Commit 4687b331 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Bjorn Helgaas
Browse files

PCI/IOV: Adjust ->barsz[] when changing BAR size 



pci_rebar_set_size() adjusts BAR size for both normal and IOV BARs. The
struct pci_sriov keeps a cached copy of BAR size in ->barsz[] which is not
adjusted by pci_rebar_set_size() but by pci_iov_resource_set_size().
pci_iov_resource_set_size() is called also from
pci_resize_resource_set_size().

The current arrangement is problematic once BAR resize algorithm starts to
roll back changes properly in case of a failure. The normal resource
fitting algorithm rolls back resource size using the struct
pci_dev_resource easily but also calling pci_resize_resource_set_size() or
pci_iov_resource_set_size() to roll back BAR size would be an extra burden,
whereas combining ->barsz[] update with pci_rebar_set_size() naturally
rolls back it when restoring the old BAR size on a different layer of the
BAR resize operation.

Thus, rework pci_rebar_set_size() to also update ->barsz[].

Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Tested-by: Alex Bennée <alex.bennee@linaro.org> # AVA, AMD GPU
Link: https://patch.msgid.link/20251113162628.5946-3-ilpo.jarvinen@linux.intel.com
parent 91c4c89d

drivers/pci/iov.c

+4 −11
Original line number Diff line number Diff line
@@ -158,8 +158,7 @@ resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno) 
	return dev->sriov->barsz[pci_resource_num_to_vf_bar(resno)];

}



void pci_iov_resource_set_size(struct pci_dev *dev, int resno,

			       resource_size_t size)

void pci_iov_resource_set_size(struct pci_dev *dev, int resno, int size)

{

	if (!pci_resource_is_iov(resno)) {

		pci_warn(dev, "%s is not an IOV resource\n",
@@ -167,7 +166,8 @@ void pci_iov_resource_set_size(struct pci_dev *dev, int resno, 
		return;

	}



	dev->sriov->barsz[pci_resource_num_to_vf_bar(resno)] = size;

	resno = pci_resource_num_to_vf_bar(resno);

	dev->sriov->barsz[resno] = pci_rebar_size_to_bytes(size);

}



bool pci_iov_is_memory_decoding_enabled(struct pci_dev *dev)
@@ -1340,7 +1340,6 @@ EXPORT_SYMBOL_GPL(pci_sriov_configure_simple); 
int pci_iov_vf_bar_set_size(struct pci_dev *dev, int resno, int size)

{

	u32 sizes;

	int ret;



	if (!pci_resource_is_iov(resno))

		return -EINVAL;
@@ -1355,13 +1354,7 @@ int pci_iov_vf_bar_set_size(struct pci_dev *dev, int resno, int size) 
	if (!(sizes & BIT(size)))

		return -EINVAL;



	ret = pci_rebar_set_size(dev, resno, size);

	if (ret)

		return ret;



	pci_iov_resource_set_size(dev, resno, pci_rebar_size_to_bytes(size));



	return 0;

	return pci_rebar_set_size(dev, resno, size);

}

EXPORT_SYMBOL_GPL(pci_iov_vf_bar_set_size);

drivers/pci/pci.c

+4 −0
Original line number Diff line number Diff line
@@ -3803,6 +3803,10 @@ int pci_rebar_set_size(struct pci_dev *pdev, int bar, int size) 
	ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE;

	ctrl |= FIELD_PREP(PCI_REBAR_CTRL_BAR_SIZE, size);

	pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);



	if (pci_resource_is_iov(bar))

		pci_iov_resource_set_size(pdev, bar, size);



	return 0;

}

drivers/pci/pci.h

+2 −3
Original line number Diff line number Diff line
@@ -808,8 +808,7 @@ void pci_iov_update_resource(struct pci_dev *dev, int resno); 
resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno);

void pci_restore_iov_state(struct pci_dev *dev);

int pci_iov_bus_range(struct pci_bus *bus);

void pci_iov_resource_set_size(struct pci_dev *dev, int resno,

			       resource_size_t size);

void pci_iov_resource_set_size(struct pci_dev *dev, int resno, int size);

bool pci_iov_is_memory_decoding_enabled(struct pci_dev *dev);

static inline u16 pci_iov_vf_rebar_cap(struct pci_dev *dev)

{
@@ -851,7 +850,7 @@ static inline int pci_iov_bus_range(struct pci_bus *bus) 
	return 0;

}

static inline void pci_iov_resource_set_size(struct pci_dev *dev, int resno,

					     resource_size_t size) { }

					     int size) { }

static inline bool pci_iov_is_memory_decoding_enabled(struct pci_dev *dev)

{

	return false;

drivers/pci/setup-res.c

+4 −6
Original line number Diff line number Diff line
@@ -450,12 +450,10 @@ static void pci_resize_resource_set_size(struct pci_dev *dev, int resno, 
	resource_size_t res_size = pci_rebar_size_to_bytes(size);

	struct resource *res = pci_resource_n(dev, resno);



	if (!pci_resource_is_iov(resno)) {

	if (pci_resource_is_iov(resno))

		res_size *= pci_sriov_get_totalvfs(dev);



	resource_set_size(res, res_size);

	} else {

		resource_set_size(res, res_size * pci_sriov_get_totalvfs(dev));

		pci_iov_resource_set_size(dev, resno, res_size);

	}

}



int pci_resize_resource(struct pci_dev *dev, int resno, int size)