From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752613AbeEKKND convert rfc822-to-8bit (ORCPT ); Fri, 11 May 2018 06:13:03 -0400 Received: from ushosting.nmnhosting.com ([167.160.173.127]:41660 "EHLO ushosting.nmnhosting.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750806AbeEKKNC (ORCPT ); Fri, 11 May 2018 06:13:02 -0400 From: "Alastair D'Silva" To: "'Frederic Barrat'" , "'Alastair D'Silva'" , Cc: , , , , , , , , , , , , , , References: <20180511061303.10728-1-alastair@au1.ibm.com> <20180511061303.10728-6-alastair@au1.ibm.com> <9656b063-eafd-a882-c678-a1c4d504cd54@linux.ibm.com> In-Reply-To: <9656b063-eafd-a882-c678-a1c4d504cd54@linux.ibm.com> Subject: RE: [PATCH v5 5/7] ocxl: Expose the thread_id needed for wait on POWER9 Date: Fri, 11 May 2018 20:06:54 +1000 Message-ID: <02a401d3e90f$cdb0be90$69123bb0$@d-silva.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8BIT X-Mailer: Microsoft Outlook 16.0 Content-Language: en-au Thread-Index: AQEt5zmHT2O8EKH9DOs7VTNMP4ZkhQICfQ2uAiL96JWlVSTnUA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Frederic Barrat > Sent: Friday, 11 May 2018 7:25 PM > To: Alastair D'Silva ; linuxppc-dev@lists.ozlabs.org > Cc: linux-kernel@vger.kernel.org; linux-doc@vger.kernel.org; > mikey@neuling.org; vaibhav@linux.vnet.ibm.com; > aneesh.kumar@linux.vnet.ibm.com; malat@debian.org; > felix@linux.vnet.ibm.com; pombredanne@nexb.com; > sukadev@linux.vnet.ibm.com; npiggin@gmail.com; > gregkh@linuxfoundation.org; arnd@arndb.de; > andrew.donnellan@au1.ibm.com; fbarrat@linux.vnet.ibm.com; > corbet@lwn.net; Alastair D'Silva > Subject: Re: [PATCH v5 5/7] ocxl: Expose the thread_id needed for wait on > POWER9 > > > > Le 11/05/2018 à 08:13, Alastair D'Silva a écrit : > > From: Alastair D'Silva > > > > In order to successfully issue as_notify, an AFU needs to know the TID > > to notify, which in turn means that this information should be > > available in userspace so it can be communicated to the AFU. > > > > Signed-off-by: Alastair D'Silva > > --- > > Ok, so we keep the limitation of having only one thread per context able to > call 'wait', even though we don't have to worry about depleting the pool of > TIDs any more. I think that's acceptable, though we don't really have a reason > to justify it any more. Any reason you want to keep it that way? > No strong reason, just trying to minimise the amount of changes. We can always expand the scope later, if we have a use-case for it. > Fred > > > > drivers/misc/ocxl/context.c | 5 ++- > > drivers/misc/ocxl/file.c | 53 +++++++++++++++++++++++++++++++ > > drivers/misc/ocxl/link.c | 36 +++++++++++++++++++++ > > drivers/misc/ocxl/ocxl_internal.h | 1 + > > include/misc/ocxl.h | 9 ++++++ > > include/uapi/misc/ocxl.h | 8 +++++ > > 6 files changed, 111 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c > > index 909e8807824a..95f74623113e 100644 > > --- a/drivers/misc/ocxl/context.c > > +++ b/drivers/misc/ocxl/context.c > > @@ -34,6 +34,8 @@ int ocxl_context_init(struct ocxl_context *ctx, struct > ocxl_afu *afu, > > mutex_init(&ctx->xsl_error_lock); > > mutex_init(&ctx->irq_lock); > > idr_init(&ctx->irq_idr); > > + ctx->tidr = 0; > > + > > /* > > * Keep a reference on the AFU to make sure it's valid for the > > * duration of the life of the context @@ -65,6 +67,7 @@ int > > ocxl_context_attach(struct ocxl_context *ctx, u64 amr) > > { > > int rc; > > > > + // Locks both status & tidr > > mutex_lock(&ctx->status_mutex); > > if (ctx->status != OPENED) { > > rc = -EIO; > > @@ -72,7 +75,7 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 > amr) > > } > > > > rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid, > > - current->mm->context.id, 0, amr, current->mm, > > + current->mm->context.id, ctx->tidr, amr, current- > >mm, > > xsl_fault_error, ctx); > > if (rc) > > goto out; > > diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c index > > 038509e5d031..eb409a469f21 100644 > > --- a/drivers/misc/ocxl/file.c > > +++ b/drivers/misc/ocxl/file.c > > @@ -5,6 +5,8 @@ > > #include > > #include > > #include > > +#include > > +#include > > #include "ocxl_internal.h" > > > > > > @@ -123,11 +125,55 @@ static long afu_ioctl_get_metadata(struct > ocxl_context *ctx, > > return 0; > > } > > > > +#ifdef CONFIG_PPC64 > > +static long afu_ioctl_enable_p9_wait(struct ocxl_context *ctx, > > + struct ocxl_ioctl_p9_wait __user *uarg) { > > + struct ocxl_ioctl_p9_wait arg; > > + > > + memset(&arg, 0, sizeof(arg)); > > + > > + if (cpu_has_feature(CPU_FTR_P9_TIDR)) { > > + enum ocxl_context_status status; > > + > > + // Locks both status & tidr > > + mutex_lock(&ctx->status_mutex); > > + if (!ctx->tidr) { > > + if (set_thread_tidr(current)) > > + return -ENOENT; > > + > > + ctx->tidr = current->thread.tidr; > > + } > > + > > + status = ctx->status; > > + mutex_unlock(&ctx->status_mutex); > > + > > + if (status == ATTACHED) { > > + int rc; > > + struct link *link = ctx->afu->fn->link; > > + > > + rc = ocxl_link_update_pe(link, ctx->pasid, ctx->tidr); > > + if (rc) > > + return rc; > > + } > > + > > + arg.thread_id = ctx->tidr; > > + } else > > + return -ENOENT; > > + > > + if (copy_to_user(uarg, &arg, sizeof(arg))) > > + return -EFAULT; > > + > > + return 0; > > +} > > +#endif > > + > > #define CMD_STR(x) (x == OCXL_IOCTL_ATTACH ? "ATTACH" : > \ > > x == OCXL_IOCTL_IRQ_ALLOC ? "IRQ_ALLOC" : \ > > x == OCXL_IOCTL_IRQ_FREE ? "IRQ_FREE" : > \ > > x == OCXL_IOCTL_IRQ_SET_FD ? "IRQ_SET_FD" : > \ > > x == OCXL_IOCTL_GET_METADATA ? > "GET_METADATA" : \ > > + x == OCXL_IOCTL_ENABLE_P9_WAIT ? > "ENABLE_P9_WAIT" : \ > > "UNKNOWN") > > > > static long afu_ioctl(struct file *file, unsigned int cmd, @@ -186,6 > > +232,13 @@ static long afu_ioctl(struct file *file, unsigned int cmd, > > (struct ocxl_ioctl_metadata __user *) args); > > break; > > > > +#ifdef CONFIG_PPC64 > > + case OCXL_IOCTL_ENABLE_P9_WAIT: > > + rc = afu_ioctl_enable_p9_wait(ctx, > > + (struct ocxl_ioctl_p9_wait __user *) args); > > + break; > > +#endif > > + > > default: > > rc = -EINVAL; > > } > > diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c index > > 656e8610eec2..88876ae8f330 100644 > > --- a/drivers/misc/ocxl/link.c > > +++ b/drivers/misc/ocxl/link.c > > @@ -544,6 +544,42 @@ int ocxl_link_add_pe(void *link_handle, int pasid, > u32 pidr, u32 tidr, > > } > > EXPORT_SYMBOL_GPL(ocxl_link_add_pe); > > > > +int ocxl_link_update_pe(void *link_handle, int pasid, __u16 tid) { > > + struct link *link = (struct link *) link_handle; > > + struct spa *spa = link->spa; > > + struct ocxl_process_element *pe; > > + int pe_handle, rc; > > + > > + if (pasid > SPA_PASID_MAX) > > + return -EINVAL; > > + > > + pe_handle = pasid & SPA_PE_MASK; > > + pe = spa->spa_mem + pe_handle; > > + > > + mutex_lock(&spa->spa_lock); > > + > > + pe->tid = tid; > > + > > + /* > > + * The barrier makes sure the PE is updated > > + * before we clear the NPU context cache below, so that the > > + * old PE cannot be reloaded erroneously. > > + */ > > + mb(); > > + > > + /* > > + * hook to platform code > > + * On powerpc, the entry needs to be cleared from the context > > + * cache of the NPU. > > + */ > > + rc = pnv_ocxl_spa_remove_pe_from_cache(link->platform_data, > pe_handle); > > + WARN_ON(rc); > > + > > + mutex_unlock(&spa->spa_lock); > > + return rc; > > +} > > + > > int ocxl_link_remove_pe(void *link_handle, int pasid) > > { > > struct link *link = (struct link *) link_handle; diff --git > > a/drivers/misc/ocxl/ocxl_internal.h > > b/drivers/misc/ocxl/ocxl_internal.h > > index 5d421824afd9..a32f2151029f 100644 > > --- a/drivers/misc/ocxl/ocxl_internal.h > > +++ b/drivers/misc/ocxl/ocxl_internal.h > > @@ -77,6 +77,7 @@ struct ocxl_context { > > struct ocxl_xsl_error xsl_error; > > struct mutex irq_lock; > > struct idr irq_idr; > > + u16 tidr; // Thread ID used for P9 wait implementation > > }; > > > > struct ocxl_process_element { > > diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h index > > 51ccf76db293..9ff6ddc28e22 100644 > > --- a/include/misc/ocxl.h > > +++ b/include/misc/ocxl.h > > @@ -188,6 +188,15 @@ extern int ocxl_link_add_pe(void *link_handle, int > pasid, u32 pidr, u32 tidr, > > void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr), > > void *xsl_err_data); > > > > +/** > > + * Update values within a Process Element > > + * > > + * link_handle: the link handle associated with the process element > > + * pasid: the PASID for the AFU context > > + * tid: the new thread id for the process element */ extern int > > +ocxl_link_update_pe(void *link_handle, int pasid, __u16 tid); > > + > > /* > > * Remove a Process Element from the Shared Process Area for a link > > */ > > diff --git a/include/uapi/misc/ocxl.h b/include/uapi/misc/ocxl.h index > > 0af83d80fb3e..561e6f0dfcb7 100644 > > --- a/include/uapi/misc/ocxl.h > > +++ b/include/uapi/misc/ocxl.h > > @@ -48,6 +48,13 @@ struct ocxl_ioctl_metadata { > > __u64 reserved[13]; // Total of 16*u64 > > }; > > > > +struct ocxl_ioctl_p9_wait { > > + __u16 thread_id; // The thread ID required to wake this thread > > + __u16 reserved1; > > + __u32 reserved2; > > + __u64 reserved3[3]; > > +}; > > + > > struct ocxl_ioctl_irq_fd { > > __u64 irq_offset; > > __s32 eventfd; > > @@ -62,5 +69,6 @@ struct ocxl_ioctl_irq_fd { > > #define OCXL_IOCTL_IRQ_FREE _IOW(OCXL_MAGIC, 0x12, __u64) > > #define OCXL_IOCTL_IRQ_SET_FD _IOW(OCXL_MAGIC, 0x13, struct > ocxl_ioctl_irq_fd) > > #define OCXL_IOCTL_GET_METADATA _IOR(OCXL_MAGIC, 0x14, struct > > ocxl_ioctl_metadata) > > +#define OCXL_IOCTL_ENABLE_P9_WAIT _IOR(OCXL_MAGIC, 0x15, > struct ocxl_ioctl_p9_wait) > > > > #endif /* _UAPI_MISC_OCXL_H */ > > > > > --- > This email has been checked for viruses by AVG. > http://www.avg.com