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:
ioremap on RAM at 0x00000000fe000000 - 0x00000000fe001fff
WARNING: CPU: 1 PID: 434 at arch/x86/mm/ioremap.c:186 __ioremap_caller.constprop.0+0x2aa/0x2c0
...
Call Trace:
? pmc_core_probe+0x87/0x2d0 [intel_pmc_core]
pmc_core_probe+0x87/0x2d0 [intel_pmc_core]
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@runbox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
7d505758b1