[PATCH Cobalt 1/1] 64-bit fix

[PATCH Cobalt 1/1] 64-bit fix

[Peter Horton]

This patch adds detection of broken 64-bit mode LL/SC on Cobalt units.
With this patch my Qube2700 boots a 64-bit build fine. The later units
have some problems with the Tulip driver.

P.

--

Index: linux/arch/mips/kernel/cpu-probe.c
===================================================================
--- linux.orig/arch/mips/kernel/cpu-probe.c	2005-04-11 23:19:17.000000000 +0100
+++ linux/arch/mips/kernel/cpu-probe.c	2005-04-11 23:35:06.000000000 +0100
@@ -131,6 +131,58 @@
 	check_wait();
 }
 
+#ifdef CONFIG_MIPS64
+
+/*
+ * On RM5230/5231 all accesses to XKPHYS by LL(D) are forced
+ * to be uncached, bits 61-59 of the address are ignored.
+ *
+ * Apparently fixed on RM5230A/5231A.
+ */
+static inline int check_lld(void)
+{
+	unsigned long flags, value, match, phys, *addr;
+
+	printk("Checking for lld bug... ");
+
+	/* hope the stack is in the low 512MB */
+	phys = CPHYSADDR((unsigned long) &value);
+
+	/* write value to memory */
+	value = 0xfedcba9876543210;
+	addr = (unsigned long *) PHYS_TO_XKPHYS(K_CALG_UNCACHED, phys);
+	*addr = value;
+
+	/* stop spurious flushes */
+	local_irq_save(flags);
+
+	/* flip cached value */
+	value = ~value;
+
+	/* read value, supposedly from cache */
+	addr = (unsigned long *) PHYS_TO_XKPHYS(K_CALG_NONCOHERENT, phys);
+	asm volatile("lld %0, %1" : "=r" (match) : "m" (*addr));
+
+	local_irq_restore(flags);
+
+	match ^= value;
+
+	switch ((long) match) {
+	case 0:
+		printk("no.\n");
+		break;
+	case -1:
+		printk("yes.\n");
+		break;
+	default:
+		printk("yikes yes! (%lx/%lx@%p)\nPlease report to <linux-mips@linux-mips.org>.", value, match, &value);
+	}
+
+	return !match;
+}
+
+#endif
+
 /*
  * Probe whether cpu has config register by trying to play with
  * alternate cache bit and see whether it matters.
@@ -347,7 +399,11 @@
 		c->cputype = CPU_NEVADA;
 		c->isa_level = MIPS_CPU_ISA_IV;
 		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
-		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
+		             MIPS_CPU_DIVEC;
+#ifdef CONFIG_MIPS64
+		if (check_lld())
+#endif
+			c->options |= MIPS_CPU_LLSC;
 		c->tlbsize = 48;
 		break;
 	case PRID_IMP_R6000:
Index: linux/include/asm-mips/addrspace.h
===================================================================
--- linux.orig/include/asm-mips/addrspace.h	2005-04-11 23:19:17.000000000 +0100
+++ linux/include/asm-mips/addrspace.h	2005-04-11 23:19:20.000000000 +0100
@@ -120,7 +120,7 @@
 #define PHYS_TO_XKSEG_UNCACHED(p)	PHYS_TO_XKPHYS(K_CALG_UNCACHED,(p))
 #define PHYS_TO_XKSEG_CACHED(p)		PHYS_TO_XKPHYS(K_CALG_COH_SHAREABLE,(p))
 #define XKPHYS_TO_PHYS(p)		((p) & TO_PHYS_MASK)
-#define PHYS_TO_XKPHYS(cm,a)		(0x8000000000000000 | ((cm)<<59) | (a))
+#define PHYS_TO_XKPHYS(cm,a)		(0x8000000000000000 | ((unsigned long)(cm)<<59) | (a))
 
 #if defined (CONFIG_CPU_R4300)						\
     || defined (CONFIG_CPU_R4X00)					\

[OFF-TOPIC] Cobalt 64-bit, what for? (was: 64-bit fix)

[Dominique Quatravaux]

Peter Horton wrote:

>This patch adds detection of broken 64-bit mode LL/SC on Cobalt units.
>With this patch my Qube2700 boots a 64-bit build fine. The later units
>have some problems with the Tulip driver.
>  
>
Just out of curiosity, is there any practical interest in going 64bit on 
Cobalt besides the fun of it? One cannot possibly squeeze more than 4 Gb 
of RAM into a Cobalt box right? And doesn't 64 bit mode have costs of 
its own (doubled i-fetch bandwidth for starters)?

-- 
<< Tout n'y est pas parfait, mais on y honore certainement les jardiniers >>

			Dominique Quatravaux <dom@kilimandjaro.dyndns.org>

Re: [OFF-TOPIC] Cobalt 64-bit, what for? (was: 64-bit fix)

[Ralf Baechle]

On Fri, Apr 15, 2005 at 11:20:54AM +0200, Dominique Quatravaux wrote:

> Just out of curiosity, is there any practical interest in going 64bit on 
> Cobalt besides the fun of it?

Second hand Cobalt MIPS hardware is available fairly cheaply so it's being
used by various Linux developers for doing development work, including
64-bit work.

> One cannot possibly squeeze more than 4 Gb of RAM into a Cobalt box right?

No, the limit is significantly less.  64-bit kernels are advantagous if

 - running N32 or N64 software is desired
 - anything that takes advantage of 64-bit registers or the 32/32 fpr model
 - software is using large amounts of virtual address space.  Process size
   is limited to 2GB which is tight for some of todays codes which do their
   I/O by memory mapping files.
 - and of the course there is the "more inches" factor ;-)

> And doesn't 64 bit mode have costs of its own (doubled i-fetch bandwidth
> for starters)?

Fortunately not double and caches will further blurr the picture - but on
a system with a 32-bit processor and memory bus there will be very
noticable impact.  We're using a bunch of tricks to keep the overhead under
control.

  Ralf

Re: [OFF-TOPIC] Cobalt 64-bit, what for? (was: 64-bit fix)

[Dominic Sweetman]

Ralf Baechle (ralf@linux-mips.org) writes:

> > And doesn't 64 bit mode have costs of its own (doubled i-fetch bandwidth
> > for starters)?

64-bit MIPS CPUs still have 32-bit instructions... it's the registers
and addressing range which grow, not the instructions.

Program data segments tend to grow when you use 64-bit pointers (N64
does, but N32 - paradoxically still a 64-bit ABI - doesn't)

--
Dominic Sweetman
MIPS Technologies

Re: [OFF-TOPIC] Cobalt 64-bit, what for? (was: 64-bit fix)

[Ralf Baechle]

On Fri, Apr 15, 2005 at 11:18:08AM +0100, Dominic Sweetman wrote:

> > > And doesn't 64 bit mode have costs of its own (doubled i-fetch bandwidth
> > > for starters)?
> 
> 64-bit MIPS CPUs still have 32-bit instructions... it's the registers
> and addressing range which grow, not the instructions.

True - but number of instructions will grow, thus the bandwidth needed to
fetch them.

> Program data segments tend to grow when you use 64-bit pointers (N64
> does, but N32 - paradoxically still a 64-bit ABI - doesn't)

N32 is an ILP32 ABI so I'd count it as 32-bit.

  Ralf

Re: [PATCH Cobalt 1/1] 64-bit fix

[Martin Michlmayr]

* Peter Horton <pdh@colonel-panic.org> [2005-04-14 19:59]:
> This patch adds detection of broken 64-bit mode LL/SC on Cobalt units.
> With this patch my Qube2700 boots a 64-bit build fine. The later units
> have some problems with the Tulip driver.

Ralf, is this patch appropriate?  Can you please apply it or provide
some feedback.

> P.
> 
> --
> 
> Index: linux/arch/mips/kernel/cpu-probe.c
> ===================================================================
> --- linux.orig/arch/mips/kernel/cpu-probe.c	2005-04-11 23:19:17.000000000 +0100
> +++ linux/arch/mips/kernel/cpu-probe.c	2005-04-11 23:35:06.000000000 +0100
> @@ -131,6 +131,58 @@
>  	check_wait();
>  }
>  
> +#ifdef CONFIG_MIPS64
> +
> +/*
> + * On RM5230/5231 all accesses to XKPHYS by LL(D) are forced
> + * to be uncached, bits 61-59 of the address are ignored.
> + *
> + * Apparently fixed on RM5230A/5231A.
> + */
> +static inline int check_lld(void)
> +{
> +	unsigned long flags, value, match, phys, *addr;
> +
> +	printk("Checking for lld bug... ");
> +
> +	/* hope the stack is in the low 512MB */
> +	phys = CPHYSADDR((unsigned long) &value);
> +
> +	/* write value to memory */
> +	value = 0xfedcba9876543210;
> +	addr = (unsigned long *) PHYS_TO_XKPHYS(K_CALG_UNCACHED, phys);
> +	*addr = value;
> +
> +	/* stop spurious flushes */
> +	local_irq_save(flags);
> +
> +	/* flip cached value */
> +	value = ~value;
> +
> +	/* read value, supposedly from cache */
> +	addr = (unsigned long *) PHYS_TO_XKPHYS(K_CALG_NONCOHERENT, phys);
> +	asm volatile("lld %0, %1" : "=r" (match) : "m" (*addr));
> +
> +	local_irq_restore(flags);
> +
> +	match ^= value;
> +
> +	switch ((long) match) {
> +	case 0:
> +		printk("no.\n");
> +		break;
> +	case -1:
> +		printk("yes.\n");
> +		break;
> +	default:
> +		printk("yikes yes! (%lx/%lx@%p)\nPlease report to <linux-mips@linux-mips.org>.", value, match, &value);
> +	}
> +
> +	return !match;
> +}
> +
> +#endif
> +
>  /*
>   * Probe whether cpu has config register by trying to play with
>   * alternate cache bit and see whether it matters.
> @@ -347,7 +399,11 @@
>  		c->cputype = CPU_NEVADA;
>  		c->isa_level = MIPS_CPU_ISA_IV;
>  		c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR |
> -		             MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
> +		             MIPS_CPU_DIVEC;
> +#ifdef CONFIG_MIPS64
> +		if (check_lld())
> +#endif
> +			c->options |= MIPS_CPU_LLSC;
>  		c->tlbsize = 48;
>  		break;
>  	case PRID_IMP_R6000:
> Index: linux/include/asm-mips/addrspace.h
> ===================================================================
> --- linux.orig/include/asm-mips/addrspace.h	2005-04-11 23:19:17.000000000 +0100
> +++ linux/include/asm-mips/addrspace.h	2005-04-11 23:19:20.000000000 +0100
> @@ -120,7 +120,7 @@
>  #define PHYS_TO_XKSEG_UNCACHED(p)	PHYS_TO_XKPHYS(K_CALG_UNCACHED,(p))
>  #define PHYS_TO_XKSEG_CACHED(p)		PHYS_TO_XKPHYS(K_CALG_COH_SHAREABLE,(p))
>  #define XKPHYS_TO_PHYS(p)		((p) & TO_PHYS_MASK)
> -#define PHYS_TO_XKPHYS(cm,a)		(0x8000000000000000 | ((cm)<<59) | (a))
> +#define PHYS_TO_XKPHYS(cm,a)		(0x8000000000000000 | ((unsigned long)(cm)<<59) | (a))
>  
>  #if defined (CONFIG_CPU_R4300)						\
>      || defined (CONFIG_CPU_R4X00)					\

-- 
Martin Michlmayr
http://www.cyrius.com/

Re: [PATCH Cobalt 1/1] 64-bit fix

[Jim Gifford]

Here's a link to the updated patch. Works under 2.6.15
http://www.linuxfromscratch.org/patches/downloads/linux/linux-2.6.15-mips_fix-1.patch

This include the iomap.c, which is not accepted by Ralf.

Submitted By: Jim Gifford (patches at jg555 dot com)
Date: 2006-01-09
Initial Package Version: 2.6.15
Origin: Jim Gifford
Upstream Status: Not Accepted
Description: Various Fixes for MIPS architectures

diff -Naur linux-2.6.15.orig/arch/mips/lib/Makefile 
linux-2.6.15/arch/mips/lib/Makefile
--- linux-2.6.15.orig/arch/mips/lib/Makefile    2006-01-09 
21:32:16.000000000 +0000
+++ linux-2.6.15/arch/mips/lib/Makefile    2006-01-09 21:37:56.000000000 
+0000
@@ -5,4 +5,6 @@
 lib-y    += csum_partial_copy.o memcpy.o promlib.o strlen_user.o 
strncpy_user.o \
        strnlen_user.o uncached.o
 
+obj-y    += iomap.o
+
 EXTRA_AFLAGS := $(CFLAGS)
diff -Naur linux-2.6.15.orig/arch/mips/lib/iomap.c 
linux-2.6.15/arch/mips/lib/iomap.c
--- linux-2.6.15.orig/arch/mips/lib/iomap.c    1970-01-01 
00:00:00.000000000 +0000
+++ linux-2.6.15/arch/mips/lib/iomap.c    2006-01-09 21:37:56.000000000 
+0000
@@ -0,0 +1,78 @@
+/*
+ *  iomap.c, Memory Mapped I/O routines for MIPS architecture.
+ *
+ *  This code is based on lib/iomap.c, by Linus Torvalds.
+ *
+ *  Copyright (C) 2004-2005  Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
+ *
+ *  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 program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  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., 59 Temple Place, Suite 330, Boston, MA  
02111-1307  USA
+ */
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include <asm/io.h>
+
+void __iomem *ioport_map(unsigned long port, unsigned int nr)
+{
+    unsigned long end;
+
+    end = port + nr - 1UL;
+    if (ioport_resource.start > port ||
+        ioport_resource.end < end || port > end)
+        return NULL;
+
+    return (void __iomem *)(mips_io_port_base + port);
+}
+
+void ioport_unmap(void __iomem *addr)
+{
+}
+EXPORT_SYMBOL(ioport_map);
+EXPORT_SYMBOL(ioport_unmap);
+
+void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
+{
+    unsigned long start, len, flags;
+
+    if (dev == NULL)
+        return NULL;
+
+    start = pci_resource_start(dev, bar);
+    len = pci_resource_len(dev, bar);
+    if (!start || !len)
+        return NULL;
+
+    if (maxlen != 0 && len > maxlen)
+        len = maxlen;
+
+    flags = pci_resource_flags(dev, bar);
+    if (flags & IORESOURCE_IO)
+        return ioport_map(start, len);
+    if (flags & IORESOURCE_MEM) {
+        if (flags & IORESOURCE_CACHEABLE)
+            return ioremap_cacheable_cow(start, len);
+        return ioremap_nocache(start, len);
+    }
+
+    return NULL;
+}
+
+void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
+{
+    iounmap(addr);
+}
+EXPORT_SYMBOL(pci_iomap);
+EXPORT_SYMBOL(pci_iounmap);
diff -Naur linux-2.6.15.orig/include/asm-mips/addrspace.h 
linux-2.6.15/include/asm-mips/addrspace.h
--- linux-2.6.15.orig/include/asm-mips/addrspace.h    2006-01-03 
03:21:10.000000000 +0000
+++ linux-2.6.15/include/asm-mips/addrspace.h    2006-01-09 
20:47:10.000000000 +0000
@@ -124,7 +124,7 @@
 #define PHYS_TO_XKSEG_CACHED(p)        
PHYS_TO_XKPHYS(K_CALG_COH_SHAREABLE,(p))
 #define XKPHYS_TO_PHYS(p)        ((p) & TO_PHYS_MASK)
 #define PHYS_TO_XKPHYS(cm,a)        (_LLCONST_(0x8000000000000000) | \
-                     ((cm)<<59) | (a))
+                     ((unsigned long)(cm)<<59) | (a))
 
 #if defined (CONFIG_CPU_R4300)                        \
     || defined (CONFIG_CPU_R4X00)                    \
diff -Naur 
linux-2.6.15.orig/include/asm-mips/cobalt/cpu-feature-overrides.h 
linux-2.6.15/include/asm-mips/cobalt/cpu-feature-overrides.h
--- linux-2.6.15.orig/include/asm-mips/cobalt/cpu-feature-overrides.h    
1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.15/include/asm-mips/cobalt/cpu-feature-overrides.h    
2006-01-09 20:52:18.000000000 +0000
@@ -0,0 +1,17 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General 
Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2006 Ralf Baechle
+ */
+#ifndef __ASM_COBALT_CPU_FEATURE_OVERRIDES_H
+#define __ASM_COBALT_CPU_FEATURE_OVERRIDES_H
+
+#ifdef CONFIG_64BIT
+#define cpu_has_llsc            0
+#else
+#define cpu_has_llsc            1
+#endif
+
+#endif /* __ASM_COBALT_CPU_FEATURE_OVERRIDES_H */
diff -Naur linux-2.6.15.orig/include/asm-mips/cobalt/ide.h 
linux-2.6.15/include/asm-mips/cobalt/ide.h
--- linux-2.6.15.orig/include/asm-mips/cobalt/ide.h    1970-01-01 
00:00:00.000000000 +0000
+++ linux-2.6.15/include/asm-mips/cobalt/ide.h    2006-01-09 
20:47:10.000000000 +0000
@@ -0,0 +1,83 @@
+
+/*
+ * PIO "in" transfers can cause D-cache lines to be allocated
+ * to the data being read. If the target is the page cache then
+ * the kernel can create a user space mapping of the same page
+ * without flushing it from the D-cache. This has large potential
+ * to create cache aliases. The Cobalts seem to trigger this
+ * problem easily.
+ *
+ * MIPs doesn't have a flush_dcache_range() so we roll
+ * our own.
+ *
+ * -- pdh
+ */
+
+#define MAX_HWIFS            2
+
+#include <asm/r4kcache.h>
+
+static inline void __flush_dcache(void)
+{
+    unsigned long dc_size, dc_line, addr, end;
+
+    dc_size = current_cpu_data.dcache.ways << 
current_cpu_data.dcache.waybit;
+    dc_line = current_cpu_data.dcache.linesz;
+
+    addr = CKSEG0;
+    end = addr + dc_size;
+
+    for (; addr < end; addr += dc_line)
+        flush_dcache_line_indexed(addr);
+}
+
+static inline void __flush_dcache_range(unsigned long start, unsigned 
long end)
+{
+    unsigned long dc_size, dc_line, addr;
+
+    dc_size = current_cpu_data.dcache.ways << 
current_cpu_data.dcache.waybit;
+    dc_line = current_cpu_data.dcache.linesz;
+
+    addr = start & ~(dc_line - 1);
+    end += dc_line - 1;
+
+    if (end - addr < dc_size)
+        for (; addr < end; addr += dc_line)
+            flush_dcache_line(addr);
+    else
+        __flush_dcache();
+}
+
+static inline void __ide_insw(unsigned long port, void *addr, unsigned 
int count)
+{
+    insw(port, addr, count);
+
+    __flush_dcache_range((unsigned long) addr, (unsigned long) addr + 
count * 2);
+}
+
+static inline void __ide_insl(unsigned long port, void *addr, unsigned 
int count)
+{
+    insl(port, addr, count);
+
+    __flush_dcache_range((unsigned long) addr, (unsigned long) addr + 
count * 4);
+}
+
+static inline void __ide_mm_insw(volatile void __iomem *port, void 
*addr, unsigned int count)
+{
+    readsw(port, addr, count);
+
+    __flush_dcache_range((unsigned long) addr, (unsigned long) addr + 
count * 2);
+}
+
+static inline void __ide_mm_insl(volatile void __iomem *port, void 
*addr, unsigned int count)
+{
+    readsl(port, addr, count);
+
+    __flush_dcache_range((unsigned long) addr, (unsigned long) addr + 
count * 4);
+}
+
+#define insw            __ide_insw
+#define insl            __ide_insl
+
+#define __ide_mm_outsw        writesw
+#define __ide_mm_outsl        writesl
diff -Naur linux-2.6.15.orig/include/asm-mips/io.h 
linux-2.6.15/include/asm-mips/io.h
--- linux-2.6.15.orig/include/asm-mips/io.h    2006-01-09 
21:32:18.000000000 +0000
+++ linux-2.6.15/include/asm-mips/io.h    2006-01-09 20:47:10.000000000 
+0000
@@ -535,6 +535,62 @@
 }
 
 /*
+ * Memory Mapped I/O
+ */
+#define ioread8(addr)        readb(addr)
+#define ioread16(addr)        readw(addr)
+#define ioread32(addr)        readl(addr)
+
+#define iowrite8(b,addr)    writeb(b,addr)
+#define iowrite16(w,addr)    writew(w,addr)
+#define iowrite32(l,addr)    writel(l,addr)
+
+#define ioread8_rep(a,b,c)    readsb(a,b,c)
+#define ioread16_rep(a,b,c)    readsw(a,b,c)
+#define ioread32_rep(a,b,c)    readsl(a,b,c)
+
+#define iowrite8_rep(a,b,c)    writesb(a,b,c)
+#define iowrite16_rep(a,b,c)    writesw(a,b,c)
+#define iowrite32_rep(a,b,c)    writesl(a,b,c)
+
+/* Create a virtual mapping cookie for an IO port range */
+extern void __iomem *ioport_map(unsigned long port, unsigned int nr);
+extern void ioport_unmap(void __iomem *);
+
+/* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
+struct pci_dev;
+extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned 
long max);
+extern void pci_iounmap(struct pci_dev *dev, void __iomem *);
+
+/*
+ * Memory Mapped I/O
+ */
+#define ioread8(addr)        readb(addr)
+#define ioread16(addr)        readw(addr)
+#define ioread32(addr)        readl(addr)
+
+#define iowrite8(b,addr)    writeb(b,addr)
+#define iowrite16(w,addr)    writew(w,addr)
+#define iowrite32(l,addr)    writel(l,addr)
+
+#define ioread8_rep(a,b,c)    readsb(a,b,c)
+#define ioread16_rep(a,b,c)    readsw(a,b,c)
+#define ioread32_rep(a,b,c)    readsl(a,b,c)
+
+#define iowrite8_rep(a,b,c)    writesb(a,b,c)
+#define iowrite16_rep(a,b,c)    writesw(a,b,c)
+#define iowrite32_rep(a,b,c)    writesl(a,b,c)
+
+/* Create a virtual mapping cookie for an IO port range */
+extern void __iomem *ioport_map(unsigned long port, unsigned int nr);
+extern void ioport_unmap(void __iomem *);
+
+/* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
+struct pci_dev;
+extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned 
long max);
+extern void pci_iounmap(struct pci_dev *dev, void __iomem *);
+
+/*
  * ISA space is 'always mapped' on currently supported MIPS systems, no 
need
  * to explicitly ioremap() it. The fact that the ISA IO space is mapped
  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values


-- 
----
Jim Gifford
maillist@jg555.com

Re: [PATCH Cobalt 1/1] 64-bit fix

[Martin Michlmayr]

* Jim Gifford <maillist@jg555.com> [2006-01-16 08:32]:
> This include the iomap.c, which is not accepted by Ralf.

I suppose that's just an omission.  Here's Yuasa's patch again (with a
minor change so it applies to 2.6.15).

iomap implementation for Linux/MIPS

Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>


diff -urN linux-mips/arch/mips/lib/Makefile new/arch/mips/lib/Makefile
--- linux-mips/arch/mips/lib/Makefile	2006-01-10 11:21:15.000000000 +0000
+++ new/arch/mips/lib/Makefile	2006-01-16 16:45:26.000000000 +0000
@@ -2,7 +2,7 @@
 # Makefile for MIPS-specific library files..
 #
 
-lib-y	+= csum_partial_copy.o memcpy.o promlib.o strlen_user.o strncpy_user.o \
-	   strnlen_user.o uncached.o
+lib-y	+= csum_partial_copy.o iomap.o memcpy.o promlib.o strlen_user.o \
+	   strncpy_user.o strnlen_user.o uncached.o
 
 EXTRA_AFLAGS := $(CFLAGS)
diff -urN linux-mips/arch/mips/lib/iomap.c new/arch/mips/lib/iomap.c
--- linux-mips/arch/mips/lib/iomap.c	1970-01-01 01:00:00.000000000 +0100
+++ new/arch/mips/lib/iomap.c	2006-01-16 16:45:35.000000000 +0000
@@ -0,0 +1,78 @@
+/*
+ *  iomap.c, Memory Mapped I/O routines for MIPS architecture.
+ *
+ *  This code is based on lib/iomap.c, by Linus Torvalds.
+ *
+ *  Copyright (C) 2004-2005  Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
+ *
+ *  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 program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include <asm/io.h>
+
+void __iomem *ioport_map(unsigned long port, unsigned int nr)
+{
+	unsigned long end;
+
+	end = port + nr - 1UL;
+	if (ioport_resource.start > port ||
+	    ioport_resource.end < end || port > end)
+		return NULL;
+
+	return (void __iomem *)(mips_io_port_base + port);
+}
+
+void ioport_unmap(void __iomem *addr)
+{
+}
+EXPORT_SYMBOL(ioport_map);
+EXPORT_SYMBOL(ioport_unmap);
+
+void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
+{
+	unsigned long start, len, flags;
+
+	if (dev == NULL)
+		return NULL;
+
+	start = pci_resource_start(dev, bar);
+	len = pci_resource_len(dev, bar);
+	if (!start || !len)
+		return NULL;
+
+	if (maxlen != 0 && len > maxlen)
+		len = maxlen;
+
+	flags = pci_resource_flags(dev, bar);
+	if (flags & IORESOURCE_IO)
+		return ioport_map(start, len);
+	if (flags & IORESOURCE_MEM) {
+		if (flags & IORESOURCE_CACHEABLE)
+			return ioremap_cacheable_cow(start, len);
+		return ioremap_nocache(start, len);
+	}
+
+	return NULL;
+}
+
+void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
+{
+	iounmap(addr);
+}
+EXPORT_SYMBOL(pci_iomap);
+EXPORT_SYMBOL(pci_iounmap);
diff -urN linux-mips/include/asm-mips/io.h new/include/asm-mips/io.h
--- linux-mips/include/asm-mips/io.h	2006-01-10 11:21:59.000000000 +0000
+++ new/include/asm-mips/io.h	2006-01-16 16:45:35.000000000 +0000
@@ -535,6 +535,34 @@
 }
 
 /*
+ * Memory Mapped I/O
+ */
+#define ioread8(addr)		readb(addr)
+#define ioread16(addr)		readw(addr)
+#define ioread32(addr)		readl(addr)
+
+#define iowrite8(b,addr)	writeb(b,addr)
+#define iowrite16(w,addr)	writew(w,addr)
+#define iowrite32(l,addr)	writel(l,addr)
+
+#define ioread8_rep(a,b,c)	readsb(a,b,c)
+#define ioread16_rep(a,b,c)	readsw(a,b,c)
+#define ioread32_rep(a,b,c)	readsl(a,b,c)
+
+#define iowrite8_rep(a,b,c)	writesb(a,b,c)
+#define iowrite16_rep(a,b,c)	writesw(a,b,c)
+#define iowrite32_rep(a,b,c)	writesl(a,b,c)
+
+/* Create a virtual mapping cookie for an IO port range */
+extern void __iomem *ioport_map(unsigned long port, unsigned int nr);
+extern void ioport_unmap(void __iomem *);
+
+/* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
+struct pci_dev;
+extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
+extern void pci_iounmap(struct pci_dev *dev, void __iomem *);
+
+/*
  * ISA space is 'always mapped' on currently supported MIPS systems, no need
  * to explicitly ioremap() it. The fact that the ISA IO space is mapped
  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values

-- 
Martin Michlmayr
http://www.cyrius.com/

Re: [PATCH Cobalt 1/1] 64-bit fix

[Martin Michlmayr]

* Jim Gifford <maillist@jg555.com> [2006-01-16 08:32]:
> This include the iomap.c, which is not accepted by Ralf.

I suppose that's just an omission.  Here's Yuasa's patch again (with a
minor change so it applies to 2.6.15).

iomap implementation for Linux/MIPS

Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>


diff -urN linux-mips/arch/mips/lib/Makefile new/arch/mips/lib/Makefile
--- linux-mips/arch/mips/lib/Makefile	2006-01-10 11:21:15.000000000 +0000
+++ new/arch/mips/lib/Makefile	2006-01-16 16:45:26.000000000 +0000
@@ -2,7 +2,7 @@
 # Makefile for MIPS-specific library files..
 #
 
-lib-y	+= csum_partial_copy.o memcpy.o promlib.o strlen_user.o strncpy_user.o \
-	   strnlen_user.o uncached.o
+lib-y	+= csum_partial_copy.o iomap.o memcpy.o promlib.o strlen_user.o \
+	   strncpy_user.o strnlen_user.o uncached.o
 
 EXTRA_AFLAGS := $(CFLAGS)
diff -urN linux-mips/arch/mips/lib/iomap.c new/arch/mips/lib/iomap.c
--- linux-mips/arch/mips/lib/iomap.c	1970-01-01 01:00:00.000000000 +0100
+++ new/arch/mips/lib/iomap.c	2006-01-16 16:45:35.000000000 +0000
@@ -0,0 +1,78 @@
+/*
+ *  iomap.c, Memory Mapped I/O routines for MIPS architecture.
+ *
+ *  This code is based on lib/iomap.c, by Linus Torvalds.
+ *
+ *  Copyright (C) 2004-2005  Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
+ *
+ *  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 program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include <asm/io.h>
+
+void __iomem *ioport_map(unsigned long port, unsigned int nr)
+{
+	unsigned long end;
+
+	end = port + nr - 1UL;
+	if (ioport_resource.start > port ||
+	    ioport_resource.end < end || port > end)
+		return NULL;
+
+	return (void __iomem *)(mips_io_port_base + port);
+}
+
+void ioport_unmap(void __iomem *addr)
+{
+}
+EXPORT_SYMBOL(ioport_map);
+EXPORT_SYMBOL(ioport_unmap);
+
+void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
+{
+	unsigned long start, len, flags;
+
+	if (dev == NULL)
+		return NULL;
+
+	start = pci_resource_start(dev, bar);
+	len = pci_resource_len(dev, bar);
+	if (!start || !len)
+		return NULL;
+
+	if (maxlen != 0 && len > maxlen)
+		len = maxlen;
+
+	flags = pci_resource_flags(dev, bar);
+	if (flags & IORESOURCE_IO)
+		return ioport_map(start, len);
+	if (flags & IORESOURCE_MEM) {
+		if (flags & IORESOURCE_CACHEABLE)
+			return ioremap_cacheable_cow(start, len);
+		return ioremap_nocache(start, len);
+	}
+
+	return NULL;
+}
+
+void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
+{
+	iounmap(addr);
+}
+EXPORT_SYMBOL(pci_iomap);
+EXPORT_SYMBOL(pci_iounmap);
diff -urN linux-mips/include/asm-mips/io.h new/include/asm-mips/io.h
--- linux-mips/include/asm-mips/io.h	2006-01-10 11:21:59.000000000 +0000
+++ new/include/asm-mips/io.h	2006-01-16 16:45:35.000000000 +0000
@@ -535,6 +535,34 @@
 }
 
 /*
+ * Memory Mapped I/O
+ */
+#define ioread8(addr)		readb(addr)
+#define ioread16(addr)		readw(addr)
+#define ioread32(addr)		readl(addr)
+
+#define iowrite8(b,addr)	writeb(b,addr)
+#define iowrite16(w,addr)	writew(w,addr)
+#define iowrite32(l,addr)	writel(l,addr)
+
+#define ioread8_rep(a,b,c)	readsb(a,b,c)
+#define ioread16_rep(a,b,c)	readsw(a,b,c)
+#define ioread32_rep(a,b,c)	readsl(a,b,c)
+
+#define iowrite8_rep(a,b,c)	writesb(a,b,c)
+#define iowrite16_rep(a,b,c)	writesw(a,b,c)
+#define iowrite32_rep(a,b,c)	writesl(a,b,c)
+
+/* Create a virtual mapping cookie for an IO port range */
+extern void __iomem *ioport_map(unsigned long port, unsigned int nr);
+extern void ioport_unmap(void __iomem *);
+
+/* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
+struct pci_dev;
+extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
+extern void pci_iounmap(struct pci_dev *dev, void __iomem *);
+
+/*
  * ISA space is 'always mapped' on currently supported MIPS systems, no need
  * to explicitly ioremap() it. The fact that the ISA IO space is mapped
  * to PAGE_OFFSET is pure coincidence - it does not mean ISA values

-- 
Martin Michlmayr
http://www.cyrius.com/

Re: [PATCH Cobalt 1/1] 64-bit fix

[Ralf Baechle]

On Mon, Jan 16, 2006 at 03:45:43PM +0000, Martin Michlmayr wrote:

> * Peter Horton <pdh@colonel-panic.org> [2005-04-14 19:59]:
> > This patch adds detection of broken 64-bit mode LL/SC on Cobalt units.
> > With this patch my Qube2700 boots a 64-bit build fine. The later units
> > have some problems with the Tulip driver.
> 
> Ralf, is this patch appropriate?  Can you please apply it or provide
> some feedback.

Runtime testing for that bug is fairly expensive as it adds a branch to
every instance of every type of atomic operation.  So we really want
cpu_has_llsc to be a constant so the compiler can optimize that.

So I suggest something like this in cpu-feature-overrides.h:

[...]
/*
 * R5000 has an interesting "restriction":  ll(d)/sc(d)
 * instructions to XKPHYS region simply do uncached bus
 * requests. This breaks all the atomic bitops functions.
 * so, for 64bit IP32 kernel we just don't use ll/sc.
 * This does not affect luserland.
 */
#ifdef CONFIG_64BIT
#define cpu_has_llsc            0
#else
#define cpu_has_llsc            1
#endif
[...]

The probe would upset the IP27 cache coherency logic and crash them btw.

  Ralf

Re: [PATCH Cobalt 1/1] 64-bit fix

[Ralf Baechle]

On Mon, Jan 16, 2006 at 08:32:46AM -0800, Jim Gifford wrote:

> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> 
> Here's a link to the updated patch. Works under 2.6.15
> http://www.linuxfromscratch.org/patches/downloads/linux/linux-2.6.15-mips_fix-1.patch
> 
> This include the iomap.c, which is not accepted by Ralf.

Yes - and the reasons are archived on this list.  Reposting the patch
leaves me entirely unimpressed.

  Ralf

Re: [PATCH Cobalt 1/1] 64-bit fix

[Atsushi Nemoto]

>>>>> On Tue, 17 Jan 2006 13:51:45 +0000, Ralf Baechle <ralf@linux-mips.org> said:

>> This include the iomap.c, which is not accepted by Ralf.

ralf> Yes - and the reasons are archived on this list.  Reposting the
ralf> patch leaves me entirely unimpressed.

Ralf, is this the reason?

> Subject: Re: MIPS - 64bit woes
> From: Ralf Baechle <ralf@linux-mips.org>
> Date:	Fri, 18 Nov 2005 17:29:48 +0000
> 
> No.  It's broken for machines with multiple PCI busses and I've explicitly
> rejected the patch which is in kernel.org before.

It seems a bit obscured for me --- and perhaps for some other people.
So I asked:

> Subject: mips iomap.c (Was: Re: MIPS - 64bit woes)
> From: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
> Date:	Sun, 20 Nov 2005 02:36:41 +0900 (JST)
> 
> Could you explain a bit _how_ broken current kernel.org's
> arch/mips/lib/iomap.c ?  Is it a single mips_io_port_base issue?
> 
> I suppose it works as well as traditional way (request_region +
> in[bwl] for IO resource, request_mem_region + iomap + read[bwl] for
> MEM resource).
> 
> I think it is better than generic iomap.c (except that
> ioremap_cacheable_cow which is not available for R3000 is used).

But got no response at that time.  So I ask again.  Could you tell us
how the iomap patch broken verbosely, please?

---
Atsushi Nemoto

Re: [PATCH Cobalt 1/1] 64-bit fix

[Jim Gifford]

[-- Attachment #1: Type: text/plain, Size: 124 bytes --]

As per our conversation Ralf, here is the patch without the iomap stuff 
in it.



-- 
----
Jim Gifford
maillist@jg555.com


[-- Attachment #2: linux-2.6.15.1-mips_fix-1.patch --]
[-- Type: text/x-diff, Size: 4174 bytes --]

Submitted By: Jim Gifford (patches at jg555 dot com)
Date: 2006-01-09
Initial Package Version: 2.6.15
Origin: Jim Gifford
Upstream Status: Not Accepted
Description: Various Fixes for MIPS architectures

diff -Naur linux-2.6.15.orig/include/asm-mips/addrspace.h linux-2.6.15/include/asm-mips/addrspace.h
--- linux-2.6.15.orig/include/asm-mips/addrspace.h	2006-01-03 03:21:10.000000000 +0000
+++ linux-2.6.15/include/asm-mips/addrspace.h	2006-01-09 20:47:10.000000000 +0000
@@ -124,7 +124,7 @@
 #define PHYS_TO_XKSEG_CACHED(p)		PHYS_TO_XKPHYS(K_CALG_COH_SHAREABLE,(p))
 #define XKPHYS_TO_PHYS(p)		((p) & TO_PHYS_MASK)
 #define PHYS_TO_XKPHYS(cm,a)		(_LLCONST_(0x8000000000000000) | \
-					 ((cm)<<59) | (a))
+					 ((unsigned long)(cm)<<59) | (a))
 
 #if defined (CONFIG_CPU_R4300)						\
     || defined (CONFIG_CPU_R4X00)					\
diff -Naur linux-2.6.15.orig/include/asm-mips/cobalt/cpu-feature-overrides.h linux-2.6.15/include/asm-mips/cobalt/cpu-feature-overrides.h
--- linux-2.6.15.orig/include/asm-mips/cobalt/cpu-feature-overrides.h	1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.15/include/asm-mips/cobalt/cpu-feature-overrides.h	2006-01-09 20:52:18.000000000 +0000
@@ -0,0 +1,17 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2006 Ralf Baechle
+ */
+#ifndef __ASM_COBALT_CPU_FEATURE_OVERRIDES_H
+#define __ASM_COBALT_CPU_FEATURE_OVERRIDES_H
+
+#ifdef CONFIG_64BIT
+#define cpu_has_llsc            0
+#else
+#define cpu_has_llsc            1
+#endif
+
+#endif /* __ASM_COBALT_CPU_FEATURE_OVERRIDES_H */
diff -Naur linux-2.6.15.orig/include/asm-mips/cobalt/ide.h linux-2.6.15/include/asm-mips/cobalt/ide.h
--- linux-2.6.15.orig/include/asm-mips/cobalt/ide.h	1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.15/include/asm-mips/cobalt/ide.h	2006-01-09 20:47:10.000000000 +0000
@@ -0,0 +1,83 @@
+
+/*
+ * PIO "in" transfers can cause D-cache lines to be allocated
+ * to the data being read. If the target is the page cache then
+ * the kernel can create a user space mapping of the same page
+ * without flushing it from the D-cache. This has large potential
+ * to create cache aliases. The Cobalts seem to trigger this
+ * problem easily.
+ *
+ * MIPs doesn't have a flush_dcache_range() so we roll
+ * our own.
+ *
+ * -- pdh
+ */
+
+#define MAX_HWIFS			2
+
+#include <asm/r4kcache.h>
+
+static inline void __flush_dcache(void)
+{
+	unsigned long dc_size, dc_line, addr, end;
+
+	dc_size = current_cpu_data.dcache.ways << current_cpu_data.dcache.waybit;
+	dc_line = current_cpu_data.dcache.linesz;
+
+	addr = CKSEG0;
+	end = addr + dc_size;
+
+	for (; addr < end; addr += dc_line)
+		flush_dcache_line_indexed(addr);
+}
+
+static inline void __flush_dcache_range(unsigned long start, unsigned long end)
+{
+	unsigned long dc_size, dc_line, addr;
+
+	dc_size = current_cpu_data.dcache.ways << current_cpu_data.dcache.waybit;
+	dc_line = current_cpu_data.dcache.linesz;
+
+	addr = start & ~(dc_line - 1);
+	end += dc_line - 1;
+
+	if (end - addr < dc_size)
+		for (; addr < end; addr += dc_line)
+			flush_dcache_line(addr);
+	else
+		__flush_dcache();
+}
+
+static inline void __ide_insw(unsigned long port, void *addr, unsigned int count)
+{
+	insw(port, addr, count);
+
+	__flush_dcache_range((unsigned long) addr, (unsigned long) addr + count * 2);
+}
+
+static inline void __ide_insl(unsigned long port, void *addr, unsigned int count)
+{
+	insl(port, addr, count);
+
+	__flush_dcache_range((unsigned long) addr, (unsigned long) addr + count * 4);
+}
+
+static inline void __ide_mm_insw(volatile void __iomem *port, void *addr, unsigned int count)
+{
+	readsw(port, addr, count);
+
+	__flush_dcache_range((unsigned long) addr, (unsigned long) addr + count * 2);
+}
+
+static inline void __ide_mm_insl(volatile void __iomem *port, void *addr, unsigned int count)
+{
+	readsl(port, addr, count);
+
+	__flush_dcache_range((unsigned long) addr, (unsigned long) addr + count * 4);
+}
+
+#define insw			__ide_insw
+#define insl			__ide_insl
+
+#define __ide_mm_outsw		writesw
+#define __ide_mm_outsl		writesl

Re: [PATCH Cobalt 1/1] 64-bit fix

[Jim Gifford]

Atsushi Nemoto wrote:
> But got no response at that time.  So I ask again.  Could you tell us
> how the iomap patch broken verbosely, please?
>
>   
How can we get this resolved, this issue has been open a long time. Can 
we all work together to get a working solution in place that everyone 
will accept?

We all need to understand the concerns with the current method. The only 
issue I see from Ralf is the following:

    Broken on multiple PCI busses.

    Now the way I understand the issue is the current iomap.c only 
handles a single bus, Ralf's point is that if there are multiple busses 
this patch may not work properly. Is that a correct statement Ralf.

    So can't we have one iomap.c for single pci bus systems and one for 
multiple pci bus systems? Just a thought.

-- 
----
Jim Gifford
maillist@jg555.com

Re: [PATCH Cobalt 1/1] 64-bit fix

[Atsushi Nemoto]

>>>>> On Wed, 18 Jan 2006 09:59:54 -0800, Jim Gifford <maillist@jg555.com> said:

jim> We all need to understand the concerns with the current
jim> method. The only issue I see from Ralf is the following:

jim>     Broken on multiple PCI busses.

Yes, it is an only reason I have ever seen.

jim>     Now the way I understand the issue is the current iomap.c
jim> only handles a single bus, Ralf's point is that if there are
jim> multiple busses this patch may not work properly. Is that a
jim> correct statement Ralf.

I think the current iomap can handle multiple busses.

The traditional way (ioremap + read[bwl] for memory space and in[bwl]
for IO space) can be used on multiple PCI busses if pci resources were
properly configured.  (Though IO space address might be a bit strange
value due to single global mips_io_port_base, it works anyway.)  The
current iomap basically do same jobs.

---
Atsushi Nemoto