sh: Add kmap_coherent()/kunmap_coherent() interface for SH-4.
This wires up kmap_coherent() and kunmap_coherent() on SH-4, and
moves away from the p3map_mutex and reserved P3 space, opting to
use fixmaps for colouring instead.
The copy_user_page()/clear_user_page() implementations are moved
to this, which fixes the nasty blowups with spinlock debugging
as a result of having some of these calls nested under the page
table lock.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/mm/pg-sh4.c b/arch/sh/mm/pg-sh4.c
index df69da9..82b48e6 100644
--- a/arch/sh/mm/pg-sh4.c
+++ b/arch/sh/mm/pg-sh4.c
@@ -2,7 +2,7 @@
* arch/sh/mm/pg-sh4.c
*
* Copyright (C) 1999, 2000, 2002 Niibe Yutaka
- * Copyright (C) 2002 - 2005 Paul Mundt
+ * Copyright (C) 2002 - 2007 Paul Mundt
*
* Released under the terms of the GNU GPL v2.0.
*/
@@ -11,10 +11,35 @@
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>
-extern struct mutex p3map_mutex[];
-
#define CACHE_ALIAS (current_cpu_data.dcache.alias_mask)
+static inline void *kmap_coherent(struct page *page, unsigned long addr)
+{
+ enum fixed_addresses idx;
+ unsigned long vaddr, flags;
+ pte_t pte;
+
+ inc_preempt_count();
+
+ idx = (addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT;
+ vaddr = __fix_to_virt(FIX_CMAP_END - idx);
+ pte = mk_pte(page, PAGE_KERNEL);
+
+ local_irq_save(flags);
+ flush_tlb_one(get_asid(), vaddr);
+ local_irq_restore(flags);
+
+ update_mmu_cache(NULL, vaddr, pte);
+
+ return (void *)vaddr;
+}
+
+static inline void kunmap_coherent(struct page *page)
+{
+ dec_preempt_count();
+ preempt_check_resched();
+}
+
/*
* clear_user_page
* @to: P1 address
@@ -27,25 +52,9 @@
if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)
clear_page(to);
else {
- unsigned long phys_addr = PHYSADDR(to);
- unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);
- pgd_t *pgd = pgd_offset_k(p3_addr);
- pud_t *pud = pud_offset(pgd, p3_addr);
- pmd_t *pmd = pmd_offset(pud, p3_addr);
- pte_t *pte = pte_offset_kernel(pmd, p3_addr);
- pte_t entry;
- unsigned long flags;
-
- entry = pfn_pte(phys_addr >> PAGE_SHIFT, PAGE_KERNEL);
- mutex_lock(&p3map_mutex[(address & CACHE_ALIAS)>>12]);
- set_pte(pte, entry);
- local_irq_save(flags);
- flush_tlb_one(get_asid(), p3_addr);
- local_irq_restore(flags);
- update_mmu_cache(NULL, p3_addr, entry);
- __clear_user_page((void *)p3_addr, to);
- pte_clear(&init_mm, p3_addr, pte);
- mutex_unlock(&p3map_mutex[(address & CACHE_ALIAS)>>12]);
+ void *vto = kmap_coherent(page, address);
+ __clear_user_page(vto, to);
+ kunmap_coherent(vto);
}
}
@@ -63,25 +72,9 @@
if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)
copy_page(to, from);
else {
- unsigned long phys_addr = PHYSADDR(to);
- unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);
- pgd_t *pgd = pgd_offset_k(p3_addr);
- pud_t *pud = pud_offset(pgd, p3_addr);
- pmd_t *pmd = pmd_offset(pud, p3_addr);
- pte_t *pte = pte_offset_kernel(pmd, p3_addr);
- pte_t entry;
- unsigned long flags;
-
- entry = pfn_pte(phys_addr >> PAGE_SHIFT, PAGE_KERNEL);
- mutex_lock(&p3map_mutex[(address & CACHE_ALIAS)>>12]);
- set_pte(pte, entry);
- local_irq_save(flags);
- flush_tlb_one(get_asid(), p3_addr);
- local_irq_restore(flags);
- update_mmu_cache(NULL, p3_addr, entry);
- __copy_user_page((void *)p3_addr, from, to);
- pte_clear(&init_mm, p3_addr, pte);
- mutex_unlock(&p3map_mutex[(address & CACHE_ALIAS)>>12]);
+ void *vfrom = kmap_coherent(page, address);
+ __copy_user_page(vfrom, from, to);
+ kunmap_coherent(vfrom);
}
}