On Mon, Mar 30, 2015 at 11:38 PM, Yijing Wang <wangyijing@xxxxxxxxxx> wrote:
> On 2015/3/29 14:18, Yinghai Lu wrote:
>> On Sat, Mar 28, 2015 at 3:02 AM, Yijing Wang <wangyijing@xxxxxxxxxx> wrote:
>>> ...
>>>
>>> I compared above log and found after we did remove and rescan, the bridge requested resource size extended to 0x06000000,
>>> and when system boot up, it requested only 0x4800000.
>>>
> I tested it, remove and rescan 05:19.0 device is ok now, but
> if do the operations for the parent device of 05:19.0, the result is
> still fail.
Found the problem, attached patch should fix the problem.
Thanks
Yinghai
Subject: [PATCH] PCI: Optimize bus mem sizing to small size
Current code try to get min_align as possible and use that to
align final size.
That could cause generate wrong align/size or too big size in some case.
when we have align/size: 16M/64M
min_align/size0 will be 8M/64M, that is wrong, align must be 16M.
when we have align/size: 1M/1M, 64M/64M,
min_align/size0 will be 32M/96M, that is way too big for sum size 65M.
That will cuase allocation fails.
The patch introduce max_align/size0_max, and size0_max is just
sum of all children resource.
Prefer small size instead of small align. Only use min_align when
two size is the same.
The new size will only need to be aligned to bus window alignment.
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
drivers/pci/setup-bus.c | 50 +++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 47 insertions(+), 3 deletions(-)
Index: linux-2.6/drivers/pci/setup-bus.c
===================================================================
--- linux-2.6.orig/drivers/pci/setup-bus.c
+++ linux-2.6/drivers/pci/setup-bus.c
@@ -882,12 +882,14 @@ static void pbus_size_io(struct pci_bus
}
size0 = calculate_iosize(size, min_size, size1,
- resource_size(b_res), min_align);
+ resource_size(b_res),
+ window_alignment(bus, IORESOURCE_IO));
if (children_add_size > add_size)
add_size = children_add_size;
size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
calculate_iosize(size, min_size, add_size + size1,
- resource_size(b_res), min_align);
+ resource_size(b_res),
+ window_alignment(bus, IORESOURCE_IO));
if (!size0 && !size1) {
if (b_res->start || b_res->end)
dev_info(&bus->self->dev, "disabling bridge window %pR to %pR (unused)\n",
@@ -962,6 +964,8 @@ static int pbus_size_mem(struct pci_bus
struct resource *b_res = find_free_bus_resource(bus,
mask | IORESOURCE_PREFETCH, type);
resource_size_t children_add_size = 0;
+ resource_size_t max_align = 0, size0_max;
+ int count = 0;
if (!b_res)
return -ENOSPC;
@@ -1016,19 +1020,59 @@ static int pbus_size_mem(struct pci_bus
if (order > max_order)
max_order = order;
+ count++;
+ if (align > max_align)
+ max_align = align;
+
if (realloc_head)
children_add_size += get_res_add_size(realloc_head, r);
}
}
+ /*
+ * New rule: Prefer to small size instead of small align,
+ * when we have align/size: 1M/1M, 2M/2M,
+ * min_align/size0: 1M/3M, max_align/size0_max: 2M/3M
+ * pick 1M/3M.
+ * when we have align/size: 1M/1M, 64M/64M,
+ * min_align/size0: 32M/96M, max_align/size0_max: 64M/65M
+ * pick 64M/65M.
+ * when we have align/size: 1M/1M, 16M/64M,
+ * min_align/size0: 8M/72M, max_align/size0_max: 16M/65M
+ * pick 16M/65M.
+ * when we have align/size: 32M/64M, 128M/512M
+ * min_align/size0: 64M/576M, max_align/size0_max: 128M/576M
+ * pick 64M/576M.
+ * when we have align/size: 16M/32M, 128M/512M
+ * min_align/size0: 64M/576M, max_align/size0_max: 128M/554M
+ * pick 128M/554M.
+ * when we have align/size: 16M/64M
+ * min_align/size0: 8M/64M, max_align/size0_max: 16M/64M
+ * have to use 16M/64M.
+ */
min_align = calculate_mem_align(aligns, max_order);
min_align = max(min_align, window_alignment(bus, b_res->flags));
+ max_align = max(max_align, window_alignment(bus, b_res->flags));
+ if (count == 1)
+ min_align = max_align;
+
size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), min_align);
+ size0_max = calculate_memsize(size, min_size, 0, resource_size(b_res),
+ window_alignment(bus, b_res->flags));
+
+ if (size0_max < size0) {
+ size0 = size0_max;
+ min_align = max_align;
+ max_align--; /* to use small align for size1 calculation */
+ }
+
if (children_add_size > add_size)
add_size = children_add_size;
size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
calculate_memsize(size, min_size, add_size,
- resource_size(b_res), min_align);
+ resource_size(b_res),
+ min_align <= max_align ? min_align :
+ window_alignment(bus, b_res->flags));
if (!size0 && !size1) {
if (b_res->start || b_res->end)
dev_info(&bus->self->dev, "disabling bridge window %pR to %pR (unused)\n",
