[POWERPC] cell: handle SPE kernel mappings that cross segment boundaries

Currently, we have a possibilty that the SLBs setup during context
switch don't cover the entirety of the necessary lscsa and code
regions, if these regions cross a segment boundary.

This change checks the start and end of each region, and inserts a SLB
entry for each, if unique. We also remove the assumption that the
spu_save_code and spu_restore_code reside in the same segment, by using
the specific code array for save and restore.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 7 insertions, 4 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/switch.c b/arch/powerpc/platforms/cell/spufs/switch.c
index 96f55148a408..8cbc6574820f 100644
--- a/arch/powerpc/platforms/cell/spufs/switch.c
+++ b/arch/powerpc/platforms/cell/spufs/switch.c
@@ -691,7 +691,8 @@ 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 setup_mfc_slbs(struct spu_state *csa, struct spu *spu)
+static inline void setup_mfc_slbs(struct spu_state *csa, struct spu *spu,
+                unsigned int *code, int code_size)
 {
         /* Save, Step 47:
          * Restore, Step 30.
@@ -708,7 +709,7 @@ static inline void setup_mfc_slbs(struct spu_state *csa, struct spu *spu)
          *     translation is desired by OS environment).
          */
         spu_invalidate_slbs(spu);
-        spu_setup_kernel_slbs(spu, csa->lscsa, &spu_save_code);
+        spu_setup_kernel_slbs(spu, csa->lscsa, code, code_size);
 }
 
 static inline void set_switch_active(struct spu_state *csa, struct spu *spu)
@@ -1835,7 +1836,8 @@ static void save_lscsa(struct spu_state *prev, struct spu *spu)
          */
 
         resume_mfc_queue(prev, spu);    /* Step 46. */
-        setup_mfc_slbs(prev, spu);      /* Step 47. */
+        /* Step 47. */
+        setup_mfc_slbs(prev, spu, spu_save_code, sizeof(spu_save_code));
         set_switch_active(prev, spu);   /* Step 48. */
         enable_interrupts(prev, spu);   /* Step 49. */
         save_ls_16kb(prev, spu);        /* Step 50. */
@@ -1940,7 +1942,8 @@ static void restore_lscsa(struct spu_state *next, struct spu *spu)
         setup_spu_status_part1(next, spu);      /* Step 27. */
         setup_spu_status_part2(next, spu);      /* Step 28. */
         restore_mfc_rag(next, spu);             /* Step 29. */
-        setup_mfc_slbs(next, spu);              /* Step 30. */
+        /* Step 30. */
+        setup_mfc_slbs(next, spu, spu_restore_code, sizeof(spu_restore_code));
         set_spu_npc(next, spu);                 /* Step 31. */
         set_signot1(next, spu);                 /* Step 32. */
         set_signot2(next, spu);                 /* Step 33. */