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[v3,00/28] usb: gadget: f_tcm: Enhance UASP driver

Message ID cover.1733876548.git.Thinh.Nguyen@synopsys.com
State New
Headers show

Commit Message

Thinh Nguyen Dec. 11, 2024, 12:31 a.m. UTC
Apologies for the delay; after two years and multiple requests to resume this
series, I squeezed some time to push an update. This series applies on top of
Greg's usb-testing branch.

If possible, please help test this series and get this merged as my resources
are nil for this work.

Example Bringup Steps
=====================
To test UASP, here's an example perl script snippet to bring it up.

Note: the script was cut down and quickly rewritten, so sorry if I make
mistakes.

    my $MY_UAS_VID = xxxx;
    my $MY_UAS_PID = yyyy;
    my $SERIAL = "1234";
    my $VENDOR = "VENDOR";
    my $MY_VER = "VER";

    my $vendor_id = "my_vid";
    my $product_id = "my_pid";
    my $revision = "my_rev";

    # Must update:
    my $backing_storage = "/tmp/some_file";
    my $backing_storage_size = 1024*1024*16;
    my $use_ramdisk = 0;

    my $g = "/sys/kernel/config/usb_gadget/g1";

    system("modprobe libcomposite");
    system("modprobe usb_f_tcm");
    system("mkdir -p $g");
    system("mkdir -p $g/configs/c.1");
    system("mkdir -p $g/functions/tcm.0");
    system("mkdir -p $g/strings/0x409");
    system("mkdir -p $g/configs/c.1/strings/0x409");

    my $tp = "/sys/kernel/config/target/usb_gadget/naa.0/tpgt_1";

    my $tf;
    my $ctrl;

    if ($use_ramdisk) {
        $tf = "/sys/kernel/config/target/core/rd_mcp_0/ramdisk";
        $ctrl = 'rd_pages=524288';
    } else {
        $tf = "/sys/kernel/config/target/core/fileio_0/fileio";
        $ctrl = 'fd_dev_name=$backing_storage,fd_dev_size=$backing_storage_size,fd_async_io=1';
    }

    system("mkdir -p /etc/target");

    system("mkdir -p $tp");
    system("mkdir -p $tf");
    system("mkdir -p $tp/lun/lun_0");

    system("echo naa.0         > $tp/nexus");
    system("echo $ctrl         > $tf/control");
    system("echo 1             > $tf/attrib/emulate_ua_intlck_ctrl");
    system("echo 123           > $tf/wwn/vpd_unit_serial");
    system("echo $vendor_id    > $tf/wwn/vendor_id");
    system("echo $product_id   > $tf/wwn/product_id");
    system("echo $revision     > $tf/wwn/revision");
    system("echo 1             > $tf/enable");

    system("ln -s $tf $tp/lun/lun_0/virtual_scsi_port");
    system("echo 1             > $tp/enable");

    system("echo $MY_UAS_PID   > $g/idProduct");

    system("ln -s $g/functions/tcm.0 $g/configs/c.1");

    system("echo $MY_UAS_VID   > $g/idVendor");
    system("echo $SERIAL       > $g/strings/0x409/serialnumber");
    system("echo $VENDOR       > $g/strings/0x409/manufacturer");
    system("echo \"$MY_VER\"   > $g/strings/0x409/product");
    system("echo \"Conf 1\"    > $g/configs/c.1/strings/0x409/configuration");
    system("echo super-speed-plus > $g/max_speed");

    # Make sure the UDC is available
    system("echo $my_udc       > $g/UDC");


Target Subsystem Fixes
======================
I have eliminated unnecessary changes related to the Target subsystem and
reworked f_tcm to minimize the modifications required in the Target subsystem.
There are unimplemented Task Management Requests in the Target subsystem, but
the basic flow should still work.

Regardless, you should still need to apply at least these 2 fixes:

1) Fix Data Corruption
----------------------

Properly increment the "len" base on the command requested length instead of
the SG entry length.

If you're using File backend, then you need to fix target_core_file. If you're
using other backend such as Ramdisk, then you need a similar fix there.

---
 drivers/target/target_core_file.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index 2d78ef74633c..d9fc048c1734 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -283,7 +283,12 @@  fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 	for_each_sg(sgl, sg, sgl_nents, i) {
 		bvec_set_page(&aio_cmd->bvecs[i], sg_page(sg), sg->length,
 			      sg->offset);
-		len += sg->length;
+		if (len + sg->length >= cmd->data_length) {
+			len = cmd->data_length;
+			break;
+		} else {
+			len += sg->length;
+		}
 	}
 
 	iov_iter_bvec(&iter, is_write, aio_cmd->bvecs, sgl_nents, len);
@@ -328,7 +333,12 @@  static int fd_do_rw(struct se_cmd *cmd, struct file *fd,
 
 	for_each_sg(sgl, sg, sgl_nents, i) {
 		bvec_set_page(&bvec[i], sg_page(sg), sg->length, sg->offset);
-		len += sg->length;
+		if (len + sg->length >= data_length) {
+			len = data_length;
+			break;
+		} else {
+			len += sg->length;
+		}
 	}
 
 	iov_iter_bvec(&iter, is_write, bvec, sgl_nents, len);
-- 


2) Fix Sense Data Length
------------------------

The transport_get_sense_buffer() and transport_copy_sense_to_cmd() take
sense data length to be the allocated sense buffer length
TRANSPORT_SENSE_BUFFER. However, the sense data length is depending on
the sense data description. Check the sense data to set the proper
cmd->scsi_sense_length.

See SPC4-r37 section 4.5.2.1.
---
 drivers/target/target_core_transport.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 8d8f4ad4f59e..da75d6873ab5 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -804,8 +804,6 @@  static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
 		return NULL;
 
-	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
-
 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
 	return cmd->sense_buffer;
@@ -824,7 +822,13 @@  void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
 	}
 
 	cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
+
+	/* Sense data length = min sense data + additional sense data length */
+	cmd->scsi_sense_length = min_t(u16, cmd_sense_buf[7] + 8,
+				       TRANSPORT_SENSE_BUFFER);
+
 	memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
+
 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 }
 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
@@ -3521,12 +3525,19 @@  static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
 
 	cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
-	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
+
 	scsi_build_sense_buffer(desc_format, buffer, key, asc, ascq);
 	if (sd->add_sense_info)
 		WARN_ON_ONCE(scsi_set_sense_information(buffer,
-							cmd->scsi_sense_length,
+							TRANSPORT_SENSE_BUFFER,
 							cmd->sense_info) < 0);
+	/*
+	 * CHECK CONDITION returns sense data, and sense data is minimum 8
+	 * bytes long plus additional Sense Data Length.
+	 * See SPC4-r37 section 4.5.2.1.
+	 */
+	cmd->scsi_sense_length = min_t(u16, buffer[7] + 8,
+				       TRANSPORT_SENSE_BUFFER);
 }
 
 int