From 684bd614015188561197342fd336292e9e2ce196 Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Wed, 5 Dec 2007 13:49:31 +1100 Subject: [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 --- arch/powerpc/platforms/cell/spu_base.c | 50 +++++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 7 deletions(-) (limited to 'arch/powerpc/platforms/cell/spu_base.c') diff --git a/arch/powerpc/platforms/cell/spu_base.c b/arch/powerpc/platforms/cell/spu_base.c index 95001cdfaa2..ee37e0e39b6 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); -- cgit v1.2.3