o Merge with Linux 2.1.100.

 o Cleanup the machine dependencies of floppy and rtc.  The driver for
   the Dallas thingy in the Indy is still missing.
 o Handle allocation of zero'd pages correct for R4000SC / R4400SC.
 o Page colouring shit to match the virtual and physical colour of all
   mapped pages.  This tends to produce extreme fragmentation problems,
   so it's deactivated for now.  Users of R4000SC / R4400SC may re-enable
   the code in arch/mips/mm/init.c by removing the definition of
   CONF_GIVE_A_SHIT_ABOUT_COLOURS.  Should get them somewhat further -
   but don't shake to hard ...
 o Fixed ptrace(2)-ing of syscalls, strace is now working again.
 o Fix the interrupt forwarding from the keyboard driver to the psaux
   driver, PS/2 mice are now working on the Indy.  The fix is somewhat
   broken as it prevents generic kernels for Indy and machines which handle
   things different.
 o Things I can't remember.

1 files changed, 133 insertions, 9 deletions

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index dd2fcbad2..f9ee7c554 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -1,11 +1,10 @@
-/*
+/* $Id: init.c,v 1.5 1998/04/05 11:23:54 ralf Exp $
+ *
  * 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) 1994, 1995, 1996 by Ralf Baechle
- *
- * $Id: init.c,v 1.4 1998/03/22 23:27:15 ralf Exp $
+ * Copyright (C) 1994, 1995, 1996, 1997, 1998 by Ralf Baechle
  */
 #include <linux/config.h>
 #include <linux/init.h>
@@ -16,10 +15,12 @@
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/types.h>
+#include <linux/pagemap.h>
 #include <linux/ptrace.h>
 #include <linux/mman.h>
 #include <linux/mm.h>
 #include <linux/swap.h>
+#include <linux/swapctl.h>
 #ifdef CONFIG_BLK_DEV_INITRD
 #include <linux/blk.h>
 #endif
@@ -28,13 +29,17 @@
 #include <asm/cachectl.h>
 #include <asm/dma.h>
 #include <asm/jazzdma.h>
-#include <asm/vector.h>
 #include <asm/system.h>
 #include <asm/pgtable.h>
 #ifdef CONFIG_SGI
 #include <asm/sgialib.h>
 #endif
 
+/*
+ * Define this to effectivly disable the userpage colouring shit.
+ */
+#define CONF_GIVE_A_SHIT_ABOUT_COLOURS
+
 extern void deskstation_tyne_dma_init(void);
 extern void show_net_buffers(void);
 
@@ -48,6 +53,46 @@ asmlinkage int sys_cacheflush(void *addr, int bytes, int cache)
 }
 
 /*
+ * We have upto 8 empty zeroed pages so we can map one of the right colour
+ * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
+ * where we have to avoid VCED / VECI exceptions for good performance at
+ * any price.  Since page is never written to after the initialization we
+ * don't have to care about aliases on other CPUs.
+ */
+unsigned long empty_zero_page, zero_page_mask;
+
+static inline unsigned long setup_zero_pages(void)
+{
+	unsigned long order, size, pg;
+
+	switch (mips_cputype) {
+	case CPU_R4000SC:
+	case CPU_R4000MC:
+	case CPU_R4400SC:
+	case CPU_R4400MC:
+		order = 3;
+	default:
+		order = 0;
+	}
+
+	empty_zero_page = __get_free_pages(GFP_KERNEL, order);
+	if (!empty_zero_page)
+		panic("Oh boy, that early out of memory?");
+
+	pg = MAP_NR(empty_zero_page);
+	while(pg < MAP_NR(empty_zero_page) + (1 << order)) {
+		set_bit(PG_reserved, &mem_map[pg].flags);
+		pg++;
+	}
+
+	size = PAGE_SIZE << order;
+	zero_page_mask = (size - 1) & PAGE_MASK;
+	memset((void *)empty_zero_page, 0, size);
+
+	return size;
+}
+
+/*
  * BAD_PAGE is the page that is used for page faults when linux
  * is out-of-memory. Older versions of linux just did a
  * do_exit(), but using this instead means there is less risk
@@ -126,6 +171,83 @@ pte_t __bad_page(void)
 	return pte_mkdirty(mk_pte(page, PAGE_SHARED));
 }
 
+#ifdef __SMP__
+spinlock_t user_page_lock = SPIN_LOCK_UNLOCKED;
+#endif
+struct upcache user_page_cache[8] __attribute__((aligned(32)));
+static unsigned long user_page_order;
+unsigned long user_page_colours;
+
+unsigned long get_user_page_slow(int which)
+{
+	unsigned long chunk;
+	struct upcache *up = &user_page_cache[0];
+	struct page *p, *res;
+	int i;
+
+	do {
+		chunk = __get_free_pages(GFP_KERNEL, user_page_order);
+	} while(chunk==0);
+
+	p = mem_map + MAP_NR(chunk);
+	res = p + which;
+	spin_lock(&user_page_lock);
+	for (i=user_page_colours; i>=0; i--,p++,up++,chunk+=PAGE_SIZE) {
+		atomic_set(&p->count, 1);
+		p->age = PAGE_INITIAL_AGE;
+
+		if (p != res) {
+			if(up->count < USER_PAGE_WATER) {
+				p->next = up->list;
+				up->list = p;
+				up->count++;
+			} else
+				free_pages(chunk, 0);
+		}
+	}
+	spin_unlock(&user_page_lock);
+
+	return page_address(res);
+}
+
+static inline void user_page_setup(void)
+{
+	unsigned long assoc = 0;
+	unsigned long dcache_log, icache_log, cache_log;
+	unsigned long config = read_32bit_cp0_register(CP0_CONFIG);
+
+	switch(mips_cputype) {
+	case CPU_R4000SC:
+	case CPU_R4000MC:
+	case CPU_R4400SC:
+	case CPU_R4400MC:
+		cache_log = 3;	/* => 32k, sucks  */
+		break;
+
+        case CPU_R4600:                 /* two way set associative caches?  */
+        case CPU_R4700:
+        case CPU_R5000:
+        case CPU_NEVADA:
+		assoc = 1;
+		/* fall through */
+	default:
+		/* use bigger cache  */
+		icache_log = (config >> 9) & 7;
+		dcache_log = (config >> 6) & 7;
+		if (dcache_log > icache_log)
+			cache_log = dcache_log;
+		else
+			cache_log = icache_log;
+	}
+
+#ifdef CONF_GIVE_A_SHIT_ABOUT_COLOURS
+	cache_log = assoc = 0;
+#endif
+
+	user_page_order = cache_log - assoc;
+	user_page_colours = (1 << (cache_log - assoc)) - 1;
+}
+
 void show_mem(void)
 {
 	int i, free = 0, total = 0, reserved = 0;
@@ -178,9 +300,6 @@ __initfunc(void mem_init(unsigned long start_mem, unsigned long end_mem))
 	max_mapnr = num_physpages = MAP_NR(end_mem);
 	high_memory = (void *)end_mem;
 
-	/* clear the zero-page */
-	clear_page((unsigned long)empty_zero_page);
-
 	/* mark usable pages in the mem_map[] */
 	start_mem = PAGE_ALIGN(start_mem);
 
@@ -217,13 +336,18 @@ __initfunc(void mem_init(unsigned long start_mem, unsigned long end_mem))
 			free_page(tmp);
 	}
 	tmp = nr_free_pages << PAGE_SHIFT;
+
+	/* Setup zeroed pages.  */
+	tmp -= setup_zero_pages();
+
 	printk("Memory: %luk/%luk available (%dk kernel code, %dk data)\n",
 		tmp >> 10,
 		max_mapnr << (PAGE_SHIFT-10),
 		codepages << (PAGE_SHIFT-10),
 		datapages << (PAGE_SHIFT-10));
 
-	return;
+	/* Initialize allocator for colour matched mapped pages.  */
+	user_page_setup();
 }
 
 extern char __init_begin, __init_end;