From 17c565f6031149e79b1f23942e63c002ef8dc358 Mon Sep 17 00:00:00 2001 From: Niklas Schnelle Date: Wed, 21 Jul 2021 19:58:54 +0200 Subject: [PATCH] s390/pci: fix misleading rc in clp_set_pci_fn() [ Upstream commit f7addcdd527a6dddfebe20c358b87bdb95624612 ] 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: Matthew Rosato Signed-off-by: Niklas Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin --- arch/s390/pci/pci.c | 7 ++++--- arch/s390/pci/pci_clp.c | 33 ++++++++++++++++----------------- 2 files changed, 20 insertions(+), 20 deletions(-) diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c index 8fcb7ecb7225a..77cd965cffefa 100644 --- a/arch/s390/pci/pci.c +++ b/arch/s390/pci/pci.c @@ -661,9 +661,10 @@ 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) @@ -684,7 +685,7 @@ 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; } /** diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c index d3331596ddbe1..0a0e8b8293bef 100644 --- a/arch/s390/pci/pci_clp.c +++ b/arch/s390/pci/pci_clp.c @@ -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; }