From efd532a679afae46ccfc348ca179b117cd38241d Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 5 Feb 2021 14:36:32 +0100 Subject: [PATCH] PCI: Also set up legacy files only after sysfs init MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We are already doing this for all the regular sysfs files on PCI devices, but not yet on the legacy io files on the PCI buses. Thus far no problem, but in the next patch I want to wire up iomem revoke support. That needs the vfs up and running already to make sure that iomem_get_mapping() works. Wire it up exactly like the existing code in pci_create_sysfs_dev_files(). Note that pci_remove_legacy_files() doesn't need a check since the one for pci_bus->legacy_io is sufficient. An alternative solution would be to implement a callback in sysfs to set up the address space from iomem_get_mapping() when userspace calls mmap(). This also works, but Greg didn't really like that just to work around an ordering issue when the kernel loads initially. v2: Improve commit message (Bjorn) Acked-by: Bjorn Helgaas Signed-off-by: Daniel Vetter Cc: Stephen Rothwell Cc: Jason Gunthorpe Cc: Kees Cook Cc: Dan Williams Cc: Andrew Morton Cc: John Hubbard Cc: Jérôme Glisse Cc: Jan Kara Cc: Dan Williams Cc: Greg Kroah-Hartman Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-samsung-soc@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: Bjorn Helgaas Cc: linux-pci@vger.kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20210205133632.2827730-1-daniel.vetter@ffwll.ch --- drivers/pci/pci-sysfs.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index fb072f4..0c45b4f 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -927,6 +927,9 @@ void pci_create_legacy_files(struct pci_bus *b) { int error; + if (!sysfs_initialized) + return; + b->legacy_io = kcalloc(2, sizeof(struct bin_attribute), GFP_ATOMIC); if (!b->legacy_io) @@ -1448,6 +1451,7 @@ void pci_remove_sysfs_dev_files(struct pci_dev *pdev) static int __init pci_sysfs_init(void) { struct pci_dev *pdev = NULL; + struct pci_bus *pbus = NULL; int retval; sysfs_initialized = 1; @@ -1459,6 +1463,9 @@ static int __init pci_sysfs_init(void) } } + while ((pbus = pci_find_next_bus(pbus))) + pci_create_legacy_files(pbus); + return 0; } late_initcall(pci_sysfs_init); -- 2.7.4