Commit c13066e5 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/nohash: Remove CONFIG_SMP #ifdefery in mmu_context.h 



Everything can be done even when CONFIG_SMP is not selected.

Just use IS_ENABLED() where relevant and rely on GCC to
opt out unneeded code and variables when CONFIG_SMP is not set.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/cc13b87b0f750a538621876ecc24c22a07e7c8be.1622712515.git.christophe.leroy@csgroup.eu
parent a56ab7c7

arch/powerpc/mm/nohash/mmu_context.c

+24 −42
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ 


#include <asm/mmu_context.h>

#include <asm/tlbflush.h>

#include <asm/smp.h>



#include <mm/mmu_decl.h>
@@ -86,9 +87,7 @@ void *abatron_pteptrs[2]; 


static unsigned int next_context, nr_free_contexts;

static unsigned long *context_map;

#ifdef CONFIG_SMP

static unsigned long *stale_map[NR_CPUS];

#endif

static struct mm_struct **context_mm;

static DEFINE_RAW_SPINLOCK(context_lock);
@@ -111,7 +110,6 @@ static DEFINE_RAW_SPINLOCK(context_lock); 
 * the stale map as we can just flush the local CPU

 *  -- benh

 */

#ifdef CONFIG_SMP

static unsigned int steal_context_smp(unsigned int id)

{

	struct mm_struct *mm;
@@ -164,14 +162,11 @@ static unsigned int steal_context_smp(unsigned int id) 
	/* This will cause the caller to try again */

	return MMU_NO_CONTEXT;

}

#endif  /* CONFIG_SMP */



static unsigned int steal_all_contexts(void)

{

	struct mm_struct *mm;

#ifdef CONFIG_SMP

	int cpu = smp_processor_id();

#endif

	unsigned int id;



	for (id = FIRST_CONTEXT; id <= LAST_CONTEXT; id++) {
@@ -189,9 +184,8 @@ static unsigned int steal_all_contexts(void) 
			mm->context.active = 0;

#endif

		}

#ifdef CONFIG_SMP

		if (IS_ENABLED(CONFIG_SMP))

			__clear_bit(id, stale_map[cpu]);

#endif

	}



	/* Flush the TLB for all contexts (not to be used on SMP) */
@@ -210,9 +204,7 @@ static unsigned int steal_all_contexts(void) 
static unsigned int steal_context_up(unsigned int id)

{

	struct mm_struct *mm;

#ifdef CONFIG_SMP

	int cpu = smp_processor_id();

#endif



	/* Pick up the victim mm */

	mm = context_mm[id];
@@ -226,9 +218,8 @@ static unsigned int steal_context_up(unsigned int id) 
	mm->context.id = MMU_NO_CONTEXT;



	/* XXX This clear should ultimately be part of local_flush_tlb_mm */

#ifdef CONFIG_SMP

	if (IS_ENABLED(CONFIG_SMP))

		__clear_bit(id, stale_map[cpu]);

#endif



	return id;

}
@@ -295,9 +286,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, 
			struct task_struct *tsk)

{

	unsigned int id;

#ifdef CONFIG_SMP

	unsigned int i, cpu = smp_processor_id();

#endif

	unsigned long *map;



	/* No lockless fast path .. yet */
@@ -306,7 +295,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, 
	pr_hard("[%d] activating context for mm @%p, active=%d, id=%d",

		cpu, next, next->context.active, next->context.id);



#ifdef CONFIG_SMP

	if (IS_ENABLED(CONFIG_SMP)) {

		/* Mark us active and the previous one not anymore */

		next->context.active++;

		if (prev) {
@@ -314,9 +303,9 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, 
			WARN_ON(prev->context.active < 1);

			prev->context.active--;

		}

	}



 again:

#endif /* CONFIG_SMP */



	/* If we already have a valid assigned context, skip all that */

	id = next->context.id;
@@ -337,14 +326,12 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, 


	/* No more free contexts, let's try to steal one */

	if (nr_free_contexts == 0) {

#ifdef CONFIG_SMP

		if (num_online_cpus() > 1) {

			id = steal_context_smp(id);

			if (id == MMU_NO_CONTEXT)

				goto again;

			goto stolen;

		}

#endif /* CONFIG_SMP */

		if (IS_ENABLED(CONFIG_PPC_8xx))

			id = steal_all_contexts();

		else
@@ -371,8 +358,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, 
	/* If that context got marked stale on this CPU, then flush the

	 * local TLB for it and unmark it before we use it

	 */

#ifdef CONFIG_SMP

	if (test_bit(id, stale_map[cpu])) {

	if (IS_ENABLED(CONFIG_SMP) && test_bit(id, stale_map[cpu])) {

		pr_hardcont(" | stale flush %d [%d..%d]",

			    id, cpu_first_thread_sibling(cpu),

			    cpu_last_thread_sibling(cpu));
@@ -386,7 +372,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, 
				__clear_bit(id, stale_map[i]);

		}

	}

#endif



	/* Flick the MMU and release lock */

	pr_hardcont(" -> %d\n", id);
@@ -445,7 +430,6 @@ void destroy_context(struct mm_struct *mm) 
	raw_spin_unlock_irqrestore(&context_lock, flags);

}



#ifdef CONFIG_SMP

static int mmu_ctx_cpu_prepare(unsigned int cpu)

{

	/* We don't touch CPU 0 map, it's allocated at aboot and kept
@@ -475,8 +459,6 @@ static int mmu_ctx_cpu_dead(unsigned int cpu) 
	return 0;

}



#endif /* CONFIG_SMP */



/*

 * Initialize the context management stuff.

 */
@@ -500,7 +482,7 @@ void __init mmu_context_init(void) 
	if (!context_mm)

		panic("%s: Failed to allocate %zu bytes\n", __func__,

		      sizeof(void *) * (LAST_CONTEXT + 1));

#ifdef CONFIG_SMP

	if (IS_ENABLED(CONFIG_SMP)) {

		stale_map[boot_cpuid] = memblock_alloc(CTX_MAP_SIZE, SMP_CACHE_BYTES);

		if (!stale_map[boot_cpuid])

			panic("%s: Failed to allocate %zu bytes\n", __func__,
@@ -509,7 +491,7 @@ void __init mmu_context_init(void) 
		cpuhp_setup_state_nocalls(CPUHP_POWERPC_MMU_CTX_PREPARE,

					  "powerpc/mmu/ctx:prepare",

					  mmu_ctx_cpu_prepare, mmu_ctx_cpu_dead);

#endif

	}



	printk(KERN_INFO

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