Commit f7addcdd authored by Niklas Schnelle's avatar Niklas Schnelle Committed by Heiko Carstens
Browse files

s390/pci: fix misleading rc in clp_set_pci_fn() 



Currently clp_set_pci_fn() always returns 0 as long as the CLP request
itself succeeds even if the operation itself returns a response code
other than CLP_RC_OK or CLP_RC_SETPCIFN_ALRDY. This is highly misleading
because calling code assumes that a zero rc means that the operation was
successful.

Fix this by returning the response code or cc on failure with the
exception of the special handling for CLP_RC_SETPCIFN_ALRDY. Also let's
not assume that the returned function handle for CLP_RC_SETPCIFN_ALRDY
is 0, we don't need it anyway.

Reviewed-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: default avatarNiklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent e8f06683

arch/s390/pci/pci.c

+4 −3
Original line number Diff line number Diff line
@@ -655,9 +655,10 @@ int zpci_enable_device(struct zpci_dev *zdev) 
{

	int rc;



	rc = clp_enable_fh(zdev, ZPCI_NR_DMA_SPACES);

	if (rc)

	if (clp_enable_fh(zdev, ZPCI_NR_DMA_SPACES)) {

		rc = -EIO;

		goto out;

	}



	rc = zpci_dma_init_device(zdev);

	if (rc)
@@ -678,7 +679,7 @@ int zpci_disable_device(struct zpci_dev *zdev) 
	 * The zPCI function may already be disabled by the platform, this is

	 * detected in clp_disable_fh() which becomes a no-op.

	 */

	return clp_disable_fh(zdev);

	return clp_disable_fh(zdev) ? -EIO : 0;

}



/**

arch/s390/pci/pci_clp.c

+16 −17
Original line number Diff line number Diff line
@@ -213,15 +213,19 @@ int clp_query_pci_fn(struct zpci_dev *zdev) 
}



static int clp_refresh_fh(u32 fid);

/*

 * Enable/Disable a given PCI function and update its function handle if

 * necessary

/**

 * clp_set_pci_fn() - Execute a command on a PCI function

 * @zdev: Function that will be affected

 * @nr_dma_as: DMA address space number

 * @command: The command code to execute

 *

 * Returns: 0 on success, < 0 for Linux errors (e.g. -ENOMEM), and

 * > 0 for non-success platform responses

 */

static int clp_set_pci_fn(struct zpci_dev *zdev, u8 nr_dma_as, u8 command)

{

	struct clp_req_rsp_set_pci *rrb;

	int rc, retries = 100;

	u32 fid = zdev->fid;



	rrb = clp_alloc_block(GFP_KERNEL);

	if (!rrb)
@@ -245,17 +249,16 @@ static int clp_set_pci_fn(struct zpci_dev *zdev, u8 nr_dma_as, u8 command) 
		}

	} while (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY);



	if (rc || rrb->response.hdr.rsp != CLP_RC_OK) {

		zpci_err("Set PCI FN:\n");

		zpci_err_clp(rrb->response.hdr.rsp, rc);

	}



	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {

		zdev->fh = rrb->response.fh;

	} else if (!rc && rrb->response.hdr.rsp == CLP_RC_SETPCIFN_ALRDY &&

			rrb->response.fh == 0) {

	} else if (!rc && rrb->response.hdr.rsp == CLP_RC_SETPCIFN_ALRDY) {

		/* Function is already in desired state - update handle */

		rc = clp_refresh_fh(fid);

		rc = clp_refresh_fh(zdev->fid);

	} else {

		zpci_err("Set PCI FN:\n");

		zpci_err_clp(rrb->response.hdr.rsp, rc);

		if (!rc)

			rc = rrb->response.hdr.rsp;

	}

	clp_free_block(rrb);

	return rc;
@@ -301,17 +304,13 @@ int clp_enable_fh(struct zpci_dev *zdev, u8 nr_dma_as) 


	rc = clp_set_pci_fn(zdev, nr_dma_as, CLP_SET_ENABLE_PCI_FN);

	zpci_dbg(3, "ena fid:%x, fh:%x, rc:%d\n", zdev->fid, zdev->fh, rc);

	if (rc)

		goto out;



	if (zpci_use_mio(zdev)) {

	if (!rc && zpci_use_mio(zdev)) {

		rc = clp_set_pci_fn(zdev, nr_dma_as, CLP_SET_ENABLE_MIO);

		zpci_dbg(3, "ena mio fid:%x, fh:%x, rc:%d\n",

				zdev->fid, zdev->fh, rc);

		if (rc)

			clp_disable_fh(zdev);

	}

out:

	return rc;

}