diff --git a/arch/powerpc/platforms/pseries/papr-hvpipe.c b/arch/powerpc/platforms/pseries/papr-hvpipe.c index aca905189cf2..9f2bac71bab1 100644 --- a/arch/powerpc/platforms/pseries/papr-hvpipe.c +++ b/arch/powerpc/platforms/pseries/papr-hvpipe.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include "pseries.h" #include "papr-hvpipe.h" @@ -59,6 +60,51 @@ static LIST_HEAD(hvpipe_src_list); * return code for failure. */ +/* + * ibm,send-hvpipe-msg RTAS call + * @area: Caller-provided work area buffer to send. + * @srcID: Target source for the send pipe message. + */ +static int rtas_ibm_send_hvpipe_msg(struct rtas_work_area *area, u32 srcID) +{ + const s32 token = rtas_function_token(RTAS_FN_IBM_SEND_HVPIPE_MSG); + s32 fwrc; + int ret; + + if (token == RTAS_UNKNOWN_SERVICE) + return -ENOENT; + + do { + fwrc = rtas_call(token, 2, 1, NULL, srcID, + rtas_work_area_phys(area)); + + } while (rtas_busy_delay(fwrc)); + + switch (fwrc) { + case RTAS_SUCCESS: + ret = 0; + break; + case RTAS_HARDWARE_ERROR: + ret = -EIO; + break; + case RTAS_INVALID_PARAMETER: + ret = -EINVAL; + break; + case RTAS_HVPIPE_CLOSED: + ret = -EPIPE; + break; + case RTAS_FUNC_NOT_SUPPORTED: + ret = -EOPNOTSUPP; + break; + default: + ret = -EIO; + pr_err_ratelimited("unexpected ibm,receive-hvpipe-msg status %d\n", fwrc); + break; + } + + return ret; +} + static struct hvpipe_source_info *hvpipe_find_source(u32 srcID) { struct hvpipe_source_info *src_info; @@ -78,11 +124,81 @@ static ssize_t papr_hvpipe_handle_write(struct file *file, const char __user *buf, size_t size, loff_t *off) { struct hvpipe_source_info *src_info = file->private_data; + struct rtas_work_area *work_area, *work_buf; + unsigned long ret, len; + __be64 *area_be; if (!src_info) return -EIO; - return 0; + /* + * Send HVPIPE RTAS is used to send payload to the specific + * source with the input parameters source ID and the payload + * as buffer list. Each entry in the buffer list contains + * address/length pair of the buffer. + * + * The buffer list format is as follows: + * + * Header (length of address/length pairs and the header length) + * Address of 4K buffer 1 + * Length of 4K buffer 1 used + * ... + * Address of 4K buffer n + * Length of 4K buffer n used + * + * See PAPR 7.3.32.2 ibm,send-hvpipe-msg + * + * Even though can support max 1MB payload, the hypervisor + * supports only 4048 bytes payload at present and also + * just one address/length entry. + * + * writev() interface can be added in future when the + * hypervisor supports multiple buffer list entries. + */ + /* HVPIPE_MAX_WRITE_BUFFER_SIZE = 4048 bytes */ + if ((size > (HVPIPE_HDR_LEN + HVPIPE_MAX_WRITE_BUFFER_SIZE)) || + (size <= HVPIPE_HDR_LEN)) + return -EINVAL; + + /* + * The length of (address + length) pair + the length of header + */ + len = (2 * sizeof(u64)) + sizeof(u64); + size -= HVPIPE_HDR_LEN; + buf += HVPIPE_HDR_LEN; + mutex_lock(&rtas_ibm_send_hvpipe_msg_lock); + work_area = rtas_work_area_alloc(SZ_4K); + if (!work_area) { + ret = -ENOMEM; + goto out; + } + area_be = (__be64 *)rtas_work_area_raw_buf(work_area); + /* header */ + area_be[0] = cpu_to_be64(len); + + work_buf = rtas_work_area_alloc(SZ_4K); + if (!work_buf) { + ret = -ENOMEM; + goto out_work; + } + /* First buffer address */ + area_be[1] = cpu_to_be64(rtas_work_area_phys(work_buf)); + /* First buffer address length */ + area_be[2] = cpu_to_be64(size); + + if (!copy_from_user(rtas_work_area_raw_buf(work_buf), buf, size)) { + ret = rtas_ibm_send_hvpipe_msg(work_area, src_info->srcID); + if (!ret) + ret = size + HVPIPE_HDR_LEN; + } else + ret = -EPERM; + + rtas_work_area_free(work_buf); +out_work: + rtas_work_area_free(work_area); +out: + mutex_unlock(&rtas_ibm_send_hvpipe_msg_lock); + return ret; } /* diff --git a/arch/powerpc/platforms/pseries/papr-hvpipe.h b/arch/powerpc/platforms/pseries/papr-hvpipe.h index 3b6f9e737913..6f98da4ec45f 100644 --- a/arch/powerpc/platforms/pseries/papr-hvpipe.h +++ b/arch/powerpc/platforms/pseries/papr-hvpipe.h @@ -3,6 +3,13 @@ #define _PAPR_HVPIPE_H #define HVPIPE_HMC_ID_MASK 0x02000000 /*02-HMC,00-reserved and HMC ID */ +#define HVPIPE_MAX_WRITE_BUFFER_SIZE 4048 +/* + * hvpipe specific RTAS return values + */ +#define RTAS_HVPIPE_CLOSED -4 + +#define HVPIPE_HDR_LEN sizeof(struct papr_hvpipe_hdr) struct hvpipe_source_info { struct list_head list; /* list of sources */