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path: root/drivers/pci/host/pci-mvebu.c
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Diffstat (limited to 'drivers/pci/host/pci-mvebu.c')
-rw-r--r--drivers/pci/host/pci-mvebu.c92
1 files changed, 76 insertions, 16 deletions
diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index d3d1cfd51e09..e384e2534594 100644
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -293,6 +293,58 @@ static int mvebu_pcie_hw_wr_conf(struct mvebu_pcie_port *port,
return PCIBIOS_SUCCESSFUL;
}
+/*
+ * Remove windows, starting from the largest ones to the smallest
+ * ones.
+ */
+static void mvebu_pcie_del_windows(struct mvebu_pcie_port *port,
+ phys_addr_t base, size_t size)
+{
+ while (size) {
+ size_t sz = 1 << (fls(size) - 1);
+
+ mvebu_mbus_del_window(base, sz);
+ base += sz;
+ size -= sz;
+ }
+}
+
+/*
+ * MBus windows can only have a power of two size, but PCI BARs do not
+ * have this constraint. Therefore, we have to split the PCI BAR into
+ * areas each having a power of two size. We start from the largest
+ * one (i.e highest order bit set in the size).
+ */
+static void mvebu_pcie_add_windows(struct mvebu_pcie_port *port,
+ unsigned int target, unsigned int attribute,
+ phys_addr_t base, size_t size,
+ phys_addr_t remap)
+{
+ size_t size_mapped = 0;
+
+ while (size) {
+ size_t sz = 1 << (fls(size) - 1);
+ int ret;
+
+ ret = mvebu_mbus_add_window_remap_by_id(target, attribute, base,
+ sz, remap);
+ if (ret) {
+ dev_err(&port->pcie->pdev->dev,
+ "Could not create MBus window at 0x%x, size 0x%x: %d\n",
+ base, sz, ret);
+ mvebu_pcie_del_windows(port, base - size_mapped,
+ size_mapped);
+ return;
+ }
+
+ size -= sz;
+ size_mapped += sz;
+ base += sz;
+ if (remap != MVEBU_MBUS_NO_REMAP)
+ remap += sz;
+ }
+}
+
static void mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
{
phys_addr_t iobase;
@@ -304,8 +356,8 @@ static void mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
/* If a window was configured, remove it */
if (port->iowin_base) {
- mvebu_mbus_del_window(port->iowin_base,
- port->iowin_size);
+ mvebu_pcie_del_windows(port, port->iowin_base,
+ port->iowin_size);
port->iowin_base = 0;
port->iowin_size = 0;
}
@@ -331,11 +383,11 @@ static void mvebu_pcie_handle_iobase_change(struct mvebu_pcie_port *port)
port->iowin_base = port->pcie->io.start + iobase;
port->iowin_size = ((0xFFF | ((port->bridge.iolimit & 0xF0) << 8) |
(port->bridge.iolimitupper << 16)) -
- iobase);
+ iobase) + 1;
- mvebu_mbus_add_window_remap_by_id(port->io_target, port->io_attr,
- port->iowin_base, port->iowin_size,
- iobase);
+ mvebu_pcie_add_windows(port, port->io_target, port->io_attr,
+ port->iowin_base, port->iowin_size,
+ iobase);
}
static void mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
@@ -346,8 +398,8 @@ static void mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
/* If a window was configured, remove it */
if (port->memwin_base) {
- mvebu_mbus_del_window(port->memwin_base,
- port->memwin_size);
+ mvebu_pcie_del_windows(port, port->memwin_base,
+ port->memwin_size);
port->memwin_base = 0;
port->memwin_size = 0;
}
@@ -364,10 +416,11 @@ static void mvebu_pcie_handle_membase_change(struct mvebu_pcie_port *port)
port->memwin_base = ((port->bridge.membase & 0xFFF0) << 16);
port->memwin_size =
(((port->bridge.memlimit & 0xFFF0) << 16) | 0xFFFFF) -
- port->memwin_base;
+ port->memwin_base + 1;
- mvebu_mbus_add_window_by_id(port->mem_target, port->mem_attr,
- port->memwin_base, port->memwin_size);
+ mvebu_pcie_add_windows(port, port->mem_target, port->mem_attr,
+ port->memwin_base, port->memwin_size,
+ MVEBU_MBUS_NO_REMAP);
}
/*
@@ -743,14 +796,21 @@ static resource_size_t mvebu_pcie_align_resource(struct pci_dev *dev,
/*
* On the PCI-to-PCI bridge side, the I/O windows must have at
- * least a 64 KB size and be aligned on their size, and the
- * memory windows must have at least a 1 MB size and be
- * aligned on their size
+ * least a 64 KB size and the memory windows must have at
+ * least a 1 MB size. Moreover, MBus windows need to have a
+ * base address aligned on their size, and their size must be
+ * a power of two. This means that if the BAR doesn't have a
+ * power of two size, several MBus windows will actually be
+ * created. We need to ensure that the biggest MBus window
+ * (which will be the first one) is aligned on its size, which
+ * explains the rounddown_pow_of_two() being done here.
*/
if (res->flags & IORESOURCE_IO)
- return round_up(start, max_t(resource_size_t, SZ_64K, size));
+ return round_up(start, max_t(resource_size_t, SZ_64K,
+ rounddown_pow_of_two(size)));
else if (res->flags & IORESOURCE_MEM)
- return round_up(start, max_t(resource_size_t, SZ_1M, size));
+ return round_up(start, max_t(resource_size_t, SZ_1M,
+ rounddown_pow_of_two(size)));
else
return start;
}