On Thu, May 12, 2022 at 10:25 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > > Some BIOS-es contain bugs where they add addresses which are already > used in some other manner to the PCI host bridge window returned by > the ACPI _CRS method. To avoid this Linux by default excludes > E820 reservations when allocating addresses since 2010, see: > commit 4dc2287c1805 ("x86: avoid E820 regions when allocating address > space"). > > Recently (2019) some systems have shown-up with E820 reservations which > cover the entire _CRS returned PCI bridge memory window, causing all > attempts to assign memory to PCI BARs which have not been setup by the > BIOS to fail. For example here are the relevant dmesg bits from a > Lenovo IdeaPad 3 15IIL 81WE: > > [mem 0x000000004bc50000-0x00000000cfffffff] reserved > pci_bus 0000:00: root bus resource [mem 0x65400000-0xbfffffff window] > > The ACPI specifications appear to allow this new behavior: > > The relationship between E820 and ACPI _CRS is not really very clear. > ACPI v6.3, sec 15, table 15-374, says AddressRangeReserved means: > > This range of addresses is in use or reserved by the system and is > not to be included in the allocatable memory pool of the operating > system's memory manager. > > and it may be used when: > > The address range is in use by a memory-mapped system device. > > Furthermore, sec 15.2 says: > > Address ranges defined for baseboard memory-mapped I/O devices, such > as APICs, are returned as reserved. > > A PCI host bridge qualifies as a baseboard memory-mapped I/O device, > and its apertures are in use and certainly should not be included in > the general allocatable pool, so the fact that some BIOS-es reports > the PCI aperture as "reserved" in E820 doesn't seem like a BIOS bug. > > So it seems that the excluding of E820 reserved addresses is a mistake. > > Ideally Linux would fully stop excluding E820 reserved addresses, > but then various old systems will regress. Instead keep the old behavior > for old systems, while ignoring the E820 reservations for any future > systems. > > That is ignore E820 reservations starting with systems with > a DMI BIOS year >= 2023. > > And use DMI quirks for existing systems on which excluding E820 > reservations from the _CRS returned bridge window is an issue. > > Also add pci=no_e820 and pci=use_e820 options to allow overriding > the BIOS year + DMI matching logic. > > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=206459 > BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1868899 > BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1871793 > BugLink: https://bugs.launchpad.net/bugs/1878279 > BugLink: https://bugs.launchpad.net/bugs/1880172 > BugLink: https://bugs.launchpad.net/bugs/1884232 > BugLink: https://bugs.launchpad.net/bugs/1921649 > BugLink: https://bugs.launchpad.net/bugs/1931715 > BugLink: https://bugs.launchpad.net/bugs/1932069 > Cc: Benoit Grégoire <benoitg@xxxxxxxx> > Cc: Hui Wang <hui.wang@xxxxxxxxxxxxx> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > --- > Changes in v8: > - Change the cut-off for no longer excluding E820 reservations from > the bridge window to BIOS year >= 2023 so that this only applies to > upcoming systems. > - Use DMI quirks for existing systems on which excluding E820 > reservations from the _CRS returned bridge window is an issue. > > Changes in v7: > - Re-add the pci=use_e820 and pci=no_e820 kernel cmdline options since it > turns out that some newer laptops still need pci=use_e820 > - Add DMI quirks for known newer laptops which need pci=use_e820 > > Changes in v6: > - Remove the possibility to change the behavior from the commandline > because of worries that users may use this to paper over other problems > > Changes in v5: > - Drop mention of Windows behavior from the commit msg, replace with a > reference to the specs > - Improve documentation in Documentation/admin-guide/kernel-parameters.txt > - Reword the big comment added, use "PCI host bridge window" in it and drop > all refences to Windows > > Changes in v4: > - Rewrap the big comment block to fit in 80 columns > - Add Rafael's Acked-by > - Add Cc: stable@xxxxxxxxxxxxxxx > > Changes in v3: > - Commit msg tweaks (drop dmesg timestamps, typo fix) > - Use "defined(CONFIG_...)" instead of "defined CONFIG_..." > - Add Mika's Reviewed-by > > Changes in v2: > - Replace the per model DMI quirk approach with disabling E820 reservations > checking for all systems with a BIOS year >= 2018 > - Add documentation for the new kernel-parameters to > Documentation/admin-guide/kernel-parameters.txt > --- > .../admin-guide/kernel-parameters.txt | 9 ++ > arch/x86/include/asm/pci_x86.h | 2 + > arch/x86/pci/acpi.c | 109 +++++++++++++++++- > arch/x86/pci/common.c | 8 ++ > 4 files changed, 126 insertions(+), 2 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 3f1cc5e317ed..2477b639d5c4 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -4066,6 +4066,15 @@ > please report a bug. > nocrs [X86] Ignore PCI host bridge windows from ACPI. > If you need to use this, please report a bug. > + use_e820 [X86] Use E820 reservations to exclude parts of > + PCI host bridge windows. This is a workaround > + for BIOS defects in host bridge _CRS methods. > + If you need to use this, please report a bug to > + <linux-pci@xxxxxxxxxxxxxxx>. > + no_e820 [X86] Ignore E820 reservations for PCI host > + bridge windows. This is the default on modern > + hardware. If you need to use this, please report > + a bug to <linux-pci@xxxxxxxxxxxxxxx>. > routeirq Do IRQ routing for all PCI devices. > This is normally done in pci_enable_device(), > so this option is a temporary workaround > diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h > index a0627dfae541..ce3fd3311772 100644 > --- a/arch/x86/include/asm/pci_x86.h > +++ b/arch/x86/include/asm/pci_x86.h > @@ -42,6 +42,8 @@ do { \ > #define PCI_ROOT_NO_CRS 0x100000 > #define PCI_NOASSIGN_BARS 0x200000 > #define PCI_BIG_ROOT_WINDOW 0x400000 > +#define PCI_USE_E820 0x800000 > +#define PCI_NO_E820 0x1000000 > > extern unsigned int pci_probe; > extern unsigned long pirq_table_addr; > diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c > index 562c81a51ea0..125c55b58d7e 100644 > --- a/arch/x86/pci/acpi.c > +++ b/arch/x86/pci/acpi.c > @@ -20,6 +20,7 @@ struct pci_root_info { > #endif > }; > > +static bool pci_use_e820 = true; > static bool pci_use_crs = true; > static bool pci_ignore_seg; > > @@ -42,6 +43,13 @@ static int __init set_ignore_seg(const struct dmi_system_id *id) > return 0; > } > > +static int __init set_no_e820(const struct dmi_system_id *id) > +{ > + printk(KERN_INFO "PCI: %s detected: ignoring e820 regions\n", id->ident); > + pci_use_e820 = false; > + return 0; > +} > + > static const struct dmi_system_id pci_crs_quirks[] __initconst = { > /* http://bugzilla.kernel.org/show_bug.cgi?id=14183 */ > { > @@ -136,6 +144,74 @@ static const struct dmi_system_id pci_crs_quirks[] __initconst = { > DMI_MATCH(DMI_PRODUCT_NAME, "HP xw9300 Workstation"), > }, > }, > + > + /* > + * Most Lenovo models with "IIL" in their DMI_PRODUCT_VERSION have > + * an E820 reservation which covers the entire _CRS returned 32 bit > + * PCI bridge memory window, causing all attempts to assign memory to > + * 32 bit PCI bars which have not been setup by the BIOS to fail. > + * Specifically this often causes some of the I2C controllers to not > + * work breaking touchpad support and/or this may cause issues when > + * hotplugging thunderbolt connected devices. > + * > + * This DMI match entry covers the following DMI_PRODUCT_VERSION-s with > + * an E820 reservation which covers the entire 32 bit bridge window: > + * "IdeaPad 3 14IIL05", "IdeaPad 3 15IIL05", "IdeaPad 3 17IIL05", > + * "IdeaPad 5 14IIL05", "IdeaPad 5 15IIL05", > + * "IdeaPad Slim 7 14IIL05", "IdeaPad Slim 7 15IIL05", > + * "Lenovo BS145-15IIL", > + * "Lenovo IdeaPad S145-15IIL", "Lenovo IdeaPad S340-14IIL", > + * "Lenovo IdeaPad S340-15IIL", "Lenovo IdeaPad C340-15IIL", > + * "Lenovo V14-IIL", "Lenovo V15-IIL", "Lenovo V17-IIL", > + * "Lenovo Yoga S740-14IIL", "Lenovo Yoga C940-14IIL", > + * "Yoga Slim 7 14IIL05", "Yoga Slim 7 15IIL05" > + * > + * On some of these the bridge's _CRS method *sometimes* (under unknown > + * conditions) has a 64 bit [mem 0x4000000000-0x7fffffffff window]. > + * This avoids some of the issues, but even then there are still issues > + * with assigning some 32 bit only BARs such as some Thunderbolt devs, > + * the 00:1f.5 BIOS SPI controller and BAR6 of some nvidia gfx. > + * > + * This entry also covers the following DMI_PRODUCT_VERSION-s which do > + * not need pci_use_e820=false. This quirk is a no-op for these models, > + * because there is no overlap between E820 regions and _CRS windows: > + * "IdeaPad Flex 5 14IIL05", "IdeaPad Flex 5 15IIL05", > + * "Lenovo ThinkBook 14-IIL", "Lenovo ThinkBook 15-IIL", > + * "Lenovo Yoga S940-14IIL" > + * > + * This entry fixes issues reported in the following bugs: > + * https://bugzilla.kernel.org/show_bug.cgi?id=206459 > + * https://bugzilla.redhat.com/show_bug.cgi?id=1871793 > + * https://bugzilla.redhat.com/show_bug.cgi?id=1868899 > + * https://bugs.launchpad.net/bugs/1878279 > + * https://bugs.launchpad.net/bugs/1880172 > + * https://bugs.launchpad.net/bugs/1921649 > + * https://bugs.launchpad.net/bugs/1931715 > + * https://bugs.launchpad.net/bugs/1932069 > + */ > + { > + .callback = set_no_e820, > + .ident = "Lenovo *IIL* product version", > + .matches = { > + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), > + DMI_MATCH(DMI_PRODUCT_VERSION, "IIL"), > + }, > + }, > + > + /* > + * The Acer Spin 5 (SP513-54N) has the same E820 reservation covering > + * the entire _CRS 32 bit window issue as the Lenovo *IIL* models. > + * https://bugs.launchpad.net/bugs/1884232 > + */ > + { > + .callback = set_no_e820, > + .ident = "Acer Spin 5 (SP513-54N)", > + .matches = { > + DMI_MATCH(DMI_SYS_VENDOR, "Acer"), > + DMI_MATCH(DMI_PRODUCT_NAME, "Spin SP513-54N"), > + }, > + }, > + > {} > }; > > @@ -146,6 +222,24 @@ void __init pci_acpi_crs_quirks(void) > if (year >= 0 && year < 2008 && iomem_resource.end <= 0xffffffff) > pci_use_crs = false; > > + /* > + * Some BIOS-es contain bugs where they add addresses which are already > + * used in some other manner to the PCI host bridge window returned by > + * the ACPI _CRS method. To avoid this Linux by default excludes > + * E820 reservations when allocating addresses since 2010. > + * In 2019 some systems have shown-up with E820 reservations which cover > + * the entire _CRS returned PCI host bridge window, causing all attempts > + * to assign memory to PCI BARs to fail if Linux uses E820 reservations. > + * > + * Ideally Linux would fully stop using E820 reservations, but then > + * various old systems will regress. Instead stop using E820 reservations > + * for new systems with a DMI BIOS year >= 2023; > + * and use DMI quirks for existing systems on which excluding E820 > + * reservations is known to cause issues. > + */ > + if (year >= 2023) > + pci_use_e820 = false; > + > dmi_check_system(pci_crs_quirks); > > /* > @@ -161,6 +255,15 @@ void __init pci_acpi_crs_quirks(void) > "if necessary, use \"pci=%s\" and report a bug\n", > pci_use_crs ? "Using" : "Ignoring", > pci_use_crs ? "nocrs" : "use_crs"); > + > + /* "pci=use_e820"/"pci=no_e820" on the kernel cmdline takes precedence */ > + if (pci_probe & PCI_NO_E820) > + pci_use_e820 = false; > + else if (pci_probe & PCI_USE_E820) > + pci_use_e820 = true; > + > + printk(KERN_INFO "PCI: %s E820 reservations for host bridge windows\n", > + pci_use_e820 ? "Using" : "Ignoring"); > } > > #ifdef CONFIG_PCI_MMCONFIG > @@ -301,8 +404,10 @@ static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci) > > status = acpi_pci_probe_root_resources(ci); > > - resource_list_for_each_entry(entry, &ci->resources) > - remove_e820_regions(&device->dev, entry->res); > + if (pci_use_e820) { > + resource_list_for_each_entry(entry, &ci->resources) > + remove_e820_regions(&device->dev, entry->res); > + } > > if (pci_use_crs) { > resource_list_for_each_entry_safe(entry, tmp, &ci->resources) > diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c > index 9e1e6b8d8876..ddb798603201 100644 > --- a/arch/x86/pci/common.c > +++ b/arch/x86/pci/common.c > @@ -595,6 +595,14 @@ char *__init pcibios_setup(char *str) > } else if (!strcmp(str, "nocrs")) { > pci_probe |= PCI_ROOT_NO_CRS; > return NULL; > + } else if (!strcmp(str, "use_e820")) { > + pci_probe |= PCI_USE_E820; > + add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); > + return NULL; > + } else if (!strcmp(str, "no_e820")) { > + pci_probe |= PCI_NO_E820; > + add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); > + return NULL; > #ifdef CONFIG_PHYS_ADDR_T_64BIT > } else if (!strcmp(str, "big_root_window")) { > pci_probe |= PCI_BIG_ROOT_WINDOW; > -- > 2.36.0 >