From 27d4dc7116eed98775902627ba61b70e9045e321 Mon Sep 17 00:00:00 2001 From: Vaibhav Jain Date: Wed, 29 Apr 2015 15:47:23 +0530 Subject: [PATCH] cxl: Implement an ioctl to fetch afu card-id, offset-id and mode Given a file descriptor on an afu device, libcxl currently uses the major/minor number obtained from fstat on the fd to construct path to the afu's sysfs directory. However it is possible that rather than using one of the device in /dev/cxl, a kernel driver creates its own device which export generic cxl interface to the userspace. This causes problems with libcxl as it tries to use a wrong major/minor number to construct the sysfs path and fail. So this patch introduces a new ioctl called CXL_IOCTL_GET_AFU_ID on the afu file descriptor to fetch the cxl_afu_id struct that holds the card/offset-id and mode information. These info is then used by libcxl to construct the correct path to the afu sysfs directory. Testing: - Build against pseries be/le configs - Testing with corresponding libcxl changes to verify that it constructs right sysfs path to the afu. Signed-off-by: Vaibhav Jain Acked-by: Ian Munsie Signed-off-by: Michael Ellerman --- drivers/misc/cxl/cxl.h | 2 -- drivers/misc/cxl/file.c | 22 ++++++++++++++++++++++ include/uapi/misc/cxl.h | 22 ++++++++++++++++++++++ 3 files changed, 44 insertions(+), 2 deletions(-) diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h index a1cee4767ec6..9f280e3e742e 100644 --- a/drivers/misc/cxl/cxl.h +++ b/drivers/misc/cxl/cxl.h @@ -315,8 +315,6 @@ static const cxl_p2n_reg_t CXL_PSL_WED_An = {0x0A0}; #define CXL_MAX_SLICES 4 #define MAX_AFU_MMIO_REGS 3 -#define CXL_MODE_DEDICATED 0x1 -#define CXL_MODE_DIRECTED 0x2 #define CXL_MODE_TIME_SLICED 0x4 #define CXL_SUPPORTED_MODES (CXL_MODE_DEDICATED | CXL_MODE_DIRECTED) diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c index 2364bcadb9a9..985523443829 100644 --- a/drivers/misc/cxl/file.c +++ b/drivers/misc/cxl/file.c @@ -212,6 +212,25 @@ static long afu_ioctl_process_element(struct cxl_context *ctx, return 0; } +static long afu_ioctl_get_afu_id(struct cxl_context *ctx, + struct cxl_afu_id __user *upafuid) +{ + struct cxl_afu_id afuid = { 0 }; + + afuid.card_id = ctx->afu->adapter->adapter_num; + afuid.afu_offset = ctx->afu->slice; + afuid.afu_mode = ctx->afu->current_mode; + + /* set the flag bit in case the afu is a slave */ + if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master) + afuid.flags |= CXL_AFUID_FLAG_SLAVE; + + if (copy_to_user(upafuid, &afuid, sizeof(afuid))) + return -EFAULT; + + return 0; +} + static long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct cxl_context *ctx = file->private_data; @@ -225,6 +244,9 @@ static long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg) return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg); case CXL_IOCTL_GET_PROCESS_ELEMENT: return afu_ioctl_process_element(ctx, (__u32 __user *)arg); + case CXL_IOCTL_GET_AFU_ID: + return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *) + arg); } return -EINVAL; } diff --git a/include/uapi/misc/cxl.h b/include/uapi/misc/cxl.h index cd6d789b73ec..99a8ca15fe64 100644 --- a/include/uapi/misc/cxl.h +++ b/include/uapi/misc/cxl.h @@ -32,10 +32,32 @@ struct cxl_ioctl_start_work { #define CXL_START_WORK_ALL (CXL_START_WORK_AMR |\ CXL_START_WORK_NUM_IRQS) + +/* Possible modes that an afu can be in */ +#define CXL_MODE_DEDICATED 0x1 +#define CXL_MODE_DIRECTED 0x2 + +/* possible flags for the cxl_afu_id flags field */ +#define CXL_AFUID_FLAG_SLAVE 0x1 /* In directed-mode afu is in slave mode */ + +struct cxl_afu_id { + __u64 flags; /* One of CXL_AFUID_FLAG_X */ + __u32 card_id; + __u32 afu_offset; + __u32 afu_mode; /* one of the CXL_MODE_X */ + __u32 reserved1; + __u64 reserved2; + __u64 reserved3; + __u64 reserved4; + __u64 reserved5; + __u64 reserved6; +}; + /* ioctl numbers */ #define CXL_MAGIC 0xCA #define CXL_IOCTL_START_WORK _IOW(CXL_MAGIC, 0x00, struct cxl_ioctl_start_work) #define CXL_IOCTL_GET_PROCESS_ELEMENT _IOR(CXL_MAGIC, 0x01, __u32) +#define CXL_IOCTL_GET_AFU_ID _IOR(CXL_MAGIC, 0x02, struct cxl_afu_id) #define CXL_READ_MIN_SIZE 0x1000 /* 4K */ -- 2.20.1