mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-05 10:31:46 +09:00
7d505758b1
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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.