[PATCH 5/5] habanalabs: leave space for 2xMSG_PROT in CB

From: Oded Gabbay
Date: Sat Apr 18 2020 - 04:25:00 EST


The user must leave space for 2xMSG_PROT in the external CB, so adjust the
define of max size accordingly. The driver, however, can still create a CB
with the maximum size of 2MB. Therefore, we need to add a check
specifically for the user requested size.

Signed-off-by: Oded Gabbay <oded.gabbay@xxxxxxxxx>
---
drivers/misc/habanalabs/command_buffer.c | 24 +++++++++++++++++-------
include/uapi/misc/habanalabs.h | 3 ++-
2 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/drivers/misc/habanalabs/command_buffer.c b/drivers/misc/habanalabs/command_buffer.c
index 53fddbd8e693..6cb92efce4d9 100644
--- a/drivers/misc/habanalabs/command_buffer.c
+++ b/drivers/misc/habanalabs/command_buffer.c
@@ -105,10 +105,9 @@ int hl_cb_create(struct hl_device *hdev, struct hl_cb_mgr *mgr,
goto out_err;
}

- if (cb_size > HL_MAX_CB_SIZE) {
- dev_err(hdev->dev,
- "CB size %d must be less then %d\n",
- cb_size, HL_MAX_CB_SIZE);
+ if (cb_size > SZ_2M) {
+ dev_err(hdev->dev, "CB size %d must be less than %d\n",
+ cb_size, SZ_2M);
rc = -EINVAL;
goto out_err;
}
@@ -211,7 +210,7 @@ int hl_cb_ioctl(struct hl_fpriv *hpriv, void *data)
{
union hl_cb_args *args = data;
struct hl_device *hdev = hpriv->hdev;
- u64 handle;
+ u64 handle = 0;
int rc;

if (hl_device_disabled_or_in_reset(hdev)) {
@@ -223,15 +222,26 @@ int hl_cb_ioctl(struct hl_fpriv *hpriv, void *data)

switch (args->in.op) {
case HL_CB_OP_CREATE:
- rc = hl_cb_create(hdev, &hpriv->cb_mgr, args->in.cb_size,
- &handle, hpriv->ctx->asid);
+ if (args->in.cb_size > HL_MAX_CB_SIZE) {
+ dev_err(hdev->dev,
+ "User requested CB size %d must be less than %d\n",
+ args->in.cb_size, HL_MAX_CB_SIZE);
+ rc = -EINVAL;
+ } else {
+ rc = hl_cb_create(hdev, &hpriv->cb_mgr,
+ args->in.cb_size, &handle,
+ hpriv->ctx->asid);
+ }
+
memset(args, 0, sizeof(*args));
args->out.cb_handle = handle;
break;
+
case HL_CB_OP_DESTROY:
rc = hl_cb_destroy(hdev, &hpriv->cb_mgr,
args->in.cb_handle);
break;
+
default:
rc = -ENOTTY;
break;
diff --git a/include/uapi/misc/habanalabs.h b/include/uapi/misc/habanalabs.h
index 4d593050c42b..523e511e6cff 100644
--- a/include/uapi/misc/habanalabs.h
+++ b/include/uapi/misc/habanalabs.h
@@ -209,7 +209,8 @@ struct hl_info_args {
/* Opcode to destroy previously created command buffer */
#define HL_CB_OP_DESTROY 1

-#define HL_MAX_CB_SIZE 0x200000 /* 2MB */
+/* 2MB minus 32 bytes for 2xMSG_PROT */
+#define HL_MAX_CB_SIZE (0x200000 - 32)

struct hl_cb_in {
/* Handle of CB or 0 if we want to create one */
--
2.17.1