kernel/linux.git/drivers/xen/platform-pci.c, branch linux-4.16.y

xen-platform: constify pci_device_id.

2017-08-31T13:45:55+00:00

pci_device_id are not supposed to change at runtime. All functions working with pci_device_id provided by work with const pci_device_id. So mark the non-const structs as const. Signed-off-by: Arvind Yadav Reviewed-by: Boris Ostrovsky Signed-off-by: Boris Ostrovsky

xen: Revert commits da72ff5bfcb0 and 72a9b186292d

2017-05-02T09:18:05+00:00

Recent discussion (http://marc.info/?l=xen-devel&m=149192184523741) established that commit 72a9b186292d ("xen: Remove event channel notification through Xen PCI platform device") (and thus commit da72ff5bfcb0 ("partially revert "xen: Remove event channel notification through Xen PCI platform device"")) are unnecessary and, in fact, prevent HVM guests from booting on Xen releases prior to 4.0 Therefore we revert both of those commits. The summary of that discussion is below: Here is the brief summary of the current situation: Before the offending commit (72a9b186292): 1) INTx does not work because of the reset_watches path. 2) The reset_watches path is only taken if you have Xen > 4.0 3) The Linux Kernel by default will use vector inject if the hypervisor support. So even INTx does not work no body running the kernel with Xen > 4.0 would notice. Unless he explicitly disabled this feature either in the kernel or in Xen (and this can only be disabled by modifying the code, not user-supported way to do it). After the offending commit (+ partial revert): 1) INTx is no longer support for HVM (only for PV guests). 2) Any HVM guest The kernel will not boot on Xen < 4.0 which does not have vector injection support. Since the only other mode supported is INTx which. So based on this summary, I think before commit (72a9b186292) we were in much better position from a user point of view. Signed-off-by: Boris Ostrovsky Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross

partially revert "xen: Remove event channel notification through Xen PCI platform device"

2017-01-13T18:07:23+00:00

Commit 72a9b186292d ("xen: Remove event channel notification through Xen PCI platform device") broke Linux when booting as Dom0 on Xen in a nested Xen environment (Xen installed inside a Xen VM). In this scenario, Linux is a PV guest, but at the same time it uses the platform-pci driver to receive notifications from L0 Xen. vector callbacks are not available because L1 Xen doesn't allow them. Partially revert the offending commit, by restoring IRQ based notifications for PV guests only. I restored only the code which is strictly needed and replaced the xen_have_vector_callback checks within it with xen_pv_domain() checks. Signed-off-by: Stefano Stabellini Reviewed-by: Boris Ostrovsky

xen-platform: use builtin_pci_driver

2016-11-17T12:44:26+00:00

Use builtin_pci_driver() helper to simplify the code. Signed-off-by: Geliang Tang Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross

xen: Remove event channel notification through Xen PCI platform device

2016-09-30T10:44:34+00:00

Ever since commit 254d1a3f02eb ("xen/pv-on-hvm kexec: shutdown watches from old kernel") using the INTx interrupt from Xen PCI platform device for event channel notification would just lockup the guest during bootup. postcore_initcall now calls xs_reset_watches which will eventually try to read a value from XenStore and will get stuck on read_reply at XenBus forever since the platform driver is not probed yet and its INTx interrupt handler is not registered yet. That means that the guest can not be notified at this moment of any pending event channels and none of the per-event handlers will ever be invoked (including the XenStore one) and the reply will never be picked up by the kernel. The exact stack where things get stuck during xenbus_init: -xenbus_init -xs_init -xs_reset_watches -xenbus_scanf -xenbus_read -xs_single -xs_single -xs_talkv Vector callbacks have always been the favourite event notification mechanism since their introduction in commit 38e20b07efd5 ("x86/xen: event channels delivery on HVM.") and the vector callback feature has always been advertised for quite some time by Xen that's why INTx was broken for several years now without impacting anyone. Luckily this also means that event channel notification through INTx is basically dead-code which can be safely removed without impacting anybody since it has been effectively disabled for more than 4 years with nobody complaining about it (at least as far as I'm aware of). This commit removes event channel notification through Xen PCI platform device. Cc: Boris Ostrovsky Cc: David Vrabel Cc: Juergen Gross Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: x86@kernel.org Cc: Konrad Rzeszutek Wilk Cc: Bjorn Helgaas Cc: Stefano Stabellini Cc: Julien Grall Cc: Vitaly Kuznetsov Cc: Paul Gortmaker Cc: Ross Lagerwall Cc: xen-devel@lists.xenproject.org Cc: linux-kernel@vger.kernel.org Cc: linux-pci@vger.kernel.org Cc: Anthony Liguori Signed-off-by: KarimAllah Ahmed Reviewed-by: Boris Ostrovsky Signed-off-by: David Vrabel

drivers/xen: make platform-pci.c explicitly non-modular

2016-03-21T15:14:04+00:00

The Kconfig currently controlling compilation of this code is: arch/x86/xen/Kconfig:config XEN_PVHVM arch/x86/xen/Kconfig: def_bool y ...meaning that it currently is not being built as a module by anyone. Lets remove the modular code that is essentially orphaned, so that when reading the driver there is no doubt it is builtin-only. Since module_init translates to device_initcall in the non-modular case, the init ordering remains unchanged with this commit. Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code. We also delete the MODULE_LICENSE tag etc. since all that information was (or is now) contained at the top of the file in the comments. In removing "module" from the init fcn name, we observe a namespace collision with the probe function, so we use "probe" in the name of the probe function, and "init" in the registration fcn, as per standard convention, as suggested by Stefano. Signed-off-by: Paul Gortmaker Reviewed-by: Stefano Stabellini Signed-off-by: David Vrabel

drivers: xen: Mark function as static in platform-pci.c

2014-02-28T20:26:04+00:00

Mark function as static in xen/platform-pci.c because it is not used outside this file. This eliminates the following warning in xen/platform-pci.c: drivers/xen/platform-pci.c:48:15: warning: no previous prototype for ‘alloc_xen_mmio’ [-Wmissing-prototypes] Signed-off-by: Rashika Kheria Reviewed-by: Josh Triplett Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: David Vrabel

xen-platform: fix error return code in platform_pci_init()

2014-01-07T14:59:51+00:00

Fix to return a negative error code from the error handling case instead of 0, otherwise the error condition cann't be reflected from the return value. Signed-off-by: Wei Yongjun Signed-off-by: Konrad Rzeszutek Wilk

xen/grant: Implement an grant frame array struct (v3).

2014-01-06T15:44:20+00:00

The 'xen_hvm_resume_frames' used to be an 'unsigned long' and contain the virtual address of the grants. That was OK for most architectures (PVHVM, ARM) were the grants are contiguous in memory. That however is not the case for PVH - in which case we will have to do a lookup for each virtual address for the PFN. Instead of doing that, lets make it a structure which will contain the array of PFNs, the virtual address and the count of said PFNs. Also provide a generic functions: gnttab_setup_auto_xlat_frames and gnttab_free_auto_xlat_frames to populate said structure with appropriate values for PVHVM and ARM. To round it off, change the name from 'xen_hvm_resume_frames' to a more descriptive one - 'xen_auto_xlat_grant_frames'. For PVH, in patch "xen/pvh: Piggyback on PVHVM for grant driver" we will populate the 'xen_auto_xlat_grant_frames' by ourselves. v2 moves the xen_remap in the gnttab_setup_auto_xlat_frames and also introduces xen_unmap for gnttab_free_auto_xlat_frames. Suggested-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk [v3: Based on top of 'asm/xen/page.h: remove redundant semicolon'] Acked-by: Stefano Stabellini

xen: remove deprecated IRQF_DISABLED

2013-11-06T20:31:16+00:00

This patch proposes to remove the IRQF_DISABLED flag from drivers/xen code. It's a NOOP since 2.6.35 and it will be removed one day. Note that architecture dependent fixes for IRQF_DISABLED were already submitted through separate patches. Signed-off-by: Michael Opdenacker Signed-off-by: Konrad Rzeszutek Wilk