Re: [PATCH V16 05/12] MIPS: Loongson 3: Add HT-linked PCI support

[Aurelien Jarno <aurelien@aurel32.net>]

On Wed, Jan 08, 2014 at 10:44:21AM +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 LEFI firmware interface, We don't need fixup for PCI irq routing
> (except providing a VBIOS of the integrated GPU).
> 
> 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                |   70 ++++++++++++++++
>  arch/mips/pci/ops-loongson3.c                  |  101 ++++++++++++++++++++++++
>  5 files changed, 184 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..f0367ff 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_sysconf.pci_io_base
> +#else
>  #define LOONGSON_PCIIO_BASE	0x1fd00000

If CONFIG_HT_PCI, it will use address 0x1fd00000. Does it have a chance
to work on Loongson 3?

> +#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..4a8477d
> --- /dev/null
> +++ b/arch/mips/pci/fixup-loongson3.c
> @@ -0,0 +1,70 @@
> +/*
> + * 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.

checkpatch.pl reports that the address is wrong, and it is correct. As
suggested the best option is to just remove the three lines above.

> + *
> + */
> +
> +#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 (!loongson_sysconf.vgabios_addr)
> +		return;
> +
> +	pdev->resource[PCI_ROM_RESOURCE].start =
> +		loongson_sysconf.vgabios_addr;
> +	pdev->resource[PCI_ROM_RESOURCE].end   =
> +		loongson_sysconf.vgabios_addr + 256*1024 - 1;
> +	pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_COPY;
> +
> +	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..077eafa
> --- /dev/null
> +++ b/arch/mips/pci/ops-loongson3.c
> @@ -0,0 +1,101 @@
> +#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
> +
> +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;
> +
> +	addr = (busnum << 16) | (device << 11) | (function << 8) | reg;
> +	if (busnum == 0) {
> +		if (device > 31)
> +			return PCIBIOS_DEVICE_NOT_FOUND;
> +		addrp = (void *)(TO_UNCAC(HT1LO_PCICFG_BASE) | (addr & 0xffff));
> +		type = 0;
> +
> +	} else {
> +		addrp = (void *)(TO_UNCAC(HT1LO_PCICFG_BASE_TP1) | (addr));
> +		type = 0x10000;
> +	}
> +
> +	if (access_type == PCI_ACCESS_WRITE)
> +		writel(cpu_to_le32(*data), addrp);

writel already includes the call to cpu_to_le32, so it can be written
directly as:

	writel(*data) addrp);

As cpu_to_le32 is a no-op on little endian, both work, but it is not
correct to use cpu_to_le32 here.

> +	else {
> +		*data = le32_to_cpu(readl(addrp));


Same here, this should be written as :
	
	*data = readl(addrp);

> +		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);
> +
> +	return ret;
> +}
> +
> +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