Re: [PATCH 3/4] PCI: brcmstb: add Broadcom STB PCIe host controller driver

[Jim Quinlan <jim2101024@gmail.com>]

On Thu, Nov 7, 2019 at 10:05 AM Andrew Murray <andrew.murray@arm.com> wrote:
>
> Thanks for the patch, some initial feedback below, though I will give it a
> more detailed review on your respin.
>
> On Wed, Nov 06, 2019 at 10:45:25PM +0100, Nicolas Saenz Julienne wrote:
> > From: Jim Quinlan <james.quinlan@broadcom.com>
> >
> > This commit adds the basic Broadcom STB PCIe controller.  Missing is the
> > ability to process MSI. This functionality is added in a subsequent
> > commit.
> >
> > The PCIe block contains an MDIO interface.  This is a local interface
> > only accessible by the PCIe controller.  It cannot be used or shared
> > by any other HW.  As such, the small amount of code for this
> > controller is included in this driver as there is little upside to put
> > it elsewhere.
> >
> > This is based on Jim's original submission[1] but adapted and tailored
> > specifically to bcm2711's needs (that's the Raspberry Pi 4). Support for
> > the rest of the brcmstb family will soon follow once we get support for
> > multiple dma-ranges in dma/direct.
>
> This commit message is very informative and helpful, though I feel a lot
> of this isn't relevant for a commit message (especially as much of it is
> time based comments). Instead it would be better to simply describe what
> the patch does provide, and any additional helpful notes can be provided
> under the '---' after the signed off (which won't make it into git).
>
> >
> > [1] https://patchwork.kernel.org/patch/10605959/
> >
> > Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
> > Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > ---
> >  drivers/pci/controller/Kconfig        |  12 +
> >  drivers/pci/controller/Makefile       |   1 +
> >  drivers/pci/controller/pcie-brcmstb.c | 973 ++++++++++++++++++++++++++
> >  3 files changed, 986 insertions(+)
> >  create mode 100644 drivers/pci/controller/pcie-brcmstb.c
> >
> > diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> > index f5de9119e8d3..8b3aae91d8af 100644
> > --- a/drivers/pci/controller/Kconfig
> > +++ b/drivers/pci/controller/Kconfig
> > @@ -281,6 +281,18 @@ config VMD
> >         To compile this driver as a module, choose M here: the
> >         module will be called vmd.
> >
> > +config PCIE_BRCMSTB
> > +     bool "Broadcom Brcmstb PCIe host controller"
> > +     depends on ARCH_BRCMSTB || BMIPS_GENERIC
>
> I can't see what ARCH_BRCMSTB adds here. Given this also depends
> on SOC_BRCMSTB. Are all of these depends really necessary?
>
> Also should the bool be "Broadcom STB PCIe host contoller" ?
>
> > +     depends on OF
> > +     depends on SOC_BRCMSTB
> > +     default ARCH_BRCMSTB || BMIPS_GENERIC
>
> Please also include COMPILE_TEST in here (look at the other controllers
> in the file). This helps improve testing coverage by compiling all drivers
> even if they can't be run.
>
> > +     help
> > +       Say Y here to enable PCIe host controller support for
> > +       Broadcom Settop Box SOCs.  A Broadcom SOC will may have
>
> s/Settop/Set top/ or s/Settop/STB/?
>
> > +       multiple host controllers as opposed to a single host
> > +       controller with multiple ports.
>
> I'm sure many other SOCs may have multiple controllers instead of one
> with multiple ports. I'm not sure what value this adds here. It's
> always better to describe enough information so the user can determine
> if this option will enable something they want on their hardware.
>
> > +
> >  config PCI_HYPERV_INTERFACE
> >       tristate "Hyper-V PCI Interface"
> >       depends on X86 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && X86_64
> > diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
> > index a2a22c9d91af..3fc0b0cf5b5b 100644
> > --- a/drivers/pci/controller/Makefile
> > +++ b/drivers/pci/controller/Makefile
> > @@ -30,6 +30,7 @@ obj-$(CONFIG_PCIE_MEDIATEK) += pcie-mediatek.o
> >  obj-$(CONFIG_PCIE_MOBIVEIL) += pcie-mobiveil.o
> >  obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o
> >  obj-$(CONFIG_VMD) += vmd.o
> > +obj-$(CONFIG_PCIE_BRCMSTB) += pcie-brcmstb.o
> >  # pcie-hisi.o quirks are needed even without CONFIG_PCIE_DW
> >  obj-y                                += dwc/
> >
> > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> > new file mode 100644
> > index 000000000000..880ec11d06a1
> > --- /dev/null
> > +++ b/drivers/pci/controller/pcie-brcmstb.c
> > @@ -0,0 +1,973 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/* Copyright (C) 2009 - 2019 Broadcom */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/compiler.h>
> > +#include <linux/delay.h>
> > +#include <linux/init.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/ioport.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/kernel.h>
> > +#include <linux/list.h>
> > +#include <linux/log2.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_irq.h>
> > +#include <linux/of_pci.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/pci.h>
> > +#include <linux/printk.h>
> > +#include <linux/sizes.h>
> > +#include <linux/slab.h>
> > +#include <linux/string.h>
> > +#include <linux/types.h>
> > +
> > +#include "../pci.h"
>
> Is this last include needed? Sometimes controller drivers suffer from copy and
> paste and this is often included when it isn't needed.
>
> > +
> > +/* BRCM_PCIE_CAP_REGS - Offset for the mandatory capability config regs */
> > +#define BRCM_PCIE_CAP_REGS                           0x00ac
> > +
> > +/*
> > + * Broadcom Settop Box PCIe Register Offsets. The names are from
> > + * the chip's RDB and we use them here so that a script can correlate
> > + * this code and the RDB to prevent discrepancies.
> > + */
> > +#define PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1              0x0188
> > +#define PCIE_RC_CFG_PRIV1_ID_VAL3                    0x043c
> > +#define PCIE_RC_DL_MDIO_ADDR                         0x1100
> > +#define PCIE_RC_DL_MDIO_WR_DATA                              0x1104
> > +#define PCIE_RC_DL_MDIO_RD_DATA                              0x1108
> > +#define PCIE_MISC_MISC_CTRL                          0x4008
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO             0x400c
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI             0x4010
> > +#define PCIE_MISC_RC_BAR1_CONFIG_LO                  0x402c
> > +#define PCIE_MISC_RC_BAR2_CONFIG_LO                  0x4034
> > +#define PCIE_MISC_RC_BAR2_CONFIG_HI                  0x4038
> > +#define PCIE_MISC_RC_BAR3_CONFIG_LO                  0x403c
> > +#define PCIE_MISC_PCIE_CTRL                          0x4064
> > +#define PCIE_MISC_PCIE_STATUS                                0x4068
> > +#define PCIE_MISC_REVISION                           0x406c
>
> PCIE_MISC_REVISION can be removed as it shouldn't be needed
>
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT     0x4070
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI                0x4080
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI               0x4084
> > +#define PCIE_MISC_HARD_PCIE_HARD_DEBUG                       0x4204
> > +#define PCIE_INTR2_CPU_BASE                          0x4300
> > +
> > +/*
> > + * Broadcom Settop Box PCIe Register Field shift and mask info. The
> > + * names are from the chip's RDB and we use them here so that a script
> > + * can correlate this code and the RDB to prevent discrepancies.
> > + */
> > +#define PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_MASK        0xc
> > +#define PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_SHIFT       0x2
> > +#define PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK            0xffffff
> > +#define PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_SHIFT           0x0
> > +#define PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK                       0x1000
> > +#define PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_SHIFT                      0xc
> > +#define PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK            0x2000
> > +#define PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_SHIFT           0xd
> > +#define PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK                      0x300000
> > +#define PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_SHIFT             0x14
> > +#define PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK                   0xf8000000
> > +#define PCIE_MISC_MISC_CTRL_SCB0_SIZE_SHIFT                  0x1b
> > +#define PCIE_MISC_MISC_CTRL_SCB1_SIZE_MASK                   0x7c00000
> > +#define PCIE_MISC_MISC_CTRL_SCB1_SIZE_SHIFT                  0x16
> > +#define PCIE_MISC_MISC_CTRL_SCB2_SIZE_MASK                   0x1f
> > +#define PCIE_MISC_MISC_CTRL_SCB2_SIZE_SHIFT                  0x0
> > +#define PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK                        0x1f
> > +#define PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_SHIFT                       0x0
> > +#define PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_MASK                        0x1f
> > +#define PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_SHIFT                       0x0
> > +#define PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK                        0x1f
> > +#define PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_SHIFT                       0x0
> > +#define PCIE_MISC_PCIE_CTRL_PCIE_PERSTB_MASK                 0x4
> > +#define PCIE_MISC_PCIE_CTRL_PCIE_PERSTB_SHIFT                        0x2
> > +#define PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK            0x1
> > +#define PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_SHIFT           0x0
> > +#define PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK                 0x80
> > +#define PCIE_MISC_PCIE_STATUS_PCIE_PORT_SHIFT                        0x7
> > +#define PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_MASK            0x20
> > +#define PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_SHIFT           0x5
> > +#define PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK            0x10
> > +#define PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_SHIFT           0x4
> > +#define PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK          0x40
> > +#define PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_SHIFT         0x6
> > +#define PCIE_MISC_REVISION_MAJMIN_MASK                               0xffff
> > +#define PCIE_MISC_REVISION_MAJMIN_SHIFT                              0
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_MASK  0xfff00000
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_SHIFT 0x14
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK   0xfff0
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_SHIFT  0x4
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_NUM_MASK_BITS       0xc
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI_BASE_MASK              0xff
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI_BASE_SHIFT     0x0
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI_LIMIT_MASK    0xff
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI_LIMIT_SHIFT   0x0
> > +#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK      0x2
> > +#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_SHIFT 0x1
> > +#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK              0x08000000
> > +#define PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_SHIFT     0x1b
> > +#define PCIE_RGR1_SW_INIT_1_PERST_MASK                               0x1
> > +#define PCIE_RGR1_SW_INIT_1_PERST_SHIFT                              0x0
>
> Most of the above aren't used anywhere, please remove them.
>
> > +
> > +#define BRCM_NUM_PCIE_OUT_WINS               0x4
> > +#define BRCM_MAX_SCB                 0x4
> > +
> > +#define BRCM_MSI_TARGET_ADDR_LT_4GB  0x0fffffffcULL
> > +#define BRCM_MSI_TARGET_ADDR_GT_4GB  0xffffffffcULL
>
> These two aren't used.
>
> > +
> > +#define BURST_SIZE_128                       0
> > +#define BURST_SIZE_256                       1
> > +#define BURST_SIZE_512                       2
> > +
> > +/* Offsets from PCIE_INTR2_CPU_BASE */
> > +#define STATUS                               0x0
> > +#define SET                          0x4
> > +#define CLR                          0x8
> > +#define MASK_STATUS                  0xc
> > +#define MASK_SET                     0x10
> > +#define MASK_CLR                     0x14
>
> Some of the above are not used anywhere.
>
> > +
> > +#define PCIE_BUSNUM_SHIFT            20
> > +#define PCIE_SLOT_SHIFT                      15
> > +#define PCIE_FUNC_SHIFT                      12
> > +
> > +#if defined(__BIG_ENDIAN)
> > +#define      DATA_ENDIAN                     2       /* PCIe->DDR inbound traffic */
> > +#define MMIO_ENDIAN                  2       /* CPU->PCIe outbound traffic */
> > +#else
> > +#define      DATA_ENDIAN                     0
> > +#define MMIO_ENDIAN                  0
> > +#endif
> > +
> > +#define MDIO_PORT0                   0x0
> > +#define MDIO_DATA_MASK                       0x7fffffff
> > +#define MDIO_DATA_SHIFT                      0x0
> > +#define MDIO_PORT_MASK                       0xf0000
> > +#define MDIO_PORT_SHIFT                      0x16
> > +#define MDIO_REGAD_MASK                      0xffff
> > +#define MDIO_REGAD_SHIFT             0x0
> > +#define MDIO_CMD_MASK                        0xfff00000
> > +#define MDIO_CMD_SHIFT                       0x14
> > +#define MDIO_CMD_READ                        0x1
> > +#define MDIO_CMD_WRITE                       0x0
> > +#define MDIO_DATA_DONE_MASK          0x80000000
> > +#define MDIO_RD_DONE(x)                      (((x) & MDIO_DATA_DONE_MASK) ? 1 : 0)
> > +#define MDIO_WT_DONE(x)                      (((x) & MDIO_DATA_DONE_MASK) ? 0 : 1)
> > +#define SSC_REGS_ADDR                        0x1100
> > +#define SET_ADDR_OFFSET                      0x1f
> > +#define SSC_CNTL_OFFSET                      0x2
> > +#define SSC_CNTL_OVRD_EN_MASK                0x8000
> > +#define SSC_CNTL_OVRD_EN_SHIFT               0xf
> > +#define SSC_CNTL_OVRD_VAL_MASK               0x4000
> > +#define SSC_CNTL_OVRD_VAL_SHIFT              0xe
> > +#define SSC_STATUS_OFFSET            0x1
> > +#define SSC_STATUS_SSC_MASK          0x400
> > +#define SSC_STATUS_SSC_SHIFT         0xa
> > +#define SSC_STATUS_PLL_LOCK_MASK     0x800
> > +#define SSC_STATUS_PLL_LOCK_SHIFT    0xb
> > +
> > +#define IDX_ADDR(pcie)       \
> > +     ((pcie)->reg_offsets[EXT_CFG_INDEX])
> > +#define DATA_ADDR(pcie)      \
> > +     ((pcie)->reg_offsets[EXT_CFG_DATA])
> > +#define PCIE_RGR1_SW_INIT_1(pcie) \
> > +     ((pcie)->reg_offsets[RGR1_SW_INIT_1])
> > +
> > +enum {
> > +     RGR1_SW_INIT_1,
> > +     EXT_CFG_INDEX,
> > +     EXT_CFG_DATA,
> > +};
> > +
> > +enum {
> > +     RGR1_SW_INIT_1_INIT_MASK,
> > +     RGR1_SW_INIT_1_INIT_SHIFT,
> > +     RGR1_SW_INIT_1_PERST_MASK,
> > +     RGR1_SW_INIT_1_PERST_SHIFT,
> > +};
> > +
> > +enum pcie_type {
> > +     BCM2711,
> > +};
> > +
> > +struct brcm_window {
> > +     dma_addr_t pcie_addr;
> > +     phys_addr_t cpu_addr;
> > +     dma_addr_t size;
> > +};
> > +
> > +/* Internal PCIe Host Controller Information.*/
> > +struct brcm_pcie {
> > +     struct device           *dev;
> > +     void __iomem            *base;
> > +     int                     irq;
>
> 'irq' isn't used and can be removed.
>
> > +     struct clk              *clk;
> > +     struct pci_bus          *root_bus;
> > +     struct device_node      *dn;
> > +     int                     id;
>
> 'id' isn't used and can be removed.
>
> > +     bool                    suspended;
> > +     bool                    ssc;
> > +     int                     gen;
> > +     struct brcm_window      out_wins[BRCM_NUM_PCIE_OUT_WINS];
> > +     unsigned int            rev;
>
> 'rev' isn't used and can be removed.
>
> > +     const int               *reg_offsets;
> > +     const int               *reg_field_info;
> > +     enum pcie_type          type;
> > +};
> > +
> > +struct pcie_cfg_data {
> > +     const int               *reg_field_info;
> > +     const int               *offsets;
> > +     const enum pcie_type    type;
> > +};
> > +
> > +static const int pcie_reg_field_info[] = {
> > +     [RGR1_SW_INIT_1_INIT_MASK] = 0x2,
> > +     [RGR1_SW_INIT_1_INIT_SHIFT] = 0x1,
> > +};
> > +
> > +static const int pcie_offset_bcm2711[] = {
> > +     [RGR1_SW_INIT_1] = 0x9210,
> > +     [EXT_CFG_INDEX]  = 0x9000,
> > +     [EXT_CFG_DATA]   = 0x8000,
> > +};
> > +
> > +static const struct pcie_cfg_data bcm2711_cfg = {
> > +     .reg_field_info = pcie_reg_field_info,
> > +     .offsets        = pcie_offset_bcm2711,
> > +     .type           = BCM2711,
> > +};
> > +
> > +static void __iomem *brcm_pcie_map_conf(struct pci_bus *bus, unsigned int devfn,
> > +                                     int where);
> > +
> > +static struct pci_ops brcm_pcie_ops = {
> > +     .map_bus = brcm_pcie_map_conf,
> > +     .read = pci_generic_config_read,
> > +     .write = pci_generic_config_write,
> > +};
> > +
> > +#define bcm_readl(a)         readl(a)
> > +#define bcm_writel(d, a)     writel(d, a)
> > +#define bcm_readw(a)         readw(a)
> > +#define bcm_writew(d, a)     writew(d, a)
>
> Is there much value in these macros?
>
> > +
> > +/* These macros extract/insert fields to host controller's register set. */
> > +#define RD_FLD(base, reg, field) \
> > +     rd_fld((base) + reg, reg##_##field##_MASK, reg##_##field##_SHIFT)
> > +#define WR_FLD(base, reg, field, val) \
> > +     wr_fld((base) + reg, reg##_##field##_MASK, reg##_##field##_SHIFT, val)
> > +#define WR_FLD_RB(base, reg, field, val) \
> > +     wr_fld_rb((base) + reg, reg##_##field##_MASK, \
> > +             reg##_##field##_SHIFT, val)
> > +#define WR_FLD_WITH_OFFSET(base, off, reg, field, val) \
> > +     wr_fld((base) + reg + (off), reg##_##field##_MASK, \
> > +            reg##_##field##_SHIFT, val)
> > +#define EXTRACT_FIELD(val, reg, field) \
> > +     (((val) & reg##_##field##_MASK) >> reg##_##field##_SHIFT)
> > +#define INSERT_FIELD(val, reg, field, field_val) \
> > +     (((val) & ~reg##_##field##_MASK) | \
> > +      (reg##_##field##_MASK & (field_val << reg##_##field##_SHIFT)))
> > +
> > +static u32 rd_fld(void __iomem *p, u32 mask, int shift)
> > +{
> > +     return (bcm_readl(p) & mask) >> shift;
> > +}
> > +
> > +static void wr_fld(void __iomem *p, u32 mask, int shift, u32 val)
> > +{
> > +     u32 reg = bcm_readl(p);
> > +
> > +     reg = (reg & ~mask) | ((val << shift) & mask);
> > +     bcm_writel(reg, p);
> > +}
> > +
> > +static void wr_fld_rb(void __iomem *p, u32 mask, int shift, u32 val)
> > +{
> > +     wr_fld(p, mask, shift, val);
> > +     (void)bcm_readl(p);
> > +}
> > +
> > +static const char *link_speed_to_str(int s)
> > +{
> > +     switch (s) {
> > +     case 1:
> > +             return "2.5";
> > +     case 2:
> > +             return "5.0";
> > +     case 3:
> > +             return "8.0";
> > +     default:
> > +             break;
> > +     }
> > +     return "???";
> > +}
> > +
> > +/*
> > + * The roundup_pow_of_two() from log2.h invokes
> > + * __roundup_pow_of_two(unsigned long), but we really need a
> > + * such a function to take a native u64 since unsigned long
> > + * is 32 bits on some configurations.  So we provide this helper
> > + * function below.
> > + */
> > +static u64 roundup_pow_of_two_64(u64 n)
> > +{
> > +     return 1ULL << fls64(n - 1);
> > +}
>
> Given that you use this in one place and that it is a single line, I'd
> suggest you just drop this function. Alternatively if you wanted to add
> this function to log2.h then you already have a bunch of users ready to
> be migrated to it:
>
> $ git grep "<< fls64"
> arch/sparc/mm/init_64.c:        m_end += pa_start & ~((1ul << fls64(m_mask)) - 1);
> drivers/net/ethernet/mellanox/mlx4/en_clock.c:  u64 max_val_cycles_rounded = 1ULL << fls64(max_val_cycles - 1);
> drivers/pci/controller/pcie-cadence-ep.c:       sz = 1ULL << fls64(sz - 1);
> drivers/pci/controller/pcie-cadence.c:  u64 sz = 1ULL << fls64(size - 1);
> drivers/pci/controller/pcie-rockchip-ep.c:      u64 sz = 1ULL << fls64(size - 1);
> drivers/pci/controller/pcie-rockchip-ep.c:      sz = 1ULL << fls64(sz - 1);
>
>
> > +
> > +/*
> > + * This is to convert the size of the inbound "BAR" region to the
> > + * non-linear values of PCIE_X_MISC_RC_BAR[123]_CONFIG_LO.SIZE
> > + */
> > +int encode_ibar_size(u64 size)
> > +{
> > +     int log2_in = ilog2(size);
> > +
> > +     if (log2_in >= 12 && log2_in <= 15)
> > +             /* Covers 4KB to 32KB (inclusive) */
> > +             return (log2_in - 12) + 0x1c;
> > +     else if (log2_in >= 16 && log2_in <= 37)
> > +             /* Covers 64KB to 32GB, (inclusive) */
>
> 2^37 != 32GB?
Comment should be changed
    /* Current chips implement 64KB to 32GB; allow up to 128GB for
future chips */
or the value should be changed:
    s/37/35/;
>
> > +             return log2_in - 15;
> > +     /* Something is awry so disable */
> > +     return 0;
> > +}
> > +
> > +static u32 mdio_form_pkt(int port, int regad, int cmd)
> > +{
> > +     u32 pkt = 0;
> > +
> > +     pkt |= (port << MDIO_PORT_SHIFT) & MDIO_PORT_MASK;
> > +     pkt |= (regad << MDIO_REGAD_SHIFT) & MDIO_REGAD_MASK;
> > +     pkt |= (cmd << MDIO_CMD_SHIFT) & MDIO_CMD_MASK;
> > +
> > +     return pkt;
> > +}
> > +
> > +/* negative return value indicates error */
> > +static int mdio_read(void __iomem *base, u8 port, u8 regad)
> > +{
> > +     int tries;
> > +     u32 data;
> > +
> > +     bcm_writel(mdio_form_pkt(port, regad, MDIO_CMD_READ),
> > +                base + PCIE_RC_DL_MDIO_ADDR);
> > +     bcm_readl(base + PCIE_RC_DL_MDIO_ADDR);
> > +
> > +     data = bcm_readl(base + PCIE_RC_DL_MDIO_RD_DATA);
> > +     for (tries = 0; !MDIO_RD_DONE(data) && tries < 10; tries++) {
> > +             udelay(10);
> > +             data = bcm_readl(base + PCIE_RC_DL_MDIO_RD_DATA);
> > +     }
> > +
> > +     return MDIO_RD_DONE(data)
> > +             ? (data & MDIO_DATA_MASK) >> MDIO_DATA_SHIFT
> > +             : -EIO;
> > +}
> > +
> > +/* negative return value indicates error */
> > +static int mdio_write(void __iomem *base, u8 port, u8 regad, u16 wrdata)
> > +{
> > +     int tries;
> > +     u32 data;
> > +
> > +     bcm_writel(mdio_form_pkt(port, regad, MDIO_CMD_WRITE),
> > +                base + PCIE_RC_DL_MDIO_ADDR);
> > +     bcm_readl(base + PCIE_RC_DL_MDIO_ADDR);
> > +     bcm_writel(MDIO_DATA_DONE_MASK | wrdata,
> > +                base + PCIE_RC_DL_MDIO_WR_DATA);
> > +
> > +     data = bcm_readl(base + PCIE_RC_DL_MDIO_WR_DATA);
> > +     for (tries = 0; !MDIO_WT_DONE(data) && tries < 10; tries++) {
> > +             udelay(10);
> > +             data = bcm_readl(base + PCIE_RC_DL_MDIO_WR_DATA);
> > +     }
> > +
> > +     return MDIO_WT_DONE(data) ? 0 : -EIO;
> > +}
> > +
> > +/*
> > + * Configures device for Spread Spectrum Clocking (SSC) mode; a negative
> > + * return value indicates error.
> > + */
> > +static int set_ssc(void __iomem *base)
>
> Please prefix this with brcm_pcie_ (and other similar occurances)
>
> > +{
> > +     int tmp;
> > +     u16 wrdata;
> > +     int pll, ssc;
> > +
> > +     tmp = mdio_write(base, MDIO_PORT0, SET_ADDR_OFFSET, SSC_REGS_ADDR);
> > +     if (tmp < 0)
> > +             return tmp;
> > +
> > +     tmp = mdio_read(base, MDIO_PORT0, SSC_CNTL_OFFSET);
> > +     if (tmp < 0)
> > +             return tmp;
> > +
> > +     wrdata = INSERT_FIELD(tmp, SSC_CNTL_OVRD, EN, 1);
> > +     wrdata = INSERT_FIELD(wrdata, SSC_CNTL_OVRD, VAL, 1);
> > +     tmp = mdio_write(base, MDIO_PORT0, SSC_CNTL_OFFSET, wrdata);
> > +     if (tmp < 0)
> > +             return tmp;
> > +
> > +     usleep_range(1000, 2000);
> > +     tmp = mdio_read(base, MDIO_PORT0, SSC_STATUS_OFFSET);
> > +     if (tmp < 0)
> > +             return tmp;
> > +
> > +     ssc = EXTRACT_FIELD(tmp, SSC_STATUS, SSC);
> > +     pll = EXTRACT_FIELD(tmp, SSC_STATUS, PLL_LOCK);
> > +
> > +     return (ssc && pll) ? 0 : -EIO;
> > +}
> > +
> > +/* Limits operation to a specific generation (1, 2, or 3) */
> > +static void set_gen(void __iomem *base, int gen)
> > +{
> > +     u32 lnkcap = bcm_readl(base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP);
> > +     u16 lnkctl2 = bcm_readw(base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
> > +
> > +     lnkcap = (lnkcap & ~PCI_EXP_LNKCAP_SLS) | gen;
> > +     bcm_writel(lnkcap, base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP);
> > +
> > +     lnkctl2 = (lnkctl2 & ~0xf) | gen;
> > +     bcm_writew(lnkctl2, base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
> > +}
> > +
> > +static void brcm_pcie_set_outbound_win(struct brcm_pcie *pcie,
> > +                                    unsigned int win, phys_addr_t cpu_addr,
> > +                                    dma_addr_t  pcie_addr, dma_addr_t size)
> > +{
> > +     void __iomem *base = pcie->base;
> > +     phys_addr_t cpu_addr_mb, limit_addr_mb;
> > +     u32 tmp;
> > +
> > +     /* Set the base of the pcie_addr window */
> > +     bcm_writel(lower_32_bits(pcie_addr) + MMIO_ENDIAN,
> > +                base + PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO + (win * 8));
> > +     bcm_writel(upper_32_bits(pcie_addr),
> > +                base + PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI + (win * 8));
> > +
> > +     cpu_addr_mb = cpu_addr >> 20;
> > +     limit_addr_mb = (cpu_addr + size - 1) >> 20;
> > +
> > +     /* Write the addr base low register */
> > +     WR_FLD_WITH_OFFSET(base, (win * 4),
> > +                        PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT,
> > +                        BASE, cpu_addr_mb);
> > +     /* Write the addr limit low register */
> > +     WR_FLD_WITH_OFFSET(base, (win * 4),
> > +                        PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT,
> > +                        LIMIT, limit_addr_mb);
> > +
> > +     /* Write the cpu addr high register */
> > +     tmp = (u32)(cpu_addr_mb >>
> > +             PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_NUM_MASK_BITS);
> > +     WR_FLD_WITH_OFFSET(base, (win * 8),
> > +                        PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI,
> > +                        BASE, tmp);
> > +     /* Write the cpu limit high register */
> > +     tmp = (u32)(limit_addr_mb >>
> > +             PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_NUM_MASK_BITS);
> > +     WR_FLD_WITH_OFFSET(base, (win * 8),
> > +                        PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI,
> > +                        LIMIT, tmp);
> > +}
> > +
> > +/* Configuration space read/write support */
> > +static int cfg_index(int busnr, int devfn, int reg)
> > +{
> > +     return ((PCI_SLOT(devfn) & 0x1f) << PCIE_SLOT_SHIFT)
> > +             | ((PCI_FUNC(devfn) & 0x07) << PCIE_FUNC_SHIFT)
> > +             | (busnr << PCIE_BUSNUM_SHIFT)
> > +             | (reg & ~3);
> > +}
> > +
> > +/* The controller is capable of serving in both RC and EP roles */
> > +static bool brcm_pcie_rc_mode(struct brcm_pcie *pcie)
> > +{
> > +     void __iomem *base = pcie->base;
> > +     u32 val = bcm_readl(base + PCIE_MISC_PCIE_STATUS);
> > +
> > +     return !!EXTRACT_FIELD(val, PCIE_MISC_PCIE_STATUS, PCIE_PORT);
> > +}
> > +
> > +static bool brcm_pcie_link_up(struct brcm_pcie *pcie)
> > +{
> > +     void __iomem *base = pcie->base;
> > +     u32 val = bcm_readl(base + PCIE_MISC_PCIE_STATUS);
> > +     u32 dla = EXTRACT_FIELD(val, PCIE_MISC_PCIE_STATUS, PCIE_DL_ACTIVE);
> > +     u32 plu = EXTRACT_FIELD(val, PCIE_MISC_PCIE_STATUS, PCIE_PHYLINKUP);
> > +
> > +     return  (dla && plu) ? true : false;
> > +}
> > +
> > +static void __iomem *brcm_pcie_map_conf(struct pci_bus *bus, unsigned int devfn,
> > +                                     int where)
> > +{
> > +     struct brcm_pcie *pcie = bus->sysdata;
> > +     void __iomem *base = pcie->base;
> > +     int idx;
> > +
> > +     /* Accesses to the RC go right to the RC registers if slot==0 */
> > +     if (pci_is_root_bus(bus))
> > +             return PCI_SLOT(devfn) ? NULL : base + where;
> > +
> > +     /* For devices, write to the config space index register */
> > +     idx = cfg_index(bus->number, devfn, 0);
> > +     bcm_writel(idx, pcie->base + IDX_ADDR(pcie));
> > +     return base + DATA_ADDR(pcie) + where;
> > +}
> > +
> > +static inline void brcm_pcie_bridge_sw_init_set(struct brcm_pcie *pcie,
> > +                                             unsigned int val)
> > +{
> > +     unsigned int shift = pcie->reg_field_info[RGR1_SW_INIT_1_INIT_SHIFT];
> > +     u32 mask =  pcie->reg_field_info[RGR1_SW_INIT_1_INIT_MASK];
> > +
> > +     wr_fld_rb(pcie->base + PCIE_RGR1_SW_INIT_1(pcie), mask, shift, val);
> > +}
> > +
> > +static inline void brcm_pcie_perst_set(struct brcm_pcie *pcie,
> > +                                    unsigned int val)
> > +{
> > +     wr_fld_rb(pcie->base + PCIE_RGR1_SW_INIT_1(pcie),
> > +               PCIE_RGR1_SW_INIT_1_PERST_MASK,
> > +               PCIE_RGR1_SW_INIT_1_PERST_SHIFT, val);
> > +}
> > +
> > +static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
> > +                                                     u64 *rc_bar2_size,
> > +                                                     u64 *rc_bar2_offset)
> > +{
> > +     struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
> > +     struct device *dev = pcie->dev;
> > +     struct resource_entry *entry;
> > +     u64 total_mem_size = 0;
> > +
> > +     *rc_bar2_offset = -1;
> > +
> > +     resource_list_for_each_entry(entry, &bridge->dma_ranges) {
> > +             /*
> > +              * We're promissed the RC will provide a contiguous view of
>
> s/promissed/promised/
>
> > +              * memory to downstream devices. We can then infer the
> > +              * rc_bar2_offset from the lower avaiable dma-range offset.
> > +              */
> > +             if (entry->offset < *rc_bar2_offset)
> > +                     *rc_bar2_offset = entry->offset;
> > +
> > +             total_mem_size += entry->res->end - entry->res->start + 1;
> > +     }
> > +
> > +     *rc_bar2_size = roundup_pow_of_two_64(total_mem_size);
> > +
> > +     /*
> > +      * Validate the results:
> > +      *
> > +      * The PCIe host controller by design must set the inbound viewport to
> > +      * be a contiguous arrangement of all of the system's memory.  In
> > +      * addition, its size mut be a power of two.  To further complicate
> > +      * matters, the viewport must start on a pcie-address that is aligned
> > +      * on a multiple of its size.  If a portion of the viewport does not
> > +      * represent system memory -- e.g. 3GB of memory requires a 4GB
> > +      * viewport -- we can map the outbound memory in or after 3GB and even
> > +      * though the viewport will overlap the outbound memory the controller
> > +      * will know to send outbound memory downstream and everything else
> > +      * upstream.
> > +      *
> > +      * For example:
> > +      *
> > +      * - The best-case scenario, memory up to 3GB, is to place the inbound
> > +      *   region in the first 4GB of pcie-space, as some legacy devices can
> > +      *   only address 32bits. We would also like to put the MSI under 4GB
> > +      *   as well, since some devices require a 32bit MSI target address.
> > +      *
> > +      * - If the system memory is 4GB or larger we cannot start the inbound
> > +      *   region at location 0 (since we have to allow some space for
> > +      *   outbound memory @ 3GB). So instead it will  start at the 1x
> > +      *   multiple of its size
> > +      */
> > +     if (!*rc_bar2_size || *rc_bar2_offset % *rc_bar2_size ||
> > +         (*rc_bar2_offset < SZ_4G && *rc_bar2_offset > SZ_2G)) {
> > +             dev_err(dev, "Invalid rc_bar2_offset/size: size 0x%llx, off 0x%llx\n",
> > +                     *rc_bar2_size, *rc_bar2_offset);
> > +             return -EINVAL;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int brcm_pcie_setup(struct brcm_pcie *pcie)
> > +{
> > +     struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
> > +     u64 rc_bar2_offset, rc_bar2_size;
> > +     void __iomem *base = pcie->base;
> > +     struct resource_entry *entry;
> > +     unsigned int scb_size_val;
> > +     struct resource *res;
> > +     int num_out_wins = 0;
> > +     u32 tmp;
> > +     int i, j, ret, limit;
> > +     u16 nlw, cls, lnksta;
> > +     bool ssc_good = false;
> > +     struct device *dev = pcie->dev;
> > +
> > +     /* Reset the bridge */
> > +     brcm_pcie_bridge_sw_init_set(pcie, 1);
> > +
> > +     usleep_range(100, 200);
> > +
> > +     /* Take the bridge out of reset */
> > +     brcm_pcie_bridge_sw_init_set(pcie, 0);
> > +
> > +     WR_FLD_RB(base, PCIE_MISC_HARD_PCIE_HARD_DEBUG, SERDES_IDDQ, 0);
> > +     /* Wait for SerDes to be stable */
> > +     usleep_range(100, 200);
> > +
> > +     /* Grab the PCIe hw revision number */
> > +     tmp = bcm_readl(base + PCIE_MISC_REVISION);
> > +     pcie->rev = EXTRACT_FIELD(tmp, PCIE_MISC_REVISION, MAJMIN);
>
> This isn't used anywhere
>
> > +
> > +     /* Set SCB_MAX_BURST_SIZE, CFG_READ_UR_MODE, SCB_ACCESS_EN */
> > +     tmp = INSERT_FIELD(0, PCIE_MISC_MISC_CTRL, SCB_ACCESS_EN, 1);
> > +     tmp = INSERT_FIELD(tmp, PCIE_MISC_MISC_CTRL, CFG_READ_UR_MODE, 1);
> > +     tmp = INSERT_FIELD(tmp, PCIE_MISC_MISC_CTRL, MAX_BURST_SIZE,
> > +                        BURST_SIZE_128);
> > +     bcm_writel(tmp, base + PCIE_MISC_MISC_CTRL);
> > +
> > +     ret = brcm_pcie_get_rc_bar2_size_and_offset(pcie, &rc_bar2_size,
> > +                                                 &rc_bar2_offset);
> > +     if (ret)
> > +             return ret;
> > +
> > +     tmp = lower_32_bits(rc_bar2_offset);
> > +     tmp = INSERT_FIELD(tmp, PCIE_MISC_RC_BAR2_CONFIG_LO, SIZE,
> > +                        encode_ibar_size(rc_bar2_size));
> > +     bcm_writel(tmp, base + PCIE_MISC_RC_BAR2_CONFIG_LO);
> > +     bcm_writel(upper_32_bits(rc_bar2_offset),
> > +                base + PCIE_MISC_RC_BAR2_CONFIG_HI);
> > +
> > +     scb_size_val = rc_bar2_size ?
> > +                    ilog2(rc_bar2_size) - 15 : 0xf; /* 0xf is 1GB */
> > +     WR_FLD(base, PCIE_MISC_MISC_CTRL, SCB0_SIZE, scb_size_val);
> > +
> > +     /* disable the PCIe->GISB memory window (RC_BAR1) */
> > +     WR_FLD(base, PCIE_MISC_RC_BAR1_CONFIG_LO, SIZE, 0);
> > +
> > +     /* disable the PCIe->SCB memory window (RC_BAR3) */
> > +     WR_FLD(base, PCIE_MISC_RC_BAR3_CONFIG_LO, SIZE, 0);
> > +
> > +     if (!pcie->suspended) {
> > +             /* clear any interrupts we find on boot */
> > +             bcm_writel(0xffffffff, base + PCIE_INTR2_CPU_BASE + CLR);
> > +             (void)bcm_readl(base + PCIE_INTR2_CPU_BASE + CLR);
> > +     }
> > +
> > +     /* Mask all interrupts since we are not handling any yet */
> > +     bcm_writel(0xffffffff, base + PCIE_INTR2_CPU_BASE + MASK_SET);
> > +     (void)bcm_readl(base + PCIE_INTR2_CPU_BASE + MASK_SET);
> > +
> > +     if (pcie->gen)
> > +             set_gen(base, pcie->gen);
> > +
> > +     /* Unassert the fundamental reset */
> > +     brcm_pcie_perst_set(pcie, 0);
> > +
> > +     /*
> > +      * Give the RC/EP time to wake up, before trying to configure RC.
> > +      * Intermittently check status for link-up, up to a total of 100ms
> > +      * when we don't know if the device is there, and up to 1000ms if
> > +      * we do know the device is there.
> > +      */
> > +     limit = pcie->suspended ? 1000 : 100;
> > +     for (i = 1, j = 0; j < limit && !brcm_pcie_link_up(pcie);
> > +          j += i, i = i * 2)
> > +             msleep(i + j > limit ? limit - j : i);
>
> Does it need to be this complex? Also waiting a second during resume seems
> like a long delay.

Agree on the  complexity issue.  But we've had EP chips that required
this much time on a resume for reasons unknown.   Code could be
changed to something like
for (i = 0; i <= limit; i += 100)
        if (brcm_pcie_link_up(pcie)
                break;
        else
                msleep(100);

>
> > +
> > +     if (!brcm_pcie_link_up(pcie)) {
> > +             dev_info(dev, "link down\n");
> > +             return -ENODEV;
> > +     }
> > +
> > +     if (!brcm_pcie_rc_mode(pcie)) {
> > +             dev_err(dev, "PCIe misconfigured; is in EP mode\n");
> > +             return -EINVAL;
> > +     }
> > +
> > +     resource_list_for_each_entry(entry, &bridge->windows) {
> > +             res = entry->res;
> > +
> > +             if (resource_type(res) != IORESOURCE_MEM)
> > +                     continue;
> > +
> > +             if (num_out_wins >= BRCM_NUM_PCIE_OUT_WINS) {
> > +                     dev_err(pcie->dev, "too many outbound wins\n");
> > +                     return -EINVAL;
> > +             }
> > +
> > +             brcm_pcie_set_outbound_win(pcie, num_out_wins, res->start,
> > +                                        res->start - entry->offset,
> > +                                        res->end - res->start + 1);
> > +             num_out_wins++;
> > +     }
> > +
> > +     /*
> > +      * For config space accesses on the RC, show the right class for
> > +      * a PCIe-PCIe bridge (the default setting is to be EP mode).
> > +      */
> > +     WR_FLD_RB(base, PCIE_RC_CFG_PRIV1_ID_VAL3, CLASS_CODE, 0x060400);
> > +
> > +     if (pcie->ssc) {
> > +             ret = set_ssc(base);
> > +             if (ret == 0)
> > +                     ssc_good = true;
> > +             else
> > +                     dev_err(dev, "failed attempt to enter ssc mode\n");
> > +     }
> > +
> > +     lnksta = bcm_readw(base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKSTA);
> > +     cls = lnksta & PCI_EXP_LNKSTA_CLS;
> > +     nlw = (lnksta & PCI_EXP_LNKSTA_NLW) >> PCI_EXP_LNKSTA_NLW_SHIFT;
> > +     dev_info(dev, "link up, %s Gbps x%u %s\n", link_speed_to_str(cls),
> > +              nlw, ssc_good ? "(SSC)" : "(!SSC)");
> > +
> > +     /* PCIe->SCB endian mode for BAR */
> > +     /* field ENDIAN_MODE_BAR2 = DATA_ENDIAN */
> > +     WR_FLD_RB(base, PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1,
> > +               ENDIAN_MODE_BAR2, DATA_ENDIAN);
> > +
> > +     /*
> > +      * Refclk from RC should be gated with CLKREQ# input when ASPM L0s,L1
> > +      * is enabled =>  setting the CLKREQ_DEBUG_ENABLE field to 1.
> > +      */
> > +     WR_FLD_RB(base, PCIE_MISC_HARD_PCIE_HARD_DEBUG, CLKREQ_DEBUG_ENABLE, 1);
> > +
> > +     return 0;
> > +}
> > +
> > +/* L23 is a low-power PCIe link state */
> > +static void enter_l23(struct brcm_pcie *pcie)
> > +{
> > +     void __iomem *base = pcie->base;
> > +     int l23, i;
> > +
> > +     /* assert request for L23 */
> > +     WR_FLD_RB(base, PCIE_MISC_PCIE_CTRL, PCIE_L23_REQUEST, 1);
> > +
> > +     /* Wait up to 30 msec for L23 */
> > +     l23 = RD_FLD(base, PCIE_MISC_PCIE_STATUS, PCIE_LINK_IN_L23);
> > +     for (i = 0; i < 15 && !l23; i++) {
> > +             usleep_range(2000, 2400);
> > +             l23 = RD_FLD(base, PCIE_MISC_PCIE_STATUS, PCIE_LINK_IN_L23);
> > +     }
> > +
> > +     if (!l23)
> > +             dev_err(pcie->dev, "failed to enter L23\n");
> > +}
> > +
> > +static void turn_off(struct brcm_pcie *pcie)
> > +{
> > +     void __iomem *base = pcie->base;
> > +
> > +     if (brcm_pcie_link_up(pcie))
> > +             enter_l23(pcie);
> > +     /* Assert fundamental reset */
> > +     brcm_pcie_perst_set(pcie, 1);
> > +     /* Deassert request for L23 in case it was asserted */
> > +     WR_FLD_RB(base, PCIE_MISC_PCIE_CTRL, PCIE_L23_REQUEST, 0);
> > +     /* Turn off SerDes */
> > +     WR_FLD_RB(base, PCIE_MISC_HARD_PCIE_HARD_DEBUG, SERDES_IDDQ, 1);
> > +     /* Shutdown PCIe bridge */
> > +     brcm_pcie_bridge_sw_init_set(pcie, 1);
> > +}
> > +
> > +static int brcm_pcie_suspend(struct device *dev)
> > +{
> > +     struct brcm_pcie *pcie = dev_get_drvdata(dev);
> > +
> > +     turn_off(pcie);
> > +     clk_disable_unprepare(pcie->clk);
> > +     pcie->suspended = true;
> > +
> > +     return 0;
> > +}
> > +
> > +static int brcm_pcie_resume(struct device *dev)
> > +{
> > +     struct brcm_pcie *pcie = dev_get_drvdata(dev);
> > +     void __iomem *base;
> > +     int ret;
> > +
> > +     base = pcie->base;
> > +     clk_prepare_enable(pcie->clk);
> > +
> > +     /* Take bridge out of reset so we can access the SerDes reg */
> > +     brcm_pcie_bridge_sw_init_set(pcie, 0);
> > +
> > +     /* Turn on SerDes */
> > +     WR_FLD_RB(base, PCIE_MISC_HARD_PCIE_HARD_DEBUG, SERDES_IDDQ, 0);
> > +     /* Wait for SerDes to be stable */
> > +     usleep_range(100, 200);
> > +
> > +     ret = brcm_pcie_setup(pcie);
> > +     if (ret)
> > +             return ret;
> > +
> > +     pcie->suspended = false;
> > +
> > +     return 0;
> > +}
> > +
> > +static void _brcm_pcie_remove(struct brcm_pcie *pcie)
>
> I don't see the value in the first underscore here.
We have a function _brcm_pcie_remove() and a function
brcm_pciie_remove().  The former is invoked by the latter, but the
former is also invoked later in the code as well.

Jim Quinlan
Broadcom

>
> > +{
> > +     turn_off(pcie);
> > +     clk_disable_unprepare(pcie->clk);
> > +     clk_put(pcie->clk);
> > +}
> > +
> > +static int brcm_pcie_remove(struct platform_device *pdev)
> > +{
> > +     struct brcm_pcie *pcie = platform_get_drvdata(pdev);
> > +
> > +     pci_stop_root_bus(pcie->root_bus);
> > +     pci_remove_root_bus(pcie->root_bus);
> > +     _brcm_pcie_remove(pcie);
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct of_device_id brcm_pcie_match[] = {
> > +     { .compatible = "brcm,bcm2711-pcie", .data = &bcm2711_cfg },
> > +     {},
> > +};
> > +MODULE_DEVICE_TABLE(of, brcm_pcie_match);
> > +
> > +static int brcm_pcie_probe(struct platform_device *pdev)
> > +{
> > +     struct device_node *dn = pdev->dev.of_node;
> > +     const struct of_device_id *of_id;
> > +     const struct pcie_cfg_data *data;
> > +     struct resource *res;
> > +     int ret;
> > +     struct brcm_pcie *pcie;
> > +     void __iomem *base;
> > +     struct pci_host_bridge *bridge;
> > +     struct pci_bus *child;
> > +
> > +     bridge = devm_pci_alloc_host_bridge(&pdev->dev, sizeof(*pcie));
> > +     if (!bridge)
> > +             return -ENOMEM;
> > +
> > +     pcie = pci_host_bridge_priv(bridge);
> > +
> > +     of_id = of_match_node(brcm_pcie_match, dn);
> > +     if (!of_id) {
> > +             dev_err(&pdev->dev, "failed to look up compatible string\n");
> > +             return -EINVAL;
> > +     }
> > +
> > +     data = of_id->data;
>
> Can you replace the above (from of_match_node to here) with the following?
>
> data = of_device_get_match_data(pdev->dev)
>
> > +     pcie->reg_offsets = data->offsets;
> > +     pcie->reg_field_info = data->reg_field_info;
> > +     pcie->type = data->type;
> > +     pcie->dn = dn;
> > +     pcie->dev = &pdev->dev;
> > +
> > +     /* We use the domain number as our controller number */
> > +     pcie->id = of_get_pci_domain_nr(dn);
> > +     if (pcie->id < 0)
> > +             return pcie->id;
>
> We don't do anything with this, so you can remove this.
>
> > +
> > +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +     if (!res)
> > +             return -EINVAL;
>
> The majority of controller drivers don't bother to check the return value
> here and just pass res into devm_ioremap_resource.
>
> > +
> > +     base = devm_ioremap_resource(&pdev->dev, res);
> > +     if (IS_ERR(base))
> > +             return PTR_ERR(base);
> > +
> > +     pcie->clk = of_clk_get_by_name(dn, "sw_pcie");
> > +     if (IS_ERR(pcie->clk)) {
> > +             dev_err(&pdev->dev, "could not get clock\n");
> > +             pcie->clk = NULL;
> > +     }
>
> Is this a good use-case for devm_clk_get_optional?
>
> > +     pcie->base = base;
> > +
> > +     ret = of_pci_get_max_link_speed(dn);
> > +     pcie->gen = (ret < 0) ? 0 : ret;
>
> There is no checking that gen isn't too large here, given that we pass
> this into a register later we probably want to check it here.
>
> > +
> > +     pcie->ssc = of_property_read_bool(dn, "brcm,enable-ssc");
> > +
> > +     ret = irq_of_parse_and_map(pdev->dev.of_node, 0);
> > +     if (ret == 0)
> > +             /* keep going, as we don't use this intr yet */
> > +             dev_warn(pcie->dev, "cannot get PCIe interrupt\n");
> > +     else
> > +             pcie->irq = ret;
>
> Given we don't use it yet, please remove it from this patch.
>
> > +
> > +     ret = pci_parse_request_of_pci_ranges(pcie->dev, &bridge->windows,
> > +                                           &bridge->dma_ranges, NULL);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = clk_prepare_enable(pcie->clk);
> > +     if (ret) {
> > +             dev_err(&pdev->dev, "could not enable clock\n");
> > +             return ret;
> > +     }
> > +
> > +     ret = brcm_pcie_setup(pcie);
> > +     if (ret)
> > +             goto fail;
> > +
> > +     bridge->dev.parent = &pdev->dev;
> > +     bridge->busnr = 0;
> > +     bridge->ops = &brcm_pcie_ops;
> > +     bridge->sysdata = pcie;
> > +     bridge->map_irq = of_irq_parse_and_map_pci;
> > +     bridge->swizzle_irq = pci_common_swizzle;
> > +
> > +     ret = pci_scan_root_bus_bridge(bridge);
> > +     if (ret < 0) {
> > +             dev_err(pcie->dev, "Scanning root bridge failed\n");
> > +             goto fail;
> > +     }
> > +
> > +     pci_assign_unassigned_bus_resources(bridge->bus);
> > +     list_for_each_entry(child, &bridge->bus->children, node)
> > +             pcie_bus_configure_settings(child);
> > +     pci_bus_add_devices(bridge->bus);
> > +     platform_set_drvdata(pdev, pcie);
> > +     pcie->root_bus = bridge->bus;
> > +
> > +     return 0;
> > +
> > +fail:
> > +     _brcm_pcie_remove(pcie);
> > +     return ret;
> > +}
> > +
> > +static const struct dev_pm_ops brcm_pcie_pm_ops = {
> > +     .suspend_noirq = brcm_pcie_suspend,
> > +     .resume_noirq = brcm_pcie_resume,
> > +};
> > +
> > +static struct platform_driver brcm_pcie_driver = {
> > +     .probe = brcm_pcie_probe,
> > +     .remove = brcm_pcie_remove,
> > +     .driver = {
> > +             .name = "brcm-pcie",
> > +             .owner = THIS_MODULE,
> > +             .of_match_table = brcm_pcie_match,
> > +             .pm = &brcm_pcie_pm_ops,
> > +     },
> > +};
> > +
> > +module_platform_driver(brcm_pcie_driver);
> > +
> > +MODULE_LICENSE("GPL v2");
> > +MODULE_DESCRIPTION("Broadcom STB PCIe RC driver");
> > +MODULE_AUTHOR("Broadcom");
> > --
> > 2.23.0
> >