iommu/amd: Simplify and Consolidate Virtual APIC (AVIC) Enablement

iommu/amd: Simplify and Consolidate Virtual APIC (AVIC) Enablement

Currently, enabling AVIC requires individually detect and enable GAM and
GALOG features on each IOMMU, which is difficult to keep track on
multi-IOMMU system, where the features needs to be enabled system-wide.

In addition, these features do not need to be enabled in early stage.
It can be delayed until after amd_iommu_init_pci().

Therefore, consolidate logic for detecting and enabling IOMMU GAM and
GALOG features into a helper function, enable_iommus_vapic(), which uses
the check_feature_on_all_iommus() helper function to ensure system-wide
support of the features before enabling them, and postpone until after
amd_iommu_init_pci().

The new function also check and clean up feature enablement residue from
previous boot (e.g. in case of booting into kdump kernel), which triggers
a WARN_ON (shown below) introduced by the commit a8d4a37d1bb9 ("iommu/amd:
Restore GA log/tail pointer on host resume") in iommu_ga_log_enable().

[    7.731955] ------------[ cut here ]------------
[    7.736575] WARNING: CPU: 0 PID: 1 at drivers/iommu/amd/init.c:829 iommu_ga_log_enable.isra.0+0x16f/0x190
[    7.746135] Modules linked in:
[    7.749193] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G        W        --------  ---  5.19.0-0.rc7.53.eln120.x86_64 #1
[    7.759706] Hardware name: Dell Inc. PowerEdge R7525/04D5GJ, BIOS 2.1.6 03/09/2021
[    7.767274] RIP: 0010:iommu_ga_log_enable.isra.0+0x16f/0x190
[    7.772931] Code: 20 20 00 00 8b 00 f6 c4 01 74 da 48 8b 44 24 08 65 48 2b 04 25 28 00 00 00 75 13 48 83 c4 10 5b 5d e9 f5 00 72 00 0f 0b eb e1 <0f> 0b eb dd e8 f8 66 42 00 48 8b 15 f1 85 53 01 e9 29 ff ff ff 48
[    7.791679] RSP: 0018:ffffc90000107d20 EFLAGS: 00010206
[    7.796905] RAX: ffffc90000780000 RBX: 0000000000000100 RCX: ffffc90000780000
[    7.804038] RDX: 0000000000000001 RSI: ffffc90000780000 RDI: ffff8880451f9800
[    7.811170] RBP: ffff8880451f9800 R08: ffffffffffffffff R09: 0000000000000000
[    7.818303] R10: 0000000000000000 R11: 0000000000000000 R12: 0008000000000000
[    7.825435] R13: ffff8880462ea900 R14: 0000000000000021 R15: 0000000000000000
[    7.832572] FS:  0000000000000000(0000) GS:ffff888054a00000(0000) knlGS:0000000000000000
[    7.840657] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    7.846400] CR2: ffff888054dff000 CR3: 0000000053210000 CR4: 0000000000350eb0
[    7.853533] Call Trace:
[    7.855979]  <TASK>
[    7.858085]  amd_iommu_enable_interrupts+0x180/0x270
[    7.863051]  ? iommu_setup+0x271/0x271
[    7.866803]  state_next+0x197/0x2c0
[    7.870295]  ? iommu_setup+0x271/0x271
[    7.874049]  iommu_go_to_state+0x24/0x2c
[    7.877976]  amd_iommu_init+0xf/0x29
[    7.881554]  pci_iommu_init+0xe/0x36
[    7.885133]  do_one_initcall+0x44/0x200
[    7.888975]  do_initcalls+0xc8/0xe1
[    7.892466]  kernel_init_freeable+0x14c/0x199
[    7.896826]  ? rest_init+0xd0/0xd0
[    7.900231]  kernel_init+0x16/0x130
[    7.903723]  ret_from_fork+0x22/0x30
[    7.907306]  </TASK>
[    7.909497] ---[ end trace 0000000000000000 ]---

Fixes: commit a8d4a37d1bb9 ("iommu/amd: Restore GA log/tail pointer on host resume")
Reported-by: Jerry Snitselaar <jsnitsel@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Will Deacon <will@kernel.org> (maintainer:IOMMU DRIVERS)
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20220726134348.6438-2-suravee.suthikulpanit@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>