From b6c84ba22ff3a198eb8d5552cf9b8fda1d792e54 Mon Sep 17 00:00:00 2001 From: Vaibhav Jain Date: Fri, 18 May 2018 15:12:23 +0530 Subject: cxl: Disable prefault_mode in Radix mode Currently we see a kernel-oops reported on Power-9 while attaching a context to an AFU, with radix-mode and sysfs attr 'prefault_mode' set to anything other than 'none'. The backtrace of the oops is of this form: Unable to handle kernel paging request for data at address 0x00000080 Faulting instruction address: 0xc00800000bcf3b20 cpu 0x1: Vector: 300 (Data Access) at [c00000037f003800] pc: c00800000bcf3b20: cxl_load_segment+0x178/0x290 [cxl] lr: c00800000bcf39f0: cxl_load_segment+0x48/0x290 [cxl] sp: c00000037f003a80 msr: 9000000000009033 dar: 80 dsisr: 40000000 current = 0xc00000037f280000 paca = 0xc0000003ffffe600 softe: 3 irq_happened: 0x01 pid = 3529, comm = afp_no_int cxl_prefault+0xfc/0x248 [cxl] process_element_entry_psl9+0xd8/0x1a0 [cxl] cxl_attach_dedicated_process_psl9+0x44/0x130 [cxl] native_attach_process+0xc0/0x130 [cxl] afu_ioctl+0x3f4/0x5e0 [cxl] do_vfs_ioctl+0xdc/0x890 ksys_ioctl+0x68/0xf0 sys_ioctl+0x40/0xa0 system_call+0x58/0x6c The issue is caused as on Power-8 the AFU attr 'prefault_mode' was used to improve initial storage fault performance by prefaulting process segments. However on Power-9 with radix mode we don't have Storage-Segments that we can prefault. Also prefaulting process Pages will be too costly and fine-grained. Hence, since the prefaulting mechanism doesn't makes sense of radix-mode, this patch updates prefault_mode_store() to not allow any other value apart from CXL_PREFAULT_NONE when radix mode is enabled. Fixes: f24be42aab37 ("cxl: Add psl9 specific code") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Vaibhav Jain Acked-by: Frederic Barrat Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- drivers/misc/cxl/sysfs.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) (limited to 'drivers/misc') diff --git a/drivers/misc/cxl/sysfs.c b/drivers/misc/cxl/sysfs.c index 95285b7f636f..90aa4eee8ccd 100644 --- a/drivers/misc/cxl/sysfs.c +++ b/drivers/misc/cxl/sysfs.c @@ -343,12 +343,20 @@ static ssize_t prefault_mode_store(struct device *device, struct cxl_afu *afu = to_cxl_afu(device); enum prefault_modes mode = -1; - if (!strncmp(buf, "work_element_descriptor", 23)) - mode = CXL_PREFAULT_WED; - if (!strncmp(buf, "all", 3)) - mode = CXL_PREFAULT_ALL; if (!strncmp(buf, "none", 4)) mode = CXL_PREFAULT_NONE; + else { + if (!radix_enabled()) { + + /* only allowed when not in radix mode */ + if (!strncmp(buf, "work_element_descriptor", 23)) + mode = CXL_PREFAULT_WED; + if (!strncmp(buf, "all", 3)) + mode = CXL_PREFAULT_ALL; + } else { + dev_err(device, "Cannot prefault with radix enabled\n"); + } + } if (mode == -1) return -EINVAL; -- cgit v1.2.3 From 9a6d2022bacd8fca0be6297459a02dfd28dad6ba Mon Sep 17 00:00:00 2001 From: Vaibhav Jain Date: Tue, 17 Apr 2018 10:41:02 +0530 Subject: cxl: Configure PSL to not use APC virtual machines APC virtual machines arent used on POWER-9 chips and are already disabled in on-chip CAPP. They also need to be disabled on the PSL via 'PSL Data Send Control Register' by setting bit(47). This forces the PSL to send commands to CAPP with queue.id == 0. Fixes: 5632874311db ("cxl: Add support for POWER9 DD2") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Vaibhav Jain Acked-by: Andrew Donnellan Reviewed-by: Alastair D'Silva Reviewed-by: Christophe Lombard Signed-off-by: Michael Ellerman --- drivers/misc/cxl/pci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/misc') diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index 83f1d08058fc..2e8b187956bc 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -514,9 +514,9 @@ static int init_implementation_adapter_regs_psl9(struct cxl *adapter, cxl_p1_write(adapter, CXL_PSL9_FIR_CNTL, psl_fircntl); /* Setup the PSL to transmit packets on the PCIe before the - * CAPP is enabled + * CAPP is enabled. Make sure that CAPP virtual machines are disabled */ - cxl_p1_write(adapter, CXL_PSL9_DSNDCTL, 0x0001001000002A10ULL); + cxl_p1_write(adapter, CXL_PSL9_DSNDCTL, 0x0001001000012A10ULL); /* * A response to an ASB_Notify request is returned by the -- cgit v1.2.3 From 19df39581ce99eb1fcfb119945810c9c5bc3f8d4 Mon Sep 17 00:00:00 2001 From: Alastair D'Silva Date: Fri, 11 May 2018 16:13:00 +1000 Subject: ocxl: Rename pnv_ocxl_spa_remove_pe to clarify it's action The function removes the process element from NPU cache. Signed-off-by: Alastair D'Silva Acked-by: Frederic Barrat Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- drivers/misc/ocxl/link.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/misc') diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c index f30790582dc0..656e8610eec2 100644 --- a/drivers/misc/ocxl/link.c +++ b/drivers/misc/ocxl/link.c @@ -599,7 +599,7 @@ int ocxl_link_remove_pe(void *link_handle, int pasid) * On powerpc, the entry needs to be cleared from the context * cache of the NPU. */ - rc = pnv_ocxl_spa_remove_pe(link->platform_data, pe_handle); + rc = pnv_ocxl_spa_remove_pe_from_cache(link->platform_data, pe_handle); WARN_ON(rc); pe_data = radix_tree_delete(&spa->pe_tree, pe_handle); -- cgit v1.2.3 From e948e06fc63a1c1e36ec4c8e5c510b881ff19c26 Mon Sep 17 00:00:00 2001 From: Alastair D'Silva Date: Fri, 11 May 2018 16:13:01 +1000 Subject: 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 + 4 files changed, 94 insertions(+), 1 deletion(-) (limited to 'drivers/misc') 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 { -- cgit v1.2.3 From 02a8e5bc1c06045f36423bd9632ad9f40da18d3f Mon Sep 17 00:00:00 2001 From: Alastair D'Silva Date: Fri, 11 May 2018 16:13:02 +1000 Subject: ocxl: Add an IOCTL so userspace knows what OCXL features are available In order for a userspace AFU driver to call the POWER9 specific OCXL_IOCTL_ENABLE_P9_WAIT, it needs to verify that it can actually make that call. Signed-off-by: Alastair D'Silva Acked-by: Frederic Barrat Acked-by: Andrew Donnellan Signed-off-by: Michael Ellerman --- drivers/misc/ocxl/file.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'drivers/misc') diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c index eb409a469f21..33ae46ce0a8a 100644 --- a/drivers/misc/ocxl/file.c +++ b/drivers/misc/ocxl/file.c @@ -168,12 +168,32 @@ static long afu_ioctl_enable_p9_wait(struct ocxl_context *ctx, } #endif + +static long afu_ioctl_get_features(struct ocxl_context *ctx, + struct ocxl_ioctl_features __user *uarg) +{ + struct ocxl_ioctl_features arg; + + memset(&arg, 0, sizeof(arg)); + +#ifdef CONFIG_PPC64 + if (cpu_has_feature(CPU_FTR_P9_TIDR)) + arg.flags[0] |= OCXL_IOCTL_FEATURES_FLAGS0_P9_WAIT; +#endif + + if (copy_to_user(uarg, &arg, sizeof(arg))) + return -EFAULT; + + return 0; +} + #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" : \ + x == OCXL_IOCTL_GET_FEATURES ? "GET_FEATURES" : \ "UNKNOWN") static long afu_ioctl(struct file *file, unsigned int cmd, @@ -239,6 +259,11 @@ static long afu_ioctl(struct file *file, unsigned int cmd, break; #endif + case OCXL_IOCTL_GET_FEATURES: + rc = afu_ioctl_get_features(ctx, + (struct ocxl_ioctl_features __user *) args); + break; + default: rc = -EINVAL; } -- cgit v1.2.3 From 2e5c93d6bb2f7bc17eb82748943a1b9f6b068520 Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Tue, 5 Jun 2018 09:16:21 +0000 Subject: ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait() Add the missing unlock before return from function afu_ioctl_enable_p9_wait() in the error handling case. Fixes: e948e06fc63a ("ocxl: Expose the thread_id needed for wait on POWER9") Signed-off-by: Wei Yongjun Reviewed-by: Alastair D'Silva Signed-off-by: Michael Ellerman --- drivers/misc/ocxl/file.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/misc') diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c index 33ae46ce0a8a..e6a607488f8a 100644 --- a/drivers/misc/ocxl/file.c +++ b/drivers/misc/ocxl/file.c @@ -139,8 +139,10 @@ static long afu_ioctl_enable_p9_wait(struct ocxl_context *ctx, // Locks both status & tidr mutex_lock(&ctx->status_mutex); if (!ctx->tidr) { - if (set_thread_tidr(current)) + if (set_thread_tidr(current)) { + mutex_unlock(&ctx->status_mutex); return -ENOENT; + } ctx->tidr = current->thread.tidr; } -- cgit v1.2.3