From: Jeremy Kerr Date: Wed, 5 Dec 2007 02:49:31 +0000 (+1100) Subject: [POWERPC] cell: handle SPE kernel mappings that cross segment boundaries X-Git-Tag: v2.6.25-rc1~1131^2~275^2~1 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=684bd614015188561197342fd336292e9e2ce196;p=linux-2.6 [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 Signed-off-by: Arnd Bergmann --- diff --git a/arch/powerpc/platforms/cell/spu_base.c b/arch/powerpc/platforms/cell/spu_base.c index 95001cdfaa..ee37e0e39b 100644 --- a/arch/powerpc/platforms/cell/spu_base.c +++ b/arch/powerpc/platforms/cell/spu_base.c @@ -274,20 +274,56 @@ static void __spu_kernel_slb(void *addr, struct spu_slb *slb) slb->esid = (ea & ESID_MASK) | SLB_ESID_V; } +/** + * Given an array of @nr_slbs SLB entries, @slbs, return non-zero if the + * address @new_addr is present. + */ +static inline int __slb_present(struct spu_slb *slbs, int nr_slbs, + void *new_addr) +{ + unsigned long ea = (unsigned long)new_addr; + int i; + + for (i = 0; i < nr_slbs; i++) + if (!((slbs[i].esid ^ ea) & ESID_MASK)) + return 1; + + return 0; +} + /** * Setup the SPU kernel SLBs, in preparation for a context save/restore. We * need to map both the context save area, and the save/restore code. + * + * Because the lscsa and code may cross segment boundaires, we check to see + * if mappings are required for the start and end of each range. We currently + * assume that the mappings are smaller that one segment - if not, something + * is seriously wrong. */ -void spu_setup_kernel_slbs(struct spu *spu, struct spu_lscsa *lscsa, void *code) +void spu_setup_kernel_slbs(struct spu *spu, struct spu_lscsa *lscsa, + void *code, int code_size) { - struct spu_slb code_slb, lscsa_slb; + struct spu_slb slbs[4]; + int i, nr_slbs = 0; + /* start and end addresses of both mappings */ + void *addrs[] = { + lscsa, (void *)lscsa + sizeof(*lscsa) - 1, + code, code + code_size - 1 + }; + + /* check the set of addresses, and create a new entry in the slbs array + * if there isn't already a SLB for that address */ + for (i = 0; i < ARRAY_SIZE(addrs); i++) { + if (__slb_present(slbs, nr_slbs, addrs[i])) + continue; - __spu_kernel_slb(lscsa, &lscsa_slb); - __spu_kernel_slb(code, &code_slb); + __spu_kernel_slb(addrs[i], &slbs[nr_slbs]); + nr_slbs++; + } - spu_load_slb(spu, 0, &lscsa_slb); - if (lscsa_slb.esid != code_slb.esid) - spu_load_slb(spu, 1, &code_slb); + /* Add the set of SLBs */ + for (i = 0; i < nr_slbs; i++) + spu_load_slb(spu, i, &slbs[i]); } EXPORT_SYMBOL_GPL(spu_setup_kernel_slbs); diff --git a/arch/powerpc/platforms/cell/spufs/switch.c b/arch/powerpc/platforms/cell/spufs/switch.c index 96f55148a4..8cbc657482 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. */ diff --git a/include/asm-powerpc/spu.h b/include/asm-powerpc/spu.h index 3308ed4933..314aad357d 100644 --- a/include/asm-powerpc/spu.h +++ b/include/asm-powerpc/spu.h @@ -201,8 +201,8 @@ int spu_irq_class_0_bottom(struct spu *spu); int spu_irq_class_1_bottom(struct spu *spu); void spu_irq_setaffinity(struct spu *spu, int cpu); -void spu_setup_kernel_slbs(struct spu *spu, - struct spu_lscsa *lscsa, void *code); +void spu_setup_kernel_slbs(struct spu *spu, struct spu_lscsa *lscsa, + void *code, int code_size); #ifdef CONFIG_KEXEC void crash_register_spus(struct list_head *list);