[loongson] add basic fuloong2f support
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From: Ralf Baechle on 5 Nov 2009 08:20 On Wed, Nov 04, 2009 at 05:05:47PM +0800, Wu Zhangjin wrote: > diff --git a/arch/mips/loongson/fuloong-2f/irq.c b/arch/mips/loongson/fuloong-2f/irq.c > new file mode 100644 > index 0000000..22c45fd > --- /dev/null > +++ b/arch/mips/loongson/fuloong-2f/irq.c > @@ -0,0 +1,114 @@ > +/* > + * Copyright (C) 2007 Lemote Inc. > + * Author: Fuxin Zhang, zhangfx(a)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. > + */ > + > +#include <linux/interrupt.h> > + > +#include <asm/irq_cpu.h> > +#include <asm/i8259.h> > +#include <asm/mipsregs.h> > + > +#include <loongson.h> > +#include <machine.h> > + > +#define LOONGSON_TIMER_IRQ (MIPS_CPU_IRQ_BASE + 7) /* cpu timer */ > +#define LOONGSON_PERFCNT_IRQ (MIPS_CPU_IRQ_BASE + 6) /* cpu perf counter */ > +#define LOONGSON_NORTH_BRIDGE_IRQ (MIPS_CPU_IRQ_BASE + 6) /* bonito */ > +#define LOONGSON_UART_IRQ (MIPS_CPU_IRQ_BASE + 3) /* cpu serial port */ > +#define LOONGSON_SOUTH_BRIDGE_IRQ (MIPS_CPU_IRQ_BASE + 2) /* i8259 */ > + > +#define LOONGSON_INT_BIT_INT0 (1 << 11) > +#define LOONGSON_INT_BIT_INT1 (1 << 12) > + > +static int mach_i8259_irq(void) > +{ > + int irq, isr, imr; > + > + irq = -1; > + > + if ((LOONGSON_INTISR & LOONGSON_INTEN) & LOONGSON_INT_BIT_INT0) { > + imr = inb(0x21) | (inb(0xa1) << 8); > + isr = inb(0x20) | (inb(0xa0) << 8); > + isr &= ~0x4; /* irq2 for cascade */ > + isr &= ~imr; > + irq = ffs(isr) - 1; > + } Any reason why you're not using i8259_irq() from <asm/i8259.h> here? That function not only gets the locking right, it also minimizes the number of accesses to the i8259 - which even on modern silicon can be stuningly slow. > +#if 1 > + pci_read_config_byte(pdev, PCI_LATENCY_TIMER, &val); > + printk(KERN_INFO "cs5536 acc latency 0x%x\n", val); > + pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 0xc0); > +#endif Seems like left over debug code? > + return; > +} And a useless return statement at the end of a void function. Ralf -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Wu Zhangjin on 5 Nov 2009 12:40 Hi, On Thu, 2009-11-05 at 14:16 +0100, Ralf Baechle wrote: > > + > > + if ((LOONGSON_INTISR & LOONGSON_INTEN) & LOONGSON_INT_BIT_INT0) { > > + imr = inb(0x21) | (inb(0xa1) << 8); > > + isr = inb(0x20) | (inb(0xa0) << 8); > > + isr &= ~0x4; /* irq2 for cascade */ > > + isr &= ~imr; > > + irq = ffs(isr) - 1; > > + } > > Any reason why you're not using i8259_irq() from <asm/i8259.h> here? > That function not only gets the locking right, it also minimizes the number > of accesses to the i8259 - which even on modern silicon can be stuningly > slow. > Seems there are some differences between here and the i8259_irq(), I forget the details, perhaps "Yan Hua" can give a detail explaination. > > +#if 1 > > + pci_read_config_byte(pdev, PCI_LATENCY_TIMER, &val); > > + printk(KERN_INFO "cs5536 acc latency 0x%x\n", val); > > + pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 0xc0); > > +#endif > > Seems like left over debug code? > > > + return; > > +} > > And a useless return statement at the end of a void function. > Okay, will remove them later. Regards, Wu Zhangjin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Wu Zhangjin on 6 Nov 2009 00:50 On Thu, 2009-11-05 at 14:16 +0100, Ralf Baechle wrote: > On Wed, Nov 04, 2009 at 05:05:47PM +0800, Wu Zhangjin wrote: > > > diff --git a/arch/mips/loongson/fuloong-2f/irq.c b/arch/mips/loongson/fuloong-2f/irq.c > > new file mode 100644 > > index 0000000..22c45fd > > --- /dev/null > > +++ b/arch/mips/loongson/fuloong-2f/irq.c > > @@ -0,0 +1,114 @@ > > +/* > > + * Copyright (C) 2007 Lemote Inc. > > + * Author: Fuxin Zhang, zhangfx(a)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. > > + */ > > + > > +#include <linux/interrupt.h> > > + > > +#include <asm/irq_cpu.h> > > +#include <asm/i8259.h> > > +#include <asm/mipsregs.h> > > + > > +#include <loongson.h> > > +#include <machine.h> > > + > > +#define LOONGSON_TIMER_IRQ (MIPS_CPU_IRQ_BASE + 7) /* cpu timer */ > > +#define LOONGSON_PERFCNT_IRQ (MIPS_CPU_IRQ_BASE + 6) /* cpu perf counter */ > > +#define LOONGSON_NORTH_BRIDGE_IRQ (MIPS_CPU_IRQ_BASE + 6) /* bonito */ > > +#define LOONGSON_UART_IRQ (MIPS_CPU_IRQ_BASE + 3) /* cpu serial port */ > > +#define LOONGSON_SOUTH_BRIDGE_IRQ (MIPS_CPU_IRQ_BASE + 2) /* i8259 */ > > + > > +#define LOONGSON_INT_BIT_INT0 (1 << 11) > > +#define LOONGSON_INT_BIT_INT1 (1 << 12) > > + > > +static int mach_i8259_irq(void) > > +{ > > + int irq, isr, imr; > > + > > + irq = -1; > > + > > + if ((LOONGSON_INTISR & LOONGSON_INTEN) & LOONGSON_INT_BIT_INT0) { > > + imr = inb(0x21) | (inb(0xa1) << 8); > > + isr = inb(0x20) | (inb(0xa0) << 8); > > + isr &= ~0x4; /* irq2 for cascade */ > > + isr &= ~imr; > > + irq = ffs(isr) - 1; > > + } > > Any reason why you're not using i8259_irq() from <asm/i8259.h> here? > That function not only gets the locking right, it also minimizes the number > of accesses to the i8259 - which even on modern silicon can be stuningly > slow. > Hi, Ralf Just asked Yanhua, He told me there is a bug in cs5536, if using the i8259_irq() directly, we can not get the irq. and just tried it, the kernel hang on booting. Regards, Wu Zhangjin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Ralf Baechle on 6 Nov 2009 03:30 On Fri, Nov 06, 2009 at 01:39:44PM +0800, Wu Zhangjin wrote: > > > + if ((LOONGSON_INTISR & LOONGSON_INTEN) & LOONGSON_INT_BIT_INT0) { > > > + imr = inb(0x21) | (inb(0xa1) << 8); > > > + isr = inb(0x20) | (inb(0xa0) << 8); > > > + isr &= ~0x4; /* irq2 for cascade */ > > > + isr &= ~imr; > > > + irq = ffs(isr) - 1; > > > + } > > > > Any reason why you're not using i8259_irq() from <asm/i8259.h> here? > > That function not only gets the locking right, it also minimizes the number > > of accesses to the i8259 - which even on modern silicon can be stuningly > > slow. > Just asked Yanhua, He told me there is a bug in cs5536, if using the > i8259_irq() directly, we can not get the irq. and just tried it, the > kernel hang on booting. Wonderful. Even 30 years after it was built there are still new i8259 bugs :-) This is probably worth a comment in the code. Ralf -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Wu Zhangjin on 6 Nov 2009 03:40
Hi, On Thu, 2009-11-05 at 14:16 +0100, Ralf Baechle wrote: [...] > > +static int mach_i8259_irq(void) > > +{ > > + int irq, isr, imr; > > + > > + irq = -1; > > + > > + if ((LOONGSON_INTISR & LOONGSON_INTEN) & LOONGSON_INT_BIT_INT0) { > > + imr = inb(0x21) | (inb(0xa1) << 8); > > + isr = inb(0x20) | (inb(0xa0) << 8); > > + isr &= ~0x4; /* irq2 for cascade */ > > + isr &= ~imr; > > + irq = ffs(isr) - 1; > > + } > > Any reason why you're not using i8259_irq() from <asm/i8259.h> here? > That function not only gets the locking right, it also minimizes the number > of accesses to the i8259 - which even on modern silicon can be stuningly > slow. Just checked it again, seems we can only access the ISR registers, but even if with this restriction, we can also optimize it to minimize the number of accesses to the i8259, this is the new version: + isr = inb(PIC_MASTER_CMD) & + ~inb(PIC_MASTER_IMR) & ~(1 << PIC_CASCADE_IR); + if (!isr) + isr = (inb(PIC_SLAVE_CMD) & ~inb(PIC_SLAVE_IMR)) << 8; Will resend it with this version. Thanks, Wu Zhangjin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |