[PATCH] platform/x86: intel_pmc_core: Do not ioremap RAM
From: M. Vefa Bicakci
Date: Thu Aug 15 2019 - 21:42:33 EST
On a Xen-based PVH virtual machine with more than 4 GiB of RAM,
intel_pmc_core fails initialization with the following warning message
from the kernel, indicating that the driver is attempting to ioremap
RAM:
------------[ cut here ]------------
ioremap on RAM at 0x00000000fe000000 - 0x00000000fe001fff
WARNING: CPU: 1 PID: 434 at arch/x86/mm/ioremap.c:186 __ioremap_caller.constprop.0+0x2aa/0x2c0
Modules linked in: intel_pmc_core_pltdrv(+) xen_netfront(+) intel_pmc_core \
crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel \
intel_rapl_perf pcspkr binfmt_misc u2mfn(O) xenfs xen_gntdev \
xen_gntalloc xen_blkback xen_privcmd xen_evtchn ip_tables overlay \
xen_blkfront
CPU: 1 PID: 434 Comm: systemd-udevd Tainted: G O 5.3.0-rc3-next-20190809-1 #2
RIP: 0010:__ioremap_caller.constprop.0+0x2aa/0x2c0
Code: 05 0f c9 1b 01 49 09 c6 e9 8e fe ff ff 48 8d 54 24 28 48 c7 c7 68 87 0a 82 c6 05 c4 23 2b 01 01 48 8d 74 24 18 e8 d4 4a 06 00 <0f> 0b 45 31 ff e9 fe fe ff ff e8 e7 47 06 00 0f 1f 80 00 00 00 00
RSP: 0018:ffffc900002dfa20 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffffffffc0107000 RCX: 0000000000000006
RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff88813bb17540
RBP: 00000000fe000000 R08: 000000000000015f R09: 000000000000000a
R10: 000000000000000a R11: ffffc900002df8da R12: 0000000000002000
R13: 0000000000000000 R14: 0000000000000002 R15: ffffffff822da3a0
FS: 000072ecce666940(0000) GS:ffff88813bb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000785be7346d20 CR3: 000000000d872001 CR4: 00000000003606e0
Call Trace:
? pmc_core_probe+0x87/0x2d0 [intel_pmc_core]
pmc_core_probe+0x87/0x2d0 [intel_pmc_core]
platform_drv_probe+0x35/0x80
really_probe+0x298/0x3c0
driver_probe_device+0x7a/0x100
? driver_allows_async_probing+0x50/0x50
bus_for_each_drv+0x8f/0xd0
__device_attach+0xf0/0x170
bus_probe_device+0x8e/0xa0
device_add+0x692/0x7e0
platform_device_add+0xe9/0x240
? 0xffffffffc00ec000
do_one_initcall+0x59/0x214
do_init_module+0x5c/0x230
load_module+0x258d/0x2840
? __do_sys_finit_module+0xbb/0x120
__do_sys_finit_module+0xbb/0x120
do_syscall_64+0x5f/0x1a0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x72eccf662fad
Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ab 9e 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffd3710d018 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
RAX: ffffffffffffffda RBX: 000060ab8fda2530 RCX: 000072eccf662fad
RDX: 0000000000000000 RSI: 000072eccf2bd84d RDI: 0000000000000017
RBP: 0000000000020000 R08: 0000000000000000 R09: 0000000000000007
R10: 0000000000000017 R11: 0000000000000246 R12: 000072eccf2bd84d
R13: 0000000000000000 R14: 000060ab8fd9b5e0 R15: 0000000000000007
---[ end trace 5e5421608729d6f4 ]---
This issue appears to manifest itself because of the following fallback
mechanism in the driver:
if (lpit_read_residency_count_address(&slp_s0_addr))
pmcdev->base_addr = PMC_BASE_ADDR_DEFAULT;
The validity of address PMC_BASE_ADDR_DEFAULT (i.e., 0xFE000000) is not
verified by the driver, which is what this patch introduces. With this
patch, if address PMC_BASE_ADDR_DEFAULT is in RAM, then the driver will
not attempt to ioremap the aforementioned address.
Signed-off-by: M. Vefa Bicakci <m.v.b@xxxxxxxxxx>
---
drivers/platform/x86/intel_pmc_core.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index c510d0d72475..3b6b8dcc4767 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -878,10 +878,14 @@ static int pmc_core_probe(struct platform_device *pdev)
if (pmcdev->map == &spt_reg_map && !pci_dev_present(pmc_pci_ids))
pmcdev->map = &cnp_reg_map;
- if (lpit_read_residency_count_address(&slp_s0_addr))
+ if (lpit_read_residency_count_address(&slp_s0_addr)) {
pmcdev->base_addr = PMC_BASE_ADDR_DEFAULT;
- else
+
+ if (page_is_ram(PHYS_PFN(pmcdev->base_addr)))
+ return -ENODEV;
+ } else {
pmcdev->base_addr = slp_s0_addr - pmcdev->map->slp_s0_offset;
+ }
pmcdev->regbase = ioremap(pmcdev->base_addr,
pmcdev->map->regmap_length);
--
2.21.0