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Re: [PATCH V15 05/12] MIPS: Loongson 3: Add HT-linked PCI support

To: Huacai Chen <chenhc@lemote.com>
Subject: Re: [PATCH V15 05/12] MIPS: Loongson 3: Add HT-linked PCI support
From: Aurelien Jarno <aurelien@aurel32.net>
Date: Sun, 5 Jan 2014 18:05:46 +0100
Cc: Ralf Baechle <ralf@linux-mips.org>, John Crispin <john@phrozen.org>, "Steven J. Hill" <Steven.Hill@imgtec.com>, linux-mips@linux-mips.org, Fuxin Zhang <zhangfx@lemote.com>, Zhangjin Wu <wuzhangjin@gmail.com>, Hongliang Tao <taohl@lemote.com>, Hua Yan <yanh@lemote.com>
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References: <1387109676-540-1-git-send-email-chenhc@lemote.com> <1387109676-540-6-git-send-email-chenhc@lemote.com> <20140104222401.GA20764@hall.aurel32.net> <CAAhV-H4sOKmDUr_0g2BxoG46G+yP2Xp80E2Qn1GATZTgn86U_w@mail.gmail.com>
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On Sun, Jan 05, 2014 at 05:12:33PM +0800, Huacai Chen wrote:
> On Sun, Jan 5, 2014 at 6:24 AM, Aurelien Jarno <aurelien@aurel32.net> wrote:
> 
> > On Sun, Dec 15, 2013 at 08:14:29PM +0800, Huacai Chen wrote:
> > > Loongson family machines use Hyper-Transport bus for inter-core
> > > connection and device connection. The PCI bus is a subordinate
> > > linked at HT1.
> > >
> > > With UEFI-like firmware interface, We don't need fixup for PCI irq
> > > routing.
> >
> > That part is not fully true, some fixups are still needed for the radeon
> > video card, but they can be (partly) done using the value provided by
> > the UEFI-like firmware interface.
> >
> Yes, this should be modified.
> 
> 
> >
> > >
> > > Signed-off-by: Huacai Chen <chenhc@lemote.com>
> > > Signed-off-by: Hongliang Tao <taohl@lemote.com>
> > > Signed-off-by: Hua Yan <yanh@lemote.com>
> > > ---
> > >  arch/mips/include/asm/mach-loongson/loongson.h |    7 ++
> > >  arch/mips/include/asm/mach-loongson/pci.h      |    5 +
> > >  arch/mips/pci/Makefile                         |    1 +
> > >  arch/mips/pci/fixup-loongson3.c                |   68 +++++++++++++++
> > >  arch/mips/pci/ops-loongson3.c                  |  104
> > ++++++++++++++++++++++++
> > >  5 files changed, 185 insertions(+), 0 deletions(-)
> > >  create mode 100644 arch/mips/pci/fixup-loongson3.c
> > >  create mode 100644 arch/mips/pci/ops-loongson3.c
> > >
> > > diff --git a/arch/mips/include/asm/mach-loongson/loongson.h
> > b/arch/mips/include/asm/mach-loongson/loongson.h
> > > index 5913ea0..4f28b1f 100644
> > > --- a/arch/mips/include/asm/mach-loongson/loongson.h
> > > +++ b/arch/mips/include/asm/mach-loongson/loongson.h
> > > @@ -15,6 +15,7 @@
> > >  #include <linux/init.h>
> > >  #include <linux/irq.h>
> > >  #include <linux/kconfig.h>
> > > +#include <boot_param.h>
> > >
> > >  /* loongson internal northbridge initialization */
> > >  extern void bonito_irq_init(void);
> > > @@ -101,7 +102,13 @@ static inline void do_perfcnt_IRQ(void)
> > >  #define LOONGSON_PCICFG_BASE 0x1fe80000
> > >  #define LOONGSON_PCICFG_SIZE 0x00000800      /* 2K */
> > >  #define LOONGSON_PCICFG_TOP
> >  (LOONGSON_PCICFG_BASE+LOONGSON_PCICFG_SIZE-1)
> > > +
> > > +#if defined(CONFIG_HT_PCI)
> > > +#define LOONGSON_PCIIO_BASE  loongson_pciio_base
> > > +#else
> > >  #define LOONGSON_PCIIO_BASE  0x1fd00000
> > > +#endif
> > > +
> > >  #define LOONGSON_PCIIO_SIZE  0x00100000      /* 1M */
> > >  #define LOONGSON_PCIIO_TOP   (LOONGSON_PCIIO_BASE+LOONGSON_PCIIO_SIZE-1)
> > >
> > > diff --git a/arch/mips/include/asm/mach-loongson/pci.h
> > b/arch/mips/include/asm/mach-loongson/pci.h
> > > index bc99dab..1212774 100644
> > > --- a/arch/mips/include/asm/mach-loongson/pci.h
> > > +++ b/arch/mips/include/asm/mach-loongson/pci.h
> > > @@ -40,8 +40,13 @@ extern struct pci_ops loongson_pci_ops;
> > >  #else        /* loongson2f/32bit & loongson2e */
> > >
> > >  /* this pci memory space is mapped by pcimap in pci.c */
> > > +#ifdef CONFIG_CPU_LOONGSON3
> > > +#define LOONGSON_PCI_MEM_START       0x40000000UL
> > > +#define LOONGSON_PCI_MEM_END 0x7effffffUL
> > > +#else
> > >  #define LOONGSON_PCI_MEM_START       LOONGSON_PCILO1_BASE
> > >  #define LOONGSON_PCI_MEM_END (LOONGSON_PCILO1_BASE + 0x04000000 * 2)
> > > +#endif
> > >  /* this is an offset from mips_io_port_base */
> > >  #define LOONGSON_PCI_IO_START        0x00004000UL
> > >
> > > diff --git a/arch/mips/pci/Makefile b/arch/mips/pci/Makefile
> > > index 719e455..5475859 100644
> > > --- a/arch/mips/pci/Makefile
> > > +++ b/arch/mips/pci/Makefile
> > > @@ -29,6 +29,7 @@ obj-$(CONFIG_LASAT)         += pci-lasat.o
> > >  obj-$(CONFIG_MIPS_COBALT)    += fixup-cobalt.o
> > >  obj-$(CONFIG_LEMOTE_FULOONG2E)       += fixup-fuloong2e.o
> > ops-loongson2.o
> > >  obj-$(CONFIG_LEMOTE_MACH2F)  += fixup-lemote2f.o ops-loongson2.o
> > > +obj-$(CONFIG_LEMOTE_MACH3A)  += fixup-loongson3.o ops-loongson3.o
> > >  obj-$(CONFIG_MIPS_MALTA)     += fixup-malta.o pci-malta.o
> > >  obj-$(CONFIG_PMC_MSP7120_GW) += fixup-pmcmsp.o ops-pmcmsp.o
> > >  obj-$(CONFIG_PMC_MSP7120_EVAL)       += fixup-pmcmsp.o ops-pmcmsp.o
> > > diff --git a/arch/mips/pci/fixup-loongson3.c
> > b/arch/mips/pci/fixup-loongson3.c
> > > new file mode 100644
> > > index 0000000..7b9a9c4
> > > --- /dev/null
> > > +++ b/arch/mips/pci/fixup-loongson3.c
> > > @@ -0,0 +1,68 @@
> > > +/*
> > > + * fixup-loongson3.c
> > > + *
> > > + * Copyright (C) 2012 Lemote, Inc.
> > > + * Author: Xiang Yu, xiangy@lemote.com
> > > + *         Chen Huacai, chenhc@lemote.com
> > > + *
> > > + * This program is free software; you can redistribute  it and/or
> > modify it
> > > + * under  the terms of  the GNU General  Public License as published by
> > the
> > > + * Free Software Foundation;  either version 2 of the  License, or (at
> > your
> > > + * option) any later version.
> > > + *
> > > + * THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR
> > IMPLIED
> > > + * WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED
> > WARRANTIES OF
> > > + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
> >  IN
> > > + * NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT,
> > INDIRECT,
> > > + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
> > BUT
> > > + * NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES;
> > LOSS OF
> > > + * USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED
> > AND ON
> > > + * ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR
> > TORT
> > > + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
> > USE OF
> > > + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
> > > + *
> > > + * You should have received a copy of the  GNU General Public License
> > along
> > > + * with this program; if not, write  to the Free Software Foundation,
> > Inc.,
> > > + * 675 Mass Ave, Cambridge, MA 02139, USA.
> > > + *
> > > + */
> > > +
> > > +#include <linux/pci.h>
> > > +#include <boot_param.h>
> > > +
> > > +static void print_fixup_info(const struct pci_dev * pdev)
> > > +{
> > > +     dev_info(&pdev->dev, "Device %x:%x, irq %d\n",
> > > +                     pdev->vendor, pdev->device, pdev->irq);
> > > +}
> > > +
> > > +int __init pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
> > > +{
> > > +     print_fixup_info(dev);
> > > +     return dev->irq;
> > > +}
> > > +
> > > +static void pci_fixup_radeon(struct pci_dev *pdev)
> > > +{
> > > +     if (pdev->resource[PCI_ROM_RESOURCE].start)
> > > +             return;
> > > +
> > > +     if (!vgabios_addr)
> > > +             return;
> > > +
> > > +     pdev->resource[PCI_ROM_RESOURCE].start  = vgabios_addr;
> > > +     pdev->resource[PCI_ROM_RESOURCE].end    = vgabios_addr + 256*1024
> > - 1;
> > > +     pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_COPY;
> >
> > Instead of hardcoding the size, couldn't it be determined from the
> > UEFI-like interface? For example looking at emap VIDEO_ROM? I haven't
> > check this is actually the same thing, but it might be worth to check.
> >
> > The unit of mem_size in emap is MB, this is too large for VBIOS.

ok, fine then.

> > > +
> > > +     dev_info(&pdev->dev, "BAR %d: assigned %pR for Radeon ROM\n",
> > > +                     PCI_ROM_RESOURCE,
> > &pdev->resource[PCI_ROM_RESOURCE]);
> > > +}
> > > +
> > > +DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_ATI, PCI_ANY_ID,
> > > +                             PCI_CLASS_DISPLAY_VGA, 8,
> > pci_fixup_radeon);
> > > +
> > > +/* Do platform specific device initialization at pci_enable_device()
> > time */
> > > +int pcibios_plat_dev_init(struct pci_dev *dev)
> > > +{
> > > +     return 0;
> > > +}
> > > diff --git a/arch/mips/pci/ops-loongson3.c
> > b/arch/mips/pci/ops-loongson3.c
> > > new file mode 100644
> > > index 0000000..53cb84a
> > > --- /dev/null
> > > +++ b/arch/mips/pci/ops-loongson3.c
> > > @@ -0,0 +1,104 @@
> > > +#include <linux/types.h>
> > > +#include <linux/pci.h>
> > > +#include <linux/kernel.h>
> > > +
> > > +#include <asm/mips-boards/bonito64.h>
> > > +
> > > +#include <loongson.h>
> > > +
> > > +#define PCI_ACCESS_READ  0
> > > +#define PCI_ACCESS_WRITE 1
> > > +
> > > +#define HT1LO_PCICFG_BASE      0x1a000000
> > > +#define HT1LO_PCICFG_BASE_TP1  0x1b000000
> >
> > Is it possible to determine these values from pci_config_addr? Or they
> > are representing different things maybe?
> >
> Unfortunately, they can't be determined, their values depend on address
> windows configuration.

Ok, fine.

> >
> > > +static int loongson3_pci_config_access(unsigned char access_type,
> > > +             struct pci_bus *bus, unsigned int devfn,
> > > +             int where, u32 *data)
> > > +{
> > > +     unsigned char busnum = bus->number;
> > > +     u_int64_t addr, type;
> > > +     void *addrp;
> > > +     int device = PCI_SLOT(devfn);
> > > +     int function = PCI_FUNC(devfn);
> > > +     int reg = where & ~3;
> > > +
> > > +     if (busnum == 0) {
> > > +             if (device > 31)
> > > +                     return PCIBIOS_DEVICE_NOT_FOUND;
> > > +             addr = (device << 11) | (function << 8) | reg;
> > > +             addrp = (void *)(TO_UNCAC(HT1LO_PCICFG_BASE) | (addr &
> > 0xffff));
> >
> > Why not accessing the PCI register using CKSEG1ADDR instead, like it is
> > done for other PCI hosts.
> >
> > > +             type = 0;
> > > +
> > > +     } else {
> > > +             addr = (busnum << 16) | (device << 11) | (function << 8) |
> > reg;
> >
> > You can probably can compute addr outside of the if (busnum == 0)
> >
> Yes, you are right.
> 
> 
> >
> > > +             addrp = (void *)(TO_UNCAC(HT1LO_PCICFG_BASE_TP1) | (addr));
> > > +             type = 0x10000;
> > > +     }
> > > +
> > > +     if (access_type == PCI_ACCESS_WRITE)
> > > +             *(volatile unsigned int *)addrp = cpu_to_le32(*data);
> >
> > I don't think doing i/o access that way using volatile type is correct.
> >
> > You should use writel(*data, addrp) instead, which already take care of
> > calling
> > cpu_to_le32.
> >
> > > +     else {
> > > +             *data = le32_to_cpu(*(volatile unsigned int *)addrp);
> >
> > Same here, please use readl(addrp) instead.
> >
> Yes, I'll improve it.

Great.

> >
> > > +             if (*data == 0xffffffff) {
> > > +                     *data = -1;
> > > +                     return PCIBIOS_DEVICE_NOT_FOUND;
> > > +             }
> > > +     }
> > > +     return PCIBIOS_SUCCESSFUL;
> > > +}
> > > +
> > > +static int loongson3_pci_pcibios_read(struct pci_bus *bus, unsigned int
> > devfn,
> > > +                              int where, int size, u32 * val)
> > > +{
> > > +     u32 data = 0;
> > > +     int ret = loongson3_pci_config_access(PCI_ACCESS_READ,
> > > +                     bus, devfn, where, &data);
> > > +
> > > +     if (ret != PCIBIOS_SUCCESSFUL)
> > > +             return ret;
> > > +
> > > +     if (size == 1)
> > > +             *val = (data >> ((where & 3) << 3)) & 0xff;
> > > +     else if (size == 2)
> > > +             *val = (data >> ((where & 3) << 3)) & 0xffff;
> > > +     else
> > > +             *val = data;
> > > +
> > > +     return PCIBIOS_SUCCESSFUL;
> > > +}
> > > +
> > > +static int loongson3_pci_pcibios_write(struct pci_bus *bus, unsigned
> > int devfn,
> > > +                               int where, int size, u32 val)
> > > +{
> > > +     u32 data = 0;
> > > +     int ret;
> > > +
> > > +     if (size == 4)
> > > +             data = val;
> > > +     else {
> > > +             ret = loongson3_pci_config_access(PCI_ACCESS_READ,
> > > +                             bus, devfn, where, &data);
> > > +             if (ret != PCIBIOS_SUCCESSFUL)
> > > +                     return ret;
> > > +
> > > +             if (size == 1)
> > > +                     data = (data & ~(0xff << ((where & 3) << 3))) |
> > > +                         (val << ((where & 3) << 3));
> > > +             else if (size == 2)
> > > +                     data = (data & ~(0xffff << ((where & 3) << 3))) |
> > > +                         (val << ((where & 3) << 3));
> > > +     }
> > > +
> > > +     ret = loongson3_pci_config_access(PCI_ACCESS_WRITE,
> > > +                     bus, devfn, where, &data);
> > > +     if (ret != PCIBIOS_SUCCESSFUL)
> > > +             return ret;
> > > +
> > > +     return PCIBIOS_SUCCESSFUL;
> >
> > The three lines above can be directly replace by "return ret;" for the
> > same result.
> >
> Yes, you are right.
> 
> 
> >
> > > +}
> > > +
> > > +struct pci_ops loongson_pci_ops = {
> > > +     .read = loongson3_pci_pcibios_read,
> > > +     .write = loongson3_pci_pcibios_write
> > > +};
> > > --
> > > 1.7.7.3
> > >
> > >
> > >
> >
> > --
> > Aurelien Jarno                          GPG: 1024D/F1BCDB73
> > aurelien@aurel32.net                 http://www.aurel32.net
> >
> >

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net

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