Add an operation to populate a part of a drm_mm with device
private memory.
Signed-off-by: Thomas Hellström <thomas.hellst...@linux.intel.com>
---
drivers/gpu/drm/drm_gpusvm.c | 7 ++-----
drivers/gpu/drm/drm_pagemap.c | 32 ++++++++++++++++++++++++++++++++
include/drm/drm_pagemap.h | 32 ++++++++++++++++++++++++++++++++
3 files changed, 66 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_gpusvm.c b/drivers/gpu/drm/drm_gpusvm.c
index 4fade7018507..d84e27283768 100644
--- a/drivers/gpu/drm/drm_gpusvm.c
+++ b/drivers/gpu/drm/drm_gpusvm.c
@@ -175,11 +175,8 @@
* }
*
* if (driver_migration_policy(range)) {
- * mmap_read_lock(mm);
- * devmem = driver_alloc_devmem();
- * err = drm_pagemap_migrate_to_devmem(devmem, gpusvm->mm,
gpuva_start,
- * gpuva_end,
driver_pgmap_owner());
- * mmap_read_unlock(mm);
+ * err =
drm_pagemap_populate_mm(driver_choose_drm_pagemap(),
+ * gpuva_start, gpuva_end,
gpusvm->mm);
* if (err) // CPU mappings may have changed
* goto retry;
* }
diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
index c46bb4384444..27e3f90cf49a 100644
--- a/drivers/gpu/drm/drm_pagemap.c
+++ b/drivers/gpu/drm/drm_pagemap.c
@@ -6,6 +6,7 @@
#include <linux/dma-mapping.h>
#include <linux/migrate.h>
#include <linux/pagemap.h>
+#include <drm/drm_drv.h>
#include <drm/drm_pagemap.h>
/**
@@ -782,3 +783,34 @@ struct drm_pagemap *drm_pagemap_page_to_dpagemap(struct
page *page)
return zdd->devmem_allocation->dpagemap;
}
EXPORT_SYMBOL_GPL(drm_pagemap_page_to_dpagemap);
+
+/**
+ * drm_pagemap_populate_mm() - Populate a virtual range with device memory
pages
+ * @dpagemap: Pointer to the drm_pagemap managing the device memory
+ * @start: Start of the virtual range to populate.
+ * @end: End of the virtual range to populate.
+ * @mm: Pointer to the virtual address space.
+ *
+ * Attempt to populate a virtual range with device memory pages,
+ * clearing them or migrating data from the existing pages if necessary.
+ * The function is best effort only, and implementations may vary
+ * in how hard they try to satisfy the request.
+ *
+ * Return: 0 on success, negative error code on error. If the hardware
+ * device was removed / unbound the function will return -ENODEV;
+ */
+int drm_pagemap_populate_mm(struct drm_pagemap *dpagemap,
+ unsigned long start, unsigned long end,
+ struct mm_struct *mm)
+{
+ int err;
+
+ if (!mmget_not_zero(mm))
+ return -EFAULT;
+ mmap_read_lock(mm);
+ err = dpagemap->ops->populate_mm(dpagemap, start, end, mm);
+ mmap_read_unlock(mm);
+ mmput(mm);
+
+ return err;
+}
diff --git a/include/drm/drm_pagemap.h b/include/drm/drm_pagemap.h
index 32f0d7f23075..c591736e7c48 100644
--- a/include/drm/drm_pagemap.h
+++ b/include/drm/drm_pagemap.h
@@ -92,6 +92,34 @@ struct drm_pagemap_ops {
struct device *dev,
struct drm_pagemap_device_addr addr);
+ /**
+ * @populate_mm: Populate part of the mm with @dpagemap memory,
+ * migrating existing data.
+ * @dpagemap: The struct drm_pagemap managing the memory.
+ * @start: The virtual start address in @mm
+ * @end: The virtual end address in @mm
+ * @mm: Pointer to a live mm. The caller must have an mmget()
+ * reference.
+ *
+ * The caller will have the mm lock at least in read mode.
+ * Note that there is no guarantee that the memory is resident
+ * after the function returns, it's best effort only.
+ * When the mm is not using the memory anymore,
+ * it will be released. The struct drm_pagemap might have a
+ * mechanism in place to reclaim the memory and the data will
+ * then be migrated. Typically to system memory.
+ * The implementation should hold sufficient runtime power-
+ * references while pages are used in an address space and
+ * should ideally guard against hardware device unbind in
+ * a way such that device pages are migrated back to system
+ * followed by device page removal. The implementation should
+ * return -ENODEV after device removal.
+ *
+ * Return: 0 if successful. Negative error code on error.
+ */
+ int (*populate_mm)(struct drm_pagemap *dpagemap,
+ unsigned long start, unsigned long end,
+ struct mm_struct *mm);
};
/**
@@ -202,4 +230,8 @@ void drm_pagemap_devmem_init(struct drm_pagemap_devmem
*devmem_allocation,
const struct drm_pagemap_devmem_ops *ops,
struct drm_pagemap *dpagemap, size_t size);
+int drm_pagemap_populate_mm(struct drm_pagemap *dpagemap,
+ unsigned long start, unsigned long end,
+ struct mm_struct *mm);
+
#endif
--
2.48.1
