kernel_compat.h

/*
 * Kernel version compatibility shims for building against Linux 4.9 - 6.6+
 *
 * This header provides compatibility wrappers for kernel APIs that changed
 * or were removed across kernel versions, enabling the OSAL layer and
 * wrapper modules to compile against newer kernels while the binary blobs
 * remain unchanged (they only call OSAL via opaque void* wrappers).
 */
#ifndef KERNEL_COMPAT_H
#define KERNEL_COMPAT_H

#include <linux/version.h>

/*
 * On 6.4+, EXPORT_ALIAS is a no-op so the LOG symbol alias of HI_LOG
 * is not created. Map LOG to HI_LOG at the preprocessor level.
 * This is applied globally via -include in the top-level Kbuild.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 4, 0)
#define LOG HI_LOG
#endif

/*
 * Timer API: init_timer() removed in 4.15, timer callback signature changed.
 * 4.15+: timer_setup() + void(*)(struct timer_list*) callback
 * Pre-4.15: init_timer() + void(*)(unsigned long) callback + .data field
 *
 * Since OSAL wraps timers behind opaque void* and the blobs use the old
 * callback signature void(*)(unsigned long), we use from_timer() in the
 * shim callback to recover the original context.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
#define COMPAT_TIMER_SETUP 1
#endif

/*
 * access_ok() lost its first (type) parameter in 5.0.
 * Pre-5.0: access_ok(type, addr, size)
 * 5.0+:    access_ok(addr, size)
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
#define compat_access_ok(type, addr, size) access_ok(addr, size)
#else
#define compat_access_ok(type, addr, size) access_ok(type, addr, size)
#endif

/*
 * ioremap_nocache() removed in 5.6 (ioremap is already uncached on most archs).
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 6, 0)
#define ioremap_nocache ioremap
#endif

/*
 * set_fs()/get_fs()/get_ds() removed in 5.10 (UACCESS_BUFFER / addr_limit).
 * Use kernel_read()/kernel_write() instead of vfs_read() with set_fs().
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 10, 0)
#define COMPAT_NO_SET_FS 1
#endif

/*
 * mmap_sem renamed to mmap_lock in 5.8, with helper functions.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0)
#define compat_mmap_read_lock(mm)   mmap_read_lock(mm)
#define compat_mmap_read_unlock(mm) mmap_read_unlock(mm)
#else
#define compat_mmap_read_lock(mm)   down_read(&(mm)->mmap_sem)
#define compat_mmap_read_unlock(mm) up_read(&(mm)->mmap_sem)
#endif

/*
 * do_gettimeofday() removed in 5.0.
 * Use ktime_get_real_ts64() + timespec64 instead.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)
#define COMPAT_NO_DO_GETTIMEOFDAY 1
#include <linux/ktime.h>
#include <linux/timekeeping.h>
#endif

/*
 * rtc_time_to_tm/rtc_tm_to_time removed in 5.6 in favor of
 * rtc_time64_to_tm/rtc_tm_to_time64.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 6, 0)
#define compat_rtc_time_to_tm  rtc_time64_to_tm
/* rtc_tm_to_time64() returns time64_t instead of storing via pointer */
#define compat_rtc_tm_to_time(tm, timep) do { *(timep) = rtc_tm_to_time64(tm); } while (0)
#else
#define compat_rtc_time_to_tm  rtc_time_to_tm
#define compat_rtc_tm_to_time  rtc_tm_to_time
#endif

/*
 * register_sysctl_table() removed in 6.6.
 * Use register_sysctl() instead.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 6, 0)
#define COMPAT_NO_SYSCTL_TABLE 1
#endif

/*
 * register_sysctl_paths() removed in 6.6.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 6, 0)
#define COMPAT_NO_SYSCTL_PATHS 1
#endif

/*
 * struct ctl_path removed in 6.6.
 */

/*
 * ARM32 cache flush APIs:
 * __flush_dcache_area renamed to dcache_clean_inval_poc in 5.15+ (arm64)
 * __cpuc_flush_dcache_area still available on ARM32 through 6.x
 * __cpuc_flush_kern_all still available on ARM32 through 6.x
 * outer_flush_range/outer_flush_all still available when CONFIG_CACHE_L2X0
 *
 * Note: ARM32 cache flush functions are arch-specific and remain stable.
 * ARM64 changes are handled separately.
 */
#ifdef CONFIG_64BIT
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 15, 0)
/* __flush_dcache_area was renamed */
#define compat_flush_dcache_area(addr, size) \
	dcache_clean_inval_poc((unsigned long)(addr), \
			       (unsigned long)(addr) + (size))
#else
#define compat_flush_dcache_area(addr, size) __flush_dcache_area(addr, size)
#endif
#endif /* CONFIG_64BIT */

/*
 * strlcpy() deprecated in 6.1, removed in 6.8. Use strscpy() instead.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 1, 0)
#define compat_strlcpy(dst, src, size) strscpy(dst, src, size)
#else
#define compat_strlcpy(dst, src, size) strlcpy(dst, src, size)
#endif

/*
 * PDE_DATA() renamed to pde_data() in 5.17.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 17, 0)
#define compat_pde_data(inode) pde_data(inode)
#elif defined(CONFIG_PROC_FS)
#define compat_pde_data(inode) PDE_DATA(inode)
#endif

/*
 * vm_flags field became read-only in 6.3 (use vm_flags_set/vm_flags_clear).
 * For read-only checks this doesn't matter.
 */

/*
 * sched_clock() moved to <linux/sched/clock.h> in 4.11+.
 * signal_pending() moved to <linux/sched/signal.h> in 4.11+.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
#include <linux/sched/clock.h>
#include <linux/sched/signal.h>
#endif

/*
 * struct bus_type: dev_attrs removed in 3.12, use dev_groups instead.
 * The field was technically present but deprecated since 3.11.
 */

/*
 * linux/dma-contiguous.h merged into linux/dma-map-ops.h in 5.x.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 16, 0)
#include <linux/dma-map-ops.h>
#elif LINUX_VERSION_CODE >= KERNEL_VERSION(3, 5, 0)
#include <linux/dma-contiguous.h>
#endif

/*
 * DEFINE_SEMAPHORE gained a count parameter in 6.6.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 4, 0)
#define compat_DEFINE_SEMAPHORE(name) DEFINE_SEMAPHORE(name, 1)
#else
#define compat_DEFINE_SEMAPHORE(name) DEFINE_SEMAPHORE(name)
#endif

/*
 * vm_flags became read-only in 6.3. Use vm_flags_set()/vm_flags_clear().
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
#define compat_vm_flags_set(vma, flags) vm_flags_set(vma, flags)
#else
#define compat_vm_flags_set(vma, flags) ((vma)->vm_flags |= (flags))
#endif

/*
 * get_random_int() renamed to get_random_u32() in 6.1.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 1, 0)
#define compat_get_random_int() get_random_u32()
#else
#define compat_get_random_int() get_random_int()
#endif

/*
 * struct file_operations replaced by struct proc_ops for proc files in 5.6.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 6, 0)
#define COMPAT_USE_PROC_OPS 1
#endif

/*
 * dma_alloc_from_contiguous() gained a 4th 'no_warn' parameter in 4.15.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
#define compat_dma_alloc_from_contiguous(dev, count, align) \
	dma_alloc_from_contiguous(dev, count, align, false)
#else
#define compat_dma_alloc_from_contiguous(dev, count, align) \
	dma_alloc_from_contiguous(dev, count, align)
#endif

/*
 * spi_busnum_to_master() removed in 6.4. Provide inline fallback.
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 4, 0)
#include <linux/spi/spi.h>
#if LINUX_VERSION_CODE >= KERNEL_VERSION(7, 0, 0)
extern const struct class spi_controller_class;
#define compat_spi_class spi_controller_class
#else
extern struct class spi_master_class;
#define compat_spi_class spi_master_class
#endif
static inline struct spi_controller *compat_spi_busnum_to_controller(u16 bus_num)
{
	struct device *dev;
	char name[32];
	snprintf(name, sizeof(name), "spi%u", bus_num);
	dev = class_find_device_by_name(&compat_spi_class, name);
	if (!dev)
		return NULL;
	return container_of(dev, struct spi_controller, dev);
}
#define spi_busnum_to_controller compat_spi_busnum_to_controller
#endif

/* Inserted before #endif */
/*
 * i2c_new_device renamed to i2c_new_client_device in 5.x.
 */
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 2, 0)
#define i2c_new_client_device i2c_new_device
#endif

/*
 * spi_busnum_to_master renamed to spi_busnum_to_controller in 5.x.
 * (6.4+ removal handled separately above)
 */
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0)
#define spi_busnum_to_controller spi_busnum_to_master
#endif

/*
 * Linux 7.0+ API changes
 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(7, 0, 0)

/* platform_device.h no longer implicitly included */
#include <linux/platform_device.h>

/* del_timer moved to linux/timer.h (explicit include needed) */
#include <linux/timer.h>

#endif /* >= 7.0 */

/* del_timer renamed to timer_delete in 7.0 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(7, 0, 0)
#define del_timer timer_delete
#define del_timer_sync timer_delete_sync
#endif

/* platform_driver.remove returns void since 6.11 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 11, 0)
#define compat_platform_remove_ret void
#define compat_platform_remove_return return
#else
#define compat_platform_remove_ret int
#define compat_platform_remove_return return 0
#endif

/* spi_master typedef removed in 7.0 */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(7, 0, 0)
#define spi_master spi_controller
#endif

/* from_timer macro removed in 7.0, use timer_container_of */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(7, 0, 0)
#include <linux/timer.h>
#define from_timer(var, callback_timer, timer_fieldname) \
	container_of(callback_timer, typeof(*var), timer_fieldname)
#endif

/* 7.0: register_sysctl() validates sentinel entries, causing spurious errors.
 * Use register_sysctl_sz() with explicit count to exclude sentinel. */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(7, 0, 0)
#define compat_register_sysctl(path, table) \
    register_sysctl_sz(path, table, ARRAY_SIZE(table) - 1)
#else
#define compat_register_sysctl(path, table) \
    register_sysctl(path, table)
#endif

#endif /* KERNEL_COMPAT_H */