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linuxkpi: Fix PCI BAR lazy allocation support.

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FreeBSD supports lazy allocation of PCI BAR, that is, when a device
driver's attach method is invoked, even if the device's PCI BAR
address wasn't initialized, the invocation of bus_alloc_resource_any()
(the call chain: pci_alloc_resource() -> pci_alloc_multi_resource() ->
pci_reserve_map() -> pci_write_bar()) would allocate a proper address
for the PCI BAR and write this 'lazy allocated' address into the PCI
BAR.

This model works fine for native FreeBSD device drivers, but _not_ for
device drivers shared with Linux (e.g. dev/mlx5/mlx5_core/mlx5_main.c
and ofed/drivers/net/mlx4/main.c.  Both of them use
pci_request_regions(), which doesn't work properly with the PCI BAR
lazy allocation, because pci_resource_type() -> _pci_get_rle() always
returns NULL, so pci_request_regions() doesn't have the opportunity to
invoke bus_alloc_resource_any().  We now use pci_find_bar() in
pci_resource_type(), which is able to locate all available PCI BARs
even if some of them will be lazy allocated.

Submitted by:	Dexuan Cui <decui microsoft com>
Reviewed by:	hps
MFC after:	1 week
Sponsored by:	Microsoft
Differential Revision:	https://reviews.freebsd.org/D8071
This commit is contained in:
sephe 2016-09-30 05:51:11 +00:00
parent ebcb697bd7
commit 5a37a60a62
1 changed files with 8 additions and 3 deletions
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11
sys/compat/linuxkpi/common/include/linux/pci.h
View File

@ -233,11 +233,16 @@ pci_resource_len(struct pci_dev *pdev, int bar)
static inline int
pci_resource_type(struct pci_dev *pdev, int bar)
{
struct resource_list_entry *rle;
struct pci_map *pm;
if ((rle = _pci_get_bar(pdev, bar)) == NULL)
pm = pci_find_bar(pdev->dev.bsddev, PCIR_BAR(bar));
if (!pm)
return (-1);
return (rle->type);
if (PCI_BAR_IO(pm->pm_value))
return (SYS_RES_IOPORT);
else
return (SYS_RES_MEMORY);
}
/*