completely reusable for embedded FPGAs if the enumeration is separated
> > from the pcie code.  After the devices are created, they are just mmio
> > devices.  That makes this whole scheme available for embedded FPGAs.
> >
> > The division of things would be that the pcie code would read the
> > headers and do ioremapping.  Then pass the headers to the enumeration
> > code to create the devices.  With that division, another platform that
> > is embedded could have its own code that read the headers and did the
> > iomapping and then used the separate enumeration code.
> >
> > Going through intel-pcie.c, the truly pcie specific parts are already
> > pretty well contained.  The pcie code is in probe,
> > cci_pci_ioremap_bar, cci_pci_release_regions, and the 'parse_s*'
> > functions that ultimately call cci_pci_ioremap_bar.  So it all comes
> > down to the code that calls the 'parse_s*' functions.  That is, the
> > code the reads the fme header and the port headers.  Currently, if I'm
> > reading this right, this code ioremaps each region, reads its header,
> > and creates its device before reading the next header.  So we just
> > need to change the order a little and ioremap/read all the headers
> > before starting to create devices.  That separates the pci ioremap
> > from creating the devices.  So the probe function could ioremap and
> > read in the fme header.  Then it would ioremap and read in each of the
> > port headers.  After they are read in, then pass the all these headers
> > to the separate enumeration code that will parse it and create the
> > devices.  That part is not pcie specific, right?  With the enumeration
> > code in a separate file (and assuming that the ioremap has already
> > happened),  another platform that is embedded could have its probe do
> > the iomapping and reading the headers, and then call the same
> > enumeration code.
> >
> > Actually, there's a bit more to it than that but I think this is
> > doable.  build_info_add_sub_feature() (which is called by
> > create_feature_instance) saves off resource info for each sub device.
> > Does this mean this code is ioremapping again (in
> > intel-fpga-fme-mgr.c's probe)?
> >
> > A few more things below...
> >
> >> From: Xiao Guangrong <guangrong.xiao-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> >>
> >> Device Feature List structure creates a link list of feature headers
> >> within the MMIO space to provide an extensible way of adding features.
> >>
> >> The Intel FPGA PCIe driver walks through the feature headers to enumerate
> >> feature devices, FPGA Management Engine (FME) and FPGA Port for Accelerated
> >> Function Unit (AFU), and their private sub features. For feature devices,
> >> it creates the platform devices and linked the private sub features into
> >> their platform data.
> >>
> >> Signed-off-by: Tim Whisonant <tim.whisonant-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> Signed-off-by: Enno Luebbers <enno.luebbers-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> Signed-off-by: Shiva Rao <shiva.rao-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> Signed-off-by: Christopher Rauer <christopher.rauer-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> Signed-off-by: Kang Luwei <luwei.kang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> Signed-off-by: Zhang Yi <yi.z.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> Signed-off-by: Xiao Guangrong <guangrong.xiao-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> >> Signed-off-by: Wu Hao <hao.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> ---
> >> v2: moved the code to drivers/fpga folder as suggested by Alan Tull.
> >>     switched to GPLv2 license.
> >>     fixed comments from Moritz Fischer.
> >>     fixed kbuild warning, typos and clean up the code.
> >> ---
> >>  drivers/fpga/Makefile            |   2 +-
> >>  drivers/fpga/intel-feature-dev.c | 130 ++++++
> >>  drivers/fpga/intel-feature-dev.h | 341 ++++++++++++++++
> >>  drivers/fpga/intel-pcie.c        | 841 ++++++++++++++++++++++++++++++++++++++-
> >>  4 files changed, 1311 insertions(+), 3 deletions(-)
> >>  create mode 100644 drivers/fpga/intel-feature-dev.c
> >>  create mode 100644 drivers/fpga/intel-feature-dev.h
> >>
> >> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> >> index 5613133..ad24b3d 100644
> >> --- a/drivers/fpga/Makefile
> >> +++ b/drivers/fpga/Makefile
> >> @@ -31,4 +31,4 @@ obj-$(CONFIG_OF_FPGA_REGION)          += of-fpga-region.o
> >>  # Intel FPGA Support
> >>  obj-$(CONFIG_INTEL_FPGA_PCI)           += intel-fpga-pci.o
> >>
> >> -intel-fpga-pci-objs := intel-pcie.o
> >> +intel-fpga-pci-objs := intel-pcie.o intel-feature-dev.o
> >> diff --git a/drivers/fpga/intel-feature-dev.c b/drivers/fpga/intel-feature-dev.c
> >> new file mode 100644
> >> index 0000000..68f9cba
> >> --- /dev/null
> >> +++ b/drivers/fpga/intel-feature-dev.c
> >> @@ -0,0 +1,130 @@
> >> +/*
> >> + * Intel FPGA Feature Device Driver
> >> + *
> >> + * Copyright (C) 2017 Intel Corporation, Inc.
> >> + *
> >> + * Authors:
> >> + *   Kang Luwei <luwei.kang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> + *   Zhang Yi <yi.z.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> + *   Wu Hao <hao.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> + *   Xiao Guangrong <guangrong.xiao-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> >> + *
> >> + * This work is licensed under the terms of the GNU GPL version 2. See
> >> + * the COPYING file in the top-level directory.
> >> + */
> >> +
> >> +#include "intel-feature-dev.h"
> >> +
> >> +void feature_platform_data_add(struct feature_platform_data *pdata,
> >> +                              int index, const char *name,
> >> +                              int resource_index, void __iomem *ioaddr)
> >> +{
> >> +       WARN_ON(index >= pdata->num);
> >> +
> >> +       pdata->features[index].name = name;
> >> +       pdata->features[index].resource_index = resource_index;
> >> +       pdata->features[index].ioaddr = ioaddr;
> >> +}
> 
> This function is only called once.  I understand that it is desirable
> to break things up into little functions and avoid overly long
> functions, but in this case, the calling function
> (build_info_add_sub_feature) is pretty short to begin with.   Someone
> reading the code will know what is happening better if you just add
> its contents to its calling function.
> 
> >> +
> >> +struct feature_platform_data *
> >> +feature_platform_data_alloc_and_init(struct platform_device *dev, int num)
> >> +{
> >> +       struct feature_platform_data *pdata;
> >> +
> >> +       pdata = kzalloc(feature_platform_data_size(num), GFP_KERNEL);
> >> +       if (pdata) {
> >> +               pdata->dev = dev;
> >> +               pdata->num = num;
> >> +               mutex_init(&pdata->lock);
> >> +       }
> >> +
> >> +       return pdata;
> >> +}
> 
> feature_platform_data_alloc_and_init is another function that's small,
> called once, and would be better included in its caller.
> 
> >> +
> >> +int fme_feature_num(void)
> >> +{
> >> +       return FME_FEATURE_ID_MAX;
> >> +}
> >> +
> >> +int port_feature_num(void)
> >> +{
> >> +       return PORT_FEATURE_ID_MAX;
> >> +}
> >
> > Do these need to be functions?  If so, static.  But if you can just
> > use the #define'd values that's one level of indirection we can get
> > rid of.  And when I'm going through code where there's extra levels of
> > indirection that don't do anything, it makes it harder to understand
> > ;)
> >
> >> +
> >> +int fpga_port_id(struct platform_device *pdev)
> >> +{
> >> +       struct feature_port_header *port_hdr;
> >> +       struct feature_port_capability capability;
> >> +
> >> +       port_hdr = get_feature_ioaddr_by_index(&pdev->dev,
> >> +                                              PORT_FEATURE_ID_HEADER);
> >> +       WARN_ON(!port_hdr);
> >> +
> >> +       capability.csr = readq(&port_hdr->capability);
> >> +       return capability.port_number;
> >> +}
> >> +EXPORT_SYMBOL_GPL(fpga_port_id);
> >
> > This is here because every feature is a port, right?
> >
> >> +
> >> +/*
> >> + * Enable Port by clear the port soft reset bit, which is set by default.
> >> + * The User AFU is unable to respond to any MMIO access while in reset.
> >> + * __fpga_port_enable function should only be used after __fpga_port_disable
> >> + * function.
> >> + */
> >> +void __fpga_port_enable(struct platform_device *pdev)
> >> +{
> >> +       struct feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
> >> +       struct feature_port_header *port_hdr;
> >> +       struct feature_port_control control;
> >> +
> >> +       WARN_ON(!pdata->disable_count);
> >> +
> >> +       if (--pdata->disable_count != 0)
> >> +               return;
> >> +
> >> +       port_hdr = get_feature_ioaddr_by_index(&pdev->dev,
> >> +                                              PORT_FEATURE_ID_HEADER);
> >> +       WARN_ON(!port_hdr);
> >> +
> >> +       control.csr = readq(&port_hdr->control);
> >> +       control.port_sftrst = 0x0;
> >> +       writeq(control.csr, &port_hdr->control);
> >> +}
> >> +EXPORT_SYMBOL_GPL(__fpga_port_enable);
> >> +
> >> +#define RST_POLL_INVL 10 /* us */
> >> +#define RST_POLL_TIMEOUT 1000 /* us */
> >> +
> >> +int __fpga_port_disable(struct platform_device *pdev)
> >> +{
> >> +       struct feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
> >> +       struct feature_port_header *port_hdr;
> >> +       struct feature_port_control control;
> >> +
> >> +       if (pdata->disable_count++ != 0)
> >> +               return 0;
> >> +
> >> +       port_hdr = get_feature_ioaddr_by_index(&pdev->dev,
> >> +                                              PORT_FEATURE_ID_HEADER);
> >> +       WARN_ON(!port_hdr);
> >> +
> >> +       /* Set port soft reset */
> >> +       control.csr = readq(&port_hdr->control);
> >> +       control.port_sftrst = 0x1;
> >> +       writeq(control.csr, &port_hdr->control);
> >> +
> >> +       /*
> >> +        * HW sets ack bit to 1 when all outstanding requests have been drained
> >> +        * on this port and minimum soft reset pulse width has elapsed.
> >> +        * Driver polls port_soft_reset_ack to determine if reset done by HW.
> >> +        */
> >> +       if (readq_poll_timeout(&port_hdr->control, control.csr,
> >> +                              (control.port_sftrst_ack == 1),
> >> +                              RST_POLL_INVL, RST_POLL_TIMEOUT)) {
> >> +               dev_err(&pdev->dev, "timeout, fail to reset device\n");
> >> +               return -ETIMEDOUT;
> >> +       }
> >> +
> >> +       return 0;
> >> +}
> >> +EXPORT_SYMBOL_GPL(__fpga_port_disable);
> >> diff --git a/drivers/fpga/intel-feature-dev.h b/drivers/fpga/intel-feature-dev.h
> >> new file mode 100644
> >> index 0000000..f67784a
> >> --- /dev/null
> >> +++ b/drivers/fpga/intel-feature-dev.h
> >> @@ -0,0 +1,341 @@
> >> +/*
> >> + * Intel FPGA Feature Device Driver Header File
> >> + *
> >> + * Copyright (C) 2017 Intel Corporation, Inc.
> >> + *
> >> + * Authors:
> >> + *   Kang Luwei <luwei.kang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> + *   Zhang Yi <yi.z.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> + *   Wu Hao <hao.wu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> >> + *   Xiao Guangrong <guangrong.xiao-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> >> + *
> >> + * This work is licensed under the terms of the GNU GPL version 2. See
> >> + * the COPYING file in the top-level directory.
> >> + */
> >> +
> >> +#ifndef __INTEL_FPGA_FEATURE_H
> >> +#define __INTEL_FPGA_FEATURE_H
> >> +
> >> +#include <linux/fs.h>
> >> +#include <linux/pci.h>
> >> +#include <linux/uuid.h>
> >> +#include <linux/delay.h>
> >> +#include <linux/iopoll.h>
> >> +#include <linux/platform_device.h>
> >> +
> >> +#ifndef readq
> >> +static inline u64 readq(void __iomem *addr)
> >> +{
> >> +       return readl(addr) + ((u64)readl(addr + 4) << 32);
> >> +}
> >> +#endif
> >> +
> >> +#ifndef writeq
> >> +static inline void writeq(u64 val, void __iomem *addr)
> >> +{
> >> +       writel((u32) (val), addr);
> >> +       writel((u32) (val >> 32), (addr + 4));
> >> +}
> >> +#endif
> >> +
> >> +/* maximum supported number of ports */
> >> +#define MAX_FPGA_PORT_NUM 4
> >> +/* plus one for fme device */
> >> +#define MAX_FEATURE_DEV_NUM    (MAX_FPGA_PORT_NUM + 1)
> >> +
> >> +#define FME_FEATURE_HEADER          "fme_hdr"
> >> +#define FME_FEATURE_THERMAL_MGMT    "fme_thermal"
> >> +#define FME_FEATURE_POWER_MGMT      "fme_power"
> >> +#define FME_FEATURE_GLOBAL_PERF     "fme_gperf"
> >> +#define FME_FEATURE_GLOBAL_ERR      "fme_error"
> >> +#define FME_FEATURE_PR_MGMT         "fme_pr"
> >> +
> >> +#define PORT_FEATURE_HEADER         "port_hdr"
> >> +#define PORT_FEATURE_UAFU           "port_uafu"
> >> +#define PORT_FEATURE_ERR            "port_err"
> >> +#define PORT_FEATURE_UMSG           "port_umsg"
> >> +#define PORT_FEATURE_PR             "port_pr"
> >> +#define PORT_FEATURE_STP            "port_stp"
> >> +
> >> +/* All headers and structures must be byte-packed to match the spec. */
> >> +#pragma pack(1)
> >> +
> >> +/* common header for all features */
> >> +struct feature_header {
> >> +       union {
> >> +               u64 csr;
> >> +               struct {
> >> +                       u64 id:12;
> >> +                       u64 revision:4;
> >> +                       u64 next_header_offset:24; /* offset to next header */
> >> +                       u64 rsvdz:20;
> >> +                       u64 type:4;                /* feature type */
> >> +#define FEATURE_TYPE_AFU               0x1
> >> +#define FEATURE_TYPE_PRIVATE           0x3
> >> +               };
> >> +       };
> >> +};
> >> +
> >> +/* common header for non-private features */
> >> +struct feature_afu_header {
> >> +       uuid_le guid;
> >> +       union {
> >> +               u64 csr;
> >> +               struct {
> >> +                       u64 next_afu:24;        /* pointer to next afu header */
> >> +                       u64 rsvdz:40;
> >> +               };
> >> +       };
> >> +};
> >> +
> >> +/* FME Header Register Set */
> >> +/* FME Capability Register */
> >> +struct feature_fme_capability {
> >> +       union {
> >> +               u64 csr;
> >> +               struct {
> >> +                       u64 fabric_verid:8;     /* Fabric version ID */
> >> +                       u64 socket_id:1;        /* Socket id */
> >> +                       u64 rsvdz1:3;
> >> +                       u64 pcie0_link_avl:1;   /* PCIe0 link availability */
> >> +                       u64 pcie1_link_avl:1;   /* PCIe1 link availability */
> >> +                       u64 coherent_link_avl:1;/* Coherent link availability */
> >> +                       u64 rsvdz2:1;
> >> +                       u64 iommu_support:1;    /* IOMMU or VT-d supported */
> >> +                       u64 num_ports:3;        /* Num of ports implemented */
> >> +                       u64 rsvdz3:4;
> >> +                       u64 addr_width_bits:6;  /* Address width supported */
> >> +                       u64 rsvdz4:2;
> >> +                       u64 cache_size:12;      /* Cache size in kb */
> >> +                       u64 cache_assoc:4;      /* Cache Associativity */
> >> +                       u64 rsvdz5:15;
> >> +                       u64 lock_bit:1;         /* Latched lock bit by BIOS */
> >> +               };
> >> +       };
> >> +};
> >> +
> >> +/* FME Port Offset Register */
> >> +struct feature_fme_port {
> >> +       union {
> >> +               u64 csr;
> >> +               struct {
> >> +                       u64 port_offset:24;     /* Offset to port header */
> >> +                       u64 rsvdz1:8;
> >> +                       u64 port_bar:3;         /* Bar id */
> >> +                       u64 rsvdz2:20;
> >> +                       u64 afu_access_ctrl:1;  /* AFU access type: PF/VF */
> >> +                       u64 rsvdz3:4;
> >> +                       u64 port_implemented:1; /* Port implemented or not */
> >> +                       u64 rsvdz4:3;
> >> +               };
> >> +       };
> >> +};
> >> +
> >> +struct feature_fme_header {
> >> +       struct feature_header header;
> >> +       struct feature_afu_header afu_header;
> >> +       u64 rsvd[2];
> >> +       struct feature_fme_capability capability;
> >> +       struct feature_fme_port port[MAX_FPGA_PORT_NUM];
> >> +};
> >> +
> >> +/* FME Thermal Sub Feature Register Set */
> >> +struct feature_fme_thermal {
> >> +       struct feature_header header;
> >> +};
> >> +
> >> +/* FME Power Sub Feature Register Set */
> >> +struct feature_fme_power {
> >> +       struct feature_header header;
> >> +};
> >> +
> >> +/* FME Global Performance Sub Feature Register Set */
> >> +struct feature_fme_gperf {
> >> +       struct feature_header header;
> >> +};
> >> +
> >> +/* FME Error Sub Feature Register Set */
> >> +struct feature_fme_err {
> >> +       struct feature_header header;
> >> +};
> >> +
> >> +/* FME Partial Reconfiguration Sub Feature Register Set */
> >> +struct feature_fme_pr {
> >> +       struct feature_header header;
> >> +};
> >> +
> >> +/* PORT Header Register Set */
> >> +/* Port Capability Register */
> >> +struct feature_port_capability {
> >> +       union {
> >> +               u64 csr;
> >> +               struct {
> >> +                       u64 port_number:2;      /* Port Number 0-3 */
> >> +                       u64 rsvdz1:6;
> >> +                       u64 mmio_size:16;       /* User MMIO size in KB */
> >> +                       u64 rsvdz2:8;
> >> +                       u64 sp_intr_num:4;      /* Supported interrupts num */
> >> +                       u64 rsvdz3:28;
> >> +               };
> >> +       };
> >> +};
> >> +
> >> +/* Port Control Register */
> >> +struct feature_port_control {
> >> +       union {
> >> +               u64 csr;
> >> +               struct {
> >> +                       u64 port_sftrst:1;      /* Port Soft Reset */
> >> +                       u64 rsvdz1:1;
> >> +                       u64 latency_tolerance:1;/* '1' >= 40us, '0' < 40us */
> >> +                       u64 rsvdz2:1;
> >> +                       u64 port_sftrst_ack:1;  /* HW ACK for Soft Reset */
> >> +                       u64 rsvdz3:59;
> >> +               };
> >> +       };
> >> +};
> >> +
> >> +struct feature_port_header {
> >> +       struct feature_header header;
> >> +       struct feature_afu_header afu_header;
> >> +       u64 rsvd[2];
> >> +       struct feature_port_capability capability;
> >> +       struct feature_port_control control;
> >> +};
> >> +
> >> +/* PORT Error Sub Feature Register Set */
> >> +struct feature_port_error {
> >> +       struct feature_header header;
> >> +};
> >> +
> >> +/* PORT Unordered Message Sub Feature Register Set */
> >> +struct feature_port_umsg {
> >> +       struct feature_header header;
> >> +};
> >> +
> >> +/* PORT SignalTap Sub Feature Register Set */
> >> +struct feature_port_stp {
> >> +       struct feature_header header;
> >> +};
> >> +
> >> +#pragma pack()
> >> +
> >> +struct feature {
> >> +       const char *name;
> >> +       int resource_index;
> >> +       void __iomem *ioaddr;
> >> +};
> >> +
> >> +struct feature_platform_data {
> >> +       /* list the feature dev to cci_drvdata->port_dev_list. */
> >> +       struct list_head node;
> >> +       struct mutex lock;
> >> +       struct platform_device *dev;
> >> +       unsigned int disable_count;     /* count for port disable */
> >> +
> >> +       int num;                        /* number of features */
> >> +       struct feature features[0];
> >> +};
> >> +
> >> +enum fme_feature_id {
> >> +       FME_FEATURE_ID_HEADER = 0x0,
> >> +       FME_FEATURE_ID_THERMAL_MGMT = 0x1,
> >> +       FME_FEATURE_ID_POWER_MGMT = 0x2,
> >> +       FME_FEATURE_ID_GLOBAL_PERF = 0x3,
> >> +       FME_FEATURE_ID_GLOBAL_ERR = 0x4,
> >> +       FME_FEATURE_ID_PR_MGMT = 0x5,
> >> +       FME_FEATURE_ID_MAX = 0x6,
> >> +};
> >> +
> >> +enum port_feature_id {
> >> +       PORT_FEATURE_ID_HEADER = 0x0,
> >> +       PORT_FEATURE_ID_ERROR = 0x1,
> >> +       PORT_FEATURE_ID_UMSG = 0x2,
> >> +       PORT_FEATURE_ID_PR = 0x3,
> >> +       PORT_FEATURE_ID_STP = 0x4,
> >> +       PORT_FEATURE_ID_UAFU = 0x5,
> >> +       PORT_FEATURE_ID_MAX = 0x6,
> >> +};
> >> +
> >> +int fme_feature_num(void);
> >> +int port_feature_num(void);
> >> +
> >> +#define FPGA_FEATURE_DEV_FME           "intel-fpga-fme"
> >> +#define FPGA_FEATURE_DEV_PORT          "intel-fpga-port"
> >> +
> >> +void feature_platform_data_add(struct feature_platform_data *pdata,
> >> +                              int index, const char *name,
> >> +                              int resource_index, void __iomem *ioaddr);
> >> +
> >> +static inline int feature_platform_data_size(const int num)
> >> +{
> >> +       return sizeof(struct feature_platform_data) +
> >> +               num * sizeof(struct feature);
> >> +}
> >> +
> >> +struct feature_platform_data *
> >> +feature_platform_data_alloc_and_init(struct platform_device *dev, int num);
> >> +
> >> +int fpga_port_id(struct platform_device *pdev);
> >> +
> >> +static inline int fpga_port_check_id(struct platform_device *pdev,
> >> +                                    void *pport_id)
> >> +{
> >> +       return fpga_port_id(pdev) == *(int *)pport_id;
> >> +}
> >> +
> >> +void __fpga_port_enable(struct platform_device *pdev);
> >> +int __fpga_port_disable(struct platform_device *pdev);
> >> +
> >> +static inline void fpga_port_enable(struct platform_device *pdev)
> >> +{
> >> +       struct feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
> >> +
> >> +       mutex_lock(&pdata->lock);
> >> +       __fpga_port_enable(pdev);
> >> +       mutex_unlock(&pdata->lock);
> >> +}
> >> +
> >> +static inline int fpga_port_disable(struct platform_device *pdev)
> >> +{
> >> +       struct feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
> >> +       int ret;
> >> +
> >> +       mutex_lock(&pdata->lock);
> >> +       ret = __fpga_port_disable(pdev);
> >> +       mutex_unlock(&pdata->lock);
> >> +
> >> +       return ret;
> >> +}
> >> +
> >> +static inline int __fpga_port_reset(struct platform_device *pdev)
> >> +{
> >> +       int ret;
> >> +
> >> +       ret = __fpga_port_disable(pdev);
> >> +       if (ret)
> >> +               return ret;
> >> +
> >> +       __fpga_port_enable(pdev);
> >> +       return 0;
> >> +}
> >> +
> >> +static inline int fpga_port_reset(struct platform_device *pdev)
> >> +{
> >> +       struct feature_platform_data *pdata = dev_get_platdata(&pdev->dev);
> >> +       int ret;
> >> +
> >> +       mutex_lock(&pdata->lock);
> >> +       ret = __fpga_port_reset(pdev);
> >> +       mutex_unlock(&pdata->lock);
> >> +       return ret;
> >> +}
> >> +
> >> +static inline void __iomem *
> >> +get_feature_ioaddr_by_index(struct device *dev, int index)
> >> +{
> >> +       struct feature_platform_data *pdata = dev_get_platdata(dev);
> >> +
> >> +       return pdata->features[index].ioaddr;
> >> +}
> >> +#endif
> >> diff --git a/drivers/fpga/intel-pcie.c b/drivers/fpga/intel-pcie.c
> >> index f697de4..70b8284 100644
> >> --- a/drivers/fpga/intel-pcie.c
> >> +++ b/drivers/fpga/intel-pcie.c
> >> @@ -23,10 +23,827 @@
> >>  #include <linux/stddef.h>
> >>  #include <linux/errno.h>
> >>  #include <linux/aer.h>
> >> +#include <linux/fpga/fpga-dev.h>
> >> +
> >> +#include "intel-feature-dev.h"
> >>
> >>  #define DRV_VERSION    "0.8"
> >>  #define DRV_NAME       "intel-fpga-pci"
> >>
> >> +#define INTEL_FPGA_DEV "intel-fpga-dev"
> >> +
> >> +static DEFINE_MUTEX(fpga_id_mutex);
> >> +
> >> +enum fpga_id_type {
> >> +       FME_ID,         /* fme id allocation and mapping */
> >> +       PORT_ID,        /* port id allocation and mapping */
> >> +       FPGA_ID_MAX,
> >> +};
> >> +
> >> +/* it is protected by fpga_id_mutex */
> >> +static struct idr fpga_ids[FPGA_ID_MAX];
> >> +
> >> +struct cci_drvdata {
> >> +       struct device *fme_dev;
> >> +
> >> +       struct mutex lock;
> >> +       struct list_head port_dev_list;
> >> +
> >> +       struct list_head regions; /* global list of pci bar mapping region */
> >> +};
> >> +
> >> +/* pci bar mapping info */
> >> +struct cci_pci_region {
> >> +       int bar;
> >> +       void __iomem *ioaddr;   /* pointer to mapped bar region */
> >> +       struct list_head node;
> >> +};
> >> +
> >> +static void fpga_ids_init(void)
> >> +{
> >> +       int i;
> >> +
> >> +       for (i = 0; i < ARRAY_SIZE(fpga_ids); i++)
> >> +               idr_init(fpga_ids + i);
> >> +}
> >> +
> >> +static void fpga_ids_destroy(void)
> >> +{
> >> +       int i;
> >> +
> >> +       for (i = 0; i < ARRAY_SIZE(fpga_ids); i++)
> >> +               idr_destroy(fpga_ids + i);
> >> +}
> >> +
> >> +static int alloc_fpga_id(enum fpga_id_type type, struct device *dev)
> >> +{
> >> +       int id;
> >> +
> >> +       WARN_ON(type >= FPGA_ID_MAX);
> >> +       mutex_lock(&fpga_id_mutex);
> >> +       id = idr_alloc(fpga_ids + type, dev, 0, 0, GFP_KERNEL);
> >> +       mutex_unlock(&fpga_id_mutex);
> >> +       return id;
> >> +}
> >> +
> >> +static void free_fpga_id(enum fpga_id_type type, int id)
> >> +{
> >> +       WARN_ON(type >= FPGA_ID_MAX);
> >> +       mutex_lock(&fpga_id_mutex);
> >> +       idr_remove(fpga_ids + type, id);
> >> +       mutex_unlock(&fpga_id_mutex);
> >> +}
> >> +
> >> +static void cci_pci_add_port_dev(struct pci_dev *pdev,
> >> +                                struct platform_device *port_dev)
> >> +{
> >> +       struct cci_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
> >> +       struct feature_platform_data *pdata = dev_get_platdata(&port_dev->dev);
> >> +
> >> +       mutex_lock(&drvdata->lock);
> >> +       list_add(&pdata->node, &drvdata->port_dev_list);
> >> +       get_device(&pdata->dev->dev);
> >> +       mutex_unlock(&drvdata->lock);
> >> +}
> >> +
> >> +static void cci_pci_remove_port_devs(struct pci_dev *pdev)
> >> +{
> >> +       struct cci_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
> >> +       struct feature_platform_data *pdata, *ptmp;
> >> +
> >> +       mutex_lock(&drvdata->lock);
> >> +       list_for_each_entry_safe(pdata, ptmp, &drvdata->port_dev_list, node) {
> >> +               struct platform_device *port_dev = pdata->dev;
> >> +
> >> +               /* the port should be unregistered first. */
> >> +               WARN_ON(device_is_registered(&port_dev->dev));
> >> +               list_del(&pdata->node);
> >> +               free_fpga_id(PORT_ID, port_dev->id);
> >> +               put_device(&port_dev->dev);
> >> +       }
> >> +       mutex_unlock(&drvdata->lock);
> >> +}
> >> +
> >> +/* info collection during feature dev build. */
> >> +struct build_feature_devs_info {
> >> +       struct pci_dev *pdev;
> >> +
> >> +       /*
> >> +        * PCI BAR mapping info. Parsing feature list starts from
> >> +        * BAR 0 and switch to different BARs to parse Port
> >> +        */
> >> +       void __iomem *ioaddr;
> >> +       void __iomem *ioend;
> >> +       int current_bar;
> >> +
> >> +       /* points to FME header where the port offset is figured out. */
> >> +       void __iomem *pfme_hdr;
> >> +
> >> +       /* the container device for all feature devices */
> >> +       struct fpga_dev *parent_dev;
> >> +
> >> +       /* current feature device */
> >> +       struct platform_device *feature_dev;
> >> +};
> >> +
> >> +static void cci_pci_release_regions(struct pci_dev *pdev)
> >> +{
> >> +       struct cci_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
> >> +       struct cci_pci_region *tmp, *region;
> >> +
> >> +       list_for_each_entry_safe(region, tmp, &drvdata->regions, node) {
> >> +               list_del(&region->node);
> >> +               if (region->ioaddr)
> >> +                       pci_iounmap(pdev, region->ioaddr);
> >> +               devm_kfree(&pdev->dev, region);
> >> +       }
> >> +}
> >> +
> >> +static void __iomem *cci_pci_ioremap_bar(struct pci_dev *pdev, int bar)
> >> +{
> >> +       struct cci_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
> >> +       struct cci_pci_region *region;
> >> +
> >> +       list_for_each_entry(region, &drvdata->regions, node)
> >> +               if (region->bar == bar) {
> >> +                       dev_dbg(&pdev->dev, "BAR %d region exists\n", bar);
> >> +                       return region->ioaddr;
> >> +               }
> >> +
> >> +       region = devm_kzalloc(&pdev->dev, sizeof(*region), GFP_KERNEL);
> >> +       if (!region)
> >> +               return NULL;
> >> +
> >> +       region->bar = bar;
> >> +       region->ioaddr = pci_ioremap_bar(pdev, bar);
> >> +       if (!region->ioaddr) {
> >> +               dev_err(&pdev->dev, "can't ioremap memory from BAR %d.\n", bar);
> >> +               devm_kfree(&pdev->dev, region);
> >> +               return NULL;
> >> +       }
> >> +
> >> +       list_add(&region->node, &drvdata->regions);
> >> +       return region->ioaddr;
> >> +}
> >> +
> >> +static int parse_start_from(struct build_feature_devs_info *binfo, int bar)
> >> +{
> >> +       binfo->ioaddr = cci_pci_ioremap_bar(binfo->pdev, bar);
> >> +       if (!binfo->ioaddr)
> >> +               return -ENOMEM;
> >> +
> >> +       binfo->current_bar = bar;
> >> +       binfo->ioend = binfo->ioaddr + pci_resource_len(binfo->pdev, bar);
> >> +       return 0;
> >> +}
> >> +
> >> +static int parse_start(struct build_feature_devs_info *binfo)
> >> +{
> >> +       /* fpga feature list starts from BAR 0 */
> >> +       return parse_start_from(binfo, 0);
> >> +}
> >> +
> >> +/* switch the memory mapping to BAR# @bar */
> >> +static int parse_switch_to(struct build_feature_devs_info *binfo, int bar)
> >> +{
> >> +       return parse_start_from(binfo, bar);
> >> +}
> >
> > parse_switch_to() and parse_start() are both one line wrappers for
> > parse_start_from() and are only called once.  :-) Please just use
> > parse_start_from and get rid of parse_start and parse_switch_to.  I
> > don't think this code is all that super complicated.  But as I'm
> > grepping through this code, I'm trying to see all the places that do
> > the same thing; if I have to look for multiple function names, it
> > takes longer to get what is going on here.
> >
> > Actually, cci_pci_ioremap_bar is only called in one place -
> > parse_start_from - which really just adds two lines of code.
> > parse_start_from could go away.  Just a suggestion.  The reason this
> > comes up is that cci_pci_ioremap_bar is the more descriptive function
> > name.  The parse_start/switch function names hide the biggest thing
> > they do, which is ioremapping.  They don't actually do any parsing ;)
> >
> >> +
> >> +static struct build_feature_devs_info *
> >> +build_info_alloc_and_init(struct pci_dev *pdev)
> >> +{
> >> +       struct build_feature_devs_info *binfo;
> >> +
> >> +       binfo = devm_kzalloc(&pdev->dev, sizeof(*binfo), GFP_KERNEL);
> >> +       if (binfo)
> >> +               binfo->pdev = pdev;
> >
> > build_info_alloc_and_init() is only doing a devm_kzalloc and is only
> > called once.  The code would be more readable if you just had the
> > devm_kzalloc in the function that called this
> > (cci_pci_create_feature_devs).
> >
> >> +
> >> +       return binfo;
> >> +}
> >> +
> >> +static enum fpga_id_type feature_dev_id_type(struct platform_device *pdev)
> >> +{
> >> +       if (!strcmp(pdev->name, FPGA_FEATURE_DEV_FME))
> >> +               return FME_ID;
> >> +
> >> +       if (!strcmp(pdev->name, FPGA_FEATURE_DEV_PORT))
> >> +               return PORT_ID;
> >> +
> >> +       WARN_ON(1);
> >> +       return FPGA_ID_MAX;
> >> +}
> >> +
> >> +/*
> >> + * register current feature device, it is called when we need to switch to
> >> + * another feature parsing or we have parsed all features
> >> + */
> >> +static int build_info_commit_dev(struct build_feature_devs_info *binfo)
> >> +{
> >> +       int ret;
> >> +
> >> +       if (!binfo->feature_dev)
> >> +               return 0;
> >> +
> >> +       ret = platform_device_add(binfo->feature_dev);
> >> +       if (!ret) {
> >> +               struct cci_drvdata *drvdata;
> >> +
> >> +               drvdata = dev_get_drvdata(&binfo->pdev->dev);
> >> +               if (feature_dev_id_type(binfo->feature_dev) == PORT_ID)
> >> +                       cci_pci_add_port_dev(binfo->pdev, binfo->feature_dev);
> >> +               else
> >> +                       drvdata->fme_dev = get_device(&binfo->feature_dev->dev);
> >> +
> >> +               /*
> >> +                * reset it to avoid build_info_free() freeing their resource.
> >> +                *
> >> +                * The resource of successfully registered feature devices
> >> +                * will be freed by platform_device_unregister(). See the
> >> +                * comments in build_info_create_dev().
> >> +                */
> >> +               binfo->feature_dev = NULL;
> >> +       }
> >> +
> >> +       return ret;
> >> +}
> >> +
> >> +static int
> >> +build_info_create_dev(struct build_feature_devs_info *binfo,
> >> +                     enum fpga_id_type type, int feature_nr, const char *name)
> >> +{
> >> +       struct platform_device *fdev;
> >> +       struct resource *res;
> >> +       struct feature_platform_data *pdata;
> >> +       int ret;
> >> +
> >> +       /* we will create a new device, commit current device first */
> >> +       ret = build_info_commit_dev(binfo);
> >> +       if (ret)
> >> +               return ret;
> >> +
> >> +       /*
> >> +        * we use -ENODEV as the initialization indicator which indicates
> >> +        * whether the id need to be reclaimed
> >> +        */
> >> +       fdev = binfo->feature_dev = platform_device_alloc(name, -ENODEV);
> >> +       if (!fdev)
> >> +               return -ENOMEM;
> >> +
> >> +       fdev->id = alloc_fpga_id(type, &fdev->dev);
> >> +       if (fdev->id < 0)
> >> +               return fdev->id;
> >> +
> >> +       fdev->dev.parent = &binfo->parent_dev->dev;
> >> +
> >> +       /*
> >> +        * we do not need to care for the memory which is associated with
> >> +        * the platform device. After calling platform_device_unregister(),
> >> +        * it will be automatically freed by device's release() callback,
> >> +        * platform_device_release().
> >> +        */
> >> +       pdata = feature_platform_data_alloc_and_init(fdev, feature_nr);
> >> +       if (!pdata)
> >> +               return -ENOMEM;
> >> +
> >> +       /*
> >> +        * the count should be initialized to 0 to make sure
> >> +        *__fpga_port_enable() following __fpga_port_disable()
> >> +        * works properly for port device.
> >> +        * and it should always be 0 for fme device.
> >> +        */
> >> +       WARN_ON(pdata->disable_count);
> >> +
> >> +       fdev->dev.platform_data = pdata;
> >> +       fdev->num_resources = feature_nr;
> >> +       fdev->resource = kcalloc(feature_nr, sizeof(*res), GFP_KERNEL);
> >> +       if (!fdev->resource)
> >> +               return -ENOMEM;
> >> +
> >> +       return 0;
> >> +}
> >> +
> >> +static int remove_feature_dev(struct device *dev, void *data)
> >> +{
> >> +       struct platform_device *pdev = to_platform_device(dev);
> >> +
> >> +       platform_device_unregister(pdev);
> >> +       return 0;
> >> +}
> >> +
> >> +static int remove_parent_dev(struct device *dev, void *data)
> >> +{
> >> +       /* remove platform devices attached in the parent device */
> >> +       device_for_each_child(dev, NULL, remove_feature_dev);
> >> +       fpga_dev_destroy(to_fpga_dev(dev));
> >> +       return 0;
> >> +}
> >> +
> >> +static void remove_all_devs(struct pci_dev *pdev)
> >> +{
> >> +       /* remove parent device and all its children. */
> >> +       device_for_each_child(&pdev->dev, NULL, remove_parent_dev);
> >> +}
> >> +
> >> +static void build_info_free(struct build_feature_devs_info *binfo)
> >> +{
> >> +       if (!IS_ERR_OR_NULL(binfo->parent_dev))
> >> +               remove_all_devs(binfo->pdev);
> >> +
> >> +       /*
> >> +        * it is a valid id, free it. See comments in
> >> +        * build_info_create_dev()
> >> +        */
> >> +       if (binfo->feature_dev && binfo->feature_dev->id >= 0)
> >> +               free_fpga_id(feature_dev_id_type(binfo->feature_dev),
> >> +                            binfo->feature_dev->id);
> >> +
> >> +       platform_device_put(binfo->feature_dev);
> >> +
> >> +       devm_kfree(&binfo->pdev->dev, binfo);
> >> +}
> >> +
> >> +#define FEATURE_TYPE_AFU       0x1
> >> +#define FEATURE_TYPE_PRIVATE   0x3
> >> +
> >> +/* FME and PORT GUID are fixed */
> >> +#define FEATURE_FME_GUID "f9e17764-38f0-82fe-e346-524ae92aafbf"
> >> +#define FEATURE_PORT_GUID "6b355b87-b06c-9642-eb42-8d139398b43a"
> >> +
> >> +static bool feature_is_fme(struct feature_afu_header *afu_hdr)
> >> +{
> >> +       uuid_le u;
> >> +
> >> +       uuid_le_to_bin(FEATURE_FME_GUID, &u);
> >> +
> >> +       return !uuid_le_cmp(u, afu_hdr->guid);
> >> +}
> >> +
> >> +static bool feature_is_port(struct feature_afu_header *afu_hdr)
> >> +{
> >> +       uuid_le u;
> >> +
> >> +       uuid_le_to_bin(FEATURE_PORT_GUID, &u);
> >> +
> >> +       return !uuid_le_cmp(u, afu_hdr->guid);
> >> +}
> >> +
> >> +/*
> >> + * UAFU GUID is dynamic as it can be changed after FME downloads different
> >> + * Green Bitstream to the port, so we treat the unknown GUIDs which are
> >> + * attached on port's feature list as UAFU.
> >> + */
> >> +static bool feature_is_UAFU(struct build_feature_devs_info *binfo)
> >> +{
> >> +       if (!binfo->feature_dev ||
> >> +             feature_dev_id_type(binfo->feature_dev) != PORT_ID)
> >> +               return false;
> >> +
> >> +       return true;
> >> +}
> >> +
> >> +static void
> >> +build_info_add_sub_feature(struct build_feature_devs_info *binfo,
> >> +                          int feature_id, const char *feature_name,
> >> +                          resource_size_t resource_size, void __iomem *start)
> >> +{
> >> +
> >> +       struct platform_device *fdev = binfo->feature_dev;
> >> +       struct feature_platform_data *pdata = dev_get_platdata(&fdev->dev);
> >> +       struct resource *res = &fdev->resource[feature_id];
> >> +
> >> +       res->start = pci_resource_start(binfo->pdev, binfo->current_bar) +
> >> +               start - binfo->ioaddr;
> >> +       res->end = res->start + resource_size - 1;
> >> +       res->flags = IORESOURCE_MEM;
> >> +       res->name = feature_name;
> >> +
> >> +       feature_platform_data_add(pdata, feature_id,
> >> +                                 feature_name, feature_id, start);
> >> +}
> >> +
> >> +struct feature_info {
> >> +       const char *name;
> >> +       resource_size_t resource_size;
> >> +       int feature_index;
> >> +};
> >> +
> >> +/* indexed by fme feature IDs which are defined in 'enum fme_feature_id'. */
> >> +static struct feature_info fme_features[] = {
> >> +       {
> >> +               .name = FME_FEATURE_HEADER,
> >> +               .resource_size = sizeof(struct feature_fme_header),
> >> +               .feature_index = FME_FEATURE_ID_HEADER,
> >> +       },
> >> +       {
> >> +               .name = FME_FEATURE_THERMAL_MGMT,
> >> +               .resource_size = sizeof(struct feature_fme_thermal),
> >> +               .feature_index = FME_FEATURE_ID_THERMAL_MGMT,
> >> +       },
> >> +       {
> >> +               .name = FME_FEATURE_POWER_MGMT,
> >> +               .resource_size = sizeof(struct feature_fme_power),
> >> +               .feature_index = FME_FEATURE_ID_POWER_MGMT,
> >> +       },
> >> +       {
> >> +               .name = FME_FEATURE_GLOBAL_PERF,
> >> +               .resource_size = sizeof(struct feature_fme_gperf),
> >> +               .feature_index = FME_FEATURE_ID_GLOBAL_PERF,
> >> +       },
> >> +       {
> >> +               .name = FME_FEATURE_GLOBAL_ERR,
> >> +               .resource_size = sizeof(struct feature_fme_err),
> >> +               .feature_index = FME_FEATURE_ID_GLOBAL_ERR,
> >> +       },
> >> +       {
> >> +               .name = FME_FEATURE_PR_MGMT,
> >> +               .resource_size = sizeof(struct feature_fme_pr),
> >> +               .feature_index = FME_FEATURE_ID_PR_MGMT,
> >> +       }
> >> +};
> >> +
> >> +/* indexed by port feature IDs which are defined in 'enum port_feature_id'. */
> >> +static struct feature_info port_features[] = {
> >> +       {
> >> +               .name = PORT_FEATURE_HEADER,
> >> +               .resource_size = sizeof(struct feature_port_header),
> >> +               .feature_index = PORT_FEATURE_ID_HEADER,
> >> +       },
> >> +       {
> >> +               .name = PORT_FEATURE_ERR,
> >> +               .resource_size = sizeof(struct feature_port_error),
> >> +               .feature_index = PORT_FEATURE_ID_ERROR,
> >> +       },
> >> +       {
> >> +               .name = PORT_FEATURE_UMSG,
> >> +               .resource_size = sizeof(struct feature_port_umsg),
> >> +               .feature_index = PORT_FEATURE_ID_UMSG,
> >> +       },
> >> +       {
> >> +               /* This feature isn't available for now */
> >> +               .name = PORT_FEATURE_PR,
> >> +               .resource_size = 0,
> >> +               .feature_index = PORT_FEATURE_ID_PR,
> >> +       },
> >> +       {
> >> +               .name = PORT_FEATURE_STP,
> >> +               .resource_size = sizeof(struct feature_port_stp),
> >> +               .feature_index = PORT_FEATURE_ID_STP,
> >> +       },
> >> +       {
> >> +               /*
> >> +                * For User AFU feature, its region size is not fixed, but
> >> +                * reported by register PortCapability.mmio_size. Resource
> >> +                * size of UAFU will be set while parse port device.
> >> +                */
> >> +               .name = PORT_FEATURE_UAFU,
> >> +               .resource_size = 0,
> >> +               .feature_index = PORT_FEATURE_ID_UAFU,
> >> +       },
> >> +};
> >> +
> >> +static int
> >> +create_feature_instance(struct build_feature_devs_info *binfo,
> >> +                       void __iomem *start, struct feature_info *finfo)
> >> +{
> >> +       if (binfo->ioend - start < finfo->resource_size)
> >> +               return -EINVAL;
> >> +
> >> +       build_info_add_sub_feature(binfo, finfo->feature_index, finfo->name,
> >> +                                  finfo->resource_size, start);
> >> +       return 0;
> >> +}
> >
> > build_info_add_sub_feature() is only called one time - here.  Could
> > you collapse these two functions together?
> >
> >> +
> >> +static int parse_feature_fme(struct build_feature_devs_info *binfo,
> >> +                            void __iomem *start)
> >> +{
> >> +       struct cci_drvdata *drvdata = dev_get_drvdata(&binfo->pdev->dev);
> >> +       int ret;
> >> +
> >> +       ret = build_info_create_dev(binfo, FME_ID, fme_feature_num(),
> >> +                                       FPGA_FEATURE_DEV_FME);
> >> +       if (ret)
> >> +               return ret;
> >> +
> >> +       if (drvdata->fme_dev) {
> >> +               dev_err(&binfo->pdev->dev, "Multiple FMEs are detected.\n");
> >> +               return -EINVAL;
> >> +       }
> >> +
> >> +       return create_feature_instance(binfo, start,
> >> +                                      &fme_features[FME_FEATURE_ID_HEADER]);
> >> +}
> >> +
> >> +static int parse_feature_fme_private(struct build_feature_devs_info *binfo,
> >> +                                    struct feature_header *hdr)
> >> +{
> >> +       struct feature_header header;
> >> +
> >> +       header.csr = readq(hdr);
> >> +
> >> +       if (header.id >= ARRAY_SIZE(fme_features)) {
> >> +               dev_info(&binfo->pdev->dev, "FME feature id %x is not supported yet.\n",
> >> +                        header.id);
> >> +               return 0;
> >> +       }
> >> +
> >> +       return create_feature_instance(binfo, hdr, &fme_features[header.id]);
> >> +}
> >> +
> >> +static int parse_feature_port(struct build_feature_devs_info *binfo,
> >> +                            void __iomem *start)
> >> +{
> >> +       int ret;
> >> +
> >> +       ret = build_info_create_dev(binfo, PORT_ID, port_feature_num(),
> >> +                                       FPGA_FEATURE_DEV_PORT);
> >> +       if (ret)
> >> +               return ret;
> >> +
> >> +       return create_feature_instance(binfo, start,
> >> +                                      &port_features[PORT_FEATURE_ID_HEADER]);
> >> +}
> >> +
> >> +static void enable_port_uafu(struct build_feature_devs_info *binfo,
> >> +                            void __iomem *start)
> >> +{
> >> +       enum port_feature_id id = PORT_FEATURE_ID_UAFU;
> >> +       struct feature_port_header *port_hdr;
> >> +       struct feature_port_capability capability;
> >> +
> >> +       port_hdr = (struct feature_port_header *)start;
> >> +       capability.csr = readq(&port_hdr->capability);
> >> +       port_features[id].resource_size = capability.mmio_size << 10;
> >> +
> >> +       /*
> >> +        * To enable User AFU, driver needs to clear reset bit on related port,
> >> +        * otherwise the mmio space of this user AFU will be invalid.
> >> +        */
> >> +       if (port_features[id].resource_size)
> >> +               fpga_port_reset(binfo->feature_dev);
> >> +}
> >> +
> >> +static int parse_feature_port_private(struct build_feature_devs_info *binfo,
> >> +                                     struct feature_header *hdr)
> >> +{
> >> +       struct feature_header header;
> >> +       enum port_feature_id id;
> >> +
> >> +       header.csr = readq(hdr);
> >> +       /*
> >> +        * the region of port feature id is [0x10, 0x13], + 1 to reserve 0
> >> +        * which is dedicated for port-hdr.
> >> +        */
> >> +       id = (header.id & 0x000f) + 1;
> >> +
> >> +       if (id >= ARRAY_SIZE(port_features)) {
> >> +               dev_info(&binfo->pdev->dev, "Port feature id %x is not supported yet.\n",
> >> +                        header.id);
> >> +               return 0;
> >> +       }
> >> +
> >> +       return create_feature_instance(binfo, hdr, &port_features[id]);
> >> +}
> >> +
> >> +static int parse_feature_port_uafu(struct build_feature_devs_info *binfo,
> >> +                                struct feature_header *hdr)
> >> +{
> >> +       enum port_feature_id id = PORT_FEATURE_ID_UAFU;
> >> +       int ret;
> >> +
> >> +       if (port_features[id].resource_size) {
> >> +               ret = create_feature_instance(binfo, hdr, &port_features[id]);
> >> +               port_features[id].resource_size = 0;
> >> +       } else {
> >> +               dev_err(&binfo->pdev->dev, "the uafu feature header is mis-configured.\n");
> >> +               ret = -EINVAL;
> >> +       }
> >> +
> >> +       return ret;
> >> +}
> >> +
> >> +static int parse_feature_afus(struct build_feature_devs_info *binfo,
> >> +                             struct feature_header *hdr)
> >> +{
> >> +       int ret;
> >> +       struct feature_afu_header *afu_hdr, header;
> >> +       void __iomem *start;
> >> +       void __iomem *end = binfo->ioend;
> >> +
> >> +       start = hdr;
> >> +       for (; start < end; start += header.next_afu) {
> >> +               if (end - start < (sizeof(*afu_hdr) + sizeof(*hdr)))
> >> +                       return -EINVAL;
> >> +
> >> +               hdr = start;
> >> +               afu_hdr = (struct feature_afu_header *) (hdr + 1);
> >> +               header.csr = readq(&afu_hdr->csr);
> >> +
> >> +               if (feature_is_fme(afu_hdr)) {
> >> +                       ret = parse_feature_fme(binfo, hdr);
> >> +                       binfo->pfme_hdr = hdr;
> >> +                       if (ret)
> >> +                               return ret;
> >> +               } else if (feature_is_port(afu_hdr)) {
> >> +                       ret = parse_feature_port(binfo, hdr);
> >> +                       enable_port_uafu(binfo, hdr);
> >> +                       if (ret)
> >> +                               return ret;
> >> +               } else if (feature_is_UAFU(binfo)) {
> >> +                       ret = parse_feature_port_uafu(binfo, hdr);
> >> +                       if (ret)
> >> +                               return ret;
> >> +               } else
> >> +                       dev_info(&binfo->pdev->dev, "AFU GUID %pUl is not supported yet.\n",
> >> +                                afu_hdr->guid.b);
> >> +
> >> +               if (!header.next_afu)
> >> +                       break;
> >> +       }
> >> +
> >> +       return 0;
> >> +}
> >> +
> >> +static int parse_feature_private(struct build_feature_devs_info *binfo,
> >> +                                struct feature_header *hdr)
> >> +{
> >> +       struct feature_header header;
> >> +
> >> +       header.csr = readq(hdr);
> >> +
> >> +       if (!binfo->feature_dev) {
> >> +               dev_err(&binfo->pdev->dev, "the private feature %x does not belong to any AFU.\n",
> >> +                       header.id);
> >> +               return -EINVAL;
> >> +       }
> >> +
> >> +       switch (feature_dev_id_type(binfo->feature_dev)) {
> >> +       case FME_ID:
> >> +               return parse_feature_fme_private(binfo, hdr);
> >> +       case PORT_ID:
> >> +               return parse_feature_port_private(binfo, hdr);
> >> +       default:
> >> +               dev_info(&binfo->pdev->dev, "private feature %x belonging to AFU %s is not supported yet.\n",
> >> +                        header.id, binfo->feature_dev->name);
> >> +       }
> >> +       return 0;
> >> +}
> >> +
> >> +static int parse_feature(struct build_feature_devs_info *binfo,
> >> +                        struct feature_header *hdr)
> >> +{
> >> +       struct feature_header header;
> >> +       int ret = 0;
> >> +
> >> +       header.csr = readq(hdr);
> >> +
> >> +       switch (header.type) {
> >> +       case FEATURE_TYPE_AFU:
> >> +               ret = parse_feature_afus(binfo, hdr);
> >> +               break;
> >> +       case FEATURE_TYPE_PRIVATE:
> >> +               ret = parse_feature_private(binfo, hdr);
> >> +               break;
> >> +       default:
> >> +               dev_info(&binfo->pdev->dev,
> >> +                        "Feature Type %x is not supported.\n", hdr->type);
> >> +       };
> >> +
> >> +       return ret;
> >> +}
> >> +
> >> +static int
> >> +parse_feature_list(struct build_feature_devs_info *binfo, void __iomem *start)
> >> +{
> >> +       struct feature_header *hdr, header;
> >> +       void __iomem *end = binfo->ioend;
> >> +       int ret = 0;
> >> +
> >
> > Maybe a helpful comment that we are stepping through a linked list of features.
> >
> >> +       for (; start < end; start += header.next_header_offset) {
> >> +               if (end - start < sizeof(*hdr)) {
> >> +                       dev_err(&binfo->pdev->dev, "The region is too small to contain a feature.\n");
> >> +                       ret =  -EINVAL;
> >> +                       break;
> >> +               }
> >> +
> >> +               hdr = (struct feature_header *)start;
> >> +               ret = parse_feature(binfo, hdr);
> >> +               if (ret)
> >> +                       break;
> >
> > Instead of parse_feature, this can save off the enumeration info and
> > continue to read in the linked list.  After all the headers are read
> > in, call the (separate) enumeration code to step through the saved
> > headers, parse them, and create the devices.  Since the memory is
> > iomapped during the process of reading in the headers, the enumeration
> > code doesn't have to be so pcie specific.  Then this code base is
> > better set to run on embedded devices also.
> >
> >> +
> >> +               header.csr = readq(hdr);
> >> +               if (!header.next_header_offset)
> >> +                       break;
> >> +       }
> >> +
> >> +       return ret;
> >> +}
> >> +
> >> +static int parse_ports_from_fme(struct build_feature_devs_info *binfo)
> >> +{
> >> +       struct feature_fme_header *fme_hdr;
> >> +       struct feature_fme_port port;
> >> +       int i = 0, ret = 0;
> >> +
> >> +       if (binfo->pfme_hdr == NULL) {
> >> +               dev_dbg(&binfo->pdev->dev, "VF is detected.\n");
> >> +               return ret;
> >> +       }
> >> +
> >> +       fme_hdr = binfo->pfme_hdr;
> >> +
> >> +       do {
> >> +               port.csr = readq(&fme_hdr->port[i]);
> >> +               if (!port.port_implemented)
> >> +                       break;
> >> +
> >> +               ret = parse_switch_to(binfo, port.port_bar);
> >> +               if (ret)
> >> +                       break;
> >> +
> >> +               ret = parse_feature_list(binfo,
> >> +                               binfo->ioaddr + port.port_offset);
> >> +               if (ret)
> >> +                       break;
> >> +       } while (++i < MAX_FPGA_PORT_NUM);
> >> +
> >> +       return ret;
> >> +}
> >> +
> >> +static int create_init_drvdata(struct pci_dev *pdev)
> >> +{
> >> +       struct cci_drvdata *drvdata;
> >> +
> >> +       drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
> >> +       if (!drvdata)
> >> +               return -ENOMEM;
> >> +
> >> +       mutex_init(&drvdata->lock);
> >> +       INIT_LIST_HEAD(&drvdata->port_dev_list);
> >> +       INIT_LIST_HEAD(&drvdata->regions);
> >> +
> >> +       dev_set_drvdata(&pdev->dev, drvdata);
> >> +       return 0;
> >> +}
> >> +
> >> +static void destroy_drvdata(struct pci_dev *pdev)
> >> +{
> >> +       struct cci_drvdata *drvdata = dev_get_drvdata(&pdev->dev);
> >> +
> >> +       if (drvdata->fme_dev) {
> >> +               /* fme device should be unregistered first. */
> >> +               WARN_ON(device_is_registered(drvdata->fme_dev));
> >> +               free_fpga_id(FME_ID, to_platform_device(drvdata->fme_dev)->id);
> >> +               put_device(drvdata->fme_dev);
> >> +       }
> >> +
> >> +       cci_pci_remove_port_devs(pdev);
> >> +       cci_pci_release_regions(pdev);
> >> +       dev_set_drvdata(&pdev->dev, NULL);
> >> +       devm_kfree(&pdev->dev, drvdata);
> >> +}
> >> +
> >> +static int cci_pci_create_feature_devs(struct pci_dev *pdev)
> >> +{
> >> +       struct build_feature_devs_info *binfo;
> >> +       int ret;
> >> +
> >> +       binfo = build_info_alloc_and_init(pdev);
> >> +       if (!binfo)
> >> +               return -ENOMEM;
> >> +
> >> +       binfo->parent_dev = fpga_dev_create(&pdev->dev, INTEL_FPGA_DEV);
> >> +       if (IS_ERR(binfo->parent_dev)) {
> >> +               ret = PTR_ERR(binfo->parent_dev);
> >> +               goto free_binfo_exit;
> >> +       }
> >> +
> >> +       ret = parse_start(binfo);
> >> +       if (ret)
> >> +               goto free_binfo_exit;
> >> +
> >> +       ret = parse_feature_list(binfo, binfo->ioaddr);
> >> +       if (ret)
> >> +               goto free_binfo_exit;
> >> +
> >> +       ret = parse_ports_from_fme(binfo);
> >> +       if (ret)
> >> +               goto free_binfo_exit;
> >
> > So ideally, there would be a function call here that read all the
> > headers from hardware, ioremapping as it went along.  Then after that,
> > call the enumeration code to create the devices.
> >
> >> +
> >> +       ret = build_info_commit_dev(binfo);
> >> +       if (ret)
> >> +               goto free_binfo_exit;
> >> +
> >> +       /*
> >> +        * everything is okay, reset ->parent_dev to stop it being
> >> +        * freed by build_info_free()
> >> +        */
> >> +       binfo->parent_dev = NULL;
> >> +
> >> +free_binfo_exit:
> >> +       build_info_free(binfo);
> >> +       return ret;
> >> +}
> >> +
> >>  /* PCI Device ID */
> >>  #define PCIe_DEVICE_ID_PF_INT_5_X      0xBCBD
> >>  #define PCIe_DEVICE_ID_PF_INT_6_X      0xBCC0
> >> @@ -81,9 +898,18 @@ int cci_pci_probe(struct pci_dev *pcidev, const struct pci_device_id *pcidevid)
> >>                 goto release_region_exit;
> >>         }
> >>
> >> -       /* TODO: create and add the platform device per feature list */
> >> +       ret = create_init_drvdata(pcidev);
> >> +       if (ret)
> >> +               goto release_region_exit;
> >> +
> >> +       ret = cci_pci_create_feature_devs(pcidev);
> >> +       if (ret)
> >> +               goto destroy_drvdata_exit;
> >> +
> >>         return 0;
> >>
> >> +destroy_drvdata_exit:
> >> +       destroy_drvdata(pcidev);
> >>  release_region_exit:
> >>         pci_release_regions(pcidev);
> >>  disable_error_report_exit:
> >> @@ -94,6 +920,8 @@ int cci_pci_probe(struct pci_dev *pcidev, const struct pci_device_id *pcidevid)
> >>
> >>  static void cci_pci_remove(struct pci_dev *pcidev)
> >>  {
> >> +       remove_all_devs(pcidev);
> >> +       destroy_drvdata(pcidev);
> >>         pci_release_regions(pcidev);
> >>         pci_disable_pcie_error_reporting(pcidev);
> >>         pci_disable_device(pcidev);
> >> @@ -108,14 +936,23 @@ static void cci_pci_remove(struct pci_dev *pcidev)
> >>
> >>  static int __init ccidrv_init(void)
> >>  {
> >> +       int ret;
> >> +
> >>         pr_info("Intel(R) FPGA PCIe Driver: Version %s\n", DRV_VERSION);
> >>
> >> -       return pci_register_driver(&cci_pci_driver);
> >> +       fpga_ids_init();
> >> +
> >> +       ret = pci_register_driver(&cci_pci_driver);
> >> +       if (ret)
> >> +               fpga_ids_destroy();
> >> +
> >> +       return ret;
> >>  }
> >>
> >>  static void __exit ccidrv_exit(void)
> >>  {
> >>         pci_unregister_driver(&cci_pci_driver);
> >> +       fpga_ids_destroy();
> >>  }
> >>
> >>  module_init(ccidrv_init);
> >> --
> >> 1.8.3.1
> >>
> --
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