From: Sumit Saxena <sumit.saxena@xxxxxxxxxxxx>
commit d2182b2d4b71ff0549a07f414d921525fade707b upstream.
In a Resizable BAR Control Register, bits 13:8 control the size of the BAR.
The encoded values of these bits are as follows (see PCIe r5.0, sec
7.8.6.3):
Value BAR size
0 1 MB (2^20 bytes)
1 2 MB (2^21 bytes)
2 4 MB (2^22 bytes)
...
43 8 EB (2^63 bytes)
Previously we incorrectly set the BAR size bits for a 1 MB BAR to 0x1f
instead of 0, so devices that support that size, e.g., new megaraid_sas and
mpt3sas adapters, fail to initialize during resume from S3 sleep.
Correctly calculate the BAR size bits for Resizable BAR control registers.
Link: https://lore.kernel.org/r/20190725192552.24295-1-sumit.saxena@xxxxxxxxxxxx
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203939
Fixes: d3252ace0bc6 ("PCI: Restore resized BAR state on resume")
Signed-off-by: Sumit Saxena <sumit.saxena@xxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Christian König <christian.koenig@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.19+
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/pci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1366,7 +1366,7 @@ static void pci_restore_rebar_state(stru
pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);
bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;
res = pdev->resource + bar_idx;
- size = order_base_2((resource_size(res) >> 20) | 1) - 1;
+ size = ilog2(resource_size(res)) - 20;
ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;
ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT;
pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
