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Commit 067784f6 authored by Matt Fleming's avatar Matt Fleming Committed by Paul Mundt
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sh: Allocate PMB entry slot earlier 



Simplify set_pmb_entry() by removing the possibility of not finding a
free slot in the PMB. Instead we now allocate a slot in pmb_alloc() so
that if there are no free slots we fail at allocation time, rather than
in set_pmb_entry().

Signed-off-by: default avatarMatt Fleming <matt@console-pimps.org>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 5e3679c5

arch/sh/mm/pmb.c

+39 −41
Original line number Diff line number Diff line
@@ -99,10 +99,31 @@ static inline void pmb_list_del(struct pmb_entry *pmbe) 
		}

}



static int pmb_alloc_entry(void)

{

	unsigned int pos;



repeat:

	pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);



	if (unlikely(pos > NR_PMB_ENTRIES))

		return -ENOSPC;



	if (test_and_set_bit(pos, &pmb_map))

		goto repeat;



	return pos;

}



struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,

			    unsigned long flags)

{

	struct pmb_entry *pmbe;

	int pos;



	pos = pmb_alloc_entry();

	if (pos < 0)

		return ERR_PTR(pos);



	pmbe = kmem_cache_alloc(pmb_cache, GFP_KERNEL);

	if (!pmbe)
@@ -111,6 +132,7 @@ struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn, 
	pmbe->vpn	= vpn;

	pmbe->ppn	= ppn;

	pmbe->flags	= flags;

	pmbe->entry	= pos;



	spin_lock_irq(&pmb_list_lock);

	pmb_list_add(pmbe);
@@ -131,23 +153,9 @@ void pmb_free(struct pmb_entry *pmbe) 
/*

 * Must be in P2 for __set_pmb_entry()

 */

int __set_pmb_entry(unsigned long vpn, unsigned long ppn,

		    unsigned long flags, int *entry)

void __set_pmb_entry(unsigned long vpn, unsigned long ppn,

		    unsigned long flags, int pos)

{

	unsigned int pos = *entry;



	if (unlikely(pos == PMB_NO_ENTRY))

		pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);



repeat:

	if (unlikely(pos > NR_PMB_ENTRIES))

		return -ENOSPC;



	if (test_and_set_bit(pos, &pmb_map)) {

		pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);

		goto repeat;

	}



	ctrl_outl(vpn | PMB_V, mk_pmb_addr(pos));



#ifdef CONFIG_CACHE_WRITETHROUGH
@@ -161,21 +169,13 @@ int __set_pmb_entry(unsigned long vpn, unsigned long ppn, 
#endif



	ctrl_outl(ppn | flags | PMB_V, mk_pmb_data(pos));



	*entry = pos;



	return 0;

}



int __uses_jump_to_uncached set_pmb_entry(struct pmb_entry *pmbe)

void __uses_jump_to_uncached set_pmb_entry(struct pmb_entry *pmbe)

{

	int ret;



	jump_to_uncached();

	ret = __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &pmbe->entry);

	__set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, pmbe->entry);

	back_to_cached();



	return ret;

}



void __uses_jump_to_uncached clear_pmb_entry(struct pmb_entry *pmbe)
@@ -239,8 +239,6 @@ long pmb_remap(unsigned long vaddr, unsigned long phys, 


again:

	for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++) {

		int ret;



		if (size < pmb_sizes[i].size)

			continue;
@@ -250,12 +248,7 @@ long pmb_remap(unsigned long vaddr, unsigned long phys, 
			goto out;

		}



		ret = set_pmb_entry(pmbe);

		if (ret != 0) {

			pmb_free(pmbe);

			err = -EBUSY;

			goto out;

		}

		set_pmb_entry(pmbe);



		phys	+= pmb_sizes[i].size;

		vaddr	+= pmb_sizes[i].size;
@@ -311,7 +304,16 @@ static void __pmb_unmap(struct pmb_entry *pmbe) 
	do {

		struct pmb_entry *pmblink = pmbe;



		if (pmbe->entry != PMB_NO_ENTRY)

		/*

		 * We may be called before this pmb_entry has been

		 * entered into the PMB table via set_pmb_entry(), but

		 * that's OK because we've allocated a unique slot for

		 * this entry in pmb_alloc() (even if we haven't filled

		 * it yet).

		 *

		 * Therefore, calling clear_pmb_entry() is safe as no

		 * other mapping can be using that slot.

		 */

		clear_pmb_entry(pmbe);



		pmbe = pmblink->link;
@@ -322,11 +324,7 @@ static void __pmb_unmap(struct pmb_entry *pmbe) 


static void pmb_cache_ctor(void *pmb)

{

	struct pmb_entry *pmbe = pmb;



	memset(pmb, 0, sizeof(struct pmb_entry));



	pmbe->entry = PMB_NO_ENTRY;

}



static int __uses_jump_to_uncached pmb_init(void)
@@ -349,7 +347,7 @@ static int __uses_jump_to_uncached pmb_init(void) 
	for (entry = 0; entry < nr_entries; entry++) {

		struct pmb_entry *pmbe = pmb_init_map + entry;



		__set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &entry);

		__set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, entry);

	}



	ctrl_outl(0, PMB_IRMCR);