When trying to allocate space for an endpoint function on a BAR with a
fixed size, the size saved in the 'struct pci_epf_bar' should be the fixed
size. This is expected by pci_epc_set_bar().
However, if the fixed_size is smaller that the alignment, the size saved
in the 'struct pci_epf_bar' matches the alignment and it is a problem for
pci_epc_set_bar().
To solve this, continue to allocate space that match the iATU alignment
requirement but save the size that matches what is present in the BAR.
Fixes: 2a9a801620ef ("PCI: endpoint: Add support to specify alignment for buffers allocated to BARs")
Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
---
drivers/pci/endpoint/pci-epf-core.c | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/drivers/pci/endpoint/pci-epf-core.c b/drivers/pci/endpoint/pci-epf-core.c
index b7deb0ee1760b23a24f49abf3baf53ea2f273476..fb902b751e1c965c902c5199d57969ae0a757c2e 100644
--- a/drivers/pci/endpoint/pci-epf-core.c
+++ b/drivers/pci/endpoint/pci-epf-core.c
@@ -225,6 +225,7 @@ void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar,
struct device *dev;
struct pci_epf_bar *epf_bar;
struct pci_epc *epc;
+ size_t size;
if (!addr)
return;
@@ -237,9 +238,12 @@ void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar,
epf_bar = epf->sec_epc_bar;
}
+ size = epf_bar[bar].size;
+ if (epc_features->align)
+ size = ALIGN(size, epc_features->align);
+
dev = epc->dev.parent;
- dma_free_coherent(dev, epf_bar[bar].size, addr,
- epf_bar[bar].phys_addr);
+ dma_free_coherent(dev, size, addr, epf_bar[bar].phys_addr);
epf_bar[bar].phys_addr = 0;
epf_bar[bar].addr = NULL;
@@ -266,7 +270,7 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
enum pci_epc_interface_type type)
{
u64 bar_fixed_size = epc_features->bar[bar].fixed_size;
- size_t align = epc_features->align;
+ size_t aligned_size, align = epc_features->align;
struct pci_epf_bar *epf_bar;
dma_addr_t phys_addr;
struct pci_epc *epc;
@@ -287,12 +291,17 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
return NULL;
}
size = bar_fixed_size;
+ } else {
+ /* BAR size must be power of two */
+ size = roundup_pow_of_two(size);
}
- if (align)
- size = ALIGN(size, align);
- else
- size = roundup_pow_of_two(size);
+ /*
+ * Allocate enough memory to accommodate the iATU alignment requirement.
+ * In most cases, this will be the same as .size but it might be different
+ * if, for example, the fixed size of a BAR is smaller than align
+ */
+ aligned_size = align ? ALIGN(size, align) : size;
if (type == PRIMARY_INTERFACE) {
epc = epf->epc;
@@ -303,7 +312,7 @@ void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
}
dev = epc->dev.parent;
- space = dma_alloc_coherent(dev, size, &phys_addr, GFP_KERNEL);
+ space = dma_alloc_coherent(dev, aligned_size, &phys_addr, GFP_KERNEL);
if (!space) {
dev_err(dev, "failed to allocate mem space\n");
return NULL;
--
2.47.2
