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Commit 8820a447 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/mm: constify FIRST_CONTEXT in mmu_context_nohash 



First context is now 1 for all supported platforms, so it
can be made a constant.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 9887334b

arch/powerpc/mm/mmu_context_nohash.c

+18 −19
Original line number Diff line number Diff line
@@ -54,7 +54,9 @@ 


#include "mmu_decl.h"



static unsigned int first_context, last_context;

#define FIRST_CONTEXT 1



static unsigned int last_context;

static unsigned int next_context, nr_free_contexts;

static unsigned long *context_map;

static unsigned long *stale_map[NR_CPUS];
@@ -87,7 +89,7 @@ static unsigned int steal_context_smp(unsigned int id) 
	struct mm_struct *mm;

	unsigned int cpu, max, i;



	max = last_context - first_context;

	max = last_context - FIRST_CONTEXT;



	/* Attempt to free next_context first and then loop until we manage */

	while (max--) {
@@ -100,7 +102,7 @@ static unsigned int steal_context_smp(unsigned int id) 
		if (mm->context.active) {

			id++;

			if (id > last_context)

				id = first_context;

				id = FIRST_CONTEXT;

			continue;

		}

		pr_hardcont(" | steal %d from 0x%p", id, mm);
@@ -142,7 +144,7 @@ static unsigned int steal_all_contexts(void) 
	int cpu = smp_processor_id();

	unsigned int id;



	for (id = first_context; id <= last_context; id++) {

	for (id = FIRST_CONTEXT; id <= last_context; id++) {

		/* Pick up the victim mm */

		mm = context_mm[id];
@@ -150,7 +152,7 @@ static unsigned int steal_all_contexts(void) 


		/* Mark this mm as having no context anymore */

		mm->context.id = MMU_NO_CONTEXT;

		if (id != first_context) {

		if (id != FIRST_CONTEXT) {

			context_mm[id] = NULL;

			__clear_bit(id, context_map);

#ifdef DEBUG_MAP_CONSISTENCY
@@ -163,9 +165,9 @@ static unsigned int steal_all_contexts(void) 
	/* Flush the TLB for all contexts (not to be used on SMP) */

	_tlbil_all();



	nr_free_contexts = last_context - first_context;

	nr_free_contexts = last_context - FIRST_CONTEXT;



	return first_context;

	return FIRST_CONTEXT;

}



/* Note that this will also be called on SMP if all other CPUs are
@@ -201,7 +203,7 @@ static void context_check_map(void) 
	unsigned int id, nrf, nact;



	nrf = nact = 0;

	for (id = first_context; id <= last_context; id++) {

	for (id = FIRST_CONTEXT; id <= last_context; id++) {

		int used = test_bit(id, context_map);

		if (!used)

			nrf++;
@@ -219,7 +221,7 @@ static void context_check_map(void) 
	if (nact > num_online_cpus())

		pr_err("MMU: More active contexts than CPUs ! (%d vs %d)\n",

		       nact, num_online_cpus());

	if (first_context > 0 && !test_bit(0, context_map))

	if (FIRST_CONTEXT > 0 && !test_bit(0, context_map))

		pr_err("MMU: Context 0 has been freed !!!\n");

}

#else
@@ -264,7 +266,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, 
	/* We really don't have a context, let's try to acquire one */

	id = next_context;

	if (id > last_context)

		id = first_context;

		id = FIRST_CONTEXT;

	map = context_map;



	/* No more free contexts, let's try to steal one */
@@ -289,7 +291,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, 
	while (__test_and_set_bit(id, map)) {

		id = find_next_zero_bit(map, last_context+1, id);

		if (id > last_context)

			id = first_context;

			id = FIRST_CONTEXT;

	}

 stolen:

	next_context = id + 1;
@@ -439,15 +441,12 @@ void __init mmu_context_init(void) 
	 *      -- BenH

	 */

	if (mmu_has_feature(MMU_FTR_TYPE_8xx)) {

		first_context = 1;

		last_context = 16;

		no_selective_tlbil = true;

	} else if (mmu_has_feature(MMU_FTR_TYPE_47x)) {

		first_context = 1;

		last_context = 65535;

		no_selective_tlbil = false;

	} else {

		first_context = 1;

		last_context = 255;

		no_selective_tlbil = false;

	}
@@ -473,16 +472,16 @@ void __init mmu_context_init(void) 
	printk(KERN_INFO

	       "MMU: Allocated %zu bytes of context maps for %d contexts\n",

	       2 * CTX_MAP_SIZE + (sizeof(void *) * (last_context + 1)),

	       last_context - first_context + 1);

	       last_context - FIRST_CONTEXT + 1);



	/*

	 * Some processors have too few contexts to reserve one for

	 * init_mm, and require using context 0 for a normal task.

	 * Other processors reserve the use of context zero for the kernel.

	 * This code assumes first_context < 32.

	 * This code assumes FIRST_CONTEXT < 32.

	 */

	context_map[0] = (1 << first_context) - 1;

	next_context = first_context;

	nr_free_contexts = last_context - first_context + 1;

	context_map[0] = (1 << FIRST_CONTEXT) - 1;

	next_context = FIRST_CONTEXT;

	nr_free_contexts = last_context - FIRST_CONTEXT + 1;

}