From cf184dc2dd33847f4b211b01d8c7ec0526e6c5e4 Mon Sep 17 00:00:00 2001 From: Jaiprakash Singh Date: Wed, 20 May 2015 21:17:11 -0500 Subject: fsl_ifc: Change IO accessor based on endianness IFC IO accressor are set at run time based on IFC IP registers endianness.IFC node in DTS file contains information about endianness. Signed-off-by: Jaiprakash Singh Signed-off-by: Scott Wood Acked-by: Brian Norris --- include/linux/fsl_ifc.h | 50 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) (limited to 'include') diff --git a/include/linux/fsl_ifc.h b/include/linux/fsl_ifc.h index bf0321eabbda..0023088b253b 100644 --- a/include/linux/fsl_ifc.h +++ b/include/linux/fsl_ifc.h @@ -841,9 +841,59 @@ struct fsl_ifc_ctrl { u32 nand_stat; wait_queue_head_t nand_wait; + bool little_endian; }; extern struct fsl_ifc_ctrl *fsl_ifc_ctrl_dev; +static inline u32 ifc_in32(void __iomem *addr) +{ + u32 val; + + if (fsl_ifc_ctrl_dev->little_endian) + val = ioread32(addr); + else + val = ioread32be(addr); + + return val; +} + +static inline u16 ifc_in16(void __iomem *addr) +{ + u16 val; + + if (fsl_ifc_ctrl_dev->little_endian) + val = ioread16(addr); + else + val = ioread16be(addr); + + return val; +} + +static inline u8 ifc_in8(void __iomem *addr) +{ + return ioread8(addr); +} + +static inline void ifc_out32(u32 val, void __iomem *addr) +{ + if (fsl_ifc_ctrl_dev->little_endian) + iowrite32(val, addr); + else + iowrite32be(val, addr); +} + +static inline void ifc_out16(u16 val, void __iomem *addr) +{ + if (fsl_ifc_ctrl_dev->little_endian) + iowrite16(val, addr); + else + iowrite16be(val, addr); +} + +static inline void ifc_out8(u8 val, void __iomem *addr) +{ + iowrite8(val, addr); +} #endif /* __ASM_FSL_IFC_H */ -- cgit v1.2.3-71-gd317 From 13e68d8bd05c998cae452a4f3400af1e8edd852e Mon Sep 17 00:00:00 2001 From: Daniel Axtens Date: Fri, 14 Aug 2015 17:41:25 +1000 Subject: cxl: Allow the kernel to trust that an image won't change on PERST. Provide a kernel API and a sysfs entry which allow a user to specify that when a card is PERSTed, it's image will stay the same, allowing it to participate in EEH. cxl_reset is used to reflash the card. In that case, we cannot safely assert that the image will not change. Therefore, disallow cxl_reset if the flag is set. Signed-off-by: Daniel Axtens Signed-off-by: Michael Ellerman --- Documentation/ABI/testing/sysfs-class-cxl | 10 ++++++++++ drivers/misc/cxl/api.c | 7 +++++++ drivers/misc/cxl/cxl.h | 1 + drivers/misc/cxl/pci.c | 7 +++++++ drivers/misc/cxl/sysfs.c | 26 ++++++++++++++++++++++++++ include/misc/cxl.h | 10 ++++++++++ 6 files changed, 61 insertions(+) (limited to 'include') diff --git a/Documentation/ABI/testing/sysfs-class-cxl b/Documentation/ABI/testing/sysfs-class-cxl index acfe9df83139..b07e86d4597f 100644 --- a/Documentation/ABI/testing/sysfs-class-cxl +++ b/Documentation/ABI/testing/sysfs-class-cxl @@ -223,3 +223,13 @@ Description: write only Writing 1 will issue a PERST to card which may cause the card to reload the FPGA depending on load_image_on_perst. Users: https://github.com/ibm-capi/libcxl + +What: /sys/class/cxl//perst_reloads_same_image +Date: July 2015 +Contact: linuxppc-dev@lists.ozlabs.org +Description: read/write + Trust that when an image is reloaded via PERST, it will not + have changed. + 0 = don't trust, the image may be different (default) + 1 = trust that the image will not change. +Users: https://github.com/ibm-capi/libcxl diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index 729e0851167d..6a768a9ad22f 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -327,3 +327,10 @@ int cxl_afu_reset(struct cxl_context *ctx) return cxl_afu_check_and_enable(afu); } EXPORT_SYMBOL_GPL(cxl_afu_reset); + +void cxl_perst_reloads_same_image(struct cxl_afu *afu, + bool perst_reloads_same_image) +{ + afu->adapter->perst_same_image = perst_reloads_same_image; +} +EXPORT_SYMBOL_GPL(cxl_perst_reloads_same_image); diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h index d540542f9931..cda02412b01e 100644 --- a/drivers/misc/cxl/cxl.h +++ b/drivers/misc/cxl/cxl.h @@ -493,6 +493,7 @@ struct cxl { bool user_image_loaded; bool perst_loads_image; bool perst_select_user; + bool perst_same_image; }; int cxl_alloc_one_irq(struct cxl *adapter); diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index 2b61cb1ee62c..bfbd6478c0c5 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -878,6 +878,12 @@ int cxl_reset(struct cxl *adapter) int i; u32 val; + if (adapter->perst_same_image) { + dev_warn(&dev->dev, + "cxl: refusing to reset/reflash when perst_reloads_same_image is set.\n"); + return -EINVAL; + } + dev_info(&dev->dev, "CXL reset\n"); /* pcie_warm_reset requests a fundamental pci reset which includes a @@ -1151,6 +1157,7 @@ static struct cxl *cxl_init_adapter(struct pci_dev *dev) * configure/reconfigure */ adapter->perst_loads_image = true; + adapter->perst_same_image = false; rc = cxl_configure_adapter(adapter, dev); if (rc) { diff --git a/drivers/misc/cxl/sysfs.c b/drivers/misc/cxl/sysfs.c index 31f38bc71a3d..6619cf1f6e1f 100644 --- a/drivers/misc/cxl/sysfs.c +++ b/drivers/misc/cxl/sysfs.c @@ -112,12 +112,38 @@ static ssize_t load_image_on_perst_store(struct device *device, return count; } +static ssize_t perst_reloads_same_image_show(struct device *device, + struct device_attribute *attr, + char *buf) +{ + struct cxl *adapter = to_cxl_adapter(device); + + return scnprintf(buf, PAGE_SIZE, "%i\n", adapter->perst_same_image); +} + +static ssize_t perst_reloads_same_image_store(struct device *device, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct cxl *adapter = to_cxl_adapter(device); + int rc; + int val; + + rc = sscanf(buf, "%i", &val); + if ((rc != 1) || !(val == 1 || val == 0)) + return -EINVAL; + + adapter->perst_same_image = (val == 1 ? true : false); + return count; +} + static struct device_attribute adapter_attrs[] = { __ATTR_RO(caia_version), __ATTR_RO(psl_revision), __ATTR_RO(base_image), __ATTR_RO(image_loaded), __ATTR_RW(load_image_on_perst), + __ATTR_RW(perst_reloads_same_image), __ATTR(reset, S_IWUSR, NULL, reset_adapter_store), }; diff --git a/include/misc/cxl.h b/include/misc/cxl.h index 7a6c1d6cc173..f2ffe5bd720d 100644 --- a/include/misc/cxl.h +++ b/include/misc/cxl.h @@ -200,4 +200,14 @@ unsigned int cxl_fd_poll(struct file *file, struct poll_table_struct *poll); ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count, loff_t *off); +/* + * For EEH, a driver may want to assert a PERST will reload the same image + * from flash into the FPGA. + * + * This is a property of the entire adapter, not a single AFU, so drivers + * should set this property with care! + */ +void cxl_perst_reloads_same_image(struct cxl_afu *afu, + bool perst_reloads_same_image); + #endif /* _MISC_CXL_H */ -- cgit v1.2.3-71-gd317 From d9232a3da8683cd9c9854a858bcca968fe5f3bca Mon Sep 17 00:00:00 2001 From: Ian Munsie Date: Thu, 23 Jul 2015 16:43:56 +1000 Subject: cxl: Add alternate MMIO error handling userspace programs using cxl currently have to use two strategies for dealing with MMIO errors simultaneously. They have to check every read for a return of all Fs in case the adapter has gone away and the kernel has not yet noticed, and they have to deal with SIGBUS in case the kernel has already noticed, invalidated the mapping and marked the context as failed. In order to simplify things, this patch adds an alternative approach where the kernel will return a page filled with Fs instead of delivering a SIGBUS. This allows userspace to only need to deal with one of these two error paths, and is intended for use in libraries that use cxl transparently and may not be able to safely install a signal handler. This approach will only work if certain constraints are met. Namely, if the application is both reading and writing to an address in the problem state area it cannot assume that a non-FF read is OK, as it may just be reading out a value it has previously written. Further - since only one page is used per context a write to a given offset would be visible when reading the same offset from a different page in the mapping (this only applies within a single context, not between contexts). An application could deal with this by e.g. making sure it also reads from a read-only offset after any reads to a read/write offset. Due to these constraints, this functionality must be explicitly requested by userspace when starting the context by passing in the CXL_START_WORK_ERR_FF flag. Signed-off-by: Ian Munsie Acked-by: Michael Neuling Signed-off-by: Michael Ellerman --- drivers/misc/cxl/context.c | 14 ++++++++++++++ drivers/misc/cxl/cxl.h | 4 +++- drivers/misc/cxl/file.c | 4 +++- include/uapi/misc/cxl.h | 4 +++- 4 files changed, 23 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c index 615842115848..941fda04aa9a 100644 --- a/drivers/misc/cxl/context.c +++ b/drivers/misc/cxl/context.c @@ -126,6 +126,18 @@ static int cxl_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) if (ctx->status != STARTED) { mutex_unlock(&ctx->status_mutex); pr_devel("%s: Context not started, failing problem state access\n", __func__); + if (ctx->mmio_err_ff) { + if (!ctx->ff_page) { + ctx->ff_page = alloc_page(GFP_USER); + if (!ctx->ff_page) + return VM_FAULT_OOM; + memset(page_address(ctx->ff_page), 0xff, PAGE_SIZE); + } + get_page(ctx->ff_page); + vmf->page = ctx->ff_page; + vma->vm_page_prot = pgprot_cached(vma->vm_page_prot); + return 0; + } return VM_FAULT_SIGBUS; } @@ -257,6 +269,8 @@ static void reclaim_ctx(struct rcu_head *rcu) struct cxl_context *ctx = container_of(rcu, struct cxl_context, rcu); free_page((u64)ctx->sstp); + if (ctx->ff_page) + __free_page(ctx->ff_page); ctx->sstp = NULL; kfree(ctx); diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h index 6f5386653dae..e7af256f60c5 100644 --- a/drivers/misc/cxl/cxl.h +++ b/drivers/misc/cxl/cxl.h @@ -34,7 +34,7 @@ extern uint cxl_verbose; * Bump version each time a user API change is made, whether it is * backwards compatible ot not. */ -#define CXL_API_VERSION 1 +#define CXL_API_VERSION 2 #define CXL_API_VERSION_COMPATIBLE 1 /* @@ -418,6 +418,8 @@ struct cxl_context { /* Used to unmap any mmaps when force detaching */ struct address_space *mapping; struct mutex mapping_lock; + struct page *ff_page; + bool mmio_err_ff; spinlock_t sste_lock; /* Protects segment table entries */ struct cxl_sste *sstp; diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c index 57bdb473749f..a30bf285b5bd 100644 --- a/drivers/misc/cxl/file.c +++ b/drivers/misc/cxl/file.c @@ -184,6 +184,8 @@ static long afu_ioctl_start_work(struct cxl_context *ctx, if (work.flags & CXL_START_WORK_AMR) amr = work.amr & mfspr(SPRN_UAMOR); + ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF); + /* * We grab the PID here and not in the file open to allow for the case * where a process (master, some daemon, etc) has opened the chardev on @@ -538,7 +540,7 @@ int __init cxl_file_init(void) * If these change we really need to update API. Either change some * flags or update API version number CXL_API_VERSION. */ - BUILD_BUG_ON(CXL_API_VERSION != 1); + BUILD_BUG_ON(CXL_API_VERSION != 2); BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64); BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8); BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8); diff --git a/include/uapi/misc/cxl.h b/include/uapi/misc/cxl.h index 99a8ca15fe64..1e889aa8a36e 100644 --- a/include/uapi/misc/cxl.h +++ b/include/uapi/misc/cxl.h @@ -29,8 +29,10 @@ struct cxl_ioctl_start_work { #define CXL_START_WORK_AMR 0x0000000000000001ULL #define CXL_START_WORK_NUM_IRQS 0x0000000000000002ULL +#define CXL_START_WORK_ERR_FF 0x0000000000000004ULL #define CXL_START_WORK_ALL (CXL_START_WORK_AMR |\ - CXL_START_WORK_NUM_IRQS) + CXL_START_WORK_NUM_IRQS |\ + CXL_START_WORK_ERR_FF) /* Possible modes that an afu can be in */ -- cgit v1.2.3-71-gd317