[PATCH 6/6] habanalabs: add device memory scrub ability through debugfs

Oded Gabbay
2022-05-02T08:06:31Z

From: Dafna Hirschfeld <dhirschfeld@habana.ai>

Add the ability to scrub the device memory with a given value.
Add file 'dram_mem_scrub_val' to set the value
and a file 'dram_mem_scrub' to scrub the dram.

This is very important to help during automated tests, when you want
the CI system to randomize the memory before training certain
DL topologies.

Signed-off-by: Dafna Hirschfeld <dhirschfeld@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>
---
.../ABI/testing/debugfs-driver-habanalabs | 14 ++++++
drivers/misc/habanalabs/common/debugfs.c | 49 +++++++++++++++++++
drivers/misc/habanalabs/common/habanalabs.h | 6 +++
.../misc/habanalabs/common/habanalabs_drv.c | 8 +++
drivers/misc/habanalabs/gaudi/gaudi.c | 18 ++++---
drivers/misc/habanalabs/goya/goya.c | 6 +++
drivers/misc/habanalabs/goya/goyaP.h | 1 +
7 files changed, 94 insertions(+), 8 deletions(-)

diff --git a/Documentation/ABI/testing/debugfs-driver-habanalabs b/Documentation/ABI/testing/debugfs-driver-habanalabs
index 84bf3da2bb27..0f8d20fe343f 100644
--- a/Documentation/ABI/testing/debugfs-driver-habanalabs
+++ b/Documentation/ABI/testing/debugfs-driver-habanalabs
@@ -170,6 +170,20 @@ KernelVersion: 5.1
Contact: ogabbay@kernel.org
Description: Sets the state of the third S/W led on the device

+What: /sys/kernel/debug/habanalabs/hl<n>/memory_scrub
+Date: May 2022
+KernelVersion: 5.19
+Contact: dhirschfeld@habana.ai
+Description: Allows the root user to scrub the dram memory. The scrubbing
+ value can be set using the debugfs file memory_scrub_val.
+
+What: /sys/kernel/debug/habanalabs/hl<n>/memory_scrub_val
+Date: May 2022
+KernelVersion: 5.19
+Contact: dhirschfeld@habana.ai
+Description: The value to which the dram will be set to when the user
+ scrubs the dram using 'memory_scrub' debugfs file
+
What: /sys/kernel/debug/habanalabs/hl<n>/mmu
Date: Jan 2019
KernelVersion: 5.1
diff --git a/drivers/misc/habanalabs/common/debugfs.c b/drivers/misc/habanalabs/common/debugfs.c
index a9c4f2d4139d..c6744bfc6da4 100644
--- a/drivers/misc/habanalabs/common/debugfs.c
+++ b/drivers/misc/habanalabs/common/debugfs.c
@@ -538,6 +538,39 @@ static int engines_show(struct seq_file *s, void *data)
return 0;
}

+static ssize_t hl_memory_scrub(struct file *f, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct hl_dbg_device_entry *entry = file_inode(f)->i_private;
+ struct hl_device *hdev = entry->hdev;
+ u64 val = entry->memory_scrub_val;
+ int rc;
+
+ if (!hl_device_operational(hdev, NULL)) {
+ dev_warn_ratelimited(hdev->dev, "Can't scrub memory, device is not operational\n");
+ return -EIO;
+ }
+
+ mutex_lock(&hdev->fpriv_list_lock);
+ if (hdev->is_compute_ctx_active) {
+ mutex_unlock(&hdev->fpriv_list_lock);
+ dev_err(hdev->dev, "can't scrub dram, context exist\n");
+ return -EBUSY;
+ }
+ hdev->is_in_dram_scrub = true;
+ mutex_unlock(&hdev->fpriv_list_lock);
+
+ rc = hdev->asic_funcs->scrub_device_dram(hdev, val);
+
+ mutex_lock(&hdev->fpriv_list_lock);
+ hdev->is_in_dram_scrub = false;
+ mutex_unlock(&hdev->fpriv_list_lock);
+
+ if (rc)
+ return rc;
+ return count;
+}
+
static bool hl_is_device_va(struct hl_device *hdev, u64 addr)
{
struct asic_fixed_properties *prop = &hdev->asic_prop;
@@ -1316,6 +1349,11 @@ static ssize_t hl_timeout_locked_write(struct file *f, const char __user *buf,
return count;
}

+static const struct file_operations hl_mem_scrub_fops = {
+ .owner = THIS_MODULE,
+ .write = hl_memory_scrub,
+};
+
static const struct file_operations hl_data32b_fops = {
.owner = THIS_MODULE,
.read = hl_data_read32,
@@ -1475,6 +1513,17 @@ void hl_debugfs_add_device(struct hl_device *hdev)
dev_entry->root = debugfs_create_dir(dev_name(hdev->dev),
hl_debug_root);

+ debugfs_create_x64("memory_scrub_val",
+ 0644,
+ dev_entry->root,
+ &dev_entry->memory_scrub_val);
+
+ debugfs_create_file("memory_scrub",
+ 0200,
+ dev_entry->root,
+ dev_entry,
+ &hl_mem_scrub_fops);
+
debugfs_create_x64("addr",
0644,
dev_entry->root,
diff --git a/drivers/misc/habanalabs/common/habanalabs.h b/drivers/misc/habanalabs/common/habanalabs.h
index 496d61ee07c5..59150caa98a2 100644
--- a/drivers/misc/habanalabs/common/habanalabs.h
+++ b/drivers/misc/habanalabs/common/habanalabs.h
@@ -1246,6 +1246,7 @@ struct fw_load_mgr {
* its implementation is not trivial when the driver
* is loaded in simulation mode (not upstreamed).
* @scrub_device_mem: Scrub device memory given an address and size
+ * @scrub_device_dram: Scrub the dram memory of the device.
* @get_int_queue_base: get the internal queue base address.
* @test_queues: run simple test on all queues for sanity check.
* @asic_dma_pool_zalloc: small DMA allocation of coherent memory from DMA pool.
@@ -1357,6 +1358,7 @@ struct hl_asic_funcs {
void (*asic_dma_free_coherent)(struct hl_device *hdev, size_t size,
void *cpu_addr, dma_addr_t dma_handle);
int (*scrub_device_mem)(struct hl_device *hdev, u64 addr, u64 size);
+ int (*scrub_device_dram)(struct hl_device *hdev, u64 val);
void* (*get_int_queue_base)(struct hl_device *hdev, u32 queue_id,
dma_addr_t *dma_handle, u16 *queue_len);
int (*test_queues)(struct hl_device *hdev);
@@ -2011,6 +2013,7 @@ struct hl_debugfs_entry {
* @addr: next address to read/write from/to in read/write32.
* @mmu_addr: next virtual address to translate to physical address in mmu_show.
* @userptr_lookup: the target user ptr to look up for on demand.
+ * @memory_scrub_val: the value to which the dram will be scrubbed to using cb scrub_device_dram
* @mmu_asid: ASID to use while translating in mmu_show.
* @state_dump_head: index of the latest state dump
* @i2c_bus: generic u8 debugfs file for bus value to use in i2c_data_read.
@@ -2041,6 +2044,7 @@ struct hl_dbg_device_entry {
u64 addr;
u64 mmu_addr;
u64 userptr_lookup;
+ u64 memory_scrub_val;
u32 mmu_asid;
u32 state_dump_head;
u8 i2c_bus;
@@ -2704,6 +2708,7 @@ struct hl_reset_info {
* @id_control: minor of the control device
* @cpu_pci_msb_addr: 50-bit extension bits for the device CPU's 40-bit
* addresses.
+ * @is_in_dram_scrub: true if dram scrub operation is on going.
* @disabled: is device disabled.
* @late_init_done: is late init stage was done during initialization.
* @hwmon_initialized: is H/W monitor sensors was initialized.
@@ -2834,6 +2839,7 @@ struct hl_device {
u16 id;
u16 id_control;
u16 cpu_pci_msb_addr;
+ u8 is_in_dram_scrub;
u8 disabled;
u8 late_init_done;
u8 hwmon_initialized;
diff --git a/drivers/misc/habanalabs/common/habanalabs_drv.c b/drivers/misc/habanalabs/common/habanalabs_drv.c
index 70203433e6cd..1210de39d661 100644
--- a/drivers/misc/habanalabs/common/habanalabs_drv.c
+++ b/drivers/misc/habanalabs/common/habanalabs_drv.c
@@ -158,6 +158,14 @@ int hl_device_open(struct inode *inode, struct file *filp)
goto out_err;
}

+ if (hdev->is_in_dram_scrub) {
+ dev_dbg_ratelimited(hdev->dev,
+ "Can't open %s during dram scrub\n",
+ dev_name(hdev->dev));
+ rc = -EAGAIN;
+ goto out_err;
+ }
+
if (hdev->compute_ctx_in_release) {
dev_dbg_ratelimited(hdev->dev,
"Can't open %s because another user is still releasing it\n",
diff --git a/drivers/misc/habanalabs/gaudi/gaudi.c b/drivers/misc/habanalabs/gaudi/gaudi.c
index 8e9bdbac512e..179d9d32f9a3 100644
--- a/drivers/misc/habanalabs/gaudi/gaudi.c
+++ b/drivers/misc/habanalabs/gaudi/gaudi.c
@@ -4740,12 +4740,11 @@ static void gaudi_dma_free_coherent(struct hl_device *hdev, size_t size,
dma_free_coherent(&hdev->pdev->dev, size, cpu_addr, fixed_dma_handle);
}

-static int gaudi_hbm_scrubbing(struct hl_device *hdev)
+int gaudi_scrub_device_dram(struct hl_device *hdev, u64 val)
{
struct asic_fixed_properties *prop = &hdev->asic_prop;
u64 cur_addr = DRAM_BASE_ADDR_USER;
- u32 val;
- u32 chunk_size;
+ u32 chunk_size, busy;
int rc, dma_id;

while (cur_addr < prop->dram_end_address) {
@@ -4759,8 +4758,10 @@ static int gaudi_hbm_scrubbing(struct hl_device *hdev)
"Doing HBM scrubbing for 0x%09llx - 0x%09llx\n",
cur_addr, cur_addr + chunk_size);

- WREG32(mmDMA0_CORE_SRC_BASE_LO + dma_offset, 0xdeadbeaf);
- WREG32(mmDMA0_CORE_SRC_BASE_HI + dma_offset, 0xdeadbeaf);
+ WREG32(mmDMA0_CORE_SRC_BASE_LO + dma_offset,
+ lower_32_bits(val));
+ WREG32(mmDMA0_CORE_SRC_BASE_HI + dma_offset,
+ upper_32_bits(val));
WREG32(mmDMA0_CORE_DST_BASE_LO + dma_offset,
lower_32_bits(cur_addr));
WREG32(mmDMA0_CORE_DST_BASE_HI + dma_offset,
@@ -4783,8 +4784,8 @@ static int gaudi_hbm_scrubbing(struct hl_device *hdev)
rc = hl_poll_timeout(
hdev,
mmDMA0_CORE_STS0 + dma_offset,
- val,
- ((val & DMA0_CORE_STS0_BUSY_MASK) == 0),
+ busy,
+ ((busy & DMA0_CORE_STS0_BUSY_MASK) == 0),
1000,
HBM_SCRUBBING_TIMEOUT_US);

@@ -4838,7 +4839,7 @@ static int gaudi_scrub_device_mem(struct hl_device *hdev, u64 addr, u64 size)
}

/* Scrub HBM using all DMA channels in parallel */
- rc = gaudi_hbm_scrubbing(hdev);
+ rc = gaudi_scrub_device_dram(hdev, 0xdeadbeaf);
if (rc)
dev_err(hdev->dev,
"Failed to clear HBM in mem scrub all\n");
@@ -9208,6 +9209,7 @@ static const struct hl_asic_funcs gaudi_funcs = {
.asic_dma_alloc_coherent = gaudi_dma_alloc_coherent,
.asic_dma_free_coherent = gaudi_dma_free_coherent,
.scrub_device_mem = gaudi_scrub_device_mem,
+ .scrub_device_dram = gaudi_scrub_device_dram,
.get_int_queue_base = gaudi_get_int_queue_base,
.test_queues = gaudi_test_queues,
.asic_dma_pool_zalloc = gaudi_dma_pool_zalloc,
diff --git a/drivers/misc/habanalabs/goya/goya.c b/drivers/misc/habanalabs/goya/goya.c
index f8fb6dc04269..7983c362da67 100644
--- a/drivers/misc/habanalabs/goya/goya.c
+++ b/drivers/misc/habanalabs/goya/goya.c
@@ -5434,6 +5434,11 @@ static int goya_mmu_prefetch_cache_range(struct hl_device *hdev, u32 flags, u32
return 0;
}

+int goya_scrub_device_dram(struct hl_device *hdev, u64 val)
+{
+ return -EOPNOTSUPP;
+}
+
static const struct hl_asic_funcs goya_funcs = {
.early_init = goya_early_init,
.early_fini = goya_early_fini,
@@ -5452,6 +5457,7 @@ static const struct hl_asic_funcs goya_funcs = {
.asic_dma_alloc_coherent = goya_dma_alloc_coherent,
.asic_dma_free_coherent = goya_dma_free_coherent,
.scrub_device_mem = goya_scrub_device_mem,
+ .scrub_device_dram = goya_scrub_device_dram,
.get_int_queue_base = goya_get_int_queue_base,
.test_queues = goya_test_queues,
.asic_dma_pool_zalloc = goya_dma_pool_zalloc,
diff --git a/drivers/misc/habanalabs/goya/goyaP.h b/drivers/misc/habanalabs/goya/goyaP.h
index 647f57402616..10118d4bc87d 100644
--- a/drivers/misc/habanalabs/goya/goyaP.h
+++ b/drivers/misc/habanalabs/goya/goyaP.h
@@ -177,6 +177,7 @@ struct goya_device {
enum hl_pm_mng_profile pm_mng_profile;
};

+int goya_scrub_device_dram(struct hl_device *hdev, u64 val);
int goya_set_fixed_properties(struct hl_device *hdev);
int goya_mmu_init(struct hl_device *hdev);
void goya_init_dma_qmans(struct hl_device *hdev);
--
2.25.1