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author | Yinghai Lu <yhlu.kernel@gmail.com> | 2008-09-04 21:02:44 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-09-04 21:02:44 +0200 |
commit | 268364a0f48aee2f851f9d1ef8a6cda0f3039ef1 (patch) | |
tree | 018d00aa42b74a80baf976258aa9b17abdfb44c6 /kernel/resource.c | |
parent | d210baf53b699fc61aa891c177b71d7082d3b957 (diff) | |
download | kernel_goldelico_gta04-268364a0f48aee2f851f9d1ef8a6cda0f3039ef1.zip kernel_goldelico_gta04-268364a0f48aee2f851f9d1ef8a6cda0f3039ef1.tar.gz kernel_goldelico_gta04-268364a0f48aee2f851f9d1ef8a6cda0f3039ef1.tar.bz2 |
IO resources: add reserve_region_with_split()
add reserve_region_with_split() to not lose e820 reserved entries if
they overlap with existing IO regions:
with test case by extend 0xe0000000 - 0xeffffff to 0xdd800000 -
we get:
e0000000-efffffff : PCI MMCONFIG 0
e0000000-efffffff : reserved
and in /proc/iomem we get:
found conflict for reserved [dd800000, efffffff], try to reserve with split
__reserve_region_with_split: (PCI Bus #80) [dd000000, ddffffff], res: (reserved) [dd800000, efffffff]
__reserve_region_with_split: (PCI Bus #00) [de000000, dfffffff], res: (reserved) [de000000, efffffff]
initcall pci_subsys_init+0x0/0x121 returned 0 after 381 msecs
in dmesg
various fixes and improvements suggested by Linus.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/resource.c')
-rw-r--r-- | kernel/resource.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index 03d796c..414d6fc 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -516,6 +516,74 @@ int adjust_resource(struct resource *res, resource_size_t start, resource_size_t return result; } +static void __init __reserve_region_with_split(struct resource *root, + resource_size_t start, resource_size_t end, + const char *name) +{ + struct resource *parent = root; + struct resource *conflict; + struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL); + + if (!res) + return; + + res->name = name; + res->start = start; + res->end = end; + res->flags = IORESOURCE_BUSY; + + for (;;) { + conflict = __request_resource(parent, res); + if (!conflict) + break; + if (conflict != parent) { + parent = conflict; + if (!(conflict->flags & IORESOURCE_BUSY)) + continue; + } + + /* Uhhuh, that didn't work out.. */ + kfree(res); + res = NULL; + break; + } + + if (!res) { + printk(KERN_DEBUG " __reserve_region_with_split: (%s) [%llx, %llx], res: (%s) [%llx, %llx]\n", + conflict->name, conflict->start, conflict->end, + name, start, end); + + /* failed, split and try again */ + + /* conflict coverred whole area */ + if (conflict->start <= start && conflict->end >= end) + return; + + if (conflict->start > start) + __reserve_region_with_split(root, start, conflict->start-1, name); + if (!(conflict->flags & IORESOURCE_BUSY)) { + resource_size_t common_start, common_end; + + common_start = max(conflict->start, start); + common_end = min(conflict->end, end); + if (common_start < common_end) + __reserve_region_with_split(root, common_start, common_end, name); + } + if (conflict->end < end) + __reserve_region_with_split(root, conflict->end+1, end, name); + } + +} + +void reserve_region_with_split(struct resource *root, + resource_size_t start, resource_size_t end, + const char *name) +{ + write_lock(&resource_lock); + __reserve_region_with_split(root, start, end, name); + write_unlock(&resource_lock); +} + EXPORT_SYMBOL(adjust_resource); /** |