Merge tag 'mvebu-mbus_pci-fixes-3.15' of git://git.infradead.org/linux-mvebu into fixes

From Jason Cooper:
mvebu drivers (mbus and pci) fixes for v3.15

 - pci
    - fix off-by-one for mbus window size
    - split BARs into multiple mbus windows when needed
 - mbus
    - avoid setting undefined window size
    - allow several windows with the same target/attr

* tag 'mvebu-mbus_pci-fixes-3.15' of git://git.infradead.org/linux-mvebu:
  PCI: mvebu: split PCIe BARs into multiple MBus windows when needed
  bus: mvebu-mbus: allow several windows with the same target/attribute
  bus: mvebu-mbus: Avoid setting an undefined window size
  PCI: mvebu: fix off-by-one in the computed size of the mbus windows

Signed-off-by: Olof Johansson <olof@lixom.net>

2 files changed, 92 insertions, 22 deletions

diff --git a/drivers/bus/mvebu-mbus.c b/drivers/bus/mvebu-mbus.c
index 293e2e0a0a87c7..00b73448b22ea7 100644
--- a/drivers/bus/mvebu-mbus.c
+++ b/drivers/bus/mvebu-mbus.c
@@ -56,6 +56,7 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/debugfs.h>
+#include <linux/log2.h>
 
 /*
  * DDR target is the same on all platforms.
@@ -222,12 +223,6 @@ static int mvebu_mbus_window_conflicts(struct mvebu_mbus_state *mbus,
 		 */
 		if ((u64)base < wend && end > wbase)
 			return 0;
-
-		/*
-		 * Check if target/attribute conflicts
-		 */
-		if (target == wtarget && attr == wattr)
-			return 0;
 	}
 
 	return 1;
@@ -266,6 +261,17 @@ static int mvebu_mbus_setup_window(struct mvebu_mbus_state *mbus,
 		mbus->soc->win_cfg_offset(win);
 	u32 ctrl, remap_addr;
 
+	if (!is_power_of_2(size)) {
+		WARN(true, "Invalid MBus window size: 0x%zx\n", size);
+		return -EINVAL;
+	}
+
+	if ((base & (phys_addr_t)(size - 1)) != 0) {
+		WARN(true, "Invalid MBus base/size: %pa len 0x%zx\n", &base,
+		     size);
+		return -EINVAL;
+	}
+
 	ctrl = ((size - 1) & WIN_CTRL_SIZE_MASK) |
 		(attr << WIN_CTRL_ATTR_SHIFT)    |
 		(target << WIN_CTRL_TGT_SHIFT)   |
@@ -413,6 +419,10 @@ static int mvebu_devs_debug_show(struct seq_file *seq, void *v)
 			   win, (unsigned long long)wbase,
 			   (unsigned long long)(wbase + wsize), wtarget, wattr);
 
+		if (!is_power_of_2(wsize) ||
+		    ((wbase & (u64)(wsize - 1)) != 0))
+			seq_puts(seq, " (Invalid base/size!!)");
+
 		if (win < mbus->soc->num_remappable_wins) {
 			seq_printf(seq, " (remap %016llx)\n",
 				   (unsigned long long)wremap);
diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index d3d1cfd51e095f..e384e253459473 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;
 }