This is a note to let you know that I've just added the patch titled s390/pci: refactor zpci_create_device() to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: s390-pci-refactor-zpci_create_device.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ba764dd703feacb5a9c410d191af1b6cfbe96845 Mon Sep 17 00:00:00 2001 From: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> Date: Wed, 22 Jul 2020 16:53:54 +0200 Subject: s390/pci: refactor zpci_create_device() From: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> commit ba764dd703feacb5a9c410d191af1b6cfbe96845 upstream. Currently zpci_create_device() is only called in clp_add_pci_device() which allocates the memory for the struct zpci_dev being created. There is little separation of concerns as only both functions together can create a zpci_dev and the only CLP specific code in clp_add_pci_device() is a call to clp_query_pci_fn(). Improve this by removing clp_add_pci_device() and refactor zpci_create_device() such that it alone creates and initializes the zpci_dev given the FID and Function Handle. For this we need to make clp_query_pci_fn() non-static. While at it remove the function handle parameter since we can just take that from the zpci_dev. Also move adding to the zpci_list to after the zdev has been fully created which eliminates a window where a partially initialized zdev can be found by get_zdev_by_fid(). Acked-by: Pierre Morel <pmorel@xxxxxxxxxxxxx> Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/s390/include/asm/pci.h | 4 +-- arch/s390/pci/pci.c | 57 +++++++++++++++++++++++++++++++------------- arch/s390/pci/pci_clp.c | 40 ++---------------------------- arch/s390/pci/pci_event.c | 4 +-- 4 files changed, 48 insertions(+), 57 deletions(-) --- a/arch/s390/include/asm/pci.h +++ b/arch/s390/include/asm/pci.h @@ -201,7 +201,7 @@ extern unsigned int s390_pci_no_rid; Prototypes ----------------------------------------------------------------------------- */ /* Base stuff */ -int zpci_create_device(struct zpci_dev *); +int zpci_create_device(u32 fid, u32 fh, enum zpci_state state); void zpci_remove_device(struct zpci_dev *zdev); int zpci_enable_device(struct zpci_dev *); int zpci_disable_device(struct zpci_dev *); @@ -212,7 +212,7 @@ void zpci_remove_reserved_devices(void); /* CLP */ int clp_setup_writeback_mio(void); int clp_scan_pci_devices(void); -int clp_add_pci_device(u32, u32, int); +int clp_query_pci_fn(struct zpci_dev *zdev); int clp_enable_fh(struct zpci_dev *, u8); int clp_disable_fh(struct zpci_dev *); int clp_get_state(u32 fid, enum zpci_state *state); --- a/arch/s390/pci/pci.c +++ b/arch/s390/pci/pci.c @@ -695,43 +695,68 @@ void zpci_remove_device(struct zpci_dev } } -int zpci_create_device(struct zpci_dev *zdev) +/** + * zpci_create_device() - Create a new zpci_dev and add it to the zbus + * @fid: Function ID of the device to be created + * @fh: Current Function Handle of the device to be created + * @state: Initial state after creation either Standby or Configured + * + * Creates a new zpci device and adds it to its, possibly newly created, zbus + * as well as zpci_list. + * + * Returns: 0 on success, an error value otherwise + */ +int zpci_create_device(u32 fid, u32 fh, enum zpci_state state) { + struct zpci_dev *zdev; int rc; - kref_init(&zdev->kref); + zpci_dbg(3, "add fid:%x, fh:%x, c:%d\n", fid, fh, state); + zdev = kzalloc(sizeof(*zdev), GFP_KERNEL); + if (!zdev) + return -ENOMEM; + + /* FID and Function Handle are the static/dynamic identifiers */ + zdev->fid = fid; + zdev->fh = fh; - spin_lock(&zpci_list_lock); - list_add_tail(&zdev->entry, &zpci_list); - spin_unlock(&zpci_list_lock); + /* Query function properties and update zdev */ + rc = clp_query_pci_fn(zdev); + if (rc) + goto error; + zdev->state = state; + + kref_init(&zdev->kref); + mutex_init(&zdev->lock); rc = zpci_init_iommu(zdev); if (rc) - goto out; + goto error; - mutex_init(&zdev->lock); if (zdev->state == ZPCI_FN_STATE_CONFIGURED) { rc = zpci_enable_device(zdev); if (rc) - goto out_destroy_iommu; + goto error_destroy_iommu; } rc = zpci_bus_device_register(zdev, &pci_root_ops); if (rc) - goto out_disable; + goto error_disable; + + spin_lock(&zpci_list_lock); + list_add_tail(&zdev->entry, &zpci_list); + spin_unlock(&zpci_list_lock); return 0; -out_disable: +error_disable: if (zdev->state == ZPCI_FN_STATE_ONLINE) zpci_disable_device(zdev); - -out_destroy_iommu: +error_destroy_iommu: zpci_destroy_iommu(zdev); -out: - spin_lock(&zpci_list_lock); - list_del(&zdev->entry); - spin_unlock(&zpci_list_lock); +error: + zpci_dbg(0, "add fid:%x, rc:%d\n", fid, rc); + kfree(zdev); return rc; } --- a/arch/s390/pci/pci_clp.c +++ b/arch/s390/pci/pci_clp.c @@ -181,7 +181,7 @@ static int clp_store_query_pci_fn(struct return 0; } -static int clp_query_pci_fn(struct zpci_dev *zdev, u32 fh) +int clp_query_pci_fn(struct zpci_dev *zdev) { struct clp_req_rsp_query_pci *rrb; int rc; @@ -194,7 +194,7 @@ static int clp_query_pci_fn(struct zpci_ rrb->request.hdr.len = sizeof(rrb->request); rrb->request.hdr.cmd = CLP_QUERY_PCI_FN; rrb->response.hdr.len = sizeof(rrb->response); - rrb->request.fh = fh; + rrb->request.fh = zdev->fh; rc = clp_req(rrb, CLP_LPS_PCI); if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) { @@ -212,40 +212,6 @@ out: return rc; } -int clp_add_pci_device(u32 fid, u32 fh, int configured) -{ - struct zpci_dev *zdev; - int rc = -ENOMEM; - - zpci_dbg(3, "add fid:%x, fh:%x, c:%d\n", fid, fh, configured); - zdev = kzalloc(sizeof(*zdev), GFP_KERNEL); - if (!zdev) - goto error; - - zdev->fh = fh; - zdev->fid = fid; - - /* Query function properties and update zdev */ - rc = clp_query_pci_fn(zdev, fh); - if (rc) - goto error; - - if (configured) - zdev->state = ZPCI_FN_STATE_CONFIGURED; - else - zdev->state = ZPCI_FN_STATE_STANDBY; - - rc = zpci_create_device(zdev); - if (rc) - goto error; - return 0; - -error: - zpci_dbg(0, "add fid:%x, rc:%d\n", fid, rc); - kfree(zdev); - return rc; -} - static int clp_refresh_fh(u32 fid); /* * Enable/Disable a given PCI function and update its function handle if @@ -408,7 +374,7 @@ static void __clp_add(struct clp_fh_list zdev = get_zdev_by_fid(entry->fid); if (!zdev) - clp_add_pci_device(entry->fid, entry->fh, entry->config_state); + zpci_create_device(entry->fid, entry->fh, entry->config_state); } int clp_scan_pci_devices(void) --- a/arch/s390/pci/pci_event.c +++ b/arch/s390/pci/pci_event.c @@ -89,7 +89,7 @@ static void __zpci_event_availability(st switch (ccdf->pec) { case 0x0301: /* Reserved|Standby -> Configured */ if (!zdev) { - ret = clp_add_pci_device(ccdf->fid, ccdf->fh, 1); + zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_CONFIGURED); break; } /* the configuration request may be stale */ @@ -116,7 +116,7 @@ static void __zpci_event_availability(st break; case 0x0302: /* Reserved -> Standby */ if (!zdev) { - clp_add_pci_device(ccdf->fid, ccdf->fh, 0); + zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_STANDBY); break; } zdev->fh = ccdf->fh; Patches currently in stable-queue which might be from schnelle@xxxxxxxxxxxxx are queue-5.10/s390-pci-fix-leak-of-pci-device-structure.patch queue-5.10/s390-pci-remove-superfluous-zdev-zbus-check.patch queue-5.10/s390-pci-refactor-zpci_create_device.patch