From 08914f436bdd2ed60923f49cbc402307aba20fe4 Mon Sep 17 00:00:00 2001 From: Alex Thorlton Date: Wed, 4 May 2016 17:39:52 -0500 Subject: [PATCH 1/2] x86/platform/UV: Bring back the call to map_low_mmrs in uv_system_init A while back the following commit: d394f2d9d8e1 ("x86/platform/UV: Remove EFI memmap quirk for UV2+") changed uv_system_init() to only call map_low_mmrs() on older UV1 hardware, which requires EFI_OLD_MEMMAP to be set in order to boot. The recent changes to the EFI memory mapping code in: d2f7cbe7b26a ("x86/efi: Runtime services virtual mapping") exposed some issues with the fact that we were relying on the EFI memory mapping mechanisms to map in our MMRs for us, after commit d394f2d9d8e1. Rather than revert the entire commit and go back to forcing EFI_OLD_MEMMAP on all UVs, we're going to add the call to map_low_mmrs() back into uv_system_init(), and then fix up our EFI runtime calls to use the appropriate page table. For now, UV2+ will still need efi=old_map to boot, but there will be other changes soon that should eliminate the need for this. Signed-off-by: Alex Thorlton Cc: Matt Fleming Cc: Adam Buchbinder Cc: Len Brown Cc: Borislav Petkov Cc: Russ Anderson Cc: Dimitri Sivanich Link: http://lkml.kernel.org/r/1462401592-120735-1-git-send-email-athorlton@sgi.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/x2apic_uv_x.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c index 8f4942e2bcbb..d7ce96a7daca 100644 --- a/arch/x86/kernel/apic/x2apic_uv_x.c +++ b/arch/x86/kernel/apic/x2apic_uv_x.c @@ -891,9 +891,7 @@ void __init uv_system_init(void) } pr_info("UV: Found %s hub\n", hub); - /* We now only need to map the MMRs on UV1 */ - if (is_uv1_hub()) - map_low_mmrs(); + map_low_mmrs(); m_n_config.v = uv_read_local_mmr(UVH_RH_GAM_CONFIG_MMR ); m_val = m_n_config.s.m_skt; From 886123fb3a8656699dff40afa0573df359abeb18 Mon Sep 17 00:00:00 2001 From: Chen Yu Date: Fri, 6 May 2016 11:33:39 +0800 Subject: [PATCH 2/2] x86/tsc: Read all ratio bits from MSR_PLATFORM_INFO Currently we read the tsc radio: ratio = (MSR_PLATFORM_INFO >> 8) & 0x1f; Thus we get bit 8-12 of MSR_PLATFORM_INFO, however according to the SDM (35.5), the ratio bits are bit 8-15. Ignoring the upper bits can result in an incorrect tsc ratio, which causes the TSC calibration and the Local APIC timer frequency to be incorrect. Fix this problem by masking 0xff instead. [ tglx: Massaged changelog ] Fixes: 7da7c1561366 "x86, tsc: Add static (MSR) TSC calibration on Intel Atom SoCs" Signed-off-by: Chen Yu Cc: "Rafael J. Wysocki" Cc: stable@vger.kernel.org Cc: Bin Gao Cc: Len Brown Link: http://lkml.kernel.org/r/1462505619-5516-1-git-send-email-yu.c.chen@intel.com Signed-off-by: Thomas Gleixner --- arch/x86/kernel/tsc_msr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/tsc_msr.c b/arch/x86/kernel/tsc_msr.c index 92ae6acac8a7..6aa0f4d9eea6 100644 --- a/arch/x86/kernel/tsc_msr.c +++ b/arch/x86/kernel/tsc_msr.c @@ -92,7 +92,7 @@ unsigned long try_msr_calibrate_tsc(void) if (freq_desc_tables[cpu_index].msr_plat) { rdmsr(MSR_PLATFORM_INFO, lo, hi); - ratio = (lo >> 8) & 0x1f; + ratio = (lo >> 8) & 0xff; } else { rdmsr(MSR_IA32_PERF_STATUS, lo, hi); ratio = (hi >> 8) & 0x1f;