forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
121 lines
4.1 KiB
121 lines
4.1 KiB
/* SPDX-License-Identifier: GPL-2.0-or-later */ |
|
/* |
|
* Copyright 2013 Red Hat Inc. |
|
* |
|
* Authors: Jérôme Glisse <[email protected]> |
|
* |
|
* See Documentation/vm/hmm.rst for reasons and overview of what HMM is. |
|
*/ |
|
#ifndef LINUX_HMM_H |
|
#define LINUX_HMM_H |
|
|
|
#include <linux/kconfig.h> |
|
#include <linux/pgtable.h> |
|
|
|
#include <linux/device.h> |
|
#include <linux/migrate.h> |
|
#include <linux/memremap.h> |
|
#include <linux/completion.h> |
|
#include <linux/mmu_notifier.h> |
|
|
|
/* |
|
* On output: |
|
* 0 - The page is faultable and a future call with |
|
* HMM_PFN_REQ_FAULT could succeed. |
|
* HMM_PFN_VALID - the pfn field points to a valid PFN. This PFN is at |
|
* least readable. If dev_private_owner is !NULL then this could |
|
* point at a DEVICE_PRIVATE page. |
|
* HMM_PFN_WRITE - if the page memory can be written to (requires HMM_PFN_VALID) |
|
* HMM_PFN_ERROR - accessing the pfn is impossible and the device should |
|
* fail. ie poisoned memory, special pages, no vma, etc |
|
* |
|
* On input: |
|
* 0 - Return the current state of the page, do not fault it. |
|
* HMM_PFN_REQ_FAULT - The output must have HMM_PFN_VALID or hmm_range_fault() |
|
* will fail |
|
* HMM_PFN_REQ_WRITE - The output must have HMM_PFN_WRITE or hmm_range_fault() |
|
* will fail. Must be combined with HMM_PFN_REQ_FAULT. |
|
*/ |
|
enum hmm_pfn_flags { |
|
/* Output fields and flags */ |
|
HMM_PFN_VALID = 1UL << (BITS_PER_LONG - 1), |
|
HMM_PFN_WRITE = 1UL << (BITS_PER_LONG - 2), |
|
HMM_PFN_ERROR = 1UL << (BITS_PER_LONG - 3), |
|
HMM_PFN_ORDER_SHIFT = (BITS_PER_LONG - 8), |
|
|
|
/* Input flags */ |
|
HMM_PFN_REQ_FAULT = HMM_PFN_VALID, |
|
HMM_PFN_REQ_WRITE = HMM_PFN_WRITE, |
|
|
|
HMM_PFN_FLAGS = 0xFFUL << HMM_PFN_ORDER_SHIFT, |
|
}; |
|
|
|
/* |
|
* hmm_pfn_to_page() - return struct page pointed to by a device entry |
|
* |
|
* This must be called under the caller 'user_lock' after a successful |
|
* mmu_interval_read_begin(). The caller must have tested for HMM_PFN_VALID |
|
* already. |
|
*/ |
|
static inline struct page *hmm_pfn_to_page(unsigned long hmm_pfn) |
|
{ |
|
return pfn_to_page(hmm_pfn & ~HMM_PFN_FLAGS); |
|
} |
|
|
|
/* |
|
* hmm_pfn_to_map_order() - return the CPU mapping size order |
|
* |
|
* This is optionally useful to optimize processing of the pfn result |
|
* array. It indicates that the page starts at the order aligned VA and is |
|
* 1<<order bytes long. Every pfn within an high order page will have the |
|
* same pfn flags, both access protections and the map_order. The caller must |
|
* be careful with edge cases as the start and end VA of the given page may |
|
* extend past the range used with hmm_range_fault(). |
|
* |
|
* This must be called under the caller 'user_lock' after a successful |
|
* mmu_interval_read_begin(). The caller must have tested for HMM_PFN_VALID |
|
* already. |
|
*/ |
|
static inline unsigned int hmm_pfn_to_map_order(unsigned long hmm_pfn) |
|
{ |
|
return (hmm_pfn >> HMM_PFN_ORDER_SHIFT) & 0x1F; |
|
} |
|
|
|
/* |
|
* struct hmm_range - track invalidation lock on virtual address range |
|
* |
|
* @notifier: a mmu_interval_notifier that includes the start/end |
|
* @notifier_seq: result of mmu_interval_read_begin() |
|
* @start: range virtual start address (inclusive) |
|
* @end: range virtual end address (exclusive) |
|
* @hmm_pfns: array of pfns (big enough for the range) |
|
* @default_flags: default flags for the range (write, read, ... see hmm doc) |
|
* @pfn_flags_mask: allows to mask pfn flags so that only default_flags matter |
|
* @dev_private_owner: owner of device private pages |
|
*/ |
|
struct hmm_range { |
|
struct mmu_interval_notifier *notifier; |
|
unsigned long notifier_seq; |
|
unsigned long start; |
|
unsigned long end; |
|
unsigned long *hmm_pfns; |
|
unsigned long default_flags; |
|
unsigned long pfn_flags_mask; |
|
void *dev_private_owner; |
|
}; |
|
|
|
/* |
|
* Please see Documentation/vm/hmm.rst for how to use the range API. |
|
*/ |
|
int hmm_range_fault(struct hmm_range *range); |
|
|
|
/* |
|
* HMM_RANGE_DEFAULT_TIMEOUT - default timeout (ms) when waiting for a range |
|
* |
|
* When waiting for mmu notifiers we need some kind of time out otherwise we |
|
* could potentialy wait for ever, 1000ms ie 1s sounds like a long time to |
|
* wait already. |
|
*/ |
|
#define HMM_RANGE_DEFAULT_TIMEOUT 1000 |
|
|
|
#endif /* LINUX_HMM_H */
|
|
|