[U-Boot] [PATCH v2 2/2] vexpress64: Juno: Add initialisation code for Juno R1 PCIe host bridge.

Liviu Dudau liviu.dudau at foss.arm.com
Mon Oct 19 11:10:11 CEST 2015


On Fri, 16 Oct 2015 17:58:44 +0100
Ryan Harkin <ryan.harkin at linaro.org> wrote:

> Hi Liviu,
> 
> These patches work well for me, so at the very least, you can add my
> Test-by for both:
> 
> Tested-by: Ryan Harkin <ryan.harkin at linaro.org>

Hi Ryan,

Thanks for testing this patchset.

> 
> But...
> 
> I ran checkpatch.pl across your patches and this one throws a few trivial
> warnings, mostly about 80 character lines and a few like this:
> 
> CHECK: Prefer using the BIT macro
> #97: FILE: board/armltd/vexpress64/pcie.c:60:
> +#define JUNO_RESET_CTRL_PHY        (1 << 0)
> 
> But also these:
> 
> WARNING: long udelay - prefer mdelay; see arch/arm/include/asm/delay.h
> #208: FILE: board/armltd/vexpress64/pcie.c:171:
> +    udelay(20000);
> 
> CHECK: Please don't use multiple blank lines
> #227: FILE: board/armltd/vexpress64/pcie.c:190:
> +
> +
> 
> CHECK: Please don't use multiple blank lines
> #251: FILE: board/armltd/vexpress64/pcie.h:12:
> +
> +

Interesting, when running ./scripts/checkpatch.pl in my copy of U-Boot I
get the 7 warnings about lines over 80 characters long, and the
following message:

NOTE: Ignored message types: COMPLEX_MACRO CONSIDER_KSTRTO MINMAX MULTISTATEMENT_MACRO_USE_DO_WHILE NETWORKING_BLOCK_COMMENT_STYLE USLEEP_RANGE

Not sure how to enable all the types by default and also the reason why
I've missed them.

> 
> I'm not sure who strict the rules are followed for these types of warning.
> But if you are fixing up, I also noticed a couple of whitespace nits below.
> 
> 
> On 16 October 2015 at 15:41, Liviu Dudau <Liviu.Dudau at foss.arm.com> wrote:
> 
> > Juno R1 has an XpressRICH3 PCIe host bridge that needs to be initialised
> > in order for the Linux kernel to be able to enumerate the bus. Add
> > support code here that enables the host bridge, trains the links and
> > sets up the Address Translation Tables.
> >
> > Signed-off-by: Liviu Dudau <Liviu.Dudau at foss.arm.com>
> > ---
> >  board/armltd/vexpress64/Makefile     |   2 +-
> >  board/armltd/vexpress64/pcie.c       | 196
> > +++++++++++++++++++++++++++++++++++
> >  board/armltd/vexpress64/pcie.h       |  13 +++
> >  board/armltd/vexpress64/vexpress64.c |   2 +
> >  4 files changed, 212 insertions(+), 1 deletion(-)
> >  create mode 100644 board/armltd/vexpress64/pcie.c
> >  create mode 100644 board/armltd/vexpress64/pcie.h
> >
> > diff --git a/board/armltd/vexpress64/Makefile
> > b/board/armltd/vexpress64/Makefile
> > index e009141..a35db40 100644
> > --- a/board/armltd/vexpress64/Makefile
> > +++ b/board/armltd/vexpress64/Makefile
> > @@ -5,4 +5,4 @@
> >  # SPDX-License-Identifier:     GPL-2.0+
> >  #
> >
> > -obj-y  := vexpress64.o
> > +obj-y  := vexpress64.o pcie.o
> > diff --git a/board/armltd/vexpress64/pcie.c
> > b/board/armltd/vexpress64/pcie.c
> > new file mode 100644
> > index 0000000..367efd4
> > --- /dev/null
> > +++ b/board/armltd/vexpress64/pcie.c
> > @@ -0,0 +1,196 @@
> > +/*
> > + * Copyright (C) ARM Ltd 2015
> > + *
> > + * Author: Liviu Dudau <Liviu.Dudau at arm.com>
> > + *
> > + * SPDX-Licence-Identifier:    GPL-2.0+
> > + */
> > +
> > +#include <common.h>
> > +#include <asm/io.h>
> > +#include <pci_ids.h>
> > +#include "pcie.h"
> > +
> > +/* XpressRICH3 support */
> > +#define XR3_CONFIG_BASE                        0x7ff30000
> > +#define XR3_RESET_BASE                 0x7ff20000
> > +
> > +#define XR3_PCI_ECAM_START             0x40000000
> > +#define XR3_PCI_ECAM_SIZE              28      /* as power of 2 =
> > 0x10000000 */
> > +#define XR3_PCI_IOSPACE_START          0x5f800000
> > +#define XR3_PCI_IOSPACE_SIZE           23      /* as power of 2 =
> > 0x800000 */
> > +#define XR3_PCI_MEMSPACE_START         0x50000000
> > +#define XR3_PCI_MEMSPACE_SIZE          27      /* as power of 2 =
> > 0x8000000 */
> > +#define XR3_PCI_MEMSPACE64_START       0x4000000000
> > +#define XR3_PCI_MEMSPACE64_SIZE                33      /* as power of 2 =
> > 0x200000000 */
> > +
> > +#define JUNO_V2M_MSI_START             0x2c1c0000
> > +#define JUNO_V2M_MSI_SIZE              12      /* as power of 2 = 4096 */
> > +
> > +#define XR3PCI_BASIC_STATUS            0x18
> > +#define    XR3PCI_BS_GEN_MASK          (0xf << 8)
> > +#define    XR3PCI_BS_LINK_MASK         0xff
> >
> 
> There's some strange extra whitespace in there...
> 
> +
> > +#define XR3PCI_VIRTCHAN_CREDITS                0x90
> > +#define XR3PCI_BRIDGE_PCI_IDS          0x9c
> > +#define XR3PCI_PEX_SPC2                        0xd8
> > +
> > +#define XR3PCI_ATR_PCIE_WIN0           0x600
> > +#define XR3PCI_ATR_PCIE_WIN1           0x700
> > +#define XR3PCI_ATR_AXI4_SLV0           0x800
> > +
> > +#define XR3PCI_ATR_TABLE_SIZE          0x20
> > +#define XR3PCI_ATR_SRC_ADDR_LOW                0x0
> > +#define XR3PCI_ATR_SRC_ADDR_HIGH       0x4
> > +#define XR3PCI_ATR_TRSL_ADDR_LOW       0x8
> > +#define XR3PCI_ATR_TRSL_ADDR_HIGH      0xc
> > +#define XR3PCI_ATR_TRSL_PARAM          0x10
> >
> 
> Perhaps add a newline here if you need to respin?
> 
> 
> > +/* IDs used in the XR3PCI_ATR_TRSL_PARAM */
> > +#define XR3PCI_ATR_TRSLID_AXIDEVICE    (0x420004)
> > +#define XR3PCI_ATR_TRSLID_AXIMEMORY    (0x4e0004)  /* Write-through,
> > read/write allocate */
> > +#define XR3PCI_ATR_TRSLID_PCIE_CONF    (0x000001)
> > +#define XR3PCI_ATR_TRSLID_PCIE_IO      (0x020000)
> > +#define XR3PCI_ATR_TRSLID_PCIE_MEMORY  (0x000000)
> > +
> > +#define XR3PCI_ECAM_OFFSET(b, d, o)    (((b) << 20) | \
> > +                                       (PCI_SLOT(d) << 15) | \
> > +                                       (PCI_FUNC(d) << 12) | o)
> > +
> > +#define JUNO_RESET_CTRL                        0x1004
> > +#define JUNO_RESET_CTRL_PHY            (1 << 0)
> > +#define JUNO_RESET_CTRL_RC             (1 << 1)
> > +
> > +#define JUNO_RESET_STATUS              0x1008
> > +#define JUNO_RESET_STATUS_PLL          (1 << 0)
> > +#define JUNO_RESET_STATUS_PHY          (1 << 1)
> > +#define JUNO_RESET_STATUS_RC           (1 << 2)
> > +#define JUNO_RESET_STATUS_MASK         (JUNO_RESET_STATUS_PLL | \
> > +                                        JUNO_RESET_STATUS_PHY | \
> > +                                        JUNO_RESET_STATUS_RC)
> > +
> > +void xr3pci_set_atr_entry(unsigned long base, unsigned long src_addr,
> > +                       unsigned long trsl_addr, int window_size,
> > +                       int trsl_param)
> > +{
> > +       /* X3PCI_ATR_SRC_ADDR_LOW:
> > +            - bit 0: enable entry,
> > +            - bits 1-6: ATR window size: total size in bytes:
> > 2^(ATR_WSIZE + 1)
> > +            - bits 7-11: reserved
> > +            - bits 12-31: start of source address
> > +       */
> > +       writel((u32)(src_addr & 0xfffff000) | (window_size - 1) << 1 | 1,
> > +              base + XR3PCI_ATR_SRC_ADDR_LOW);
> > +       writel((u32)(trsl_addr & 0xfffff000), base +
> > XR3PCI_ATR_TRSL_ADDR_LOW);
> > +       writel((u32)(src_addr >> 32), base + XR3PCI_ATR_SRC_ADDR_HIGH);
> > +       writel((u32)(trsl_addr >> 32), base + XR3PCI_ATR_TRSL_ADDR_HIGH);
> >
> 
> It seems odd to split TRSL_ADDR_LOW and HIGH with SRC_ADDR_HIGH in between,
> rather than doing SRC_ADDR_HIGH right after SRC_ADDR_LOW.  Is there a
> reason for that?

Mostly historical, code was copied from Linux version where there was
an #ifdef CONFIG_PHYS_ADDR_T_64BIT around the lines setting the _HIGH
registers. I will respin with the logical grouping of registers.

> 
> 
> +       writel(trsl_param, base + XR3PCI_ATR_TRSL_PARAM);
> > +
> > +       printf("ATR entry: 0x%010lx %s 0x%010lx [0x%010llx] (param:
> > 0x%06x)\n",
> > +              src_addr, (trsl_param & 0x400000) ? "<-" : "->", trsl_addr,
> > +              ((u64)1) << window_size, trsl_param);
> > +}
> > +
> > +void xr3pci_setup_atr(void)
> > +{
> > +       /* setup PCIe to CPU address translation tables */
> > +       unsigned long base = XR3_CONFIG_BASE + XR3PCI_ATR_PCIE_WIN0;
> > +
> > +       /* forward all writes from PCIe to GIC V2M (used for MSI) */
> > +       xr3pci_set_atr_entry(base, JUNO_V2M_MSI_START, JUNO_V2M_MSI_START,
> > +                            JUNO_V2M_MSI_SIZE,
> > XR3PCI_ATR_TRSLID_AXIDEVICE);
> > +
> > +       base += XR3PCI_ATR_TABLE_SIZE;
> > +
> > +       /* PCIe devices can write anywhere in memory */
> > +       xr3pci_set_atr_entry(base, PHYS_SDRAM_1, PHYS_SDRAM_1,
> > +                            31 /* grant access to all RAM under 4GB */,
> > +                            XR3PCI_ATR_TRSLID_AXIMEMORY);
> > +       base += XR3PCI_ATR_TABLE_SIZE;
> > +       xr3pci_set_atr_entry(base, PHYS_SDRAM_2, PHYS_SDRAM_2,
> > +                            XR3_PCI_MEMSPACE64_SIZE,
> > +                            XR3PCI_ATR_TRSLID_AXIMEMORY);
> > +
> > +
> > +       /* setup CPU to PCIe address translation table */
> > +       base = XR3_CONFIG_BASE + XR3PCI_ATR_AXI4_SLV0;
> > +
> > +       /* setup ECAM space to bus configuration interface */
> > +       xr3pci_set_atr_entry(base, XR3_PCI_ECAM_START, 0,
> > XR3_PCI_ECAM_SIZE,
> > +                            XR3PCI_ATR_TRSLID_PCIE_CONF);
> > +
> > +       base += XR3PCI_ATR_TABLE_SIZE;
> > +
> > +       /* setup IO space translation */
> > +       xr3pci_set_atr_entry(base, XR3_PCI_IOSPACE_START,
> > XR3_PCI_IOSPACE_START,
> > +                            XR3_PCI_IOSPACE_SIZE,
> > XR3PCI_ATR_TRSLID_PCIE_IO);
> > +
> > +       base += XR3PCI_ATR_TABLE_SIZE;
> > +
> > +       /* setup 32bit MEM space translation */
> > +       xr3pci_set_atr_entry(base, XR3_PCI_MEMSPACE_START,
> > XR3_PCI_MEMSPACE_START,
> > +                            XR3_PCI_MEMSPACE_SIZE,
> > XR3PCI_ATR_TRSLID_PCIE_MEMORY);
> > +
> > +       base += XR3PCI_ATR_TABLE_SIZE;
> > +
> > +       /* setup 64bit MEM space translation */
> > +       xr3pci_set_atr_entry(base, XR3_PCI_MEMSPACE64_START,
> > XR3_PCI_MEMSPACE64_START,
> > +                            XR3_PCI_MEMSPACE64_SIZE,
> > XR3PCI_ATR_TRSLID_PCIE_MEMORY);
> > +}
> > +
> > +void xr3pci_init(void)
> > +{
> > +       u32 val;
> > +       int timeout = 200;
> > +
> > +       /* Initialise the XpressRICH3 PCIe host bridge */
> > +
> > +       /* add credits */
> > +       writel(0x00f0b818, XR3_CONFIG_BASE + XR3PCI_VIRTCHAN_CREDITS);
> > +       writel(0x1, XR3_CONFIG_BASE + XR3PCI_VIRTCHAN_CREDITS);
> >
> 
> The equivalent code in EDK2 looks like this:
> 
>   // Add credits
>   PCIE_ROOTPORT_WRITE32 (PCIE_VC_CRED, 0x00f0b818);
>   PCIE_ROOTPORT_WRITE32 (PCIE_VC_CRED + 4, 0x1);
> 
> I'm wondering if you were supposed to use the "+ 4" or if EDK2 should drop
> the "+ 4"?

Well, this is embarrassing: when I've restructured the code I've
dropped the +4 from the second writel. EDK2 is correct, as is the
"reference" code from here: 

https://github.com/ARM-software/linux/blob/master/drivers/pci/host/pci-xr3.c

I will send a v3 with the fixes incorporated.

Best regards,
Liviu

> 
> 
> 
> > +       /* allow ECRC */
> > +       writel(0x6006, XR3_CONFIG_BASE + XR3PCI_PEX_SPC2);
> >
> +       /* setup the correct class code for the host bridge */
> > +       writel(PCI_CLASS_BRIDGE_PCI << 16, XR3_CONFIG_BASE +
> > XR3PCI_BRIDGE_PCI_IDS);
> > +
> > +       /* reset phy and root complex */
> > +       writel(JUNO_RESET_CTRL_PHY | JUNO_RESET_CTRL_RC,
> > +              XR3_RESET_BASE + JUNO_RESET_CTRL);
> > +
> > +       do {
> > +               udelay(1000);
> > +               val = readl(XR3_RESET_BASE + JUNO_RESET_STATUS);
> > +       } while (--timeout &&
> > +               (val & JUNO_RESET_STATUS_MASK) != JUNO_RESET_STATUS_MASK);
> > +
> > +       if (!timeout) {
> > +               printf("PCI XR3 Root complex reset timed out\n");
> > +               return;
> > +       }
> > +
> > +       /* Wait for the link to train */
> > +       udelay(20000);
> > +       timeout = 20;
> > +
> > +       do {
> > +               udelay(1000);
> > +               val = readl(XR3_CONFIG_BASE + XR3PCI_BASIC_STATUS);
> > +       } while (--timeout && !(val & XR3PCI_BS_LINK_MASK));
> > +
> > +       if (!(val & XR3PCI_BS_LINK_MASK)) {
> > +               printf("Failed to negociate a link!\n");
> >
> 
> "negotiate"
> 
> 
> > +               return;
> > +       }
> > +
> > +       printf("PCIe XR3 Host Bridge enabled: x%d link (Gen %d)\n",
> > +              val & XR3PCI_BS_LINK_MASK, (val & XR3PCI_BS_GEN_MASK) >> 8);
> > +
> > +       xr3pci_setup_atr();
> > +}
> > +
> > +
> > +void vexpress64_pcie_init(void)
> > +{
> > +#ifdef CONFIG_TARGET_VEXPRESS64_JUNO
> > +       xr3pci_init();
> > +#endif
> > +}
> > diff --git a/board/armltd/vexpress64/pcie.h
> > b/board/armltd/vexpress64/pcie.h
> > new file mode 100644
> > index 0000000..d645385
> > --- /dev/null
> > +++ b/board/armltd/vexpress64/pcie.h
> > @@ -0,0 +1,13 @@
> > +#ifndef __VEXPRESS64_PCIE_H__
> > +#define __VEXPRESS64_PCIE_H__
> > +
> > +#ifdef CONFIG_TARGET_VEXPRESS64_JUNO
> > +void vexpress64_pcie_init(void);
> > +#else
> > +static inline void vexpress64_pcie_init(void)
> > +{
> > +}
> > +#endif
> > +
> > +
> > +#endif /* __VEXPRESS64_PCIE_H__ */
> > diff --git a/board/armltd/vexpress64/vexpress64.c
> > b/board/armltd/vexpress64/vexpress64.c
> > index 6df9d60..f4e8084 100644
> > --- a/board/armltd/vexpress64/vexpress64.c
> > +++ b/board/armltd/vexpress64/vexpress64.c
> > @@ -13,6 +13,7 @@
> >  #include <linux/compiler.h>
> >  #include <dm/platdata.h>
> >  #include <dm/platform_data/serial_pl01x.h>
> > +#include "pcie.h"
> >
> >  DECLARE_GLOBAL_DATA_PTR;
> >
> > @@ -29,6 +30,7 @@ U_BOOT_DEVICE(vexpress_serials) = {
> >
> >  int board_init(void)
> >  {
> > +       vexpress64_pcie_init();
> >         return 0;
> >  }
> >
> > --
> > 2.6.0
> >
> >




-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯


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