hldio.h

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * hldio.h - NVMe Direct I/O (HLDIO) infrastructure for Habana Labs Driver
  4 *
  5 * This feature requires specific hardware setup and must not be built
  6 * under COMPILE_TEST.
  7 */
  8
  9#ifndef __HL_HLDIO_H__
 10#define __HL_HLDIO_H__
 11
 12#include <linux/types.h>
 13#include <linux/fs.h>
 14#include <linux/seq_file.h>
 15#include <linux/ktime.h>     /* ktime functions */
 16#include <linux/delay.h>     /* usleep_range */
 17#include <linux/kernel.h>    /* might_sleep_if */
 18#include <linux/errno.h>     /* error codes */
 19
 20/* Forward declarations */
 21struct hl_device;
 22struct file;
 23
 24/* Enable only if Kconfig selected */
 25#ifdef CONFIG_HL_HLDIO
 26/**
 27 * struct hl_p2p_region - describes a single P2P memory region
 28 * @p2ppages: array of page structs for the P2P memory
 29 * @p2pmem: virtual address of the P2P memory region
 30 * @device_pa: physical address on the device
 31 * @bar_offset: offset within the BAR
 32 * @size: size of the region in bytes
 33 * @bar: BAR number containing this region
 34 */
 35struct hl_p2p_region {
 36	struct page **p2ppages;
 37	void *p2pmem;
 38	u64 device_pa;
 39	u64 bar_offset;
 40	u64 size;
 41	int bar;
 42};
 43
 44/**
 45 * struct hl_dio_stats - Direct I/O statistics
 46 * @total_ops: total number of operations attempted
 47 * @successful_ops: number of successful operations
 48 * @failed_ops: number of failed operations
 49 * @bytes_transferred: total bytes successfully transferred
 50 * @last_len_read: length of the last read operation
 51 */
 52struct hl_dio_stats {
 53	u64 total_ops;
 54	u64 successful_ops;
 55	u64 failed_ops;
 56	u64 bytes_transferred;
 57	size_t last_len_read;
 58};
 59
 60/**
 61 * struct hl_dio - describes habanalabs direct storage interaction interface
 62 * @p2prs: array of p2p regions
 63 * @inflight_ios: percpu counter for inflight ios
 64 * @np2prs: number of elements in p2prs
 65 * @io_enabled: 1 if io is enabled 0 otherwise
 66 */
 67struct hl_dio {
 68	struct hl_p2p_region *p2prs;
 69	s64 __percpu *inflight_ios;
 70	u8 np2prs;
 71	u8 io_enabled;
 72};
 73
 74int hl_dio_ssd2hl(struct hl_device *hdev, struct hl_ctx *ctx, int fd,
 75		  u64 device_va, off_t off_bytes, size_t len_bytes,
 76		  size_t *len_read);
 77void hl_p2p_region_fini_all(struct hl_device *hdev);
 78int hl_p2p_region_init(struct hl_device *hdev, struct hl_p2p_region *p2pr);
 79int hl_dio_start(struct hl_device *hdev);
 80void hl_dio_stop(struct hl_device *hdev);
 81
 82/* Init/teardown */
 83int hl_hldio_init(struct hl_device *hdev);
 84void hl_hldio_fini(struct hl_device *hdev);
 85
 86/* File operations */
 87long hl_hldio_ioctl(struct file *filep, unsigned int cmd, unsigned long arg);
 88
 89/* DebugFS hooks */
 90#ifdef CONFIG_DEBUG_FS
 91void hl_hldio_debugfs_init(struct hl_device *hdev);
 92void hl_hldio_debugfs_fini(struct hl_device *hdev);
 93#else
 94static inline void hl_hldio_debugfs_init(struct hl_device *hdev) { }
 95static inline void hl_hldio_debugfs_fini(struct hl_device *hdev) { }
 96#endif
 97
 98#else /* !CONFIG_HL_HLDIO */
 99
100struct hl_p2p_region;
101/* Stubs when HLDIO is disabled */
102static inline int hl_dio_ssd2hl(struct hl_device *hdev, struct hl_ctx *ctx, int fd,
103		  u64 device_va, off_t off_bytes, size_t len_bytes,
104		  size_t *len_read)
105{ return -EOPNOTSUPP; }
106static inline void hl_p2p_region_fini_all(struct hl_device *hdev) {}
107static inline int hl_p2p_region_init(struct hl_device *hdev, struct hl_p2p_region *p2pr)
108{ return -EOPNOTSUPP; }
109static inline int hl_dio_start(struct hl_device *hdev) { return -EOPNOTSUPP; }
110static inline void hl_dio_stop(struct hl_device *hdev) {}
111
112static inline int hl_hldio_init(struct hl_device *hdev) { return 0; }
113static inline void hl_hldio_fini(struct hl_device *hdev) { }
114static inline long hl_hldio_ioctl(struct file *f, unsigned int c,
115				  unsigned long a)
116{ return -ENOTTY; }
117static inline void hl_hldio_debugfs_init(struct hl_device *hdev) { }
118static inline void hl_hldio_debugfs_fini(struct hl_device *hdev) { }
119
120#endif /* CONFIG_HL_HLDIO */
121
122/* Simplified polling macro for HLDIO (no simulator support) */
123#define hl_poll_timeout_condition(hdev, cond, sleep_us, timeout_us) \
124({ \
125	ktime_t __timeout = ktime_add_us(ktime_get(), timeout_us); \
126	might_sleep_if(sleep_us); \
127	(void)(hdev); /* keep signature consistent, hdev unused */ \
128	for (;;) { \
129		mb(); /* ensure ordering of memory operations */ \
130		if (cond) \
131			break; \
132		if (timeout_us && ktime_compare(ktime_get(), __timeout) > 0) \
133			break; \
134		if (sleep_us) \
135			usleep_range((sleep_us >> 2) + 1, sleep_us); \
136	} \
137	(cond) ? 0 : -ETIMEDOUT; \
138})
139
140#ifdef CONFIG_HL_HLDIO
141bool hl_device_supports_nvme(struct hl_device *hdev);
142#else
143static inline bool hl_device_supports_nvme(struct hl_device *hdev) { return false; }
144#endif
145
146#endif /* __HL_HLDIO_H__ */