From b1db551324f72fa14ad82ca31237a7ed418104df Mon Sep 17 00:00:00 2001 From: Christophe Lombard Date: Thu, 11 Jan 2018 09:55:25 +0100 Subject: [PATCH] cxl: Add support for ASB_Notify on POWER9 The POWER9 core supports a new feature: ASB_Notify which requires the support of the Special Purpose Register: TIDR. The ASB_Notify command, generated by the AFU, will attempt to wake-up the host thread identified by the particular LPID:PID:TID. This patch assign a unique TIDR (thread id) for the current thread which will be used in the process element entry. Signed-off-by: Christophe Lombard Reviewed-by: Philippe Bergheaud Acked-by: Frederic Barrat Reviewed-by: Vaibhav Jain Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/process.c | 1 + drivers/misc/cxl/context.c | 2 ++ drivers/misc/cxl/cxl.h | 3 +++ drivers/misc/cxl/cxllib.c | 3 ++- drivers/misc/cxl/file.c | 15 +++++++++++++-- drivers/misc/cxl/native.c | 13 ++++++++++++- include/uapi/misc/cxl.h | 10 ++++++---- 7 files changed, 39 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 1563d1190da3..9eb78ec0ce5b 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1590,6 +1590,7 @@ int set_thread_tidr(struct task_struct *t) return 0; } +EXPORT_SYMBOL_GPL(set_thread_tidr); #endif /* CONFIG_PPC64 */ diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c index 12a41b2753f0..7ff315ad3692 100644 --- a/drivers/misc/cxl/context.c +++ b/drivers/misc/cxl/context.c @@ -45,6 +45,8 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master) ctx->pid = NULL; /* Set in start work ioctl */ mutex_init(&ctx->mapping_lock); ctx->mapping = NULL; + ctx->tidr = 0; + ctx->assign_tidr = false; if (cxl_is_power8()) { spin_lock_init(&ctx->sste_lock); diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h index e46a4062904a..53149fbd780e 100644 --- a/drivers/misc/cxl/cxl.h +++ b/drivers/misc/cxl/cxl.h @@ -630,6 +630,9 @@ struct cxl_context { struct list_head extra_irq_contexts; struct mm_struct *mm; + + u16 tidr; + bool assign_tidr; }; struct cxl_irq_info; diff --git a/drivers/misc/cxl/cxllib.c b/drivers/misc/cxl/cxllib.c index dc9bc1807fdf..30ccba436b3b 100644 --- a/drivers/misc/cxl/cxllib.c +++ b/drivers/misc/cxl/cxllib.c @@ -199,10 +199,11 @@ int cxllib_get_PE_attributes(struct task_struct *task, */ attr->pid = mm->context.id; mmput(mm); + attr->tid = task->thread.tidr; } else { attr->pid = 0; + attr->tid = 0; } - attr->tid = 0; return 0; } EXPORT_SYMBOL_GPL(cxllib_get_PE_attributes); diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c index 76c0b0ca9388..93fd381f6484 100644 --- a/drivers/misc/cxl/file.c +++ b/drivers/misc/cxl/file.c @@ -173,7 +173,7 @@ static long afu_ioctl_start_work(struct cxl_context *ctx, * flags are set it's invalid */ if (work.reserved1 || work.reserved2 || work.reserved3 || - work.reserved4 || work.reserved5 || work.reserved6 || + work.reserved4 || work.reserved5 || (work.flags & ~CXL_START_WORK_ALL)) { rc = -EINVAL; goto out; @@ -186,12 +186,16 @@ static long afu_ioctl_start_work(struct cxl_context *ctx, rc = -EINVAL; goto out; } + if ((rc = afu_register_irqs(ctx, work.num_interrupts))) goto out; if (work.flags & CXL_START_WORK_AMR) amr = work.amr & mfspr(SPRN_UAMOR); + if (work.flags & CXL_START_WORK_TID) + ctx->assign_tidr = true; + ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF); /* @@ -263,8 +267,15 @@ static long afu_ioctl_start_work(struct cxl_context *ctx, goto out; } - ctx->status = STARTED; rc = 0; + if (work.flags & CXL_START_WORK_TID) { + work.tid = ctx->tidr; + if (copy_to_user(uwork, &work, sizeof(work))) + rc = -EFAULT; + } + + ctx->status = STARTED; + out: mutex_unlock(&ctx->status_mutex); return rc; diff --git a/drivers/misc/cxl/native.c b/drivers/misc/cxl/native.c index 02b6b45b4c20..1b3d7c65ea3f 100644 --- a/drivers/misc/cxl/native.c +++ b/drivers/misc/cxl/native.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include "cxl.h" @@ -655,6 +656,7 @@ static void update_ivtes_directed(struct cxl_context *ctx) static int process_element_entry_psl9(struct cxl_context *ctx, u64 wed, u64 amr) { u32 pid; + int rc; cxl_assign_psn_space(ctx); @@ -673,7 +675,16 @@ static int process_element_entry_psl9(struct cxl_context *ctx, u64 wed, u64 amr) pid = ctx->mm->context.id; } - ctx->elem->common.tid = 0; + /* Assign a unique TIDR (thread id) for the current thread */ + if (!(ctx->tidr) && (ctx->assign_tidr)) { + rc = set_thread_tidr(current); + if (rc) + return -ENODEV; + ctx->tidr = current->thread.tidr; + pr_devel("%s: current tidr: %d\n", __func__, ctx->tidr); + } + + ctx->elem->common.tid = cpu_to_be32(ctx->tidr); ctx->elem->common.pid = cpu_to_be32(pid); ctx->elem->sr = cpu_to_be64(calculate_sr(ctx)); diff --git a/include/uapi/misc/cxl.h b/include/uapi/misc/cxl.h index 49e8fd08855a..56376d3907d8 100644 --- a/include/uapi/misc/cxl.h +++ b/include/uapi/misc/cxl.h @@ -20,20 +20,22 @@ struct cxl_ioctl_start_work { __u64 work_element_descriptor; __u64 amr; __s16 num_interrupts; - __s16 reserved1; - __s32 reserved2; + __u16 tid; + __s32 reserved1; + __u64 reserved2; __u64 reserved3; __u64 reserved4; __u64 reserved5; - __u64 reserved6; }; #define CXL_START_WORK_AMR 0x0000000000000001ULL #define CXL_START_WORK_NUM_IRQS 0x0000000000000002ULL #define CXL_START_WORK_ERR_FF 0x0000000000000004ULL +#define CXL_START_WORK_TID 0x0000000000000008ULL #define CXL_START_WORK_ALL (CXL_START_WORK_AMR |\ CXL_START_WORK_NUM_IRQS |\ - CXL_START_WORK_ERR_FF) + CXL_START_WORK_ERR_FF |\ + CXL_START_WORK_TID) /* Possible modes that an afu can be in */ -- 2.30.2