From: Ivan Kokshaysky Date: Sun, 30 Mar 2008 15:50:14 +0000 (+0400) Subject: PCI: clean up resource alignment management X-Git-Tag: v2.6.26-rc1~1119^2~9 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=884525655d07fdee9245716b998ecdc45cdd8007;p=linux-2.6 PCI: clean up resource alignment management Done per Linus' request and suggestions. Linus has explained that better than I'll be able to explain: On Thu, Mar 27, 2008 at 10:12:10AM -0700, Linus Torvalds wrote: > Actually, before we go any further, there might be a less intrusive > alternative: add just a couple of flags to the resource flags field (we > still have something like 8 unused bits on 32-bit), and use those to > implement a generic "resource_alignment()" routine. > > Two flags would do it: > > - IORESOURCE_SIZEALIGN: size indicates alignment (regular PCI device > resources) > > - IORESOURCE_STARTALIGN: start field is alignment (PCI bus resources > during probing) > > and then the case of both flags zero (or both bits set) would actually be > "invalid", and we would also clear the IORESOURCE_STARTALIGN flag when we > actually allocate the resource (so that we don't use the "start" field as > alignment incorrectly when it no longer indicates alignment). > > That wouldn't be totally generic, but it would have the nice property of > automatically at least add sanity checking for that whole "res->start has > the odd meaning of 'alignment' during probing" and remove the need for a > new field, and it would allow us to have a generic "resource_alignment()" > routine that just gets a resource pointer. Besides, I removed IORESOURCE_BUS_HAS_VGA flag which was unused for ages. Signed-off-by: Ivan Kokshaysky Cc: Linus Torvalds Cc: Gary Hade Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index c2e99fd87f..33d9b8bea6 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -235,7 +235,7 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) res->flags |= l & ~PCI_BASE_ADDRESS_IO_MASK; } res->end = res->start + (unsigned long) sz; - res->flags |= pci_calc_resource_flags(l); + res->flags |= pci_calc_resource_flags(l) | IORESOURCE_SIZEALIGN; if (is_64bit_memory(l)) { u32 szhi, lhi; @@ -288,7 +288,8 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) if (sz) { res->flags = (l & IORESOURCE_ROM_ENABLE) | IORESOURCE_MEM | IORESOURCE_PREFETCH | - IORESOURCE_READONLY | IORESOURCE_CACHEABLE; + IORESOURCE_READONLY | IORESOURCE_CACHEABLE | + IORESOURCE_SIZEALIGN; res->start = l & PCI_ROM_ADDRESS_MASK; res->end = res->start + (unsigned long) sz; } diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index f7cb8e0758..5cf84568c9 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -65,6 +65,7 @@ static void pbus_assign_resources_sorted(struct pci_bus *bus) res = list->res; idx = res - &list->dev->resource[0]; if (pci_assign_resource(list->dev, idx)) { + /* FIXME: get rid of this */ res->start = 0; res->end = 0; res->flags = 0; @@ -327,6 +328,7 @@ static void pbus_size_io(struct pci_bus *bus) /* Alignment of the IO window is always 4K */ b_res->start = 4096; b_res->end = b_res->start + size - 1; + b_res->flags |= IORESOURCE_STARTALIGN; } /* Calculate the size of the bus and minimal alignment which @@ -401,6 +403,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, unsigned long } b_res->start = min_align; b_res->end = size + min_align - 1; + b_res->flags |= IORESOURCE_STARTALIGN; return 1; } diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c index bad509e40f..7d35cdf457 100644 --- a/drivers/pci/setup-res.c +++ b/drivers/pci/setup-res.c @@ -137,10 +137,16 @@ int pci_assign_resource(struct pci_dev *dev, int resno) size = res->end - res->start + 1; min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM; - /* The bridge resources are special, as their - size != alignment. Sizing routines return - required alignment in the "start" field. */ - align = (resno < PCI_BRIDGE_RESOURCES) ? size : res->start; + + align = resource_alignment(res); + if (!align) { + printk(KERN_ERR "PCI: Cannot allocate resource (bogus " + "alignment) %d [%llx:%llx] (flags %lx) of %s\n", + resno, (unsigned long long)res->start, + (unsigned long long)res->end, res->flags, + pci_name(dev)); + return -EINVAL; + } /* First, try exact prefetching match.. */ ret = pci_bus_alloc_resource(bus, res, size, align, min, @@ -164,8 +170,10 @@ int pci_assign_resource(struct pci_dev *dev, int resno) res->flags & IORESOURCE_IO ? "I/O" : "mem", resno, (unsigned long long)size, (unsigned long long)res->start, pci_name(dev)); - } else if (resno < PCI_BRIDGE_RESOURCES) { - pci_update_resource(dev, res, resno); + } else { + res->flags &= ~IORESOURCE_STARTALIGN; + if (resno < PCI_BRIDGE_RESOURCES) + pci_update_resource(dev, res, resno); } return ret; @@ -226,29 +234,25 @@ void pdev_sort_resources(struct pci_dev *dev, struct resource_list *head) if (r->flags & IORESOURCE_PCI_FIXED) continue; - r_align = r->end - r->start; - if (!(r->flags) || r->parent) continue; + + r_align = resource_alignment(r); if (!r_align) { - printk(KERN_WARNING "PCI: Ignore bogus resource %d " - "[%llx:%llx] of %s\n", + printk(KERN_WARNING "PCI: bogus alignment of resource " + "%d [%llx:%llx] (flags %lx) of %s\n", i, (unsigned long long)r->start, - (unsigned long long)r->end, pci_name(dev)); + (unsigned long long)r->end, r->flags, + pci_name(dev)); continue; } - r_align = (i < PCI_BRIDGE_RESOURCES) ? r_align + 1 : r->start; for (list = head; ; list = list->next) { resource_size_t align = 0; struct resource_list *ln = list->next; - int idx; - if (ln) { - idx = ln->res - &ln->dev->resource[0]; - align = (idx < PCI_BRIDGE_RESOURCES) ? - ln->res->end - ln->res->start + 1 : - ln->res->start; - } + if (ln) + align = resource_alignment(ln->res); + if (r_align > align) { tmp = kmalloc(sizeof(*tmp), GFP_KERNEL); if (!tmp) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 605d237364..d5d40a9f79 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -44,7 +44,9 @@ struct resource_list { #define IORESOURCE_CACHEABLE 0x00004000 #define IORESOURCE_RANGELENGTH 0x00008000 #define IORESOURCE_SHADOWABLE 0x00010000 -#define IORESOURCE_BUS_HAS_VGA 0x00080000 + +#define IORESOURCE_SIZEALIGN 0x00020000 /* size indicates alignment */ +#define IORESOURCE_STARTALIGN 0x00040000 /* start field is alignment */ #define IORESOURCE_DISABLED 0x10000000 #define IORESOURCE_UNSET 0x20000000 @@ -110,6 +112,7 @@ extern int allocate_resource(struct resource *root, struct resource *new, void *alignf_data); int adjust_resource(struct resource *res, resource_size_t start, resource_size_t size); +resource_size_t resource_alignment(struct resource *res); /* Convenience shorthand with allocation */ #define request_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name)) diff --git a/kernel/resource.c b/kernel/resource.c index 82aea814d4..cee12cc47c 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -486,6 +486,24 @@ int adjust_resource(struct resource *res, resource_size_t start, resource_size_t EXPORT_SYMBOL(adjust_resource); +/** + * resource_alignment - calculate resource's alignment + * @res: resource pointer + * + * Returns alignment on success, 0 (invalid alignment) on failure. + */ +resource_size_t resource_alignment(struct resource *res) +{ + switch (res->flags & (IORESOURCE_SIZEALIGN | IORESOURCE_STARTALIGN)) { + case IORESOURCE_SIZEALIGN: + return res->end - res->start + 1; + case IORESOURCE_STARTALIGN: + return res->start; + default: + return 0; + } +} + /* * This is compatibility stuff for IO resources. *