Linux-PCI Archive on lore.kernel.org
 help / color / Atom feed
From: Bandan Das <bsd@redhat.com>
To: "Bjorn Helgaas" <bhelgaas@google.com>,
	"Christian König" <christian.koenig@amd.com>
Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org
Subject: [PATCH] x86/pci: Add a break condition when enabling BAR
Date: Thu, 07 Dec 2017 03:00:21 -0500
Message-ID: <jpga7yvotm2.fsf@linux.bootlegged.copy> (raw)


On an old flaky system with AMD Opteron 6320, boot hangs
with the following trace since commit fa564ad9:

[   28.181012] Hardware name: HP ProLiant DL385p Gen8, BIOS A28 09/03/2014
[   28.184022] RIP: 0010:lock_acquire+0xd5/0x1e0
[   28.185010] RSP: 0018:ffffb7ad818c39a8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11
[   28.187010] RAX: ffffa074fb39b140 RBX: 0000000000000246 RCX: 0000000000000000
[   28.189014] RDX: ffffffffb20a55a9 RSI: 0000000000040009 RDI: 0000000000000246
[   28.191012] RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000000
[   28.193020] R10: 0000000000000001 R11: 00000000dac664b5 R12: 0000000000000000
[   28.196013] R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
[   28.197011] FS:  0000000000000000(0000) GS:ffffa074fbd00000(0000) knlGS:0000000000000000
[   28.201014] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   28.201014] CR2: 0000000000000000 CR3: 00000003b6e10000 CR4: 00000000000406e0
[   28.205008] Call Trace:
[   28.205013]  ? request_resource_conflict+0x19/0x40
[   28.207013]  _raw_write_lock+0x2e/0x40
[   28.209008]  ? request_resource_conflict+0x19/0x40
[   28.209010]  request_resource_conflict+0x19/0x40
[   28.212013]  pci_amd_enable_64bit_bar+0x103/0x1a0
[   28.213025]  pci_fixup_device+0xd4/0x210
[   28.213025]  pci_setup_device+0x193/0x570
[   28.215010]  ? get_device+0x13/0x20
[   28.217008]  pci_scan_single_device+0x98/0xd0
[   28.217011]  pci_scan_slot+0x90/0x130
[   28.219010]  pci_scanild_bus_extend+0x3a/0x270
[   28.321008]  acpi_pci_root_create+0x1a9/0x210
[   28.321014]  ? pci_acpi_scan_root+0x135/0x1b0
[   28.324013]  pci_acpi_scan_root+0x15f/0x1b0
[   28.325008]  acpi_pci_root_add+0x283/0x560
[   28.325014]  ? acpi_match_device_ids+0xc/0x20
[   28.327013]  acpi_bus_attach+0xf9/0x1c0
[   28.329008]  acpi_bus_attach+0x82/0x1c0
[   28.329044]  acpi_bus_attach+0x82/0x1c0
[   28.331010]  acpi_bus_scan+0x47/0xa0
[   28.333008]  acpi_scan_init+0x12d/0x28d
[   28.333013]  ? bus_register+0x208/0x280
[   28.333013]  acpi_init+0x30f/0x36f
[   28.335010]  ? acpi_sleep_proc_init+0x24/0x24
[   28.337013]  do_one_initcall+0x4d/0x19c
[   28.337013]  ? do_early_param+0x29/0x86
[   28.340013]  kernel_init_freeable+0x209/0x2a4
[   28.341008]  ? set_debug_rodata+0x11/0x11
[   28.341011]  ? rest_init+0xc0/0xc0
[   28.343013]  kernel_init+0xa/0x104
[   28.345008]  ret_from_fork+0x24/0x30
[   28.345010] Code: 24 08 49 c1 e9 09 49 83 f1 01 41 83 e1 01 e8 73
e4 ff ff 65 48 8b 04 25 c0 d4 00 00 48 89 df c7 80 fc 0c 00 00 00 00
00 00 57 9d <0f> 1f 44 00 00 48 83 c4 30 5b 5d 41 5c 41 5d 41 5e 41 5f
c3 65

Since request_resource() will unconditionally return a conflict for invalid
regions, there will be no way to break out of the loop when enabling 64bit BAR.
Add checks and exit the loop in these cases without attempting to enable
BAR.

Signed-off-by: Bandan Das <bsd@redhat.com>
---
 arch/x86/pci/fixup.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index 1e996df..8933a1b 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -696,8 +696,13 @@ static void pci_amd_enable_64bit_bar(struct pci_dev *dev)
 	res->end = 0xfd00000000ull - 1;
 
 	/* Just grab the free area behind system memory for this */
-	while ((conflict = request_resource_conflict(&iomem_resource, res)))
+	while ((conflict = request_resource_conflict(&iomem_resource, res))) {
+		if ((res->start > res->end) ||
+		    (res->start < iomem_resource.start) ||
+		    (res->end > iomem_resource.end))
+			break;
 		res->start = conflict->end + 1;
+	}
 
 	dev_info(&dev->dev, "adding root bus resource %pR\n", res);
 
-- 
2.9.4

             reply index

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-07  8:00 Bandan Das [this message]
2017-12-07 13:13 ` Christian König
2017-12-07 19:41   ` Bandan Das
2017-12-07 20:11     ` Bjorn Helgaas

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=jpga7yvotm2.fsf@linux.bootlegged.copy \
    --to=bsd@redhat.com \
    --cc=bhelgaas@google.com \
    --cc=christian.koenig@amd.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-PCI Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-pci/0 linux-pci/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-pci linux-pci/ https://lore.kernel.org/linux-pci \
		linux-pci@vger.kernel.org
	public-inbox-index linux-pci

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-pci


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git