[POWERPC] Fix spu SLB invalidations

The SPU code doesn't properly invalidate SPUs SLBs when necessary,
for example when changing a segment size from the hugetlbfs code. In
addition, it saves and restores the SLB content on context switches
which makes it harder to properly handle those invalidations.

This patch removes the saving & restoring for now, something more
efficient might be found later on. It also adds a spu_flush_all_slbs(mm)
that can be used by the core mm code to flush the SLBs of all SPEs that
are running a given mm at the time of the flush.

In order to do that, it adds a spinlock to the list of all SPEs and move
some bits & pieces from spufs to spu_base.c

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 5 insertions, 70 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index 7dbf57c3028..39823cec084 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -127,14 +127,6 @@ static void spu_remove_from_active_list(struct spu *spu)
 	mutex_unlock(&spu_prio->active_mutex[node]);
 }
 
-static inline void mm_needs_global_tlbie(struct mm_struct *mm)
-{
-	int nr = (NR_CPUS > 1) ? NR_CPUS : NR_CPUS + 1;
-
-	/* Global TLBIE broadcast required with SPEs. */
-	__cpus_setall(&mm->cpu_vm_mask, nr);
-}
-
 static BLOCKING_NOTIFIER_HEAD(spu_switch_notifier);
 
 static void spu_switch_notify(struct spu *spu, struct spu_context *ctx)
@@ -167,8 +159,7 @@ static void spu_bind_context(struct spu *spu, struct spu_context *ctx)
 	ctx->spu = spu;
 	ctx->ops = &spu_hw_ops;
 	spu->pid = current->pid;
-	spu->mm = ctx->owner;
-	mm_needs_global_tlbie(spu->mm);
+	spu_associate_mm(spu, ctx->owner);
 	spu->ibox_callback = spufs_ibox_callback;
 	spu->wbox_callback = spufs_wbox_callback;
 	spu->stop_callback = spufs_stop_callback;
@@ -205,7 +196,7 @@ static void spu_unbind_context(struct spu *spu, struct spu_context *ctx)
 	spu->stop_callback = NULL;
 	spu->mfc_callback = NULL;
 	spu->dma_callback = NULL;
-	spu->mm = NULL;
+	spu_associate_mm(spu, NULL);
 	spu->pid = 0;
 	ctx->ops = &spu_backing_ops;
 	ctx->spu = NULL;
diff --git a/arch/powerpc/platforms/cell/spufs/switch.c b/arch/powerpc/platforms/cell/spufs/switch.c
index c08981ff7fc..fd91c73de34 100644
--- a/arch/powerpc/platforms/cell/spufs/switch.c
+++ b/arch/powerpc/platforms/cell/spufs/switch.c
@@ -468,26 +468,6 @@ static inline void wait_purge_complete(struct spu_state *csa, struct spu *spu)
 			 MFC_CNTL_PURGE_DMA_COMPLETE);
 }
 
-static inline void save_mfc_slbs(struct spu_state *csa, struct spu *spu)
-{
-	struct spu_priv2 __iomem *priv2 = spu->priv2;
-	int i;
-
-	/* Save, Step 29:
-	 *     If MFC_SR1[R]='1', save SLBs in CSA.
-	 */
-	if (spu_mfc_sr1_get(spu) & MFC_STATE1_RELOCATE_MASK) {
-		csa->priv2.slb_index_W = in_be64(&priv2->slb_index_W);
-		for (i = 0; i < 8; i++) {
-			out_be64(&priv2->slb_index_W, i);
-			eieio();
-			csa->slb_esid_RW[i] = in_be64(&priv2->slb_esid_RW);
-			csa->slb_vsid_RW[i] = in_be64(&priv2->slb_vsid_RW);
-			eieio();
-		}
-	}
-}
-
 static inline void setup_mfc_sr1(struct spu_state *csa, struct spu *spu)
 {
 	/* Save, Step 30:
@@ -708,20 +688,6 @@ static inline void resume_mfc_queue(struct spu_state *csa, struct spu *spu)
 	out_be64(&priv2->mfc_control_RW, MFC_CNTL_RESUME_DMA_QUEUE);
 }
 
-static inline void invalidate_slbs(struct spu_state *csa, struct spu *spu)
-{
-	struct spu_priv2 __iomem *priv2 = spu->priv2;
-
-	/* Save, Step 45:
-	 * Restore, Step 19:
-	 *     If MFC_SR1[R]=1, write 0 to SLB_Invalidate_All.
-	 */
-	if (spu_mfc_sr1_get(spu) & MFC_STATE1_RELOCATE_MASK) {
-		out_be64(&priv2->slb_invalidate_all_W, 0UL);
-		eieio();
-	}
-}
-
 static inline void get_kernel_slb(u64 ea, u64 slb[2])
 {
 	u64 llp;
@@ -765,7 +731,7 @@ static inline void setup_mfc_slbs(struct spu_state *csa, struct spu *spu)
 	 *     MFC_SR1[R]=1 (in other words, assume that
 	 *     translation is desired by OS environment).
 	 */
-	invalidate_slbs(csa, spu);
+	spu_invalidate_slbs(spu);
 	get_kernel_slb((unsigned long)&spu_save_code[0], code_slb);
 	get_kernel_slb((unsigned long)csa->lscsa, lscsa_slb);
 	load_mfc_slb(spu, code_slb, 0);
@@ -1718,27 +1684,6 @@ static inline void check_ppuint_mb_stat(struct spu_state *csa, struct spu *spu)
 	}
 }
 
-static inline void restore_mfc_slbs(struct spu_state *csa, struct spu *spu)
-{
-	struct spu_priv2 __iomem *priv2 = spu->priv2;
-	int i;
-
-	/* Restore, Step 68:
-	 *     If MFC_SR1[R]='1', restore SLBs from CSA.
-	 */
-	if (csa->priv1.mfc_sr1_RW & MFC_STATE1_RELOCATE_MASK) {
-		for (i = 0; i < 8; i++) {
-			out_be64(&priv2->slb_index_W, i);
-			eieio();
-			out_be64(&priv2->slb_esid_RW, csa->slb_esid_RW[i]);
-			out_be64(&priv2->slb_vsid_RW, csa->slb_vsid_RW[i]);
-			eieio();
-		}
-		out_be64(&priv2->slb_index_W, csa->priv2.slb_index_W);
-		eieio();
-	}
-}
-
 static inline void restore_mfc_sr1(struct spu_state *csa, struct spu *spu)
 {
 	/* Restore, Step 69:
@@ -1875,7 +1820,6 @@ static void save_csa(struct spu_state *prev, struct spu *spu)
 	set_mfc_tclass_id(prev, spu);	/* Step 26. */
 	purge_mfc_queue(prev, spu);	/* Step 27. */
 	wait_purge_complete(prev, spu);	/* Step 28. */
-	save_mfc_slbs(prev, spu);	/* Step 29. */
 	setup_mfc_sr1(prev, spu);	/* Step 30. */
 	save_spu_npc(prev, spu);	/* Step 31. */
 	save_spu_privcntl(prev, spu);	/* Step 32. */
@@ -1987,7 +1931,7 @@ static void harvest(struct spu_state *prev, struct spu *spu)
 	reset_spu_privcntl(prev, spu);	        /* Step 16. */
 	reset_spu_lslr(prev, spu);              /* Step 17. */
 	setup_mfc_sr1(prev, spu);	        /* Step 18. */
-	invalidate_slbs(prev, spu);	        /* Step 19. */
+	spu_invalidate_slbs(spu);        	/* Step 19. */
 	reset_ch_part1(prev, spu);	        /* Step 20. */
 	reset_ch_part2(prev, spu);	        /* Step 21. */
 	enable_interrupts(prev, spu);	        /* Step 22. */
@@ -2055,7 +1999,7 @@ static void restore_csa(struct spu_state *next, struct spu *spu)
 	restore_spu_mb(next, spu);	        /* Step 65. */
 	check_ppu_mb_stat(next, spu);	        /* Step 66. */
 	check_ppuint_mb_stat(next, spu);	/* Step 67. */
-	restore_mfc_slbs(next, spu);	        /* Step 68. */
+	spu_invalidate_slbs(spu);		/* Modified Step 68. */
 	restore_mfc_sr1(next, spu);	        /* Step 69. */
 	restore_other_spu_access(next, spu);	/* Step 70. */
 	restore_spu_runcntl(next, spu);	        /* Step 71. */