From e948e06fc63a1c1e36ec4c8e5c510b881ff19c26 Mon Sep 17 00:00:00 2001 From: Alastair D'Silva Date: Fri, 11 May 2018 16:13:01 +1000 Subject: [PATCH] ocxl: Expose the thread_id needed for wait on POWER9 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 Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- 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 @@ unlock: } 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 */ -- 2.30.2