[PATCH 5/9] habanalabs: don't do memory scrubbing when unmapping

From: Oded Gabbay
Date: Thu Jun 23 2022 - 16:42:40 EST


From: Dafna Hirschfeld <dhirschfeld@xxxxxxxxx>

There is no need to do memory scrub when unmapping anymore as it is
an overhead as long as we have a single user at any given time.

Remove that code and change return value of free_phys_pg_pack to void

Signed-off-by: Dafna Hirschfeld <dhirschfeld@xxxxxxxxx>
Reviewed-by: Oded Gabbay <ogabbay@xxxxxxxxxx>
Signed-off-by: Oded Gabbay <ogabbay@xxxxxxxxxx>
---
drivers/misc/habanalabs/common/memory.c | 36 +++++--------------------
1 file changed, 6 insertions(+), 30 deletions(-)

diff --git a/drivers/misc/habanalabs/common/memory.c b/drivers/misc/habanalabs/common/memory.c
index d5e6500f8a1f..039fd87021ab 100644
--- a/drivers/misc/habanalabs/common/memory.c
+++ b/drivers/misc/habanalabs/common/memory.c
@@ -305,33 +305,20 @@ static void dram_pg_pool_do_release(struct kref *ref)
*
* This function does the following:
* - For DRAM memory only
- * - iterate over the pack, scrub and free each physical block structure by
+ * - iterate over the pack, free each physical block structure by
* returning it to the general pool.
- * In case of error during scrubbing, initiate hard reset.
- * Once hard reset is triggered, scrubbing is bypassed while freeing the
- * memory continues.
* - Free the hl_vm_phys_pg_pack structure.
*/
-static int free_phys_pg_pack(struct hl_device *hdev,
+static void free_phys_pg_pack(struct hl_device *hdev,
struct hl_vm_phys_pg_pack *phys_pg_pack)
{
struct hl_vm *vm = &hdev->vm;
u64 i;
- int rc = 0;

if (phys_pg_pack->created_from_userptr)
goto end;

if (phys_pg_pack->contiguous) {
- if (hdev->memory_scrub && !hdev->disabled) {
- rc = hdev->asic_funcs->scrub_device_mem(hdev,
- phys_pg_pack->pages[0],
- phys_pg_pack->total_size);
- if (rc)
- dev_err(hdev->dev,
- "Failed to scrub contiguous device memory\n");
- }
-
gen_pool_free(vm->dram_pg_pool, phys_pg_pack->pages[0],
phys_pg_pack->total_size);

@@ -340,15 +327,6 @@ static int free_phys_pg_pack(struct hl_device *hdev,
dram_pg_pool_do_release);
} else {
for (i = 0 ; i < phys_pg_pack->npages ; i++) {
- if (hdev->memory_scrub && !hdev->disabled && rc == 0) {
- rc = hdev->asic_funcs->scrub_device_mem(
- hdev,
- phys_pg_pack->pages[i],
- phys_pg_pack->page_size);
- if (rc)
- dev_err(hdev->dev,
- "Failed to scrub device memory\n");
- }
gen_pool_free(vm->dram_pg_pool,
phys_pg_pack->pages[i],
phys_pg_pack->page_size);
@@ -357,14 +335,11 @@ static int free_phys_pg_pack(struct hl_device *hdev,
}
}

- if (rc && !hdev->disabled)
- hl_device_reset(hdev, HL_DRV_RESET_HARD);
-
end:
kvfree(phys_pg_pack->pages);
kfree(phys_pg_pack);

- return rc;
+ return;
}

/**
@@ -409,7 +384,8 @@ static int free_device_memory(struct hl_ctx *ctx, struct hl_mem_in *args)
atomic64_sub(phys_pg_pack->total_size, &ctx->dram_phys_mem);
atomic64_sub(phys_pg_pack->total_size, &hdev->dram_used_mem);

- return free_phys_pg_pack(hdev, phys_pg_pack);
+ free_phys_pg_pack(hdev, phys_pg_pack);
+ return 0;
} else {
spin_unlock(&vm->idr_lock);
dev_err(hdev->dev,
@@ -1278,7 +1254,7 @@ static int map_device_va(struct hl_ctx *ctx, struct hl_mem_in *args, u64 *device
*device_addr = ret_vaddr;

if (is_userptr)
- rc = free_phys_pg_pack(hdev, phys_pg_pack);
+ free_phys_pg_pack(hdev, phys_pg_pack);

return rc;

--
2.25.1