| Message ID | 1414466730-15591-5-git-send-email-imunsie@au.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | eb01d4c2388ce3b5bcc120d0f72912117ed7599d |
| Delegated to: | Michael Ellerman |
| Headers | show |
Ian Munsie <imunsie@au1.ibm.com> writes: > From: Ian Munsie <imunsie@au1.ibm.com> > > In certain circumstances the PSL (Power Service Layer, which provides > translation services for CXL hardware) can send an interrupt for a > segment miss that the kernel has already handled. This can happen if > multiple translations for the same segment are queued in the PSL before > the kernel has restarted the first translation. > > The CXL driver does not expect this situation and does not check if a > segment had already been handled. This could cause a duplicate segment > table entry which in turn caused a PSL error taking down the card. > > This patch fixes the issue by checking for existing entries in the > segment table that match the segment it is trying to insert to avoid > inserting duplicate entries. > > This patch requires "powerpc/copro: Use appropriate ESID mask in > copro_calculate_slb" for the sste_matches function to operate correctly. > > Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> > --- > drivers/misc/cxl/fault.c | 28 ++++++++++++++++++++++------ > 1 file changed, 22 insertions(+), 6 deletions(-) > > diff --git a/drivers/misc/cxl/fault.c b/drivers/misc/cxl/fault.c > index cb4f323..c99e896 100644 > --- a/drivers/misc/cxl/fault.c > +++ b/drivers/misc/cxl/fault.c > @@ -21,11 +21,20 @@ > > #include "cxl.h" > > -/* This finds a free SSTE for the given SLB */ > +static bool sste_matches(struct cxl_sste *sste, struct copro_slb > *slb) inline ? > +{ > + return ((sste->vsid_data == cpu_to_be64(slb->vsid)) && > + (sste->esid_data == cpu_to_be64(slb->esid))); why comparing converting to big endian ? The natural way is to do it other way right ?. (be64_to_cpu(sste->vsid_data) == slb->vsid) > +} > + > +/* > + * This finds a free SSTE for the given SLB, or returns NULL if it's already in > + * the segment table. > + */ > static struct cxl_sste* find_free_sste(struct cxl_context *ctx, > struct copro_slb *slb) > { > - struct cxl_sste *primary, *sste; > + struct cxl_sste *primary, *sste, *ret = NULL; > unsigned int mask = (ctx->sst_size >> 7) - 1; /* SSTP0[SegTableSize] */ > unsigned int entry; > unsigned int hash; > @@ -38,15 +47,19 @@ static struct cxl_sste* find_free_sste(struct cxl_context *ctx, > primary = ctx->sstp + (hash << 3); > > for (entry = 0, sste = primary; entry < 8; entry++, sste++) { > - if (!(be64_to_cpu(sste->esid_data) & SLB_ESID_V)) > - return sste; > + if (!ret && !(be64_to_cpu(sste->esid_data) & SLB_ESID_V)) > + ret = sste; > + if (sste_matches(sste, slb)) > + return NULL; > } > + if (ret) > + return ret; > > /* Nothing free, select an entry to cast out */ > - sste = primary + ctx->sst_lru; > + ret = primary + ctx->sst_lru; > ctx->sst_lru = (ctx->sst_lru + 1) & 0x7; > > - return sste; > + return ret; > } > > static void cxl_load_segment(struct cxl_context *ctx, struct copro_slb *slb) > @@ -57,12 +70,15 @@ static void cxl_load_segment(struct cxl_context *ctx, struct copro_slb *slb) > > spin_lock_irqsave(&ctx->sste_lock, flags); > sste = find_free_sste(ctx, slb); > + if (!sste) > + goto out_unlock; > > pr_devel("CXL Populating SST[%li]: %#llx %#llx\n", > sste - ctx->sstp, slb->vsid, slb->esid); > > sste->vsid_data = cpu_to_be64(slb->vsid); > sste->esid_data = cpu_to_be64(slb->esid); > +out_unlock: > spin_unlock_irqrestore(&ctx->sste_lock, flags); > } > > -- > 2.1.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
diff --git a/drivers/misc/cxl/fault.c b/drivers/misc/cxl/fault.c index cb4f323..c99e896 100644 --- a/drivers/misc/cxl/fault.c +++ b/drivers/misc/cxl/fault.c @@ -21,11 +21,20 @@ #include "cxl.h" -/* This finds a free SSTE for the given SLB */ +static bool sste_matches(struct cxl_sste *sste, struct copro_slb *slb) +{ + return ((sste->vsid_data == cpu_to_be64(slb->vsid)) && + (sste->esid_data == cpu_to_be64(slb->esid))); +} + +/* + * This finds a free SSTE for the given SLB, or returns NULL if it's already in + * the segment table. + */ static struct cxl_sste* find_free_sste(struct cxl_context *ctx, struct copro_slb *slb) { - struct cxl_sste *primary, *sste; + struct cxl_sste *primary, *sste, *ret = NULL; unsigned int mask = (ctx->sst_size >> 7) - 1; /* SSTP0[SegTableSize] */ unsigned int entry; unsigned int hash; @@ -38,15 +47,19 @@ static struct cxl_sste* find_free_sste(struct cxl_context *ctx, primary = ctx->sstp + (hash << 3); for (entry = 0, sste = primary; entry < 8; entry++, sste++) { - if (!(be64_to_cpu(sste->esid_data) & SLB_ESID_V)) - return sste; + if (!ret && !(be64_to_cpu(sste->esid_data) & SLB_ESID_V)) + ret = sste; + if (sste_matches(sste, slb)) + return NULL; } + if (ret) + return ret; /* Nothing free, select an entry to cast out */ - sste = primary + ctx->sst_lru; + ret = primary + ctx->sst_lru; ctx->sst_lru = (ctx->sst_lru + 1) & 0x7; - return sste; + return ret; } static void cxl_load_segment(struct cxl_context *ctx, struct copro_slb *slb) @@ -57,12 +70,15 @@ static void cxl_load_segment(struct cxl_context *ctx, struct copro_slb *slb) spin_lock_irqsave(&ctx->sste_lock, flags); sste = find_free_sste(ctx, slb); + if (!sste) + goto out_unlock; pr_devel("CXL Populating SST[%li]: %#llx %#llx\n", sste - ctx->sstp, slb->vsid, slb->esid); sste->vsid_data = cpu_to_be64(slb->vsid); sste->esid_data = cpu_to_be64(slb->esid); +out_unlock: spin_unlock_irqrestore(&ctx->sste_lock, flags); }