[SPARC32] Fix BUG-on-swapout

[SPARC32] Fix BUG-on-swapout

[Keith M Wesolowski]

This fixes BUG-on-swapout for srmmu-based systems.  The problem is
caused by kmap_atomic_to_page being fed an aliased (pagetable) address
and returning bogons.  This also adjusts the pkmap and fixmap base
addresses so they cannot overlap.

Dave, unless it's braindead, please apply.

diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/arch/sparc/Kconfig 2.5-sparc-smp/arch/sparc/Kconfig
--- 2.5-sparc/arch/sparc/Kconfig	Sat Jan  3 02:08:07 2004
+++ 2.5-sparc-smp/arch/sparc/Kconfig	Sat Jan  3 02:11:02 2004
@@ -313,6 +313,13 @@
 	  This results in a large slowdown, but helps to find certain types
 	  of memory corruptions.
 
+config DEBUG_HIGHMEM
+	bool "Highmem debugging"
+	depends on DEBUG_KERNEL && HIGHMEM
+	help
+	  This options enables addition error checking for high memory systems.
+	  Disable for production systems.
+
 config DEBUG_SPINLOCK_SLEEP
 	bool "Sleep-inside-spinlock checking"
 	depends on DEBUG_KERNEL
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/arch/sparc/mm/fault.c 2.5-sparc-smp/arch/sparc/mm/fault.c
--- 2.5-sparc/arch/sparc/mm/fault.c	Sat Jan  3 02:08:08 2004
+++ 2.5-sparc-smp/arch/sparc/mm/fault.c	Sat Jan  3 02:11:02 2004
@@ -36,7 +36,7 @@
 
 #define ELEMENTS(arr) (sizeof (arr)/sizeof (arr[0]))
 
-extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS];
+extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
 extern int prom_node_root;
 
 /* At boot time we determine these two values necessary for setting
@@ -72,7 +72,7 @@
 		mlist = mlist->theres_more;
 		bytes = mlist->num_bytes;
 		tally += bytes;
-		if (i >= SPARC_PHYS_BANKS-1) {
+		if (i > SPARC_PHYS_BANKS-1) {
 			printk ("The machine has more banks than "
 				"this kernel can support\n"
 				"Increase the SPARC_PHYS_BANKS "
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/arch/sparc/mm/highmem.c 2.5-sparc-smp/arch/sparc/mm/highmem.c
--- 2.5-sparc/arch/sparc/mm/highmem.c	Sat Jan  3 02:08:08 2004
+++ 2.5-sparc-smp/arch/sparc/mm/highmem.c	Sat Jan  3 02:27:24 2004
@@ -27,6 +27,7 @@
 #include <asm/pgalloc.h>
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
+#include <asm/fixmap.h>
 
 void *kmap_atomic(struct page *page, enum km_type type)
 {
@@ -39,7 +40,7 @@
 		return page_address(page);
 
 	idx = type + KM_TYPE_NR*smp_processor_id();
-	vaddr = fix_kmap_begin + idx * PAGE_SIZE;
+	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
 
 /* XXX Fix - Anton */
 #if 0
@@ -48,11 +49,10 @@
 	flush_cache_all();
 #endif
 
-#if HIGHMEM_DEBUG
-	if (!pte_none(*(kmap_pte+idx)))
-		BUG();
+#ifdef CONFIG_DEBUG_HIGHMEM
+	BUG_ON(!pte_none(*(kmap_pte-idx)));
 #endif
-	set_pte(kmap_pte+idx, mk_pte(page, kmap_prot));
+	set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
 /* XXX Fix - Anton */
 #if 0
 	__flush_tlb_one(vaddr);
@@ -65,17 +65,17 @@
 
 void kunmap_atomic(void *kvaddr, enum km_type type)
 {
-	unsigned long vaddr = (unsigned long) kvaddr;
+#ifdef CONFIG_DEBUG_HIGHMEM
+	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
 	unsigned long idx = type + KM_TYPE_NR*smp_processor_id();
 
-	if (vaddr < fix_kmap_begin) { // FIXME
+	if (vaddr < FIXADDR_START) { // FIXME
 		dec_preempt_count();
 		preempt_check_resched();
 		return;
 	}
 
-	if (vaddr != fix_kmap_begin + idx * PAGE_SIZE)
-		BUG();
+	BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx));
 
 /* XXX Fix - Anton */
 #if 0
@@ -84,12 +84,11 @@
 	flush_cache_all();
 #endif
 
-#ifdef HIGHMEM_DEBUG
 	/*
 	 * force other mappings to Oops if they'll try to access
 	 * this pte without first remap it
 	 */
-	pte_clear(kmap_pte+idx);
+	pte_clear(kmap_pte-idx);
 /* XXX Fix - Anton */
 #if 0
 	__flush_tlb_one(vaddr);
@@ -97,6 +96,25 @@
 	flush_tlb_all();
 #endif
 #endif
+
 	dec_preempt_count();
 	preempt_check_resched();
+}
+
+/* We may be fed a pagetable here by ptep_to_xxx and others. */
+struct page *kmap_atomic_to_page(void *ptr)
+{
+	unsigned long idx, vaddr = (unsigned long)ptr;
+	pte_t *pte;
+
+	if (vaddr < SRMMU_NOCACHE_VADDR)
+		return virt_to_page(ptr);
+	if (vaddr < PKMAP_BASE)
+		return pfn_to_page(__nocache_pa(vaddr) >> PAGE_SHIFT);
+	BUG_ON(vaddr < FIXADDR_START);
+	BUG_ON(vaddr > FIXADDR_TOP);
+
+	idx = virt_to_fix(vaddr);
+	pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
+	return pte_page(*pte);
 }
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/arch/sparc/mm/init.c 2.5-sparc-smp/arch/sparc/mm/init.c
--- 2.5-sparc/arch/sparc/mm/init.c	Sat Jan  3 02:08:08 2004
+++ 2.5-sparc-smp/arch/sparc/mm/init.c	Sat Jan  3 02:11:02 2004
@@ -41,7 +41,7 @@
 
 unsigned long page_kernel;
 
-struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS];
+struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
 unsigned long sparc_unmapped_base;
 
 struct pgtable_cache_struct pgt_quicklists;
@@ -61,17 +61,13 @@
 EXPORT_SYMBOL(kmap_prot);
 EXPORT_SYMBOL(kmap_pte);
 
-/* These are set in {srmmu,sun4c}_paging_init() */
-unsigned long fix_kmap_begin;
-unsigned long fix_kmap_end;
-
-#define kmap_get_fixed_pte(vaddr) \
+#define kmap_get_fixmap_pte(vaddr) \
 	pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr))
 
 void __init kmap_init(void)
 {
 	/* cache the first kmap pte */
-	kmap_pte = kmap_get_fixed_pte(fix_kmap_begin);
+	kmap_pte = kmap_get_fixmap_pte(__fix_to_virt(FIX_KMAP_BEGIN));
 	kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);
 }
 
@@ -385,12 +381,12 @@
 {
 	unsigned long tmp;
 
-#ifdef DEBUG_HIGHMEM
+#ifdef CONFIG_DEBUG_HIGHMEM
 	printk("mapping high region %08lx - %08lx\n", start_pfn, end_pfn);
 #endif
 
 	for (tmp = start_pfn; tmp < end_pfn; tmp++) {
-		struct page *page = mem_map + tmp;
+		struct page *page = pfn_to_page(tmp);
 
 		ClearPageReserved(page);
 		set_bit(PG_highmem, &page->flags);
@@ -407,7 +403,18 @@
 	int initpages = 0; 
 	int i;
 
-	highmem_start_page = mem_map + highstart_pfn;
+	highmem_start_page = pfn_to_page(highstart_pfn);
+
+	if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
+		prom_printf("BUG: fixmap and pkmap areas overlap\n");
+		prom_printf("pkbase: 0x%lx pkend: 0x%lx fixstart 0x%lx\n",
+		       PKMAP_BASE,
+		       (unsigned long)PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
+		       FIXADDR_START);
+		prom_printf("Please mail sparclinux@vger.kernel.org.\n");
+		prom_halt();
+	}
+
 
 	/* Saves us work later. */
 	memset((void *)&empty_zero_page, 0, PAGE_SIZE);
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/arch/sparc/mm/io-unit.c 2.5-sparc-smp/arch/sparc/mm/io-unit.c
--- 2.5-sparc/arch/sparc/mm/io-unit.c	Sat Jan  3 02:08:08 2004
+++ 2.5-sparc-smp/arch/sparc/mm/io-unit.c	Sat Jan  3 02:11:02 2004
@@ -65,7 +65,7 @@
 	
 	for (xptend = iounit->page_table + (16 * PAGE_SIZE) / sizeof(iopte_t);
 	     xpt < xptend;)
-	     	*xpt++ = 0;
+	     	iopte_val(*xpt++) = 0;
 }
 
 /* One has to hold iounit->lock to call this */
@@ -199,7 +199,7 @@
 			pmdp = pmd_offset(pgdp, addr);
 			ptep = pte_offset_map(pmdp, addr);
 
-			set_pte(ptep, pte_val(mk_pte(virt_to_page(page), dvma_prot)));
+			set_pte(ptep, mk_pte(virt_to_page(page), dvma_prot));
 			
 			i = ((addr - IOUNIT_DMA_BASE) >> PAGE_SHIFT);
 
@@ -207,7 +207,7 @@
 				struct iounit_struct *iounit = (struct iounit_struct *)sbus->iommu;
 
 				iopte = (iopte_t *)(iounit->page_table + i);
-				*iopte = __iopte(MKIOPTE(__pa(page)));
+				*iopte = MKIOPTE(__pa(page));
 			}
 		}
 		addr += PAGE_SIZE;
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/arch/sparc/mm/iommu.c 2.5-sparc-smp/arch/sparc/mm/iommu.c
--- 2.5-sparc/arch/sparc/mm/iommu.c	Sat Jan  3 02:08:08 2004
+++ 2.5-sparc-smp/arch/sparc/mm/iommu.c	Sat Jan  3 02:11:02 2004
@@ -405,7 +405,7 @@
 	iopte_t *iopte = iommu->page_table;
 
 	iopte += ((busa - iommu->start) >> PAGE_SHIFT);
-	return pfn_to_page((pte_val(*iopte) & IOPTE_PAGE) >> (PAGE_SHIFT-4));
+	return pfn_to_page((iopte_val(*iopte) & IOPTE_PAGE) >> (PAGE_SHIFT-4));
 }
 #endif
 
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/arch/sparc/mm/srmmu.c 2.5-sparc-smp/arch/sparc/mm/srmmu.c
--- 2.5-sparc/arch/sparc/mm/srmmu.c	Sat Jan  3 02:08:08 2004
+++ 2.5-sparc-smp/arch/sparc/mm/srmmu.c	Sat Jan  3 02:11:02 2004
@@ -139,10 +139,6 @@
 /* these will be initialized in srmmu_nocache_calcsize() */
 unsigned long srmmu_nocache_size;
 unsigned long srmmu_nocache_end;
-unsigned long pkmap_base;
-unsigned long pkmap_base_end;
-extern unsigned long fix_kmap_begin;
-extern unsigned long fix_kmap_end;
 
 /* 1 bit <=> 256 bytes of nocache <=> 64 PTEs */
 #define SRMMU_NOCACHE_BITMAP_SHIFT (PAGE_SHIFT - 4)
@@ -154,11 +150,6 @@
 void *srmmu_nocache_bitmap;
 static struct bit_map srmmu_nocache_map;
 
-/* This makes sense. Honest it does - Anton */
-#define __nocache_pa(VADDR) (((unsigned long)VADDR) - SRMMU_NOCACHE_VADDR + __pa((unsigned long)srmmu_nocache_pool))
-#define __nocache_va(PADDR) (__va((unsigned long)PADDR) - (unsigned long)srmmu_nocache_pool + SRMMU_NOCACHE_VADDR)
-#define __nocache_fix(VADDR) __va(__nocache_pa(VADDR))
-
 static unsigned long srmmu_pte_pfn(pte_t pte)
 {
 	if (srmmu_device_memory(pte_val(pte))) {
@@ -322,10 +313,7 @@
 		printk("Size 0x%x unaligned int nocache request\n", size);
 		size += SRMMU_NOCACHE_BITMAP_SHIFT-1;
 	}
-	if (align > SRMMU_NOCACHE_ALIGN_MAX) {
-		BUG();
-		return 0;
-	}
+	BUG_ON(align > SRMMU_NOCACHE_ALIGN_MAX);
 
 	offset = bit_map_string_get(&srmmu_nocache_map,
 		       			size >> SRMMU_NOCACHE_BITMAP_SHIFT,
@@ -361,7 +349,7 @@
 		    vaddr, (unsigned long)SRMMU_NOCACHE_VADDR);
 		BUG();
 	}
-	if (vaddr >= srmmu_nocache_end) {
+	if (vaddr+size >= srmmu_nocache_end) {
 		printk("Vaddr %lx is bigger than nocache end 0x%lx\n",
 		    vaddr, srmmu_nocache_end);
 		BUG();
@@ -403,17 +391,15 @@
 
  /* P3 XXX The 4x overuse: corroborated by /proc/meminfo. */
 	// if (srmmu_nocache_npages < 256) srmmu_nocache_npages = 256;
-	if (srmmu_nocache_npages < 550) srmmu_nocache_npages = 550;
+	if (srmmu_nocache_npages < SRMMU_MIN_NOCACHE_PAGES)
+		srmmu_nocache_npages = SRMMU_MIN_NOCACHE_PAGES;
 
 	/* anything above 1280 blows up */
-	if (srmmu_nocache_npages > 1280) srmmu_nocache_npages = 1280;
+	if (srmmu_nocache_npages > SRMMU_MAX_NOCACHE_PAGES)
+		srmmu_nocache_npages = SRMMU_MAX_NOCACHE_PAGES;
 
 	srmmu_nocache_size = srmmu_nocache_npages * PAGE_SIZE;
 	srmmu_nocache_end = SRMMU_NOCACHE_VADDR + srmmu_nocache_size;
-	fix_kmap_begin = srmmu_nocache_end;
-	fix_kmap_end = fix_kmap_begin + (KM_TYPE_NR * NR_CPUS - 1) * PAGE_SIZE;
-	pkmap_base = SRMMU_NOCACHE_VADDR + srmmu_nocache_size + 0x40000;
-	pkmap_base_end = pkmap_base + LAST_PKMAP * PAGE_SIZE;
 }
 
 void srmmu_nocache_init(void)
@@ -453,7 +439,7 @@
 		if (srmmu_cache_pagetables)
 			pteval |= SRMMU_CACHE;
 
-		srmmu_set_pte(__nocache_fix(pte), pteval);
+		srmmu_set_pte(__nocache_fix(pte), __pte(pteval));
 
 		vaddr += PAGE_SIZE;
 		paddr += PAGE_SIZE;
@@ -1083,6 +1069,8 @@
 			memset(__nocache_fix(ptep), 0, SRMMU_PTE_SZ_SOFT);
 			srmmu_pmd_set(__nocache_fix(pmdp), ptep);
 		}
+		if (start > (0xffffffffUL - SRMMU_PMD_SIZE_SOFT))
+			break;
 		start = (start + SRMMU_PMD_SIZE) & SRMMU_PMD_MASK;
 	}
 }
@@ -1111,6 +1099,8 @@
 			memset(ptep, 0, SRMMU_PTE_SZ_SOFT);
 			srmmu_pmd_set(pmdp, ptep);
 		}
+		if (start > (0xffffffffUL - SRMMU_PMD_SIZE_SOFT))
+			break;
 		start = (start + SRMMU_PMD_SIZE) & SRMMU_PMD_MASK;
 	}
 }
@@ -1315,12 +1305,13 @@
 	srmmu_allocate_ptable_skeleton(DVMA_VADDR, DVMA_END);
 #endif
 
-	srmmu_allocate_ptable_skeleton(fix_kmap_begin, fix_kmap_end);
-	srmmu_allocate_ptable_skeleton(pkmap_base, pkmap_base_end);
-
-	pgd = pgd_offset_k(pkmap_base);
-	pmd = srmmu_pmd_offset(pgd, pkmap_base);
-	pte = srmmu_pte_offset(pmd, pkmap_base);
+	srmmu_allocate_ptable_skeleton(
+		__fix_to_virt(__end_of_fixed_addresses - 1), FIXADDR_TOP);
+	srmmu_allocate_ptable_skeleton(PKMAP_BASE, PKMAP_END);
+
+	pgd = pgd_offset_k(PKMAP_BASE);
+	pmd = srmmu_pmd_offset(pgd, PKMAP_BASE);
+	pte = srmmu_pte_offset(pmd, PKMAP_BASE);
 	pkmap_page_table = pte;
 
 	flush_cache_all();
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/arch/sparc/mm/sun4c.c 2.5-sparc-smp/arch/sparc/mm/sun4c.c
--- 2.5-sparc/arch/sparc/mm/sun4c.c	Sat Jan  3 02:08:08 2004
+++ 2.5-sparc-smp/arch/sparc/mm/sun4c.c	Sat Jan  3 02:11:02 2004
@@ -2028,18 +2028,12 @@
 extern unsigned long bootmem_init(unsigned long *pages_avail);
 extern unsigned long last_valid_pfn;
 
-extern unsigned long fix_kmap_begin;
-extern unsigned long fix_kmap_end;
-
 void __init sun4c_paging_init(void)
 {
 	int i, cnt;
 	unsigned long kernel_end, vaddr;
 	extern struct resource sparc_iomap;
 	unsigned long end_pfn, pages_avail;
-
-	fix_kmap_begin = KERNBASE + SRMMU_MAXMEM; /* Why bother with SRMMU_MAXMEM? */
-	fix_kmap_end = fix_kmap_begin + ((KM_TYPE_NR*NR_CPUS)-1)*PAGE_SIZE;
 
 	kernel_end = (unsigned long) &end;
 	kernel_end += (SUN4C_REAL_PGDIR_SIZE * 4);
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/include/asm-sparc/fixmap.h 2.5-sparc-smp/include/asm-sparc/fixmap.h
--- 2.5-sparc/include/asm-sparc/fixmap.h	Wed Dec 31 16:00:00 1969
+++ 2.5-sparc-smp/include/asm-sparc/fixmap.h	Fri Jan  2 09:37:26 2004
@@ -0,0 +1,111 @@
+/*
+ * fixmap.h: compile-time virtual memory allocation
+ *
+ * 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) 1998 Ingo Molnar
+ *
+ * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
+ */
+
+#ifndef _ASM_FIXMAP_H
+#define _ASM_FIXMAP_H
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <asm/page.h>
+#ifdef CONFIG_HIGHMEM
+#include <linux/threads.h>
+#include <asm/kmap_types.h>
+#endif
+
+/*
+ * Here we define all the compile-time 'special' virtual
+ * addresses. The point is to have a constant address at
+ * compile time, but to set the physical address only
+ * in the boot process. We allocate these special  addresses
+ * from the top of unused virtual memory (0xfd000000 - 1 page) backwards.
+ * Also this lets us do fail-safe vmalloc(), we
+ * can guarantee that these special addresses and
+ * vmalloc()-ed addresses never overlap.
+ *
+ * these 'compile-time allocated' memory buffers are
+ * fixed-size 4k pages. (or larger if used with an increment
+ * highger than 1) use fixmap_set(idx,phys) to associate
+ * physical memory with fixmap indices.
+ *
+ * TLB entries of such buffers will not be flushed across
+ * task switches.
+ */
+
+/*
+ * on UP currently we will have no trace of the fixmap mechanism,
+ * no page table allocations, etc. This might change in the
+ * future, say framebuffers for the console driver(s) could be
+ * fix-mapped?
+ */
+enum fixed_addresses {
+	FIX_HOLE,
+#ifdef CONFIG_HIGHMEM
+	FIX_KMAP_BEGIN,
+	FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
+#endif
+	__end_of_fixed_addresses
+};
+
+extern void __set_fixmap (enum fixed_addresses idx,
+					unsigned long phys, pgprot_t flags);
+
+#define set_fixmap(idx, phys) \
+		__set_fixmap(idx, phys, PAGE_KERNEL)
+/*
+ * Some hardware wants to get fixmapped without caching.
+ */
+#define set_fixmap_nocache(idx, phys) \
+		__set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
+/*
+ * used by vmalloc.c.
+ *
+ * Leave one empty page between IO pages at 0xfd000000 and
+ * the start of the fixmap.
+ */
+#define FIXADDR_TOP	(0xfcfff000UL)
+#define FIXADDR_SIZE	((__end_of_fixed_addresses) << PAGE_SHIFT)
+#define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE)
+
+#define __fix_to_virt(x)	(FIXADDR_TOP - ((x) << PAGE_SHIFT))
+#define __virt_to_fix(x)	((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
+
+extern void __this_fixmap_does_not_exist(void);
+
+/*
+ * 'index to address' translation. If anyone tries to use the idx
+ * directly without tranlation, we catch the bug with a NULL-deference
+ * kernel oops. Illegal ranges of incoming indices are caught too.
+ */
+static inline unsigned long fix_to_virt(const unsigned int idx)
+{
+	/*
+	 * this branch gets completely eliminated after inlining,
+	 * except when someone tries to use fixaddr indices in an
+	 * illegal way. (such as mixing up address types or using
+	 * out-of-range indices).
+	 *
+	 * If it doesn't get removed, the linker will complain
+	 * loudly with a reasonably clear error message..
+	 */
+	if (idx >= __end_of_fixed_addresses)
+		__this_fixmap_does_not_exist();
+
+        return __fix_to_virt(idx);
+}
+
+static inline unsigned long virt_to_fix(const unsigned long vaddr)
+{
+	BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
+	return __virt_to_fix(vaddr);
+}
+
+#endif
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/include/asm-sparc/highmem.h 2.5-sparc-smp/include/asm-sparc/highmem.h
--- 2.5-sparc/include/asm-sparc/highmem.h	Sat Jan  3 02:08:30 2004
+++ 2.5-sparc-smp/include/asm-sparc/highmem.h	Sat Jan  3 02:11:28 2004
@@ -21,10 +21,10 @@
 #ifdef __KERNEL__
 
 #include <linux/interrupt.h>
+#include <asm/fixmap.h>
+#include <asm/vaddrs.h>
 #include <asm/kmap_types.h>
-
-/* undef for production */
-#define HIGHMEM_DEBUG 1
+#include <asm/pgtsrmmu.h>
 
 /* declarations for highmem.c */
 extern unsigned long highstart_pfn, highend_pfn;
@@ -33,12 +33,6 @@
 extern pgprot_t kmap_prot;
 extern pte_t *pkmap_page_table;
 
-/* This gets set in {srmmu,sun4c}_paging_init() */
-extern unsigned long fix_kmap_begin;
-
-/* Only used and set with srmmu? */
-extern unsigned long pkmap_base;
-
 extern void kmap_init(void) __init;
 
 /*
@@ -46,19 +40,21 @@
  * easily, subsequent pte tables have to be allocated in one physical
  * chunk of RAM.
  */
+#define PKMAP_BASE (SRMMU_NOCACHE_VADDR + (SRMMU_MAX_NOCACHE_PAGES << PAGE_SHIFT))
 #define LAST_PKMAP 1024
 
 #define LAST_PKMAP_MASK (LAST_PKMAP - 1)
-#define PKMAP_NR(virt)  ((virt - pkmap_base) >> PAGE_SHIFT)
-#define PKMAP_ADDR(nr)  (pkmap_base + ((nr) << PAGE_SHIFT))
+#define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
+#define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
+
+#define PKMAP_END (PKMAP_ADDR(LAST_PKMAP))
 
 extern void *kmap_high(struct page *page);
 extern void kunmap_high(struct page *page);
 
 static inline void *kmap(struct page *page)
 {
-	if (in_interrupt())
-		BUG();
+	BUG_ON(in_interrupt());
 	if (page < highmem_start_page)
 		return page_address(page);
 	return kmap_high(page);
@@ -66,8 +62,7 @@
 
 static inline void kunmap(struct page *page)
 {
-	if (in_interrupt())
-		BUG();
+	BUG_ON(in_interrupt());
 	if (page < highmem_start_page)
 		return;
 	kunmap_high(page);
@@ -75,19 +70,7 @@
 
 extern void *kmap_atomic(struct page *page, enum km_type type);
 extern void kunmap_atomic(void *kvaddr, enum km_type type);
-
-static inline struct page *kmap_atomic_to_page(void *ptr)
-{
-	unsigned long idx, vaddr = (unsigned long)ptr;
-	pte_t *pte;
-
-	if (vaddr < fix_kmap_begin)
-		return virt_to_page(ptr);
-
-	idx = ((vaddr - fix_kmap_begin) >> PAGE_SHIFT);
-	pte = kmap_pte + idx;
-	return pte_page(*pte);
-}
+extern struct page *kmap_atomic_to_page(void *vaddr);
 
 #define flush_cache_kmaps()	flush_cache_all()
 
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/include/asm-sparc/kmap_types.h 2.5-sparc-smp/include/asm-sparc/kmap_types.h
--- 2.5-sparc/include/asm-sparc/kmap_types.h	Sat Jan  3 02:08:30 2004
+++ 2.5-sparc-smp/include/asm-sparc/kmap_types.h	Sat Jan  3 02:11:28 2004
@@ -11,6 +11,7 @@
 	KM_BIO_DST_IRQ,
 	KM_PTE0,
 	KM_PTE1,
+	KM_PTE2,
 	KM_IRQ0,
 	KM_IRQ1,
 	KM_SOFTIRQ0,
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/include/asm-sparc/page.h 2.5-sparc-smp/include/asm-sparc/page.h
--- 2.5-sparc/include/asm-sparc/page.h	Sat Jan  3 02:08:30 2004
+++ 2.5-sparc-smp/include/asm-sparc/page.h	Sat Jan  3 02:11:28 2004
@@ -54,7 +54,7 @@
 
 #define SPARC_PHYS_BANKS 32
 
-extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS];
+extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
 
 /* Cache alias structure.  Entry is valid if context != -1. */
 struct cache_palias {
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/include/asm-sparc/pgtsrmmu.h 2.5-sparc-smp/include/asm-sparc/pgtsrmmu.h
--- 2.5-sparc/include/asm-sparc/pgtsrmmu.h	Sat Jan  3 02:08:30 2004
+++ 2.5-sparc-smp/include/asm-sparc/pgtsrmmu.h	Sat Jan  3 02:11:28 2004
@@ -109,6 +109,13 @@
 
 #ifndef __ASSEMBLY__
 
+/* This makes sense. Honest it does - Anton */
+/* XXX Yes but it's ugly as sin.  FIXME. -KMW */
+extern void *srmmu_nocache_pool;
+#define __nocache_pa(VADDR) (((unsigned long)VADDR) - SRMMU_NOCACHE_VADDR + __pa((unsigned long)srmmu_nocache_pool))
+#define __nocache_va(PADDR) (__va((unsigned long)PADDR) - (unsigned long)srmmu_nocache_pool + SRMMU_NOCACHE_VADDR)
+#define __nocache_fix(VADDR) __va(__nocache_pa(VADDR))
+
 /* Accessing the MMU control register. */
 extern __inline__ unsigned int srmmu_get_mmureg(void)
 {
diff -Nur --exclude=RCS --exclude=CVS --exclude=SCCS --exclude=BitKeeper --exclude=ChangeSet 2.5-sparc/include/asm-sparc/vaddrs.h 2.5-sparc-smp/include/asm-sparc/vaddrs.h
--- 2.5-sparc/include/asm-sparc/vaddrs.h	Sat Jan  3 02:08:30 2004
+++ 2.5-sparc-smp/include/asm-sparc/vaddrs.h	Sat Jan  3 02:11:28 2004
@@ -16,6 +16,9 @@
 
 #define SRMMU_NOCACHE_VADDR	(KERNBASE + SRMMU_MAXMEM)
 				/* = 0x0fc000000 */
+/* XXX Empiricals - this needs to go away - KMW */
+#define SRMMU_MIN_NOCACHE_PAGES (550)
+#define SRMMU_MAX_NOCACHE_PAGES	(1280)
 
 /* The following constant is used in mm/srmmu.c::srmmu_nocache_calcsize()
  * to determine the amount of memory that will be reserved as nocache:


-- 
Keith M Wesolowski <wesolows@foobazco.org> http://foobazco.org/~wesolows
------(( Project Foobazco Coordinator and Network Administrator ))------
	"May Buddha bless all stubborn people!"
				-- Uliassutai Karakorum Blake

Re: [SPARC32] Fix BUG-on-swapout

[David S. Miller]

On Mon, 5 Jan 2004 20:08:05 -0800
Keith M Wesolowski <wesolows@foobazco.org> wrote:

> This fixes BUG-on-swapout for srmmu-based systems.  The problem is
> caused by kmap_atomic_to_page being fed an aliased (pagetable) address
> and returning bogons.  This also adjusts the pkmap and fixmap base
> addresses so they cannot overlap.
> 
> Dave, unless it's braindead, please apply.

Looks good, I'll apply.

Thanks Keith.

Re: [SPARC32] Fix BUG-on-swapout

[Pete Zaitcev]

On Mon, Jan 05, 2004 at 08:08:05PM -0800, Keith M Wesolowski wrote:
> 
> This fixes BUG-on-swapout for srmmu-based systems.  The problem is
> caused by kmap_atomic_to_page being fed an aliased (pagetable) address
> and returning bogons.  This also adjusts the pkmap and fixmap base
> addresses so they cannot overlap.

Go, Keith!

> --- 2.5-sparc/arch/sparc/mm/fault.c	Sat Jan  3 02:08:08 2004
> +++ 2.5-sparc-smp/arch/sparc/mm/fault.c	Sat Jan  3 02:11:02 2004
> @@ -36,7 +36,7 @@
>  
>  #define ELEMENTS(arr) (sizeof (arr)/sizeof (arr[0]))
>  
> -extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS];
> +extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
>  extern int prom_node_root;
>  
>  /* At boot time we determine these two values necessary for setting

> --- 2.5-sparc/include/asm-sparc/page.h	Sat Jan  3 02:08:30 2004
> +++ 2.5-sparc-smp/include/asm-sparc/page.h	Sat Jan  3 02:11:28 2004
> @@ -54,7 +54,7 @@
>  
>  #define SPARC_PHYS_BANKS 32
>  
> -extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS];
> +extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
>  
>  /* Cache alias structure.  Entry is valid if context != -1. */
>  struct cache_palias {

Seems that the first one can be just removed altogether,
since you're on it.

> --- 2.5-sparc/include/asm-sparc/kmap_types.h	Sat Jan  3 02:08:30 2004
> +++ 2.5-sparc-smp/include/asm-sparc/kmap_types.h	Sat Jan  3 02:11:28 2004
> @@ -11,6 +11,7 @@
>  	KM_BIO_DST_IRQ,
>  	KM_PTE0,
>  	KM_PTE1,
> +	KM_PTE2,
>  	KM_IRQ0,
>  	KM_IRQ1,
>  	KM_SOFTIRQ0,

Is this needed for anything?

-- Pete

Re: [SPARC32] Fix BUG-on-swapout

[Keith M Wesolowski]

On Mon, Jan 05, 2004 at 11:55:44PM -0500, Pete Zaitcev wrote:

> > -extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS];
> > +extern struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
> 
> Seems that the first one can be just removed altogether,
> since you're on it.

Yes, you're right.  I'll nuke it in my next go-round with mm.  Thanks.

> > +	KM_PTE2,
> 
> Is this needed for anything?

Not at the moment.  It is used on other arches for HIGHPTE however.
Thus far I've not dreamed up a sane way to implement that, but a fresh
batch of srmmu mushrooms just came in so I'm optimistic. :-)

The options I've considered:

Uncache-in-place.  We can't do large mappings, which wastes memory and
blows TLB locality to hell.

Uncache-in-place for user pagetables, allocate the kernel pagetables
from an uncached block as we do now.  This effectively requires user
pagetables in highmem, which not all boxes have.

Abuse the zone allocator to force pagetable allocations to come from
preassigned regions which are either small-mapped (kernel pte) or
unmapped (HIGHPTE for user pagetables).  Uncache these in place.
Incredibly evil, needlessly complex, and you can still run out.

The 2.2 way.

Leave it the way it is and put in a less fragmentation-happy
allocator.  Sorry, no HIGHPTE.

Please drop your ideas in the suggestion box.  Thanks.

-- 
Keith M Wesolowski <wesolows@foobazco.org> http://foobazco.org/~wesolows
------(( Project Foobazco Coordinator and Network Administrator ))------
	"May Buddha bless all stubborn people!"
				-- Uliassutai Karakorum Blake