On Mon, Mar 29, 2021 at 04:47:59PM +0800, Kai-Heng Feng wrote: > Built-in grahpics on HP EliteDesk 805 G6 doesn't work because graphics > can't get the BAR it needs: > [ 0.611504] pci_bus 0000:00: root bus resource [mem > 0x10020200000-0x100303fffff window] > [ 0.611505] pci_bus 0000:00: root bus resource [mem > 0x10030400000-0x100401fffff window] > ... > [ 0.638083] pci 0000:00:08.1: bridge window [mem 0xd2000000-0xd23fffff] > [ 0.638086] pci 0000:00:08.1: bridge window [mem > 0x10030000000-0x100401fffff 64bit pref] > [ 0.962086] pci 0000:00:08.1: can't claim BAR 15 [mem > 0x10030000000-0x100401fffff 64bit pref]: no compatible bridge window > [ 0.962086] pci 0000:00:08.1: [mem 0x10030000000-0x100401fffff 64bit pref] > clipped to [mem 0x10030000000-0x100303fffff 64bit pref] > [ 0.962086] pci 0000:00:08.1: bridge window [mem > 0x10030000000-0x100303fffff 64bit pref] > [ 0.962086] pci 0000:07:00.0: can't claim BAR 0 [mem > 0x10030000000-0x1003fffffff 64bit pref]: no compatible bridge window > [ 0.962086] pci 0000:07:00.0: can't claim BAR 2 [mem > 0x10040000000-0x100401fffff 64bit pref]: no compatible bridge window > > However, the root bus has two continuous regions that can contain the > child resource requested. > > So try to find another parent region if two regions are continuous and > can contain child resource. This change makes the grahpics works on the > system in question.
The BIOS description of PCI0 is interesting: pci_bus 0000:00: root bus resource [mem 0x10000000000-0x100201fffff window] pci_bus 0000:00: root bus resource [mem 0x10020200000-0x100303fffff window] pci_bus 0000:00: root bus resource [mem 0x10030400000-0x100401fffff window] So the PCI0 _CRS apparently gave us: [mem 0x10000000000-0x100201fffff] size 0x20200000 (512MB + 2MB) [mem 0x10020200000-0x100303fffff] size 0x10200000 (256MB + 2MB) [mem 0x10030400000-0x100401fffff] size 0x0fe00000 (254MB) These are all contiguous, so we'd have no problem if we coalesced them into a single window: [mem 0x10000000000-0x100401fffff window] size 0x40200000 (1GB + 2MB) I think we currently keep these root bus resources separate because if we ever support _SRS for host bridges, the argument we give to _SRS must be exactly the same format as what we got from _CRS (see ACPI v6.3, sec 6.2.16, and pnpacpi_set_resources()). pnpacpi_encode_resources() is currently very simple-minded and copies each device resource back into a single _SRS entry. But (1) we don't support _SRS for host bridges, and (2) if we ever do, we can make pnpacpi_encode_resources() smarter so it breaks things back up. So I think we should try to fix this by coalescing these adjacent resources from _CRS so we end up with a single root bus resource that covers all contiguous regions. Typos, etc: - No need for the timestamps; they're not relevant to the problem. - s/grahpics/graphics/ (two occurrences above) - s/continuous/contiguous/ (three occurrences above) > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212013 > Signed-off-by: Kai-Heng Feng <kai.heng.f...@canonical.com> > --- > arch/microblaze/pci/pci-common.c | 4 +-- > arch/powerpc/kernel/pci-common.c | 8 ++--- > arch/sparc/kernel/pci.c | 4 +-- > drivers/pci/pci.c | 60 +++++++++++++++++++++++++++----- > drivers/pci/setup-res.c | 21 +++++++---- > drivers/pcmcia/rsrc_nonstatic.c | 4 +-- > include/linux/pci.h | 6 ++-- > 7 files changed, 80 insertions(+), 27 deletions(-) > > diff --git a/arch/microblaze/pci/pci-common.c > b/arch/microblaze/pci/pci-common.c > index 557585f1be41..8e65832fb510 100644 > --- a/arch/microblaze/pci/pci-common.c > +++ b/arch/microblaze/pci/pci-common.c > @@ -669,7 +669,7 @@ static void pcibios_allocate_bus_resources(struct pci_bus > *bus) > { > struct pci_bus *b; > int i; > - struct resource *res, *pr; > + struct resource *res, *pr = NULL; > > pr_debug("PCI: Allocating bus resources for %04x:%02x...\n", > pci_domain_nr(bus), bus->number); > @@ -688,7 +688,7 @@ static void pcibios_allocate_bus_resources(struct pci_bus > *bus) > * and as such ensure proper re-allocation > * later. > */ > - pr = pci_find_parent_resource(bus->self, res); > + pci_find_parent_resource(bus->self, res, &pr, NULL); > if (pr == res) { > /* this happens when the generic PCI > * code (wrongly) decides that this > diff --git a/arch/powerpc/kernel/pci-common.c > b/arch/powerpc/kernel/pci-common.c > index 001e90cd8948..f865354b746d 100644 > --- a/arch/powerpc/kernel/pci-common.c > +++ b/arch/powerpc/kernel/pci-common.c > @@ -1196,7 +1196,7 @@ static void pcibios_allocate_bus_resources(struct > pci_bus *bus) > { > struct pci_bus *b; > int i; > - struct resource *res, *pr; > + struct resource *res, *pr = NULL; > > pr_debug("PCI: Allocating bus resources for %04x:%02x...\n", > pci_domain_nr(bus), bus->number); > @@ -1213,7 +1213,7 @@ static void pcibios_allocate_bus_resources(struct > pci_bus *bus) > pr = (res->flags & IORESOURCE_IO) ? > &ioport_resource : &iomem_resource; > else { > - pr = pci_find_parent_resource(bus->self, res); > + pci_find_parent_resource(bus->self, res, &pr, NULL); > if (pr == res) { > /* this happens when the generic PCI > * code (wrongly) decides that this > @@ -1265,12 +1265,12 @@ static void pcibios_allocate_bus_resources(struct > pci_bus *bus) > > static inline void alloc_resource(struct pci_dev *dev, int idx) > { > - struct resource *pr, *r = &dev->resource[idx]; > + struct resource *pr = NULL, *r = &dev->resource[idx]; > > pr_debug("PCI: Allocating %s: Resource %d: %pR\n", > pci_name(dev), idx, r); > > - pr = pci_find_parent_resource(dev, r); > + pci_find_parent_resource(dev, r, &pr, NULL); > if (!pr || (pr->flags & IORESOURCE_UNSET) || > request_resource(pr, r) < 0) { > printk(KERN_WARNING "PCI: Cannot allocate resource region %d" > diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c > index 9c2b720bfd20..b4006798e4e1 100644 > --- a/arch/sparc/kernel/pci.c > +++ b/arch/sparc/kernel/pci.c > @@ -621,7 +621,7 @@ static void pci_bus_register_of_sysfs(struct pci_bus *bus) > static void pci_claim_legacy_resources(struct pci_dev *dev) > { > struct pci_bus_region region; > - struct resource *p, *root, *conflict; > + struct resource *p, *root = NULL, *conflict; > > if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) > return; > @@ -637,7 +637,7 @@ static void pci_claim_legacy_resources(struct pci_dev > *dev) > region.end = region.start + 0x1ffffUL; > pcibios_bus_to_resource(dev->bus, p, ®ion); > > - root = pci_find_parent_resource(dev, p); > + pci_find_parent_resource(dev, p, &root, NULL); > if (!root) { > pci_info(dev, "can't claim VGA legacy %pR: no compatible bridge > window\n", p); > goto err; > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 16a17215f633..abbcd2dcdc02 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -693,20 +693,25 @@ u8 pci_find_ht_capability(struct pci_dev *dev, int > ht_cap) > EXPORT_SYMBOL_GPL(pci_find_ht_capability); > > /** > - * pci_find_parent_resource - return resource region of parent bus of given > + * pci_find_parent_resource - find resource region of parent bus of given > * region > * @dev: PCI device structure contains resources to be searched > * @res: child resource record for which parent is sought > + * @first: the first region that contains the child resource > + * @second: the second region that combines with the first region to fully > + * contains the child resource > * > * For given resource region of given device, return the resource region of > * parent bus the given region is contained in. > */ > -struct resource *pci_find_parent_resource(const struct pci_dev *dev, > - struct resource *res) > +void pci_find_parent_resource(const struct pci_dev *dev, > + struct resource *res, > + struct resource **first, > + struct resource **second) > { > const struct pci_bus *bus = dev->bus; > struct resource *r; > - int i; > + int i, overlaps = 0; > > pci_bus_for_each_resource(bus, r, i) { > if (!r) > @@ -718,8 +723,10 @@ struct resource *pci_find_parent_resource(const struct > pci_dev *dev, > * not, the allocator made a mistake. > */ > if (r->flags & IORESOURCE_PREFETCH && > - !(res->flags & IORESOURCE_PREFETCH)) > - return NULL; > + !(res->flags & IORESOURCE_PREFETCH)) { > + *first = NULL; > + return; > + } > > /* > * If we're below a transparent bridge, there may > @@ -729,10 +736,47 @@ struct resource *pci_find_parent_resource(const struct > pci_dev *dev, > * on pci_bus_for_each_resource() giving us those > * first. > */ > - return r; > + *first = r; > + return; > } > } > - return NULL; > + > + if (!second) > + return; > + > + pci_bus_for_each_resource(bus, r, i) { > + if (!r) > + continue; > + if (resource_overlaps(r, res)) { > + if (r->flags & IORESOURCE_PREFETCH && > + !(res->flags & IORESOURCE_PREFETCH)) > + continue; > + > + if (!overlaps++) > + *first = r; > + else { > + *second = r; > + break; > + } > + } > + } > + > + if (overlaps != 2) > + goto out; > + > + if ((*first)->start > (*second)->start) > + swap(*first, *second); > + > + if ((*first)->end + 1 != (*second)->start) > + goto out; > + > + if ((*first)->start <= res->start && (*second)->end >= res->end) > + return; > +out: > + > + *first = NULL; > + *second = NULL; > + return; > } > EXPORT_SYMBOL(pci_find_parent_resource); > > diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c > index 7f1acb3918d0..e39615321d81 100644 > --- a/drivers/pci/setup-res.c > +++ b/drivers/pci/setup-res.c > @@ -131,7 +131,7 @@ void pci_update_resource(struct pci_dev *dev, int resno) > int pci_claim_resource(struct pci_dev *dev, int resource) > { > struct resource *res = &dev->resource[resource]; > - struct resource *root, *conflict; > + struct resource *first = NULL, *second = NULL, *conflict; > > if (res->flags & IORESOURCE_UNSET) { > pci_info(dev, "can't claim BAR %d %pR: no address assigned\n", > @@ -147,21 +147,28 @@ int pci_claim_resource(struct pci_dev *dev, int > resource) > if (res->flags & IORESOURCE_ROM_SHADOW) > return 0; > > - root = pci_find_parent_resource(dev, res); > - if (!root) { > + pci_find_parent_resource(dev, res, &first, &second); > + if (!first) { > pci_info(dev, "can't claim BAR %d %pR: no compatible bridge > window\n", > resource, res); > res->flags |= IORESOURCE_UNSET; > return -EINVAL; > } > > - conflict = request_resource_conflict(root, res); > + if (second) > + first->end = second->end; > + > + conflict = request_resource_conflict(first, res); > if (conflict) { > + if (second) > + first->end = second->start - 1; > + > pci_info(dev, "can't claim BAR %d %pR: address conflict with %s > %pR\n", > resource, res, conflict->name, conflict); > res->flags |= IORESOURCE_UNSET; > return -EBUSY; > - } > + } else if (second) > + second->start = second->end = 0; > > return 0; > } > @@ -195,7 +202,7 @@ resource_size_t __weak pcibios_retrieve_fw_addr(struct > pci_dev *dev, int idx) > static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev, > int resno, resource_size_t size) > { > - struct resource *root, *conflict; > + struct resource *root = NULL, *conflict; > resource_size_t fw_addr, start, end; > > fw_addr = pcibios_retrieve_fw_addr(dev, resno); > @@ -208,7 +215,7 @@ static int pci_revert_fw_address(struct resource *res, > struct pci_dev *dev, > res->end = res->start + size - 1; > res->flags &= ~IORESOURCE_UNSET; > > - root = pci_find_parent_resource(dev, res); > + pci_find_parent_resource(dev, res, &root, NULL); > if (!root) { > if (res->flags & IORESOURCE_IO) > root = &ioport_resource; > diff --git a/drivers/pcmcia/rsrc_nonstatic.c b/drivers/pcmcia/rsrc_nonstatic.c > index 3b05760e69d6..2fba42d7486e 100644 > --- a/drivers/pcmcia/rsrc_nonstatic.c > +++ b/drivers/pcmcia/rsrc_nonstatic.c > @@ -73,7 +73,7 @@ static struct resource * > claim_region(struct pcmcia_socket *s, resource_size_t base, > resource_size_t size, int type, char *name) > { > - struct resource *res, *parent; > + struct resource *res, *parent = NULL; > > parent = type & IORESOURCE_MEM ? &iomem_resource : &ioport_resource; > res = pcmcia_make_resource(base, size, type | IORESOURCE_BUSY, name); > @@ -81,7 +81,7 @@ claim_region(struct pcmcia_socket *s, resource_size_t base, > if (res) { > #ifdef CONFIG_PCI > if (s && s->cb_dev) > - parent = pci_find_parent_resource(s->cb_dev, res); > + pci_find_parent_resource(s->cb_dev, res, &parent, NULL); > #endif > if (!parent || request_resource(parent, res)) { > kfree(res); > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 86c799c97b77..dd1455be5247 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1049,8 +1049,10 @@ void pci_device_add(struct pci_dev *dev, struct > pci_bus *bus); > unsigned int pci_scan_child_bus(struct pci_bus *bus); > void pci_bus_add_device(struct pci_dev *dev); > void pci_read_bridge_bases(struct pci_bus *child); > -struct resource *pci_find_parent_resource(const struct pci_dev *dev, > - struct resource *res); > +void pci_find_parent_resource(const struct pci_dev *dev, > + struct resource *res, > + struct resource **first, > + struct resource **second); > u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin); > int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge); > u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp); > -- > 2.30.2 >
