[+cc Andy, Benjamin, Keith] On Sun, Jun 12, 2022 at 04:43:25PM +0200, Hans de Goede wrote: > Clipping the bridge windows directly from pci_acpi_root_prepare_resources() > instead of clipping from arch_remove_reservations(), has a number of > unforseen consequences. > > If there is an e820 reservation in the middle of a bridge window, then > the smallest of the 2 remaining parts of the window will be also clipped > off. Where as the previous code would clip regions requested by devices, > rather then the entire window, leaving regions which were either entirely > above or below a reservation in the middle of the window alone. > > E.g. on the Steam Deck this leads to this log message: > > acpi PNP0A08:00: clipped [mem 0x80000000-0xf7ffffff window] to [mem 0xa0100000-0xf7ffffff window] > > which then gets followed by these log messages: > > pci 0000:00:01.2: can't claim BAR 14 [mem 0x80600000-0x806fffff]: no compatible bridge window > pci 0000:00:01.3: can't claim BAR 14 [mem 0x80500000-0x805fffff]: no compatible bridge window > > and many more of these. Ultimately this leads to the Steam Deck > no longer booting properly, so revert the change. > > Note this is not a clean revert, this revert keeps the later change > to make the clipping dependent on a new pci_use_e820 bool, moving > the checking of this bool to arch_remove_reservations(). > > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=216109 > Fixes: 4c5e242d3e93 ("x86/PCI: Clip only host bridge windows for E820 regions") > Reported-and-tested-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Applied to for-linus for v5.19. Thanks for cleaning up my mess, Hans. > --- > arch/x86/include/asm/e820/api.h | 5 ----- > arch/x86/include/asm/pci_x86.h | 8 ++++++++ > arch/x86/kernel/resource.c | 14 +++++++++----- > arch/x86/pci/acpi.c | 8 +------- > 4 files changed, 18 insertions(+), 17 deletions(-) > > diff --git a/arch/x86/include/asm/e820/api.h b/arch/x86/include/asm/e820/api.h > index 5a39ed59b6db..e8f58ddd06d9 100644 > --- a/arch/x86/include/asm/e820/api.h > +++ b/arch/x86/include/asm/e820/api.h > @@ -4,9 +4,6 @@ > > #include <asm/e820/types.h> > > -struct device; > -struct resource; > - > extern struct e820_table *e820_table; > extern struct e820_table *e820_table_kexec; > extern struct e820_table *e820_table_firmware; > @@ -46,8 +43,6 @@ extern void e820__register_nosave_regions(unsigned long limit_pfn); > > extern int e820__get_entry_type(u64 start, u64 end); > > -extern void remove_e820_regions(struct device *dev, struct resource *avail); > - > /* > * Returns true iff the specified range [start,end) is completely contained inside > * the ISA region. > diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h > index f52a886d35cf..70533fdcbf02 100644 > --- a/arch/x86/include/asm/pci_x86.h > +++ b/arch/x86/include/asm/pci_x86.h > @@ -69,6 +69,8 @@ void pcibios_scan_specific_bus(int busn); > > /* pci-irq.c */ > > +struct pci_dev; > + > struct irq_info { > u8 bus, devfn; /* Bus, device and function */ > struct { > @@ -246,3 +248,9 @@ static inline void mmio_config_writel(void __iomem *pos, u32 val) > # define x86_default_pci_init_irq NULL > # define x86_default_pci_fixup_irqs NULL > #endif > + > +#if defined(CONFIG_PCI) && defined(CONFIG_ACPI) > +extern bool pci_use_e820; > +#else > +#define pci_use_e820 false > +#endif > diff --git a/arch/x86/kernel/resource.c b/arch/x86/kernel/resource.c > index db2b350a37b7..bba1abd05bfe 100644 > --- a/arch/x86/kernel/resource.c > +++ b/arch/x86/kernel/resource.c > @@ -1,7 +1,8 @@ > // SPDX-License-Identifier: GPL-2.0 > -#include <linux/dev_printk.h> > #include <linux/ioport.h> > +#include <linux/printk.h> > #include <asm/e820/api.h> > +#include <asm/pci_x86.h> > > static void resource_clip(struct resource *res, resource_size_t start, > resource_size_t end) > @@ -24,14 +25,14 @@ static void resource_clip(struct resource *res, resource_size_t start, > res->start = end + 1; > } > > -void remove_e820_regions(struct device *dev, struct resource *avail) > +static void remove_e820_regions(struct resource *avail) > { > int i; > struct e820_entry *entry; > u64 e820_start, e820_end; > struct resource orig = *avail; > > - if (!(avail->flags & IORESOURCE_MEM)) > + if (!pci_use_e820) > return; > > for (i = 0; i < e820_table->nr_entries; i++) { > @@ -41,7 +42,7 @@ void remove_e820_regions(struct device *dev, struct resource *avail) > > resource_clip(avail, e820_start, e820_end); > if (orig.start != avail->start || orig.end != avail->end) { > - dev_info(dev, "clipped %pR to %pR for e820 entry [mem %#010Lx-%#010Lx]\n", > + pr_info("clipped %pR to %pR for e820 entry [mem %#010Lx-%#010Lx]\n", > &orig, avail, e820_start, e820_end); > orig = *avail; > } > @@ -55,6 +56,9 @@ void arch_remove_reservations(struct resource *avail) > * the low 1MB unconditionally, as this area is needed for some ISA > * cards requiring a memory range, e.g. the i82365 PCMCIA controller. > */ > - if (avail->flags & IORESOURCE_MEM) > + if (avail->flags & IORESOURCE_MEM) { > resource_clip(avail, BIOS_ROM_BASE, BIOS_ROM_END); > + > + remove_e820_regions(avail); > + } > } > diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c > index a4f43054bc79..2f82480fd430 100644 > --- a/arch/x86/pci/acpi.c > +++ b/arch/x86/pci/acpi.c > @@ -8,7 +8,6 @@ > #include <linux/pci-acpi.h> > #include <asm/numa.h> > #include <asm/pci_x86.h> > -#include <asm/e820/api.h> > > struct pci_root_info { > struct acpi_pci_root_info common; > @@ -20,7 +19,7 @@ struct pci_root_info { > #endif > }; > > -static bool pci_use_e820 = true; > +bool pci_use_e820 = true; > static bool pci_use_crs = true; > static bool pci_ignore_seg; > > @@ -387,11 +386,6 @@ static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci) > > status = acpi_pci_probe_root_resources(ci); > > - 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) > if (resource_is_pcicfg_ioport(entry->res)) > -- > 2.36.0 >
