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drm/gpusvm: refactor core API to use pages struct

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Refactor the core API of get/unmap/free pages to all operate on
drm_gpusvm_pages. In the next patch we want to export a simplified core
API without needing fully blown svm range etc.

Suggested-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250828142430.615826-14-matthew.auld@intel.com
This commit is contained in:
Matthew Auld
2025-08-28 15:24:35 +01:00
parent f70da6f99d
commit 6364afd532
1 changed files with 110 additions and 51 deletions
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161
drivers/gpu/drm/drm_gpusvm.c
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@@ -980,19 +980,18 @@ err_mmunlock:
EXPORT_SYMBOL_GPL(drm_gpusvm_range_find_or_insert);
/**
* __drm_gpusvm_range_unmap_pages() - Unmap pages associated with a GPU SVM range (internal)
* __drm_gpusvm_unmap_pages() - Unmap pages associated with GPU SVM pages (internal)
* @gpusvm: Pointer to the GPU SVM structure
* @range: Pointer to the GPU SVM range structure
* @svm_pages: Pointer to the GPU SVM pages structure
* @npages: Number of pages to unmap
*
* This function unmap pages associated with a GPU SVM range. Assumes and
* This function unmap pages associated with a GPU SVM pages struct. Assumes and
* asserts correct locking is in place when called.
*/
static void __drm_gpusvm_range_unmap_pages(struct drm_gpusvm *gpusvm,
struct drm_gpusvm_range *range,
unsigned long npages)
static void __drm_gpusvm_unmap_pages(struct drm_gpusvm *gpusvm,
struct drm_gpusvm_pages *svm_pages,
unsigned long npages)
{
struct drm_gpusvm_pages *svm_pages = &range->pages;
struct drm_pagemap *dpagemap = svm_pages->dpagemap;
struct device *dev = gpusvm->drm->dev;
unsigned long i, j;
@@ -1028,17 +1027,15 @@ static void __drm_gpusvm_range_unmap_pages(struct drm_gpusvm *gpusvm,
}
/**
* drm_gpusvm_range_free_pages() - Free pages associated with a GPU SVM range
* __drm_gpusvm_free_pages() - Free dma array associated with GPU SVM pages
* @gpusvm: Pointer to the GPU SVM structure
* @range: Pointer to the GPU SVM range structure
* @svm_pages: Pointer to the GPU SVM pages structure
*
* This function frees the dma address array associated with a GPU SVM range.
*/
static void drm_gpusvm_range_free_pages(struct drm_gpusvm *gpusvm,
struct drm_gpusvm_range *range)
static void __drm_gpusvm_free_pages(struct drm_gpusvm *gpusvm,
struct drm_gpusvm_pages *svm_pages)
{
struct drm_gpusvm_pages *svm_pages = &range->pages;
lockdep_assert_held(&gpusvm->notifier_lock);
if (svm_pages->dma_addr) {
@@ -1072,8 +1069,8 @@ void drm_gpusvm_range_remove(struct drm_gpusvm *gpusvm,
return;
drm_gpusvm_notifier_lock(gpusvm);
__drm_gpusvm_range_unmap_pages(gpusvm, range, npages);
drm_gpusvm_range_free_pages(gpusvm, range);
__drm_gpusvm_unmap_pages(gpusvm, &range->pages, npages);
__drm_gpusvm_free_pages(gpusvm, &range->pages);
__drm_gpusvm_range_remove(notifier, range);
drm_gpusvm_notifier_unlock(gpusvm);
@@ -1138,6 +1135,28 @@ void drm_gpusvm_range_put(struct drm_gpusvm_range *range)
}
EXPORT_SYMBOL_GPL(drm_gpusvm_range_put);
/**
* drm_gpusvm_pages_valid() - GPU SVM range pages valid
* @gpusvm: Pointer to the GPU SVM structure
* @svm_pages: Pointer to the GPU SVM pages structure
*
* This function determines if a GPU SVM range pages are valid. Expected be
* called holding gpusvm->notifier_lock and as the last step before committing a
* GPU binding. This is akin to a notifier seqno check in the HMM documentation
* but due to wider notifiers (i.e., notifiers which span multiple ranges) this
* function is required for finer grained checking (i.e., per range) if pages
* are valid.
*
* Return: True if GPU SVM range has valid pages, False otherwise
*/
static bool drm_gpusvm_pages_valid(struct drm_gpusvm *gpusvm,
struct drm_gpusvm_pages *svm_pages)
{
lockdep_assert_held(&gpusvm->notifier_lock);
return svm_pages->flags.has_devmem_pages || svm_pages->flags.has_dma_mapping;
}
/**
* drm_gpusvm_range_pages_valid() - GPU SVM range pages valid
* @gpusvm: Pointer to the GPU SVM structure
@@ -1155,11 +1174,7 @@ EXPORT_SYMBOL_GPL(drm_gpusvm_range_put);
bool drm_gpusvm_range_pages_valid(struct drm_gpusvm *gpusvm,
struct drm_gpusvm_range *range)
{
struct drm_gpusvm_pages *svm_pages = &range->pages;
lockdep_assert_held(&gpusvm->notifier_lock);
return svm_pages->flags.has_devmem_pages || svm_pages->flags.has_dma_mapping;
return drm_gpusvm_pages_valid(gpusvm, &range->pages);
}
EXPORT_SYMBOL_GPL(drm_gpusvm_range_pages_valid);
@@ -1173,57 +1188,59 @@ EXPORT_SYMBOL_GPL(drm_gpusvm_range_pages_valid);
*
* Return: True if GPU SVM range has valid pages, False otherwise
*/
static bool
drm_gpusvm_range_pages_valid_unlocked(struct drm_gpusvm *gpusvm,
struct drm_gpusvm_range *range)
static bool drm_gpusvm_pages_valid_unlocked(struct drm_gpusvm *gpusvm,
struct drm_gpusvm_pages *svm_pages)
{
struct drm_gpusvm_pages *svm_pages = &range->pages;
bool pages_valid;
if (!svm_pages->dma_addr)
return false;
drm_gpusvm_notifier_lock(gpusvm);
pages_valid = drm_gpusvm_range_pages_valid(gpusvm, range);
pages_valid = drm_gpusvm_pages_valid(gpusvm, svm_pages);
if (!pages_valid)
drm_gpusvm_range_free_pages(gpusvm, range);
__drm_gpusvm_free_pages(gpusvm, svm_pages);
drm_gpusvm_notifier_unlock(gpusvm);
return pages_valid;
}
/**
* drm_gpusvm_range_get_pages() - Get pages for a GPU SVM range
* drm_gpusvm_get_pages() - Get pages and populate GPU SVM pages struct
* @gpusvm: Pointer to the GPU SVM structure
* @range: Pointer to the GPU SVM range structure
* @svm_pages: The SVM pages to populate. This will contain the dma-addresses
* @mm: The mm corresponding to the CPU range
* @notifier: The corresponding notifier for the given CPU range
* @pages_start: Start CPU address for the pages
* @pages_end: End CPU address for the pages (exclusive)
* @ctx: GPU SVM context
*
* This function gets pages for a GPU SVM range and ensures they are mapped for
* DMA access.
* This function gets and maps pages for CPU range and ensures they are
* mapped for DMA access.
*
* Return: 0 on success, negative error code on failure.
*/
int drm_gpusvm_range_get_pages(struct drm_gpusvm *gpusvm,
struct drm_gpusvm_range *range,
const struct drm_gpusvm_ctx *ctx)
static int drm_gpusvm_get_pages(struct drm_gpusvm *gpusvm,
struct drm_gpusvm_pages *svm_pages,
struct mm_struct *mm,
struct mmu_interval_notifier *notifier,
unsigned long pages_start,
unsigned long pages_end,
const struct drm_gpusvm_ctx *ctx)
{
struct drm_gpusvm_pages *svm_pages = &range->pages;
struct mmu_interval_notifier *notifier = &range->notifier->notifier;
struct hmm_range hmm_range = {
.default_flags = HMM_PFN_REQ_FAULT | (ctx->read_only ? 0 :
HMM_PFN_REQ_WRITE),
.notifier = notifier,
.start = drm_gpusvm_range_start(range),
.end = drm_gpusvm_range_end(range),
.start = pages_start,
.end = pages_end,
.dev_private_owner = gpusvm->device_private_page_owner,
};
struct mm_struct *mm = gpusvm->mm;
void *zdd;
unsigned long timeout =
jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
unsigned long i, j;
unsigned long npages = npages_in_range(drm_gpusvm_range_start(range),
drm_gpusvm_range_end(range));
unsigned long npages = npages_in_range(pages_start, pages_end);
unsigned long num_dma_mapped;
unsigned int order = 0;
unsigned long *pfns;
@@ -1236,7 +1253,7 @@ int drm_gpusvm_range_get_pages(struct drm_gpusvm *gpusvm,
retry:
hmm_range.notifier_seq = mmu_interval_read_begin(notifier);
if (drm_gpusvm_range_pages_valid_unlocked(gpusvm, range))
if (drm_gpusvm_pages_valid_unlocked(gpusvm, svm_pages))
goto set_seqno;
pfns = kvmalloc_array(npages, sizeof(*pfns), GFP_KERNEL);
@@ -1390,7 +1407,7 @@ set_seqno:
return 0;
err_unmap:
__drm_gpusvm_range_unmap_pages(gpusvm, range, num_dma_mapped);
__drm_gpusvm_unmap_pages(gpusvm, svm_pages, num_dma_mapped);
drm_gpusvm_notifier_unlock(gpusvm);
err_free:
kvfree(pfns);
@@ -1398,8 +1415,58 @@ err_free:
goto retry;
return err;
}
/**
* drm_gpusvm_range_get_pages() - Get pages for a GPU SVM range
* @gpusvm: Pointer to the GPU SVM structure
* @range: Pointer to the GPU SVM range structure
* @ctx: GPU SVM context
*
* This function gets pages for a GPU SVM range and ensures they are mapped for
* DMA access.
*
* Return: 0 on success, negative error code on failure.
*/
int drm_gpusvm_range_get_pages(struct drm_gpusvm *gpusvm,
struct drm_gpusvm_range *range,
const struct drm_gpusvm_ctx *ctx)
{
return drm_gpusvm_get_pages(gpusvm, &range->pages, gpusvm->mm,
&range->notifier->notifier,
drm_gpusvm_range_start(range),
drm_gpusvm_range_end(range), ctx);
}
EXPORT_SYMBOL_GPL(drm_gpusvm_range_get_pages);
/**
* drm_gpusvm_unmap_pages() - Unmap GPU svm pages
* @gpusvm: Pointer to the GPU SVM structure
* @svm_pages: Pointer to the GPU SVM pages structure
* @npages: Number of pages in @svm_pages.
* @ctx: GPU SVM context
*
* This function unmaps pages associated with a GPU SVM pages struct. If
* @in_notifier is set, it is assumed that gpusvm->notifier_lock is held in
* write mode; if it is clear, it acquires gpusvm->notifier_lock in read mode.
* Must be called in the invalidate() callback of the corresponding notifier for
* IOMMU security model.
*/
static void drm_gpusvm_unmap_pages(struct drm_gpusvm *gpusvm,
struct drm_gpusvm_pages *svm_pages,
unsigned long npages,
const struct drm_gpusvm_ctx *ctx)
{
if (ctx->in_notifier)
lockdep_assert_held_write(&gpusvm->notifier_lock);
else
drm_gpusvm_notifier_lock(gpusvm);
__drm_gpusvm_unmap_pages(gpusvm, svm_pages, npages);
if (!ctx->in_notifier)
drm_gpusvm_notifier_unlock(gpusvm);
}
/**
* drm_gpusvm_range_unmap_pages() - Unmap pages associated with a GPU SVM range
* @gpusvm: Pointer to the GPU SVM structure
@@ -1419,15 +1486,7 @@ void drm_gpusvm_range_unmap_pages(struct drm_gpusvm *gpusvm,
unsigned long npages = npages_in_range(drm_gpusvm_range_start(range),
drm_gpusvm_range_end(range));
if (ctx->in_notifier)
lockdep_assert_held_write(&gpusvm->notifier_lock);
else
drm_gpusvm_notifier_lock(gpusvm);
__drm_gpusvm_range_unmap_pages(gpusvm, range, npages);
if (!ctx->in_notifier)
drm_gpusvm_notifier_unlock(gpusvm);
return drm_gpusvm_unmap_pages(gpusvm, &range->pages, npages, ctx);
}
EXPORT_SYMBOL_GPL(drm_gpusvm_range_unmap_pages);