habanalabs: add new mem ioctl op for mapping hw blocks

For future ASIC support the driver allows user to map certain regions
in the device's configuration space for direct access from userspace.

Signed-off-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

5 files changed, 137 insertions, 8 deletions

diff --git a/drivers/misc/habanalabs/common/device.c b/drivers/misc/habanalabs/common/device.c
index 13405d47d843..59219c862ca0 100644
--- a/drivers/misc/habanalabs/common/device.c
+++ b/drivers/misc/habanalabs/common/device.c
@@ -142,6 +142,9 @@ static int hl_mmap(struct file *filp, struct vm_area_struct *vma)
 	switch (vm_pgoff & HL_MMAP_TYPE_MASK) {
 	case HL_MMAP_TYPE_CB:
 		return hl_cb_mmap(hpriv, vma);
+
+	case HL_MMAP_TYPE_BLOCK:
+		return hl_hw_block_mmap(hpriv, vma);
 	}
 
 	return -EINVAL;
diff --git a/drivers/misc/habanalabs/common/habanalabs.h b/drivers/misc/habanalabs/common/habanalabs.h
index 4129e4e6a7b5..e105612ed577 100644
--- a/drivers/misc/habanalabs/common/habanalabs.h
+++ b/drivers/misc/habanalabs/common/habanalabs.h
@@ -28,17 +28,18 @@
 #define HL_NAME				"habanalabs"
 
 /* Use upper bits of mmap offset to store habana driver specific information.
- * bits[63:62] - Encode mmap type
+ * bits[63:61] - Encode mmap type
  * bits[45:0]  - mmap offset value
  *
  * NOTE: struct vm_area_struct.vm_pgoff uses offset in pages. Hence, these
  *  defines are w.r.t to PAGE_SIZE
  */
-#define HL_MMAP_TYPE_SHIFT		(62 - PAGE_SHIFT)
-#define HL_MMAP_TYPE_MASK		(0x3ull << HL_MMAP_TYPE_SHIFT)
+#define HL_MMAP_TYPE_SHIFT		(61 - PAGE_SHIFT)
+#define HL_MMAP_TYPE_MASK		(0x7ull << HL_MMAP_TYPE_SHIFT)
+#define HL_MMAP_TYPE_BLOCK		(0x4ull << HL_MMAP_TYPE_SHIFT)
 #define HL_MMAP_TYPE_CB			(0x2ull << HL_MMAP_TYPE_SHIFT)
 
-#define HL_MMAP_OFFSET_VALUE_MASK	(0x3FFFFFFFFFFFull >> PAGE_SHIFT)
+#define HL_MMAP_OFFSET_VALUE_MASK	(0x1FFFFFFFFFFFull >> PAGE_SHIFT)
 #define HL_MMAP_OFFSET_VALUE_GET(off)	(off & HL_MMAP_OFFSET_VALUE_MASK)
 
 #define HL_PENDING_RESET_PER_SEC	10
@@ -856,6 +857,8 @@ enum div_select_defs {
  * @descramble_addr: Routine to de-scramble the address prior of
  *                  showing it to users.
  * @ack_protection_bits_errors: ack and dump all security violations
+ * @get_hw_block_id: retrieve a HW block id to be used by the user to mmap it.
+ * @hw_block_mmap: mmap a HW block with a given id.
  */
 struct hl_asic_funcs {
 	int (*early_init)(struct hl_device *hdev);
@@ -968,6 +971,10 @@ struct hl_asic_funcs {
 	u64 (*scramble_addr)(struct hl_device *hdev, u64 addr);
 	u64 (*descramble_addr)(struct hl_device *hdev, u64 addr);
 	void (*ack_protection_bits_errors)(struct hl_device *hdev);
+	int (*get_hw_block_id)(struct hl_device *hdev, u64 block_addr,
+			u32 *block_id);
+	int (*hw_block_mmap)(struct hl_device *hdev, struct vm_area_struct *vma,
+			u32 block_id, u32 block_size);
 };
 
 
@@ -2167,6 +2174,7 @@ int hl_cb_create(struct hl_device *hdev, struct hl_cb_mgr *mgr,
 			bool map_cb, u64 *handle);
 int hl_cb_destroy(struct hl_device *hdev, struct hl_cb_mgr *mgr, u64 cb_handle);
 int hl_cb_mmap(struct hl_fpriv *hpriv, struct vm_area_struct *vma);
+int hl_hw_block_mmap(struct hl_fpriv *hpriv, struct vm_area_struct *vma);
 struct hl_cb *hl_cb_get(struct hl_device *hdev,	struct hl_cb_mgr *mgr,
 			u32 handle);
 void hl_cb_put(struct hl_cb *cb);
diff --git a/drivers/misc/habanalabs/common/memory.c b/drivers/misc/habanalabs/common/memory.c
index 36de0d05d3a2..7171e8820a2d 100644
--- a/drivers/misc/habanalabs/common/memory.c
+++ b/drivers/misc/habanalabs/common/memory.c
@@ -1289,11 +1289,88 @@ vm_type_err:
 	return rc;
 }
 
+static int map_block(struct hl_device *hdev, u64 address, u64 *handle)
+{
+	u32 block_id = 0;
+	int rc;
+
+	rc = hdev->asic_funcs->get_hw_block_id(hdev, address, &block_id);
+
+	*handle = block_id | HL_MMAP_TYPE_BLOCK;
+	*handle <<= PAGE_SHIFT;
+
+	return rc;
+}
+
+static void hw_block_vm_close(struct vm_area_struct *vma)
+{
+	struct hl_ctx *ctx = (struct hl_ctx *) vma->vm_private_data;
+
+	hl_ctx_put(ctx);
+	vma->vm_private_data = NULL;
+}
+
+static const struct vm_operations_struct hw_block_vm_ops = {
+	.close = hw_block_vm_close
+};
+
+/**
+ * hl_hw_block_mmap() - mmap a hw block to user.
+ * @hpriv: pointer to the private data of the fd
+ * @vma: pointer to vm_area_struct of the process
+ *
+ * Driver increments context reference for every HW block mapped in order
+ * to prevent user from closing FD without unmapping first
+ */
+int hl_hw_block_mmap(struct hl_fpriv *hpriv, struct vm_area_struct *vma)
+{
+	struct hl_device *hdev = hpriv->hdev;
+	u32 block_id, block_size;
+	int rc;
+
+	/* We use the page offset to hold the block id and thus we need to clear
+	 * it before doing the mmap itself
+	 */
+	block_id = vma->vm_pgoff;
+	vma->vm_pgoff = 0;
+
+	/* Driver only allows mapping of a complete HW block */
+	block_size = vma->vm_end - vma->vm_start;
+
+#ifdef _HAS_TYPE_ARG_IN_ACCESS_OK
+	if (!access_ok(VERIFY_WRITE,
+		(void __user *) (uintptr_t) vma->vm_start, block_size)) {
+#else
+	if (!access_ok((void __user *) (uintptr_t) vma->vm_start, block_size)) {
+#endif
+		dev_err(hdev->dev,
+			"user pointer is invalid - 0x%lx\n",
+			vma->vm_start);
+
+		return -EINVAL;
+	}
+
+	vma->vm_ops = &hw_block_vm_ops;
+	vma->vm_private_data = hpriv->ctx;
+
+	hl_ctx_get(hdev, hpriv->ctx);
+
+	rc = hdev->asic_funcs->hw_block_mmap(hdev, vma, block_id, block_size);
+	if (rc) {
+		hl_ctx_put(hpriv->ctx);
+		return rc;
+	}
+
+	vma->vm_pgoff = block_id;
+
+	return 0;
+}
+
 static int mem_ioctl_no_mmu(struct hl_fpriv *hpriv, union hl_mem_args *args)
 {
 	struct hl_device *hdev = hpriv->hdev;
 	struct hl_ctx *ctx = hpriv->ctx;
-	u64 device_addr = 0;
+	u64 block_handle, device_addr = 0;
 	u32 handle = 0;
 	int rc;
 
@@ -1337,6 +1414,12 @@ static int mem_ioctl_no_mmu(struct hl_fpriv *hpriv, union hl_mem_args *args)
 		rc = 0;
 		break;
 
+	case HL_MEM_OP_MAP_BLOCK:
+		rc = map_block(hdev, args->in.map_block.block_addr,
+							&block_handle);
+		args->out.handle = block_handle;
+		break;
+
 	default:
 		dev_err(hdev->dev, "Unknown opcode for memory IOCTL\n");
 		rc = -ENOTTY;
@@ -1353,7 +1436,7 @@ int hl_mem_ioctl(struct hl_fpriv *hpriv, void *data)
 	union hl_mem_args *args = data;
 	struct hl_device *hdev = hpriv->hdev;
 	struct hl_ctx *ctx = hpriv->ctx;
-	u64 device_addr = 0;
+	u64 block_handle, device_addr = 0;
 	u32 handle = 0;
 	int rc;
 
@@ -1439,6 +1522,12 @@ int hl_mem_ioctl(struct hl_fpriv *hpriv, void *data)
 		rc = unmap_device_va(ctx, &args->in, false);
 		break;
 
+	case HL_MEM_OP_MAP_BLOCK:
+		rc = map_block(hdev, args->in.map_block.block_addr,
+							&block_handle);
+		args->out.handle = block_handle;
+		break;
+
 	default:
 		dev_err(hdev->dev, "Unknown opcode for memory IOCTL\n");
 		rc = -ENOTTY;
diff --git a/drivers/misc/habanalabs/gaudi/gaudi.c b/drivers/misc/habanalabs/gaudi/gaudi.c
index b49e10394ed4..e1c6072e5fb3 100644
--- a/drivers/misc/habanalabs/gaudi/gaudi.c
+++ b/drivers/misc/habanalabs/gaudi/gaudi.c
@@ -8471,6 +8471,19 @@ static u64 gaudi_get_device_time(struct hl_device *hdev)
 	return device_time | RREG32(mmPSOC_TIMESTAMP_CNTCVL);
 }
 
+static int gaudi_get_hw_block_id(struct hl_device *hdev, u64 block_addr,
+					u32 *block_id)
+{
+	return -EPERM;
+}
+
+static int gaudi_block_mmap(struct hl_device *hdev,
+				struct vm_area_struct *vma,
+				u32 block_id, u32 block_size)
+{
+	return -EPERM;
+}
+
 static const struct hl_asic_funcs gaudi_funcs = {
 	.early_init = gaudi_early_init,
 	.early_fini = gaudi_early_fini,
@@ -8550,7 +8563,9 @@ static const struct hl_asic_funcs gaudi_funcs = {
 	.collective_wait_create_jobs = gaudi_collective_wait_create_jobs,
 	.scramble_addr = hl_mmu_scramble_addr,
 	.descramble_addr = hl_mmu_descramble_addr,
-	.ack_protection_bits_errors = gaudi_ack_protection_bits_errors
+	.ack_protection_bits_errors = gaudi_ack_protection_bits_errors,
+	.get_hw_block_id = gaudi_get_hw_block_id,
+	.hw_block_mmap = gaudi_block_mmap
 };
 
 /**
diff --git a/drivers/misc/habanalabs/goya/goya.c b/drivers/misc/habanalabs/goya/goya.c
index db951d622ad5..6b4c41188495 100644
--- a/drivers/misc/habanalabs/goya/goya.c
+++ b/drivers/misc/habanalabs/goya/goya.c
@@ -5382,6 +5382,18 @@ static void goya_ctx_fini(struct hl_ctx *ctx)
 
 }
 
+static int goya_get_hw_block_id(struct hl_device *hdev, u64 block_addr,
+				u32 *block_id)
+{
+	return -EPERM;
+}
+
+static int goya_block_mmap(struct hl_device *hdev, struct vm_area_struct *vma,
+				u32 block_id, u32 block_size)
+{
+	return -EPERM;
+}
+
 static const struct hl_asic_funcs goya_funcs = {
 	.early_init = goya_early_init,
 	.early_fini = goya_early_fini,
@@ -5461,7 +5473,9 @@ static const struct hl_asic_funcs goya_funcs = {
 	.collective_wait_create_jobs = goya_collective_wait_create_jobs,
 	.scramble_addr = hl_mmu_scramble_addr,
 	.descramble_addr = hl_mmu_descramble_addr,
-	.ack_protection_bits_errors = goya_ack_protection_bits_errors
+	.ack_protection_bits_errors = goya_ack_protection_bits_errors,
+	.get_hw_block_id = goya_get_hw_block_id,
+	.hw_block_mmap = goya_block_mmap
 };
 
 /*