On Mon, Dec 05, 2016 at 05:11:30PM -0600, Benjamin Fair wrote:
> This patch extends the capability of libfdt to parse the contents of device
> trees in a similar manner to fdt_address_cells and fdt_size_cells.
>
> It adds helper functions which read the address and size of a device from
> the reg property and performs basic sanity checks. Some functions also
> parse the values into integers in the host endianness.
>
> The functions do not perform translation to a physical address using the
> ranges properties of parents, but this enhancement may be added as a
> separate function in the future.
>
> Signed-off-by: Benjamin Fair <b-fair@xxxxxx>
> ---
>
> Changes since v1:
>
> * Split functions into smaller pieces
> -> Also added wrapper functions to perform the full set of actions
> * Changed types of addresses and sizes to uint64_t
> * Removed unneeded constants
> * Renamed and exported fdt_read_integer()
>
> libfdt/fdt_addresses.c | 118 ++++++++++++++++++++++++++++++++++++++++
> libfdt/libfdt.h | 145 +++++++++++++++++++++++++++++++++++++++++++++++++
> libfdt/version.lds | 5 ++
> tests/.gitignore | 1 +
> tests/Makefile.tests | 2 +-
> tests/addr_size.c | 130 ++++++++++++++++++++++++++++++++++++++++++++
> tests/addresses.dts | 11 ++++
> tests/run_tests.sh | 1 +
> 8 files changed, 412 insertions(+), 1 deletion(-)
> create mode 100644 tests/addr_size.c
>
> diff --git a/libfdt/fdt_addresses.c b/libfdt/fdt_addresses.c
> index eff4dbc..752f9ef 100644
> --- a/libfdt/fdt_addresses.c
> +++ b/libfdt/fdt_addresses.c
> @@ -94,3 +94,121 @@ int fdt_size_cells(const void *fdt, int nodeoffset)
>
> return val;
> }
> +
> +int fdt_read_integer(const fdt32_t *cells, int n, uint64_t *out)
I like this.
> +{
> + int i;
> +
> + /* Make sure the result will fit */
> + if (n > sizeof(*out) / sizeof(*cells))
> + return -FDT_ERR_BADNCELLS;
> +
> + for (*out = 0, i = 0; i < n; i++) {
> + *out <<= sizeof(*cells) * 8;
> + *out |= fdt32_to_cpu(cells[i]);
> + }
> +
> + return 0;
> +}
> +
> +int fdt_addr_size(const void *fdt, int nodeoffset, int idx,
> + const fdt32_t **addrp, const fdt32_t **sizep)
> +{
> + int parent;
> + int ac, sc;
> +
> + parent = fdt_parent_offset(fdt, nodeoffset);
> + if (parent < 0)
> + return parent;
> +
> + ac = fdt_address_cells(fdt, parent);
> + if (ac < 0)
> + return ac;
> +
> + sc = fdt_size_cells(fdt, parent);
> + if (sc < 0)
> + return sc;
> +
> + return fdt_addr_size_cellcount(fdt, nodeoffset, idx,
> + ac, addrp, sc, sizep);
> +}
> +
> +int fdt_addr_size_cellcount(const void *fdt, int nodeoffset, int idx,
> + int ac, const fdt32_t **addrp,
> + int sc, const fdt32_t **sizep)
I think this is a reasonable interface, but I don't like the name.
It's just called "fdt_addr_size" but addr and size of what? There are
plenty of things besides 'reg' that encode addresses and sizes.
I'd suggest fdt_reg_cellcount() for this. Then
fdt_reg_cellcount_int() for the version that converts to integers
(when possible).
I'd then suggest an intermediate interface fdt_reg() and fdt_reg_int()
which takes a parent/bus node offset instead of explicit
#address-cells and #size-cells values.
Then, say, fdt_reg_simple() and fdt_reg_simple_int() for the expensive
versions using fdt_parent_offset().
As Simon Glass says, also put a note about the expense of the last in
libfdt.h
> +{
> + int reg_stride;
> + int res;
> + const fdt32_t *reg;
> +
> + reg = fdt_getprop(fdt, nodeoffset, "reg", &res);
> + if (res < 0)
> + return res;
> +
> + reg_stride = ac + sc;
> + /*
> + * res is the number of bytes read and must be an even multiple of the
> + * sum of ac and sc.
> + */
> + if ((res % (reg_stride * sizeof(fdt32_t))) != 0)
> + return -FDT_ERR_BADVALUE;
> + /* Check that there are enough entries in reg */
> + if (res < reg_stride * (idx + 1))
> + return -FDT_ERR_BADVALUE;
> +
> + if (addrp)
> + *addrp = ®[reg_stride * idx];
> + if (sizep)
> + *sizep = ®[ac + reg_stride * idx];
> +
> + return 0;
> +}
> +
> +int fdt_integer_addr_size(const void *fdt, int nodeoffset, int idx,
> + uint64_t *addrp, uint64_t *sizep)
> +{
> + int parent;
> + int ac, sc;
> +
> + parent = fdt_parent_offset(fdt, nodeoffset);
> + if (parent < 0)
> + return parent;
> +
> + ac = fdt_address_cells(fdt, parent);
> + if (ac < 0)
> + return ac;
> +
> + sc = fdt_size_cells(fdt, parent);
> + if (sc < 0)
> + return sc;
> +
> + return fdt_integer_addr_size_cellcount(fdt, nodeoffset, idx,
> + ac, addrp, sc, sizep);
> +}
> +
> +int fdt_integer_addr_size_cellcount(const void *fdt, int nodeoffset, int idx,
> + int ac, uint64_t *addr,
> + int sc, uint64_t *size)
> +{
> + const fdt32_t *fdt_addr, *fdt_size;
> + int res;
> +
> + res = fdt_addr_size_cellcount(fdt, nodeoffset, idx,
> + ac, &fdt_addr, sc, &fdt_size);
> + if (res < 0)
> + return res;
> +
> + if (addr) {
> + res = fdt_read_integer(fdt_addr, ac, addr);
> + if (res < 0)
> + return res;
> + }
> +
> + if (size) {
> + res = fdt_read_integer(fdt_size, sc, size);
> + if (res < 0)
> + return res;
> + }
> +
> + return 0;
> +}
> diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h
> index c69e918..9eaf790 100644
> --- a/libfdt/libfdt.h
> +++ b/libfdt/libfdt.h
> @@ -1085,6 +1085,151 @@ int fdt_address_cells(const void *fdt, int nodeoffset);
> */
> int fdt_size_cells(const void *fdt, int nodeoffset);
>
> +/**
> + * fdt_read_integer - parse an array of cells into an integer
> + * @cells: pointer to an array of cells
> + * @n: number of cells to parse
> + * @out: pointer to where the value should be stored (will be overwritten)
> + *
> + * Given an array of cells from a property, convert the first n of them into a
> + * single integer in the host's endianness.
> + *
> + * returns:
> + * 0, on success
> + * -FDT_ERR_BADNCELLS, if n is greater than 2
> + */
> +int fdt_read_integer(const fdt32_t *cells, int n, uint64_t *out);
> +
> +/**
> + * fdt_addr_size - get pointers to the address and/or size values from the reg
> + * property of a device node.
> + * @fdt: pointer to the device tree blob
> + * @nodeoffset: offset of the node to find the address and/or size from
> + * @idx: which address/size pair to read
> + * @addrp: pointer to where address pointer will be stored (will be
> + * overwritten) or NULL
> + * @sizep: pointer to where size pointer will be stored (will be overwritten)
> + * or NULL
> + *
> + * When the node has a valid reg property, returns pointers to the address
> + * and/or size values stored there. It does not parse the cell arrays into a
> + * single integer or covert them to host endianness.
> + *
> + * returns:
> + * 0, on success
> + * -FDT_ERR_BADVALUE, if there is an unexpected number of entries in the
> + * reg property
> + * -FDT_ERR_NOTFOUND, if the node does not have a reg property
> + * -FDT_ERR_BADNCELLS, if the number of address or size cells is invalid
> + * -FDT_ERR_BADMAGIC,
> + * -FDT_ERR_BADSTATE,
> + * -FDT_ERR_BADSTRUCTURE,
> + * -FDT_ERR_BADVERSION,
> + * -FDT_ERR_TRUNCATED, standard meanings
> + */
> +int fdt_addr_size(const void *fdt, int nodeoffset, int idx,
> + const fdt32_t **addrp, const fdt32_t **sizep);
> +
> +/**
> + * fdt_addr_size_cellcount - get pointers to the address and/or size values
> + * from the reg property of a device node given the
> + * number of address and size cells.
> + * @fdt: pointer to the device tree blob
> + * @nodeoffset: offset of the node to find the address and/or size from
> + * @idx: which address/size pair to read
> + * @ac: number of address cells
> + * @addrp: pointer to where address pointer will be stored (will be
> + * overwritten) or NULL
> + * @sc: number of size cells
> + * @sizep: pointer to where size pointer will be stored (will be overwritten)
> + * or NULL
> + *
> + * When the node has a valid reg property, returns pointers to the address
> + * and/or size values stored there. It does not parse the cell arrays into a
> + * single integer or covert them to host endianness. This version uses values
> + * for #address-cells and #size-cells which are passed in as arguments, rather
> + * than reading them from the parent node. Therefore, this version is much
> + * faster if these values are already known.
> + *
> + * returns:
> + * 0, on success
> + * -FDT_ERR_BADVALUE, if there is an unexpected number of entries in the
> + * reg property
> + * -FDT_ERR_NOTFOUND, if the node does not have a reg property
> + * -FDT_ERR_BADMAGIC,
> + * -FDT_ERR_BADSTATE,
> + * -FDT_ERR_BADSTRUCTURE,
> + * -FDT_ERR_BADVERSION,
> + * -FDT_ERR_TRUNCATED, standard meanings
> + */
> +int fdt_addr_size_cellcount(const void *fdt, int nodeoffset, int idx,
> + int ac, const fdt32_t **addrp,
> + int sc, const fdt32_t **sizep);
> +
> +/**
> + * fdt_integer_addr_size - find address and/or size from the reg property of a
> + * device node and return them as integers.
> + * @fdt: pointer to the device tree blob
> + * @nodeoffset: offset of the node to find the address and/or size from
> + * @idx: which address/size pair to read
> + * @addrp: pointer to where address will be stored (will be overwritten) or NULL
> + * @sizep: pointer to where size will be stored (will be overwritten) or NULL
> + *
> + * When the node has a valid reg property, returns the address and/or size
> + * values stored there as integers in the host endianness. It does not perform
> + * any type of translation based on the parent bus(es).
> + *
> + * returns:
> + * 0, on success
> + * -FDT_ERR_BADVALUE, if there is an unexpected number of entries in the
> + * reg property
> + * -FDT_ERR_NOTFOUND, if the node does not have a reg property
> + * -FDT_ERR_BADNCELLS, if the number of address or size cells is invalid
> + * or greater than 2 (which is the maximum currently supported)
> + * -FDT_ERR_BADMAGIC,
> + * -FDT_ERR_BADSTATE,
> + * -FDT_ERR_BADSTRUCTURE,
> + * -FDT_ERR_BADVERSION,
> + * -FDT_ERR_TRUNCATED, standard meanings
> + */
> +int fdt_integer_addr_size(const void *fdt, int nodeoffset, int idx,
> + uint64_t *addrp, size_t *sizep);
> +
> +/**
> + * fdt_integer_addr_size_cellcount - find address and/or size from the reg
> + * property of a device node and return them
> + * as integers.
> + * @fdt: pointer to the device tree blob
> + * @nodeoffset: offset of the node to find the address and/or size from
> + * @idx: which address/size pair to read
> + * @ac: number of address cells
> + * @addrp: pointer to where address will be stored (will be overwritten) or NULL
> + * @sc: number of size cells
> + * @sizep: pointer to where size will be stored (will be overwritten) or NULL
> + *
> + * When the node has a valid reg property, returns the address and/or size
> + * values stored there as integers in the host endianness. It does not perform
> + * any type of translation based on the parent bus(es). This version uses
> + * values for #address-cells and #size-cells which are passed in as arguments,
> + * rather than reading them from the parent node. Therefore, this version is
> + * much faster if these values are already known.
> + *
> + * returns:
> + * 0, on success
> + * -FDT_ERR_BADVALUE, if there is an unexpected number of entries in the
> + * reg property
> + * -FDT_ERR_NOTFOUND, if the node does not have a reg property
> + * -FDT_ERR_BADNCELLS, if the number of address or size cells is invalid
> + * or greater than 2 (which is the maximum currently supported)
> + * -FDT_ERR_BADMAGIC,
> + * -FDT_ERR_BADSTATE,
> + * -FDT_ERR_BADSTRUCTURE,
> + * -FDT_ERR_BADVERSION,
> + * -FDT_ERR_TRUNCATED, standard meanings
> + */
> +int fdt_integer_addr_size_cellcount(const void *fdt, int nodeoffset, int idx,
> + int ac, uint64_t *addr,
> + int sc, uint64_t *size);
>
> /**********************************************************************/
> /* Write-in-place functions */
> diff --git a/libfdt/version.lds b/libfdt/version.lds
> index cff0358..0106f9d 100644
> --- a/libfdt/version.lds
> +++ b/libfdt/version.lds
> @@ -59,6 +59,11 @@ LIBFDT_1.2 {
> fdt_next_subnode;
> fdt_address_cells;
> fdt_size_cells;
> + fdt_read_integer;
> + fdt_addr_size;
> + fdt_addr_size_cellcount;
> + fdt_integer_addr_size;
> + fdt_integer_addr_size_cellcount;
> fdt_stringlist_contains;
> fdt_resize;
> fdt_overlay_apply;
> diff --git a/tests/.gitignore b/tests/.gitignore
> index 354b565..9018414 100644
> --- a/tests/.gitignore
> +++ b/tests/.gitignore
> @@ -42,6 +42,7 @@ tmp.*
> /path_offset
> /path_offset_aliases
> /phandle_format
> +/addr_size
> /property_iterate
> /propname_escapes
> /references
> diff --git a/tests/Makefile.tests b/tests/Makefile.tests
> index eb039c5..c715421 100644
> --- a/tests/Makefile.tests
> +++ b/tests/Makefile.tests
> @@ -8,7 +8,7 @@ LIB_TESTS_L = get_mem_rsv \
> char_literal \
> sized_cells \
> notfound \
> - addr_size_cells \
> + addr_size_cells addr_size \
> stringlist \
> setprop_inplace nop_property nop_node \
> sw_tree1 \
> diff --git a/tests/addr_size.c b/tests/addr_size.c
> new file mode 100644
> index 0000000..4ee4c1b
> --- /dev/null
> +++ b/tests/addr_size.c
> @@ -0,0 +1,130 @@
> +/*
> + * libfdt - Flat Device Tree manipulation
> + * Testcase for address and size handling
> + * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
> + *
> + * Based on addr_size_cells.c by David Gibson, <david@xxxxxxxxxxxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU Lesser General Public License as published by
> + * the Free Software Foundation; either version 2.1 of the License, or (at
> + * your option) any later version.
> + *
> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
> + * whether express or implied; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * Lesser General Public License for more details.
> + */
> +
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <stdint.h>
> +
> +#include <libfdt.h>
> +
> +#include "tests.h"
> +#include "testdata.h"
> +
> +static void check_node_integer(const void *fdt, const char *path, int idx,
> + uint64_t addr, uint64_t size)
> +{
> + int offset, res;
> + uint64_t xaddr, xsize;
> +
> + offset = fdt_path_offset(fdt, path);
> + if (offset < 0)
> + FAIL("Couldn't find path %s", path);
> +
> + res = fdt_integer_addr_size(fdt, offset, idx, &xaddr, &xsize);
> + if (res < 0)
> + FAIL("fdt_integer_addr_size gave error: %s", fdt_strerror(res));
> +
> + if (xaddr != addr)
> + FAIL("Physical address for %s is %lx instead of %lx\n", path,
> + xaddr, addr);
> +
> + if (xsize != size)
> + FAIL("Size for %s is %lx instead of %lx\n", path,
> + xsize, size);
> +}
> +
> +static void check_node(const void *fdt, const char *path, int idx,
> + uint64_t addr, uint64_t size)
> +{
> + int offset, parent, res;
> + int ac, sc;
> + const fdt32_t *xaddr_fdt, *xsize_fdt;
> + uint64_t xaddr, xsize;
> +
> + offset = fdt_path_offset(fdt, path);
> + if (offset < 0)
> + FAIL("Couldn't find path %s", path);
> +
> + parent = fdt_parent_offset(fdt, offset);
> + if (parent < 0)
> + FAIL("Couldn't get parent: %s", fdt_strerror(parent));
> +
> + ac = fdt_address_cells(fdt, parent);
> + if (ac < 0)
> + FAIL("Couldn't read #address-cells: %s", fdt_strerror(ac));
> +
> + sc = fdt_size_cells(fdt, parent);
> + if (sc < 0)
> + FAIL("Couldn't read #size-cells: %s", fdt_strerror(sc));
> +
> + res = fdt_addr_size_cellcount(fdt, offset, idx, ac, &xaddr_fdt, sc,
> + &xsize_fdt);
> + if (res < 0)
> + FAIL("Couldn't find entries in reg: %s", fdt_strerror(res));
> +
> + res = fdt_read_integer(xaddr_fdt, ac, &xaddr);
> + if (res < 0)
> + FAIL("Couldn't parse entries in reg: %s", fdt_strerror(res));
> +
> + res = fdt_read_integer(xsize_fdt, sc, &xsize);
> + if (res < 0)
> + FAIL("Couldn't parse entries in reg: %s", fdt_strerror(res));
> +
> + if (xaddr != addr)
> + FAIL("Physical address for %s is %lx instead of %lx\n", path,
> + xaddr, addr);
> +
> + if (xsize != size)
> + FAIL("Size for %s is %lx instead of %lx\n", path,
> + xsize, size);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + void *fdt;
> +
> + if (argc != 2)
> + CONFIG("Usage: %s <dtb file>\n", argv[0]);
> +
> + test_init(argc, argv);
> + fdt = load_blob(argv[1]);
> +
> + check_node(fdt, "/identity-bus@0/id-device@400", 0,
> + 0x400, 0x100);
> + check_node(fdt, "/simple-bus@1000000/sb-device@8000000800", 0,
> + 0x8000000800, 0x200);
> + check_node(fdt, "/identity-bus@0/id-device@400", 1,
> + 0x400000000, 0x100000030);
> + check_node(fdt, "/simple-bus@1000000/sb-device@8000000800", 1,
> + 0x70000000, 0x700);
> + check_node(fdt, "/simple-bus@1000000/sb-device@8000000800", 2,
> + 0x1050000000, 0x20);
> +
> + check_node_integer(fdt, "/identity-bus@0/id-device@400", 0,
> + 0x400, 0x100);
> + check_node_integer(fdt, "/simple-bus@1000000/sb-device@8000000800", 0,
> + 0x8000000800, 0x200);
> + check_node_integer(fdt, "/identity-bus@0/id-device@400", 1,
> + 0x400000000, 0x100000030);
> + check_node_integer(fdt, "/simple-bus@1000000/sb-device@8000000800", 1,
> + 0x70000000, 0x700);
> + check_node_integer(fdt, "/simple-bus@1000000/sb-device@8000000800", 2,
> + 0x1050000000, 0x20);
> + PASS();
> +}
> diff --git a/tests/addresses.dts b/tests/addresses.dts
> index a2faaf5..32c4379 100644
> --- a/tests/addresses.dts
> +++ b/tests/addresses.dts
> @@ -6,10 +6,21 @@
> #size-cells = <2>;
>
> identity-bus@0 {
> + #address-cells = <2>;
> + #size-cells = <2>;
> + id-device@400 {
> + reg = <0x0 0x00000400 0x0 0x00000100>,
> + <0x4 0x00000000 0x1 0x00000030>;
> + };
> };
>
> simple-bus@1000000 {
> #address-cells = <2>;
> #size-cells = <1>;
> + sb-device@8000000800 {
> + reg = <0x80 0x00000800 0x200>,
> + <0x00 0x70000000 0x700>,
> + <0x10 0x50000000 0x020>;
> + };
> };
> };
> diff --git a/tests/run_tests.sh b/tests/run_tests.sh
> index e4139dd..96aca48 100755
> --- a/tests/run_tests.sh
> +++ b/tests/run_tests.sh
> @@ -243,6 +243,7 @@ libfdt_tests () {
>
> run_dtc_test -I dts -O dtb -o addresses.test.dtb addresses.dts
> run_test addr_size_cells addresses.test.dtb
> + run_test addr_size addresses.test.dtb
>
> run_dtc_test -I dts -O dtb -o stringlist.test.dtb stringlist.dts
> run_test stringlist stringlist.test.dtb
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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