[PATCH v4 1/3] PCI: designware-ep: Fix find_first_zero_bit() usage

Niklas Cassel
2017-12-12T14:16:50Z

find_first_zero_bit()'s parameter 'size' is defined in bits,
not in bytes.

find_first_zero_bit() is called with size in bytes rather than bits,
which thus defines a too low upper limit, causing
dw_pcie_ep_inbound_atu() to assign iatu index #4 to both bar 4
and bar 5, which makes bar 5 overwrite the settings set by bar 4.

Since the sizes of the bitmaps are known, dynamically allocate the
bitmaps, and use the correct size when calling find_first_zero_bit().

Additionally, make sure that ep->num_ob_windows and ep->num_ib_windows,
which are obtained from device tree, are smaller than the maximum number
of iATUs (MAX_IATU_IN/MAX_IATU_OUT).

Fixes: f8aed6ec624f ("PCI: dwc: designware: Add EP mode support")
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
---
drivers/pci/dwc/pcie-designware-ep.c | 34 ++++++++++++++++++++++++++--------
drivers/pci/dwc/pcie-designware.h | 8 ++++++--
2 files changed, 32 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
index d53d5f168363..d5eb143040e3 100644
--- a/drivers/pci/dwc/pcie-designware-ep.c
+++ b/drivers/pci/dwc/pcie-designware-ep.c
@@ -70,8 +70,7 @@ static int dw_pcie_ep_inbound_atu(struct dw_pcie_ep *ep, enum pci_barno bar,
u32 free_win;
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);

- free_win = find_first_zero_bit(&ep->ib_window_map,
- sizeof(ep->ib_window_map));
+ free_win = find_first_zero_bit(ep->ib_window_map, ep->num_ib_windows);
if (free_win >= ep->num_ib_windows) {
dev_err(pci->dev, "no free inbound window\n");
return -EINVAL;
@@ -85,7 +84,7 @@ static int dw_pcie_ep_inbound_atu(struct dw_pcie_ep *ep, enum pci_barno bar,
}

ep->bar_to_atu[bar] = free_win;
- set_bit(free_win, &ep->ib_window_map);
+ set_bit(free_win, ep->ib_window_map);

return 0;
}
@@ -96,8 +95,7 @@ static int dw_pcie_ep_outbound_atu(struct dw_pcie_ep *ep, phys_addr_t phys_addr,
u32 free_win;
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);

- free_win = find_first_zero_bit(&ep->ob_window_map,
- sizeof(ep->ob_window_map));
+ free_win = find_first_zero_bit(ep->ob_window_map, ep->num_ob_windows);
if (free_win >= ep->num_ob_windows) {
dev_err(pci->dev, "no free outbound window\n");
return -EINVAL;
@@ -106,7 +104,7 @@ static int dw_pcie_ep_outbound_atu(struct dw_pcie_ep *ep, phys_addr_t phys_addr,
dw_pcie_prog_outbound_atu(pci, free_win, PCIE_ATU_TYPE_MEM,
phys_addr, pci_addr, size);

- set_bit(free_win, &ep->ob_window_map);
+ set_bit(free_win, ep->ob_window_map);
ep->outbound_addr[free_win] = phys_addr;

return 0;
@@ -121,7 +119,7 @@ static void dw_pcie_ep_clear_bar(struct pci_epc *epc, enum pci_barno bar)
dw_pcie_ep_reset_bar(pci, bar);

dw_pcie_disable_atu(pci, atu_index, DW_PCIE_REGION_INBOUND);
- clear_bit(atu_index, &ep->ib_window_map);
+ clear_bit(atu_index, ep->ib_window_map);
}

static int dw_pcie_ep_set_bar(struct pci_epc *epc, enum pci_barno bar,
@@ -175,7 +173,7 @@ static void dw_pcie_ep_unmap_addr(struct pci_epc *epc, phys_addr_t addr)
return;

dw_pcie_disable_atu(pci, atu_index, DW_PCIE_REGION_OUTBOUND);
- clear_bit(atu_index, &ep->ob_window_map);
+ clear_bit(atu_index, ep->ob_window_map);
}

static int dw_pcie_ep_map_addr(struct pci_epc *epc, phys_addr_t addr,
@@ -298,12 +296,32 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
dev_err(dev, "unable to read *num-ib-windows* property\n");
return ret;
}
+ if (ep->num_ib_windows > MAX_IATU_IN) {
+ dev_err(dev, "invalid *num-ib-windows*\n");
+ return -EINVAL;
+ }

ret = of_property_read_u32(np, "num-ob-windows", &ep->num_ob_windows);
if (ret < 0) {
dev_err(dev, "unable to read *num-ob-windows* property\n");
return ret;
}
+ if (ep->num_ob_windows > MAX_IATU_OUT) {
+ dev_err(dev, "invalid *num-ob-windows*\n");
+ return -EINVAL;
+ }
+
+ ep->ib_window_map = devm_kzalloc(dev, sizeof(long) *
+ BITS_TO_LONGS(ep->num_ib_windows),
+ GFP_KERNEL);
+ if (!ep->ib_window_map)
+ return -ENOMEM;
+
+ ep->ob_window_map = devm_kzalloc(dev, sizeof(long) *
+ BITS_TO_LONGS(ep->num_ob_windows),
+ GFP_KERNEL);
+ if (!ep->ob_window_map)
+ return -ENOMEM;

addr = devm_kzalloc(dev, sizeof(phys_addr_t) * ep->num_ob_windows,
GFP_KERNEL);
diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index e5d9d77b778e..e6fd0b024b21 100644
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -113,6 +113,10 @@
#define MAX_MSI_IRQS 32
#define MAX_MSI_CTRLS (MAX_MSI_IRQS / 32)

+/* Maximum number of inbound/outbound iATUs */
+#define MAX_IATU_IN 256
+#define MAX_IATU_OUT 256
+
struct pcie_port;
struct dw_pcie;
struct dw_pcie_ep;
@@ -192,8 +196,8 @@ struct dw_pcie_ep {
size_t page_size;
u8 bar_to_atu[6];
phys_addr_t *outbound_addr;
- unsigned long ib_window_map;
- unsigned long ob_window_map;
+ unsigned long *ib_window_map;
+ unsigned long *ob_window_map;
u32 num_ib_windows;
u32 num_ob_windows;
};
--
2.14.2