Message ID | 20190620041203.12274-1-alastair@au1.ibm.com (mailing list archive) |
---|---|
State | Accepted |
Headers | show |
Series | [v2] ocxl: Allow contexts to be attached with a NULL mm | expand |
Context | Check | Description |
---|---|---|
snowpatch_ozlabs/apply_patch | success | Successfully applied on branch next (e610a466d16a086e321f0bd421e2fc75cff28605) |
snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 84 lines checked |
Alastair D'Silva's on June 20, 2019 2:12 pm: > From: Alastair D'Silva <alastair@d-silva.org> > > If an OpenCAPI context is to be used directly by a kernel driver, there > may not be a suitable mm to use. > > The patch makes the mm parameter to ocxl_context_attach optional. > > Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Yeah I don't think you need to manage a kernel context explicitly because it will always be flushed with tlbie, comment helps. For the powerpc/mm bit, Acked-by: Nicholas Piggin <npiggin@gmail.com>
Le 20/06/2019 à 06:12, Alastair D'Silva a écrit : > From: Alastair D'Silva <alastair@d-silva.org> > > If an OpenCAPI context is to be used directly by a kernel driver, there > may not be a suitable mm to use. > > The patch makes the mm parameter to ocxl_context_attach optional. > > Signed-off-by: Alastair D'Silva <alastair@d-silva.org> > --- Thanks for the update. Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> > arch/powerpc/mm/book3s64/radix_tlb.c | 5 +++++ > drivers/misc/ocxl/context.c | 9 ++++++--- > drivers/misc/ocxl/link.c | 28 ++++++++++++++++++++++++---- > 3 files changed, 35 insertions(+), 7 deletions(-) > > diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c > index bb9835681315..ce8a77fae6a7 100644 > --- a/arch/powerpc/mm/book3s64/radix_tlb.c > +++ b/arch/powerpc/mm/book3s64/radix_tlb.c > @@ -666,6 +666,11 @@ EXPORT_SYMBOL(radix__flush_tlb_page); > #define radix__flush_all_mm radix__local_flush_all_mm > #endif /* CONFIG_SMP */ > > +/* > + * If kernel TLBIs ever become local rather than global, then > + * drivers/misc/ocxl/link.c:ocxl_link_add_pe will need some work, as it > + * assumes kernel TLBIs are global. > + */ > void radix__flush_tlb_kernel_range(unsigned long start, unsigned long end) > { > _tlbie_pid(0, RIC_FLUSH_ALL); > diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c > index bab9c9364184..994563a078eb 100644 > --- a/drivers/misc/ocxl/context.c > +++ b/drivers/misc/ocxl/context.c > @@ -69,6 +69,7 @@ static void xsl_fault_error(void *data, u64 addr, u64 dsisr) > int ocxl_context_attach(struct ocxl_context *ctx, u64 amr, struct mm_struct *mm) > { > int rc; > + unsigned long pidr = 0; > > // Locks both status & tidr > mutex_lock(&ctx->status_mutex); > @@ -77,9 +78,11 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 amr, struct mm_struct *mm) > goto out; > } > > - rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid, > - mm->context.id, ctx->tidr, amr, mm, > - xsl_fault_error, ctx); > + if (mm) > + pidr = mm->context.id; > + > + rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid, pidr, ctx->tidr, > + amr, mm, xsl_fault_error, ctx); > if (rc) > goto out; > > diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c > index cce5b0d64505..58d111afd9f6 100644 > --- a/drivers/misc/ocxl/link.c > +++ b/drivers/misc/ocxl/link.c > @@ -224,6 +224,17 @@ static irqreturn_t xsl_fault_handler(int irq, void *data) > ack_irq(spa, ADDRESS_ERROR); > return IRQ_HANDLED; > } > + > + if (!pe_data->mm) { > + /* > + * translation fault from a kernel context - an OpenCAPI > + * device tried to access a bad kernel address > + */ > + rcu_read_unlock(); > + pr_warn("Unresolved OpenCAPI xsl fault in kernel context\n"); > + ack_irq(spa, ADDRESS_ERROR); > + return IRQ_HANDLED; > + } > WARN_ON(pe_data->mm->context.id != pid); > > if (mmget_not_zero(pe_data->mm)) { > @@ -523,7 +534,13 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr, > pe->amr = cpu_to_be64(amr); > pe->software_state = cpu_to_be32(SPA_PE_VALID); > > - mm_context_add_copro(mm); > + /* > + * For user contexts, register a copro so that TLBIs are seen > + * by the nest MMU. If we have a kernel context, TLBIs are > + * already global. > + */ > + if (mm) > + mm_context_add_copro(mm); > /* > * Barrier is to make sure PE is visible in the SPA before it > * is used by the device. It also helps with the global TLBI > @@ -546,7 +563,8 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr, > * have a reference on mm_users. Incrementing mm_count solves > * the problem. > */ > - mmgrab(mm); > + if (mm) > + mmgrab(mm); > trace_ocxl_context_add(current->pid, spa->spa_mem, pasid, pidr, tidr); > unlock: > mutex_unlock(&spa->spa_lock); > @@ -652,8 +670,10 @@ int ocxl_link_remove_pe(void *link_handle, int pasid) > if (!pe_data) { > WARN(1, "Couldn't find pe data when removing PE\n"); > } else { > - mm_context_remove_copro(pe_data->mm); > - mmdrop(pe_data->mm); > + if (pe_data->mm) { > + mm_context_remove_copro(pe_data->mm); > + mmdrop(pe_data->mm); > + } > kfree_rcu(pe_data, rcu); > } > unlock: >
On 20/6/19 2:12 pm, Alastair D'Silva wrote: > From: Alastair D'Silva <alastair@d-silva.org> > > If an OpenCAPI context is to be used directly by a kernel driver, there > may not be a suitable mm to use. > > The patch makes the mm parameter to ocxl_context_attach optional. > > Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Acked-by: Andrew Donnellan <ajd@linux.ibm.com> > --- > arch/powerpc/mm/book3s64/radix_tlb.c | 5 +++++ > drivers/misc/ocxl/context.c | 9 ++++++--- > drivers/misc/ocxl/link.c | 28 ++++++++++++++++++++++++---- > 3 files changed, 35 insertions(+), 7 deletions(-) > > diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c > index bb9835681315..ce8a77fae6a7 100644 > --- a/arch/powerpc/mm/book3s64/radix_tlb.c > +++ b/arch/powerpc/mm/book3s64/radix_tlb.c > @@ -666,6 +666,11 @@ EXPORT_SYMBOL(radix__flush_tlb_page); > #define radix__flush_all_mm radix__local_flush_all_mm > #endif /* CONFIG_SMP */ > > +/* > + * If kernel TLBIs ever become local rather than global, then > + * drivers/misc/ocxl/link.c:ocxl_link_add_pe will need some work, as it > + * assumes kernel TLBIs are global. > + */ > void radix__flush_tlb_kernel_range(unsigned long start, unsigned long end) > { > _tlbie_pid(0, RIC_FLUSH_ALL); > diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c > index bab9c9364184..994563a078eb 100644 > --- a/drivers/misc/ocxl/context.c > +++ b/drivers/misc/ocxl/context.c > @@ -69,6 +69,7 @@ static void xsl_fault_error(void *data, u64 addr, u64 dsisr) > int ocxl_context_attach(struct ocxl_context *ctx, u64 amr, struct mm_struct *mm) > { > int rc; > + unsigned long pidr = 0; > > // Locks both status & tidr > mutex_lock(&ctx->status_mutex); > @@ -77,9 +78,11 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 amr, struct mm_struct *mm) > goto out; > } > > - rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid, > - mm->context.id, ctx->tidr, amr, mm, > - xsl_fault_error, ctx); > + if (mm) > + pidr = mm->context.id; > + > + rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid, pidr, ctx->tidr, > + amr, mm, xsl_fault_error, ctx); > if (rc) > goto out; > > diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c > index cce5b0d64505..58d111afd9f6 100644 > --- a/drivers/misc/ocxl/link.c > +++ b/drivers/misc/ocxl/link.c > @@ -224,6 +224,17 @@ static irqreturn_t xsl_fault_handler(int irq, void *data) > ack_irq(spa, ADDRESS_ERROR); > return IRQ_HANDLED; > } > + > + if (!pe_data->mm) { > + /* > + * translation fault from a kernel context - an OpenCAPI > + * device tried to access a bad kernel address > + */ > + rcu_read_unlock(); > + pr_warn("Unresolved OpenCAPI xsl fault in kernel context\n"); > + ack_irq(spa, ADDRESS_ERROR); > + return IRQ_HANDLED; > + } > WARN_ON(pe_data->mm->context.id != pid); > > if (mmget_not_zero(pe_data->mm)) { > @@ -523,7 +534,13 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr, > pe->amr = cpu_to_be64(amr); > pe->software_state = cpu_to_be32(SPA_PE_VALID); > > - mm_context_add_copro(mm); > + /* > + * For user contexts, register a copro so that TLBIs are seen > + * by the nest MMU. If we have a kernel context, TLBIs are > + * already global. > + */ > + if (mm) > + mm_context_add_copro(mm); > /* > * Barrier is to make sure PE is visible in the SPA before it > * is used by the device. It also helps with the global TLBI > @@ -546,7 +563,8 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr, > * have a reference on mm_users. Incrementing mm_count solves > * the problem. > */ > - mmgrab(mm); > + if (mm) > + mmgrab(mm); > trace_ocxl_context_add(current->pid, spa->spa_mem, pasid, pidr, tidr); > unlock: > mutex_unlock(&spa->spa_lock); > @@ -652,8 +670,10 @@ int ocxl_link_remove_pe(void *link_handle, int pasid) > if (!pe_data) { > WARN(1, "Couldn't find pe data when removing PE\n"); > } else { > - mm_context_remove_copro(pe_data->mm); > - mmdrop(pe_data->mm); > + if (pe_data->mm) { > + mm_context_remove_copro(pe_data->mm); > + mmdrop(pe_data->mm); > + } > kfree_rcu(pe_data, rcu); > } > unlock: >
diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c index bb9835681315..ce8a77fae6a7 100644 --- a/arch/powerpc/mm/book3s64/radix_tlb.c +++ b/arch/powerpc/mm/book3s64/radix_tlb.c @@ -666,6 +666,11 @@ EXPORT_SYMBOL(radix__flush_tlb_page); #define radix__flush_all_mm radix__local_flush_all_mm #endif /* CONFIG_SMP */ +/* + * If kernel TLBIs ever become local rather than global, then + * drivers/misc/ocxl/link.c:ocxl_link_add_pe will need some work, as it + * assumes kernel TLBIs are global. + */ void radix__flush_tlb_kernel_range(unsigned long start, unsigned long end) { _tlbie_pid(0, RIC_FLUSH_ALL); diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c index bab9c9364184..994563a078eb 100644 --- a/drivers/misc/ocxl/context.c +++ b/drivers/misc/ocxl/context.c @@ -69,6 +69,7 @@ static void xsl_fault_error(void *data, u64 addr, u64 dsisr) int ocxl_context_attach(struct ocxl_context *ctx, u64 amr, struct mm_struct *mm) { int rc; + unsigned long pidr = 0; // Locks both status & tidr mutex_lock(&ctx->status_mutex); @@ -77,9 +78,11 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 amr, struct mm_struct *mm) goto out; } - rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid, - mm->context.id, ctx->tidr, amr, mm, - xsl_fault_error, ctx); + if (mm) + pidr = mm->context.id; + + rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid, pidr, ctx->tidr, + amr, mm, xsl_fault_error, ctx); if (rc) goto out; diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c index cce5b0d64505..58d111afd9f6 100644 --- a/drivers/misc/ocxl/link.c +++ b/drivers/misc/ocxl/link.c @@ -224,6 +224,17 @@ static irqreturn_t xsl_fault_handler(int irq, void *data) ack_irq(spa, ADDRESS_ERROR); return IRQ_HANDLED; } + + if (!pe_data->mm) { + /* + * translation fault from a kernel context - an OpenCAPI + * device tried to access a bad kernel address + */ + rcu_read_unlock(); + pr_warn("Unresolved OpenCAPI xsl fault in kernel context\n"); + ack_irq(spa, ADDRESS_ERROR); + return IRQ_HANDLED; + } WARN_ON(pe_data->mm->context.id != pid); if (mmget_not_zero(pe_data->mm)) { @@ -523,7 +534,13 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr, pe->amr = cpu_to_be64(amr); pe->software_state = cpu_to_be32(SPA_PE_VALID); - mm_context_add_copro(mm); + /* + * For user contexts, register a copro so that TLBIs are seen + * by the nest MMU. If we have a kernel context, TLBIs are + * already global. + */ + if (mm) + mm_context_add_copro(mm); /* * Barrier is to make sure PE is visible in the SPA before it * is used by the device. It also helps with the global TLBI @@ -546,7 +563,8 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr, * have a reference on mm_users. Incrementing mm_count solves * the problem. */ - mmgrab(mm); + if (mm) + mmgrab(mm); trace_ocxl_context_add(current->pid, spa->spa_mem, pasid, pidr, tidr); unlock: mutex_unlock(&spa->spa_lock); @@ -652,8 +670,10 @@ int ocxl_link_remove_pe(void *link_handle, int pasid) if (!pe_data) { WARN(1, "Couldn't find pe data when removing PE\n"); } else { - mm_context_remove_copro(pe_data->mm); - mmdrop(pe_data->mm); + if (pe_data->mm) { + mm_context_remove_copro(pe_data->mm); + mmdrop(pe_data->mm); + } kfree_rcu(pe_data, rcu); } unlock: