From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 4.19 111/128] platform/x86: intel_pmc_core: Do not ioremap RAM Date: Sun, 22 Sep 2019 14:54:01 -0400 Message-ID: <20190922185418.2158-111-sashal@kernel.org> References: <20190922185418.2158-1-sashal@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190922185418.2158-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "M. Vefa Bicakci" , Andy Shevchenko , Sasha Levin , platform-driver-x86@vger.kernel.org List-Id: platform-driver-x86.vger.kernel.org From: "M. Vefa Bicakci" [ Upstream commit 7d505758b1e556cdf65a5e451744fe0ae8063d17 ] 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 Signed-off-by: Andy Shevchenko Signed-off-by: Sasha Levin --- 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 088d1c2047e6b..36bd2545afb62 100644 --- a/drivers/platform/x86/intel_pmc_core.c +++ b/drivers/platform/x86/intel_pmc_core.c @@ -685,10 +685,14 @@ static int __init pmc_core_probe(void) 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); -- 2.20.1