pci/controller/pci-hyperv.c

13  * VM within Hyper-V, there may seem to be no PCI bus at all in the VM
16  * Each root PCI bus has its own PCI domain, which is called "Segment" in
26  * underlying hypervisor to adjust the mappings in the I/O MMU so that each
29  * interrupts, and will report that the Interrupt Line register in the
37  * the PCI back-end driver in Hyper-V.
74  * Supported protocol versions in the order of probing - highest go
98  * should be generous in ensuring that we don't ever run out.
154  * which is all this driver does.  This representation is the one used in
168  * Pretty much as defined in the PCI Specifications.
205  * @delivery_mode:	As defined in Intel's Programmer's
207  * @vector_count:	Number of contiguous entries in the
211  *			in PCI 2.2, this can be between 1 and
212  *			32. For "MSI-X," as first defined in PCI
229  * @delivery_mode:	As defined in Intel's Programmer's
231  * @vector_count:	Number of contiguous entries in the
235  *			in PCI 2.2, this can be between 1 and
236  *			32. For "MSI-X," as first defined in PCI
239  * @processor_count:	number of bits enabled in array.
252  *	Everything is the same as in 'hv_msi_desc2' except that the size of the
268  * @vector_count:	same as in hv_msi_desc
286  * Specific message formats are defined later in the file.
524  * processed in order and deferred so that they don't run in the context
709 	 * into the irqdata data structure in migrate_one_irq() ->
831 	 * set to whatever is in the GIC configuration.
945  * @resp_packet_size:	Size in bytes of the packet
1031 	struct hv_mmio_read_input *in;
1040 	in = *this_cpu_ptr(hyperv_pcpu_input_arg);
1041 	out = *this_cpu_ptr(hyperv_pcpu_input_arg) + sizeof(*in);
1042 	in->gpa = gpa;
1043 	in->size = size;
1045 	ret = hv_do_hypercall(HVCALL_MMIO_READ, in, out);
1065 	struct hv_mmio_write_input *in;
1072 	in = *this_cpu_ptr(hyperv_pcpu_input_arg);
1073 	in->gpa = gpa;
1074 	in->size = size;
1077 		*(u8 *)(in->data) = val;
1080 		*(u16 *)(in->data) = val;
1083 		*(u32 *)(in->data) = val;
1087 	ret = hv_do_hypercall(HVCALL_MMIO_WRITE, in, NULL);
1095  * of pages in memory-mapped I/O space.  Writing to the first page chooses
1097  * written to, the following page maps in the entire configuration space of
1342  * Hyper-V SR-IOV provides a backchannel mechanism in software for
1344  * "configuration blocks" are similar in concept to PCI configuration space,
1345  * but instead of doing reads and writes in 32-bit chunks through a very slow
1348  * Nearly every SR-IOV device contains just such a communications channel in
1349  * hardware, so using this one in software is usually optional.  Using the
1376  * @resp_packet_size:	Size in bytes of the response packet
1407  * the back-end driver running in the Hyper-V parent partition.
1410  * @len:		Size in bytes of buf.
1476  * @resp_packet_size:	Size in bytes of the response packet
1489  * back-end driver running in the Hyper-V parent partition.
1492  * @len:		Size in bytes of buf.
1533 	 * specified in write_blk->byte_count.
1619  * messages that are in use, keeping the interrupt redirection
1699 	 * Create MSI w/ dummy vCPU set, overwritten by subsequent retarget in
1710  * interrupted is specified later in hv_irq_unmask() and communicated to Hyper-V
1713  * interrupts based on the vCPU specified in message sent to the vPCI VSP in
1729  * With Hyper-V in Nov 2022, the HVCALL_RETARGET_INTERRUPT hypercall does *not*
1738  * by subsequent retarget in hv_irq_unmask().
1805  * @msg:	Buffer that is filled in by this function
1809  * asking for a mapping for that tuple in this partition.  The
1896 		 * value gets sent to the hypervisor in unmask().  This needs
1967 	 * in the tasklet.
1990 		 * in vmbus_reset_channel_cb().
2117  * Return:	Size in bytes of the consumed MMIO space.
2153 	 * for a child device are a power of 2 in size and aligned in memory,
2160 					"There's an I/O BAR in this list!\n");
2190  * prepopulate_bars() - Fill in BARs with defaults
2194  * for a device have values upon first scan. So fill them in.
2197  * enforced in other parts of the code, is that the beginning of
2229 	 * Clear the memory enable bit, in case it's already set. This occurs
2230 	 * in the suspend path of hibernation, where the device is suspended,
2291 				 * in the core PCI driver doesn't cause Hyper-V
2309  * Assign entries in sysfs pci slot directory.
2339  * Remove entries in sysfs pci slot directory.
2371 			 * (e.g. in a KDUMP kernel) or with NUMA disabled via
2421  * @resp_packet_size:	The size in bytes of resp.
2548  * @work:	Work struct embedded in struct hv_dr_work
2594 		/* Throw this away if the list still has stuff in it. */
2815  * @work:	Work struct embedded in internal device struct
2870 	/* For the get_pcichild() in hv_pci_eject_device() */
2872 	/* For the two refs got in new_pcichild_device() */
3081  * @version:		Array of supported channel protocol versions in
3083  * @num_version:	Number of elements in the version array.
3200  * in the kernel such that it comprehends either PCI devices
3202  * node (in this case, VMBus) or change it such that it
3211  * bridge windows.  These descriptors have to exist in this form
3212  * in order to satisfy the code which will get invoked when the
3373 		 * devices to release resources allocated in the
3460  * used in local terms.)  This is nice for Windows, and lines up
3461  * with the FDO/PDO split, which doesn't exist in Linux.  Linux
3588  * Check if the PCI domain number is in use, and return another number if
3589  * it is in use.
3649 	 * The PCI bus "domain" is what is called "segment" in ACPI and other
3652 	 * not in use.
3654 	 * Note that, since this code only runs in a Hyper-V VM, Hyper-V
3659 	 * collisions) in the same VM.
3684 	 * ACPI companion in pcibios_root_bridge_prepare() and
3835 		/* Remove all children in the list */
3840 			/* For the two refs got in new_pcichild_device() */
3935 	 * before calling vmbus_close(), since it runs in a process context
3936 	 * as a callback in dpm_suspend().  When it starts to run, the channel
3937 	 * callback hv_pci_onchannelcallback(), which runs in a tasklet
3939 	 * items onto hbus->wq in hv_pci_devices_present() and
4027 	/* Only use the version that was in use before hibernation. */