mm/hmm: remove hmm_mirror and related
The only two users of this are now converted to use mmu_interval_notifier,
delete all the code and update hmm.rst.
Link: https://lore.kernel.org/r/20191112202231.3856-14-jgg@ziepe.ca
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index cb69bf1..1225b3c 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -68,29 +68,6 @@
#include <linux/completion.h>
#include <linux/mmu_notifier.h>
-
-/*
- * struct hmm - HMM per mm struct
- *
- * @mm: mm struct this HMM struct is bound to
- * @lock: lock protecting ranges list
- * @ranges: list of range being snapshotted
- * @mirrors: list of mirrors for this mm
- * @mmu_notifier: mmu notifier to track updates to CPU page table
- * @mirrors_sem: read/write semaphore protecting the mirrors list
- * @wq: wait queue for user waiting on a range invalidation
- * @notifiers: count of active mmu notifiers
- */
-struct hmm {
- struct mmu_notifier mmu_notifier;
- spinlock_t ranges_lock;
- struct list_head ranges;
- struct list_head mirrors;
- struct rw_semaphore mirrors_sem;
- wait_queue_head_t wq;
- long notifiers;
-};
-
/*
* hmm_pfn_flag_e - HMM flag enums
*
@@ -143,9 +120,8 @@ enum hmm_pfn_value_e {
/*
* struct hmm_range - track invalidation lock on virtual address range
*
- * @notifier: an optional mmu_interval_notifier
- * @notifier_seq: when notifier is used this is the result of
- * mmu_interval_read_begin()
+ * @notifier: a mmu_interval_notifier that includes the start/end
+ * @notifier_seq: result of mmu_interval_read_begin()
* @hmm: the core HMM structure this range is active against
* @vma: the vm area struct for the range
* @list: all range lock are on a list
@@ -162,8 +138,6 @@ enum hmm_pfn_value_e {
struct hmm_range {
struct mmu_interval_notifier *notifier;
unsigned long notifier_seq;
- struct hmm *hmm;
- struct list_head list;
unsigned long start;
unsigned long end;
uint64_t *pfns;
@@ -172,33 +146,9 @@ struct hmm_range {
uint64_t default_flags;
uint64_t pfn_flags_mask;
uint8_t pfn_shift;
- bool valid;
};
/*
- * hmm_range_wait_until_valid() - wait for range to be valid
- * @range: range affected by invalidation to wait on
- * @timeout: time out for wait in ms (ie abort wait after that period of time)
- * Return: true if the range is valid, false otherwise.
- */
-static inline bool hmm_range_wait_until_valid(struct hmm_range *range,
- unsigned long timeout)
-{
- return wait_event_timeout(range->hmm->wq, range->valid,
- msecs_to_jiffies(timeout)) != 0;
-}
-
-/*
- * hmm_range_valid() - test if a range is valid or not
- * @range: range
- * Return: true if the range is valid, false otherwise.
- */
-static inline bool hmm_range_valid(struct hmm_range *range)
-{
- return range->valid;
-}
-
-/*
* hmm_device_entry_to_page() - return struct page pointed to by a device entry
* @range: range use to decode device entry value
* @entry: device entry value to get corresponding struct page from
@@ -268,111 +218,6 @@ static inline uint64_t hmm_device_entry_from_pfn(const struct hmm_range *range,
}
/*
- * Mirroring: how to synchronize device page table with CPU page table.
- *
- * A device driver that is participating in HMM mirroring must always
- * synchronize with CPU page table updates. For this, device drivers can either
- * directly use mmu_notifier APIs or they can use the hmm_mirror API. Device
- * drivers can decide to register one mirror per device per process, or just
- * one mirror per process for a group of devices. The pattern is:
- *
- * int device_bind_address_space(..., struct mm_struct *mm, ...)
- * {
- * struct device_address_space *das;
- *
- * // Device driver specific initialization, and allocation of das
- * // which contains an hmm_mirror struct as one of its fields.
- * ...
- *
- * ret = hmm_mirror_register(&das->mirror, mm, &device_mirror_ops);
- * if (ret) {
- * // Cleanup on error
- * return ret;
- * }
- *
- * // Other device driver specific initialization
- * ...
- * }
- *
- * Once an hmm_mirror is registered for an address space, the device driver
- * will get callbacks through sync_cpu_device_pagetables() operation (see
- * hmm_mirror_ops struct).
- *
- * Device driver must not free the struct containing the hmm_mirror struct
- * before calling hmm_mirror_unregister(). The expected usage is to do that when
- * the device driver is unbinding from an address space.
- *
- *
- * void device_unbind_address_space(struct device_address_space *das)
- * {
- * // Device driver specific cleanup
- * ...
- *
- * hmm_mirror_unregister(&das->mirror);
- *
- * // Other device driver specific cleanup, and now das can be freed
- * ...
- * }
- */
-
-struct hmm_mirror;
-
-/*
- * struct hmm_mirror_ops - HMM mirror device operations callback
- *
- * @update: callback to update range on a device
- */
-struct hmm_mirror_ops {
- /* release() - release hmm_mirror
- *
- * @mirror: pointer to struct hmm_mirror
- *
- * This is called when the mm_struct is being released. The callback
- * must ensure that all access to any pages obtained from this mirror
- * is halted before the callback returns. All future access should
- * fault.
- */
- void (*release)(struct hmm_mirror *mirror);
-
- /* sync_cpu_device_pagetables() - synchronize page tables
- *
- * @mirror: pointer to struct hmm_mirror
- * @update: update information (see struct mmu_notifier_range)
- * Return: -EAGAIN if mmu_notifier_range_blockable(update) is false
- * and callback needs to block, 0 otherwise.
- *
- * This callback ultimately originates from mmu_notifiers when the CPU
- * page table is updated. The device driver must update its page table
- * in response to this callback. The update argument tells what action
- * to perform.
- *
- * The device driver must not return from this callback until the device
- * page tables are completely updated (TLBs flushed, etc); this is a
- * synchronous call.
- */
- int (*sync_cpu_device_pagetables)(
- struct hmm_mirror *mirror,
- const struct mmu_notifier_range *update);
-};
-
-/*
- * struct hmm_mirror - mirror struct for a device driver
- *
- * @hmm: pointer to struct hmm (which is unique per mm_struct)
- * @ops: device driver callback for HMM mirror operations
- * @list: for list of mirrors of a given mm
- *
- * Each address space (mm_struct) being mirrored by a device must register one
- * instance of an hmm_mirror struct with HMM. HMM will track the list of all
- * mirrors for each mm_struct.
- */
-struct hmm_mirror {
- struct hmm *hmm;
- const struct hmm_mirror_ops *ops;
- struct list_head list;
-};
-
-/*
* Retry fault if non-blocking, drop mmap_sem and return -EAGAIN in that case.
*/
#define HMM_FAULT_ALLOW_RETRY (1 << 0)
@@ -381,15 +226,9 @@ struct hmm_mirror {
#define HMM_FAULT_SNAPSHOT (1 << 1)
#ifdef CONFIG_HMM_MIRROR
-int hmm_mirror_register(struct hmm_mirror *mirror, struct mm_struct *mm);
-void hmm_mirror_unregister(struct hmm_mirror *mirror);
-
/*
* Please see Documentation/vm/hmm.rst for how to use the range API.
*/
-int hmm_range_register(struct hmm_range *range, struct hmm_mirror *mirror);
-void hmm_range_unregister(struct hmm_range *range);
-
long hmm_range_fault(struct hmm_range *range, unsigned int flags);
long hmm_range_dma_map(struct hmm_range *range,
@@ -401,24 +240,6 @@ long hmm_range_dma_unmap(struct hmm_range *range,
dma_addr_t *daddrs,
bool dirty);
#else
-int hmm_mirror_register(struct hmm_mirror *mirror, struct mm_struct *mm)
-{
- return -EOPNOTSUPP;
-}
-
-void hmm_mirror_unregister(struct hmm_mirror *mirror)
-{
-}
-
-int hmm_range_register(struct hmm_range *range, struct hmm_mirror *mirror)
-{
- return -EOPNOTSUPP;
-}
-
-void hmm_range_unregister(struct hmm_range *range)
-{
-}
-
static inline long hmm_range_fault(struct hmm_range *range, unsigned int flags)
{
return -EOPNOTSUPP;