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Commit 8cf1a743 authored by Paul Mundt's avatar Paul Mundt
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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: default avatarPaul Mundt <lethal@linux-sh.org>
parent f695baf2

arch/sh/mm/cache-sh4.c

+0 −11
Original line number Diff line number Diff line
@@ -77,16 +77,8 @@ static void __init emit_cache_params(void) 
/*

 * SH-4 has virtually indexed and physically tagged cache.

 */



/* Worst case assumed to be 64k cache, direct-mapped i.e. 4 synonym bits. */

#define MAX_P3_MUTEXES 16



struct mutex p3map_mutex[MAX_P3_MUTEXES];



void __init p3_cache_init(void)

{

	int i;



	compute_alias(&current_cpu_data.icache);

	compute_alias(&current_cpu_data.dcache);
@@ -109,9 +101,6 @@ void __init p3_cache_init(void) 


	if (ioremap_page_range(P3SEG, P3SEG + (PAGE_SIZE * 4), 0, PAGE_KERNEL))

		panic("%s failed.", __FUNCTION__);



	for (i = 0; i < current_cpu_data.dcache.n_aliases; i++)

		mutex_init(&p3map_mutex[i]);

}



/*

arch/sh/mm/pg-sh4.c

+34 −41
Original line number Diff line number Diff line
@@ -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 @@ void clear_user_page(void *to, unsigned long address, struct page *page) 
	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 @@ void copy_user_page(void *to, void *from, unsigned long address, 
	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);

	}

}

include/asm-sh/fixmap.h

+5 −3
Original line number Diff line number Diff line
@@ -46,6 +46,9 @@ 
 * fix-mapped?

 */

enum fixed_addresses {

#define FIX_N_COLOURS 16

	FIX_CMAP_BEGIN,

	FIX_CMAP_END = FIX_CMAP_BEGIN + FIX_N_COLOURS,

#ifdef CONFIG_HIGHMEM

	FIX_KMAP_BEGIN,	/* reserved pte's for temporary kernel mappings */

	FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
@@ -106,5 +109,4 @@ 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