Commit 192f1bf7 authored by Nirmoy Das's avatar Nirmoy Das Committed by Christian König
Browse files

PCI: Add pci_rebar_bytes_to_size() 



Users of pci_resize_resource() need a way to calculate BAR size
from desired bytes. Add a helper function and export it so that
modular drivers can use it.

Signed-off-by: default avatarDarren Salt <devspam@moreofthesa.me.uk>
Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarNirmoy Das <nirmoy.das@amd.com>
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20210107175017.15893-3-nirmoy.das@amd.com
parent 8fbdbb66

drivers/pci/pci.c

+1 −1
Original line number Diff line number Diff line
@@ -1644,7 +1644,7 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) 
		pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl);

		bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX;

		res = pdev->resource + bar_idx;

		size = ilog2(resource_size(res)) - 20;

		size = pci_rebar_bytes_to_size(resource_size(res));

		ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;

		ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT;

		pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);

include/linux/pci.h

+8 −0
Original line number Diff line number Diff line
@@ -1232,6 +1232,14 @@ void pci_update_resource(struct pci_dev *dev, int resno); 
int __must_check pci_assign_resource(struct pci_dev *dev, int i);

int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align);

void pci_release_resource(struct pci_dev *dev, int resno);

static inline int pci_rebar_bytes_to_size(u64 bytes)

{

	bytes = roundup_pow_of_two(bytes);



	/* Return BAR size as defined in the resizable BAR specification */

	return max(ilog2(bytes), 20) - 20;

}



u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar);

int __must_check pci_resize_resource(struct pci_dev *dev, int i, int size);

int pci_select_bars(struct pci_dev *dev, unsigned long flags);