[U-Boot] [PATCH] fdt: add new fdt address parsing functions
Stephen Warren
swarren at wwwdotorg.org
Thu Aug 6 23:31:02 CEST 2015
From: Stephen Warren <swarren at nvidia.com>
fdtdec_get_addr_size() hard-codes the number of cells used to represent
an address or size in DT. This is incorrect in many cases depending on
the DT binding for a particular node or property (e.g. it is incorrect
for the "reg" property). In most cases, DT parsing code must use the
properties #address-cells and #size-cells to parse addres properties.
This change splits up the implementation of fdtdec_get_addr_size() so
that the core logic can be used for both hard-coded and non-hard-coded
cases. Various wrapper functions are implemented that support cases
where hard-coded cell counts should or should not be used, and where
the client does and doesn't know the parent node ID that contains the
properties #address-cells and #size-cells.
dev_get_addr() is updated to use the new functions.
Core functionality in fdtdec_get_addr_size_fixed() is widely tested via
fdtdec_get_addr_size(). I tested fdtdec_get_addr_size_auto_noparent() and
dev_get_addr() by manually modifying the Tegra I2C driver to invoke them.
Much of the core implementation of fdtdec_get_addr_size_fixed(),
fdtdec_get_addr_size_auto_parent(), and
fdtdec_get_addr_size_auto_noparent() comes from Thierry Reding's
previous commit "fdt: Fix fdtdec_get_addr_size() for 64-bit".
Based-on-work-by: Thierry Reding <treding at nvidia.com>
Cc: Thierry Reding <treding at nvidia.com>
Cc: Simon Glass <sjg at chromium.org>
Cc: Michal Suchanek <hramrach at gmail.com>
Signed-off-by: Stephen Warren <swarren at nvidia.com>
---
For patch context, this patch relies on Thierry's "fdt: Fix
fdtdec_get_addr_size() for 64-bit" having been reverted.
---
drivers/core/device.c | 5 ++-
include/fdtdec.h | 111 +++++++++++++++++++++++++++++++++++++++++++----
lib/fdtdec.c | 116 +++++++++++++++++++++++++++++++++++++++++---------
3 files changed, 202 insertions(+), 30 deletions(-)
diff --git a/drivers/core/device.c b/drivers/core/device.c
index 51b1b44e5b0a..917dd85551d3 100644
--- a/drivers/core/device.c
+++ b/drivers/core/device.c
@@ -555,7 +555,10 @@ const char *dev_get_uclass_name(struct udevice *dev)
#ifdef CONFIG_OF_CONTROL
fdt_addr_t dev_get_addr(struct udevice *dev)
{
- return fdtdec_get_addr(gd->fdt_blob, dev->of_offset, "reg");
+ return fdtdec_get_addr_size_auto_parent(gd->fdt_blob,
+ dev->parent->of_offset,
+ dev->of_offset, "reg",
+ 0, NULL);
}
#else
fdt_addr_t dev_get_addr(struct udevice *dev)
diff --git a/include/fdtdec.h b/include/fdtdec.h
index 4b3f8d13c356..04fe16bf15d2 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -308,10 +308,90 @@ int fdtdec_next_compatible(const void *blob, int node,
int fdtdec_next_compatible_subnode(const void *blob, int node,
enum fdt_compat_id id, int *depthp);
-/**
- * Look up an address property in a node and return it as an address.
- * The property must hold either one address with no trailing data or
- * one address with a length. This is only tested on 32-bit machines.
+/*
+ * Look up an address property in a node and return the parsed address, and
+ * optionally the parsed size.
+ *
+ * This variant assumes a known and fixed number of cells are used to
+ * represent the address and size.
+ *
+ * You probably don't want to use this function directly except to parse
+ * non-standard properties, and never to parse the "reg" property. Instead,
+ * use one of the "auto" variants below, which automatically honor the
+ * #address-cells and #size-cells properties in the parent node.
+ *
+ * @param blob FDT blob
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param index which address to retrieve from a list of addresses. Often 0.
+ * @param na the number of cells used to represent an address
+ * @param ns the number of cells used to represent a size
+ * @param sizep a pointer to store the size into. Use NULL if not required
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr_size_fixed(const void *blob, int node,
+ const char *prop_name, int index, int na, int ns,
+ fdt_size_t *sizep);
+
+/*
+ * Look up an address property in a node and return the parsed address, and
+ * optionally the parsed size.
+ *
+ * This variant automatically determines the number of cells used to represent
+ * the address and size by parsing the provided parent node's #address-cells
+ * and #size-cells properties.
+ *
+ * @param blob FDT blob
+ * @param parent parent node of @node
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param index which address to retrieve from a list of addresses. Often 0.
+ * @param sizep a pointer to store the size into. Use NULL if not required
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr_size_auto_parent(const void *blob, int parent,
+ int node, const char *prop_name, int index, fdt_size_t *sizep);
+
+/*
+ * Look up an address property in a node and return the parsed address, and
+ * optionally the parsed size.
+ *
+ * This variant automatically determines the number of cells used to represent
+ * the address and size by parsing the parent node's #address-cells
+ * and #size-cells properties. The parent node is automatically found.
+ *
+ * The automatic parent lookup implemented by this function is slow.
+ * Consequently, fdtdec_get_addr_size_auto_parent() should be used where
+ * possible.
+ *
+ * @param blob FDT blob
+ * @param parent parent node of @node
+ * @param node node to examine
+ * @param prop_name name of property to find
+ * @param index which address to retrieve from a list of addresses. Often 0.
+ * @param sizep a pointer to store the size into. Use NULL if not required
+ * @return address, if found, or FDT_ADDR_T_NONE if not
+ */
+fdt_addr_t fdtdec_get_addr_size_auto_noparent(const void *blob, int node,
+ const char *prop_name, int index, fdt_size_t *sizep);
+
+/*
+ * Look up an address property in a node and return the parsed address.
+ *
+ * This variant hard-codes the number of cells used to represent the address
+ * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
+ * always returns the first address value in the property (index 0).
+ *
+ * Use of this function is not recommended due to the hard-coding of cell
+ * counts. There is no programmatic validation that these hard-coded values
+ * actually match the device tree content in any way at all. This assumption
+ * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
+ * set in the U-Boot build and exercising strict control over DT content to
+ * ensure use of matching #address-cells/#size-cells properties. However, this
+ * approach is error-prone; those familiar with DT will not expect the
+ * assumption to exist, and could easily invalidate it. If the assumption is
+ * invalidated, this function will not report the issue, and debugging will
+ * be required. Instead, use fdtdec_get_addr_size_auto_parent().
*
* @param blob FDT blob
* @param node node to examine
@@ -321,14 +401,29 @@ int fdtdec_next_compatible_subnode(const void *blob, int node,
fdt_addr_t fdtdec_get_addr(const void *blob, int node,
const char *prop_name);
-/**
- * Look up an address property in a node and return it as an address.
- * The property must hold one address with a length. This is only tested
- * on 32-bit machines.
+/*
+ * Look up an address property in a node and return the parsed address, and
+ * optionally the parsed size.
+ *
+ * This variant hard-codes the number of cells used to represent the address
+ * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
+ * always returns the first address value in the property (index 0).
+ *
+ * Use of this function is not recommended due to the hard-coding of cell
+ * counts. There is no programmatic validation that these hard-coded values
+ * actually match the device tree content in any way at all. This assumption
+ * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
+ * set in the U-Boot build and exercising strict control over DT content to
+ * ensure use of matching #address-cells/#size-cells properties. However, this
+ * approach is error-prone; those familiar with DT will not expect the
+ * assumption to exist, and could easily invalidate it. If the assumption is
+ * invalidated, this function will not report the issue, and debugging will
+ * be required. Instead, use fdtdec_get_addr_size_auto_parent().
*
* @param blob FDT blob
* @param node node to examine
* @param prop_name name of property to find
+ * @param sizep a pointer to store the size into. Use NULL if not required
* @return address, if found, or FDT_ADDR_T_NONE if not
*/
fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 95b59b586ff0..3afec045e9bd 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -1,3 +1,5 @@
+#define DEBUG
+
/*
* Copyright (c) 2011 The Chromium OS Authors.
* SPDX-License-Identifier: GPL-2.0+
@@ -87,32 +89,104 @@ const char *fdtdec_get_compatible(enum fdt_compat_id id)
return compat_names[id];
}
-fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
- const char *prop_name, fdt_size_t *sizep)
+fdt_addr_t fdtdec_get_addr_size_fixed(const void *blob, int node,
+ const char *prop_name, int index, int na, int ns,
+ fdt_size_t *sizep)
{
- const fdt_addr_t *cell;
+ const fdt32_t *prop, *prop_end;
+ const fdt32_t *prop_addr, *prop_size, *prop_after_size;
int len;
+ fdt_addr_t addr;
debug("%s: %s: ", __func__, prop_name);
- cell = fdt_getprop(blob, node, prop_name, &len);
- if (cell && ((!sizep && len == sizeof(fdt_addr_t)) ||
- len == sizeof(fdt_addr_t) * 2)) {
- fdt_addr_t addr = fdt_addr_to_cpu(*cell);
- if (sizep) {
- const fdt_size_t *size;
-
- size = (fdt_size_t *)((char *)cell +
- sizeof(fdt_addr_t));
- *sizep = fdt_size_to_cpu(*size);
- debug("addr=%08lx, size=%llx\n",
- (ulong)addr, (u64)*sizep);
- } else {
- debug("%08lx\n", (ulong)addr);
- }
- return addr;
+
+ if (na > (sizeof(fdt_addr_t) / sizeof(fdt32_t))) {
+ debug("(na too large for fdt_addr_t type)\n");
+ return FDT_ADDR_T_NONE;
}
- debug("(not found)\n");
- return FDT_ADDR_T_NONE;
+
+ if (ns > (sizeof(fdt_size_t) / sizeof(fdt32_t))) {
+ debug("(ns too large for fdt_size_t type)\n");
+ return FDT_ADDR_T_NONE;
+ }
+
+ prop = fdt_getprop(blob, node, prop_name, &len);
+ if (!prop) {
+ debug("(not found)\n");
+ return FDT_ADDR_T_NONE;
+ }
+ prop_end = prop + (len / sizeof(*prop));
+
+ prop_addr = prop + (index * (na + ns));
+ prop_size = prop_addr + na;
+ prop_after_size = prop_size + ns;
+ if (prop_after_size > prop_end) {
+ debug("(not enough data: expected >= %d cells, got %d cells)\n",
+ (u32)(prop_after_size - prop), ((u32)(prop_end - prop)));
+ return FDT_ADDR_T_NONE;
+ }
+
+ addr = fdtdec_get_number(prop_addr, na);
+
+ if (sizep) {
+ *sizep = fdtdec_get_number(prop_size, ns);
+ debug("addr=%08llx, size=%llx\n", (u64)addr, (u64)*sizep);
+ } else {
+ debug("addr=%08llx\n", (u64)addr);
+ }
+
+ return addr;
+}
+
+fdt_addr_t fdtdec_get_addr_size_auto_parent(const void *blob, int parent,
+ int node, const char *prop_name, int index, fdt_size_t *sizep)
+{
+ int na, ns;
+
+ debug("%s: ", __func__);
+
+ na = fdt_address_cells(blob, parent);
+ if (na < 1) {
+ debug("(bad #address-cells)\n");
+ return FDT_ADDR_T_NONE;
+ }
+
+ ns = fdt_size_cells(blob, parent);
+ if (ns < 1) {
+ debug("(bad #size-cells)\n");
+ return FDT_ADDR_T_NONE;
+ }
+
+ debug("na=%d, ns=%d, ", na, ns);
+
+ return fdtdec_get_addr_size_fixed(blob, node, prop_name, index, na,
+ ns, sizep);
+}
+
+fdt_addr_t fdtdec_get_addr_size_auto_noparent(const void *blob, int node,
+ const char *prop_name, int index, fdt_size_t *sizep)
+{
+ int parent;
+
+ debug("%s: ", __func__);
+
+ parent = fdt_parent_offset(blob, node);
+ if (parent < 0) {
+ debug("(no parent found)\n");
+ return FDT_ADDR_T_NONE;
+ }
+
+ return fdtdec_get_addr_size_auto_parent(blob, parent, node, prop_name,
+ index, sizep);
+}
+
+fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
+ const char *prop_name, fdt_size_t *sizep)
+{
+ return fdtdec_get_addr_size_fixed(blob, node, prop_name, 0,
+ sizeof(fdt_addr_t) / sizeof(fdt32_t),
+ sizeof(fdt_size_t) / sizeof(fdt32_t),
+ sizep);
}
fdt_addr_t fdtdec_get_addr(const void *blob, int node,
--
1.9.1
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