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From:   =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
To:     Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        Rob Herring <robh@kernel.org>,
        =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= <kw@linux.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Hajo Noerenberg <hajo-linux-bugzilla@noerenberg.de>
Cc:     linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] PCI: mvebu: Dispose INTx irqs prior to removing INTx domain
Date:   Sat,  9 Jul 2022 18:18:58 +0200
Message-Id: <20220709161858.15031-1-pali@kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

Documentation for irq_domain_remove() says that all mapping within the
domain must be disposed prior to domain remove.

Currently INTx irqs are not disposed in pci-mvebu.c device unbind callback
which cause that kernel crashes after unloading driver and trying to read
/sys/kernel/debug/irq/irqs/<num> or /proc/interrupts.

Fixes: ec075262648f ("PCI: mvebu: Implement support for legacy INTx interrupts")
Reported-by: Hajo Noerenberg <hajo-linux-bugzilla@noerenberg.de>
Signed-off-by: Pali Rohár <pali@kernel.org>
---
Depends on patch:
https://lore.kernel.org/linux-pci/20220524122817.7199-1-pali@kernel.org/

Here is the captured kernel crash which happens without this patch:

$ cat /sys/kernel/debug/irq/irqs/64
[  301.571370] 8<--- cut here ---
[  301.574496] Unable to handle kernel paging request at virtual address 0a00002a
[  301.581736] [0a00002a] *pgd=00000000
[  301.585323] Internal error: Oops: 80000005 [#1] SMP ARM
[  301.590560] Modules linked in:
[  301.593621] CPU: 1 PID: 4641 Comm: cat Not tainted 5.16.0-rc1+ #192
[  301.599905] Hardware name: Marvell Armada 380/385 (Device Tree)
[  301.605836] PC is at 0xa00002a
[  301.608896] LR is at irq_debug_show+0x210/0x2d4
[  301.613440] pc : [<0a00002a>]    lr : [<c018ca40>]    psr: 200000b3
[  301.619721] sp : c797fdd8  ip : 0000000b  fp : 0a00002b
[  301.624957] r10: c0d9a364  r9 : 00000001  r8 : 00000000
[  301.630192] r7 : c18fee18  r6 : c0da2a74  r5 : c18fee00  r4 : c66ec050
[  301.636734] r3 : 00000001  r2 : c18fee18  r1 : 00000000  r0 : c66ec050
[  301.643275] Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA Thumb  Segment none
[  301.650689] Control: 10c5387d  Table: 0790c04a  DAC: 00000051
[  301.656446] Register r0 information: slab seq_file start c66ec050 pointer offset 0
[  301.664040] Register r1 information: NULL pointer
[  301.668755] Register r2 information: slab kmalloc-256 start c18fee00 pointer offset 24 size 256
[  301.677480] Register r3 information: non-paged memory
[  301.682543] Register r4 information: slab seq_file start c66ec050 pointer offset 0
[  301.690133] Register r5 information: slab kmalloc-256 start c18fee00 pointer offset 0 size 256
[  301.698770] Register r6 information: non-slab/vmalloc memory
[  301.704442] Register r7 information: slab kmalloc-256 start c18fee00 pointer offset 24 size 256
[  301.713165] Register r8 information: NULL pointer
[  301.717879] Register r9 information: non-paged memory
[  301.722941] Register r10 information: non-slab/vmalloc memory
[  301.728699] Register r11 information: non-paged memory
[  301.733848] Register r12 information: non-paged memory
[  301.738997] Process cat (pid: 4641, stack limit = 0xf591166e)
[  301.744756] Stack: (0xc797fdd8 to 0xc7980000)
[  301.749123] fdc0:                                                       0000000a 830d3f3e
[  301.757321] fde0: c1004f48 c0d9a374 c7a9cc10 c66ec050 00000000 c88af900 c797fe80 7ffff000
[  301.765518] fe00: 00400cc0 c66ec068 00000001 c02c5cb8 00000000 00000000 c66ec078 c797fe68
[  301.773715] fe20: c1cdf6c0 c7a9cc10 ffffffea c88af900 00000010 00000000 00000000 c88af900
[  301.781911] fe40: c1004f48 c797ff78 00001000 00004004 c03efcb8 c02c6100 00001000 00000000
[  301.790108] fe60: bec73e04 00001000 00000000 00000000 00001000 c797fe60 00000001 00000000
[  301.798304] fe80: c88af900 00000000 00000000 00000000 00000000 00000000 00000000 40040000
[  301.806501] fea0: 00000000 00000000 c1004f48 830d3f3e c88af900 c02c6018 c1c7a770 bec73e04
[  301.814697] fec0: 00001000 c797ff78 00000001 c03efd0c 00001000 c88af900 00000000 bec73e04
[  301.822894] fee0: c1004f48 c797ff78 00000001 c029c728 c887ca20 01100cca 0000004f 0045f000
[  301.831091] ff00: 00000254 c790c010 c790c010 00000000 00000000 00000000 c5f6117c eeece9b8
[  301.839288] ff20: 00000000 830d3f3e 00000000 c797ffb0 c79fc000 80000007 0045f5b8 00000254
[  301.847484] ff40: c79fc040 00000004 c887ca20 830d3f3e 00000000 c1004f48 c88af900 00000000
[  301.855681] ff60: 00000000 c88af900 bec73e04 00001000 00000000 c029cd68 00000000 00000000
[  301.863877] ff80: 00000000 830d3f3e 00000000 00000000 01000000 00000003 c0100284 c1b8abc0
[  301.872074] ffa0: 00000003 c0100060 00000000 00000000 00000003 bec73e04 00001000 00000000
[  301.880270] ffc0: 00000000 00000000 01000000 00000003 00000003 00000001 00000001 00000000
[  301.888468] ffe0: bec73d98 bec73d88 b6f81f88 b6f81410 60000010 00000003 00000000 00000000
[  301.896666] [<c018ca40>] (irq_debug_show) from [<c02c5cb8>] (seq_read_iter+0x1a4/0x504)
[  301.904700] [<c02c5cb8>] (seq_read_iter) from [<c02c6100>] (seq_read+0xe8/0x12c)
[  301.912117] [<c02c6100>] (seq_read) from [<c03efd0c>] (full_proxy_read+0x54/0x70)
[  301.919623] [<c03efd0c>] (full_proxy_read) from [<c029c728>] (vfs_read+0xa0/0x2c8)
[  301.927214] [<c029c728>] (vfs_read) from [<c029cd68>] (ksys_read+0x58/0xd0)
[  301.934195] [<c029cd68>] (ksys_read) from [<c0100060>] (ret_fast_syscall+0x0/0x54)
[  301.941785] Exception stack(0xc797ffa8 to 0xc797fff0)
[  301.946849] ffa0:                   00000000 00000000 00000003 bec73e04 00001000 00000000
[  301.955045] ffc0: 00000000 00000000 01000000 00000003 00000003 00000001 00000001 00000000
[  301.963241] ffe0: bec73d98 bec73d88 b6f81f88 b6f81410
[  301.968304] Code: bad PC value
[  301.971365] ---[ end trace fe25fd26d042b605 ]---
[  301.975992] Kernel panic - not syncing: Fatal exception
[  301.981229] CPU0: stopping
[  301.983946] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G      D           5.16.0-rc1+ #192
[  301.991884] Hardware name: Marvell Armada 380/385 (Device Tree)
[  301.997817] [<c010e120>] (unwind_backtrace) from [<c010a170>] (show_stack+0x10/0x14)
[  302.005587] [<c010a170>] (show_stack) from [<c0bbf108>] (dump_stack_lvl+0x40/0x4c)
[  302.013179] [<c0bbf108>] (dump_stack_lvl) from [<c010c3f8>] (do_handle_IPI+0xf4/0x128)
[  302.021117] [<c010c3f8>] (do_handle_IPI) from [<c010c444>] (ipi_handler+0x18/0x20)
[  302.028707] [<c010c444>] (ipi_handler) from [<c0185c5c>] (handle_percpu_devid_irq+0x78/0x124)
[  302.037256] [<c0185c5c>] (handle_percpu_devid_irq) from [<c017ffb8>] (generic_handle_domain_irq+0x44/0x88)
[  302.046938] [<c017ffb8>] (generic_handle_domain_irq) from [<c05f051c>] (gic_handle_irq+0x74/0x88)
[  302.055839] [<c05f051c>] (gic_handle_irq) from [<c0bc7ef8>] (generic_handle_arch_irq+0x34/0x44)
[  302.064564] [<c0bc7ef8>] (generic_handle_arch_irq) from [<c0100b10>] (__irq_svc+0x50/0x68)
[  302.072851] Exception stack(0xc1001f00 to 0xc1001f48)
[  302.077916] 1f00: 000d6830 00000000 00000001 c0116be0 c1004f90 c1004fd4 00000001 00000000
[  302.086114] 1f20: c1004f48 c0f5d2a8 c1009e80 00000000 00000000 c1001f50 c01076f4 c01076f8
[  302.094309] 1f40: 60000013 ffffffff
[  302.097804] [<c0100b10>] (__irq_svc) from [<c01076f8>] (arch_cpu_idle+0x38/0x3c)
[  302.105223] [<c01076f8>] (arch_cpu_idle) from [<c0bcf3a0>] (default_idle_call+0x1c/0x2c)
[  302.113338] [<c0bcf3a0>] (default_idle_call) from [<c015db34>] (do_idle+0x1c8/0x218)
[  302.121106] [<c015db34>] (do_idle) from [<c015de40>] (cpu_startup_entry+0x18/0x20)
[  302.128697] [<c015de40>] (cpu_startup_entry) from [<c0f00fec>] (start_kernel+0x650/0x694)
[  302.136901] Rebooting in 3 seconds..
---
 drivers/pci/controller/pci-mvebu.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c
index 31f53a019b8f..951030052358 100644
--- a/drivers/pci/controller/pci-mvebu.c
+++ b/drivers/pci/controller/pci-mvebu.c
@@ -1713,8 +1713,15 @@ static int mvebu_pcie_remove(struct platform_device *pdev)
 		mvebu_writel(port, ~PCIE_INT_ALL_MASK, PCIE_INT_CAUSE_OFF);
 
 		/* Remove IRQ domains. */
-		if (port->intx_irq_domain)
+		if (port->intx_irq_domain) {
+			int virq, j;
+			for (j = 0; j < PCI_NUM_INTX; j++) {
+				virq = irq_find_mapping(port->intx_irq_domain, j);
+				if (virq > 0)
+					irq_dispose_mapping(virq);
+			}
 			irq_domain_remove(port->intx_irq_domain);
+		}
 
 		/* Free config space for emulated root bridge. */
 		pci_bridge_emul_cleanup(&port->bridge);
-- 
2.20.1