From: Benjamin Fair <b-fair@xxxxxx> 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 a helper function which reads the address and size of a device from the reg property and performs basic sanity checks. It does 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> Reviewed-by: Simon Glass <sjg@xxxxxxxxxxxx> Signed-off-by: Dave Gerlach <d-gerlach@xxxxxx> --- This is a rebase and resend of v2 found here [1] which never received any comments. v2 was resent rather than v3 because of this comment [2] from David Gibson. [1] https://www.spinics.net/lists/devicetree-compiler/msg00970.html [2] https://www.spinics.net/lists/devicetree-compiler/msg01067.html libfdt/fdt_addresses.c | 62 ++++++++++++++++++++++++++++++++++++++++++ libfdt/libfdt.h | 33 ++++++++++++++++++++++ libfdt/version.lds | 1 + tests/.gitignore | 1 + tests/Makefile.tests | 2 +- tests/addr_size.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++ tests/addresses.dts | 11 ++++++++ tests/run_tests.sh | 1 + 8 files changed, 184 insertions(+), 1 deletion(-) create mode 100644 tests/addr_size.c diff --git a/libfdt/fdt_addresses.c b/libfdt/fdt_addresses.c index eff4dbcc729d..92cbed95f8ba 100644 --- a/libfdt/fdt_addresses.c +++ b/libfdt/fdt_addresses.c @@ -55,6 +55,9 @@ #include "libfdt_internal.h" +#define BYTES_PER_CELL 4 +#define BITS_PER_CELL 32 + int fdt_address_cells(const void *fdt, int nodeoffset) { const fdt32_t *ac; @@ -94,3 +97,62 @@ int fdt_size_cells(const void *fdt, int nodeoffset) return val; } + +static uint64_t _fdt_read_cells(const fdt32_t *cells, int n) +{ + int i; + uint64_t res; + + /* TODO: Support values larger than 2 cells */ + if (n > 2) + return -FDT_ERR_BADNCELLS; + + res = 0; + for (i = 0; i < n; i++) { + res <<= BITS_PER_CELL; + res |= fdt32_to_cpu(cells[i]); + } + + return res; +} + +int fdt_simple_addr_size(const void *fdt, int nodeoffset, int idx, + uintptr_t *addr, size_t *size) +{ + int parent; + int ac, sc, reg_stride; + int res; + const fdt32_t *reg; + + reg = fdt_getprop(fdt, nodeoffset, "reg", &res); + if (res < 0) + return res; + + parent = fdt_parent_offset(fdt, nodeoffset); + if (parent < 0) + return res; + + ac = fdt_address_cells(fdt, parent); + if (ac < 0) + return ac; + + sc = fdt_size_cells(fdt, parent); + if (sc < 0) + return sc; + + 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 * BYTES_PER_CELL)) != 0) + return -FDT_ERR_BADVALUE; + + if (addr) + *addr = (uintptr_t) _fdt_read_cells(®[reg_stride * idx], ac); + if (size) + *size = (size_t) _fdt_read_cells(®[ac + reg_stride * idx], + sc); + + return 0; +} diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h index a248b1b57a97..60da2b97d048 100644 --- a/libfdt/libfdt.h +++ b/libfdt/libfdt.h @@ -1098,6 +1098,39 @@ int fdt_address_cells(const void *fdt, int nodeoffset); */ int fdt_size_cells(const void *fdt, int nodeoffset); +/** + * + * fdt_simple_addr_size - read address and/or size 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 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. It does not perform any type of translation based on + * the parent bus(es). + * + * NOTE: This function is expensive, as it must scan the device tree + * structure from the start to nodeoffset, *twice*, with fdt_parent_offset. + * + * 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_simple_addr_size(const void *fdt, int nodeoffset, int idx, + uintptr_t *addrp, size_t *sizep); /**********************************************************************/ /* Write-in-place functions */ diff --git a/libfdt/version.lds b/libfdt/version.lds index cff0358f2314..075ffab44ef3 100644 --- a/libfdt/version.lds +++ b/libfdt/version.lds @@ -59,6 +59,7 @@ LIBFDT_1.2 { fdt_next_subnode; fdt_address_cells; fdt_size_cells; + fdt_simple_addr_size; fdt_stringlist_contains; fdt_resize; fdt_overlay_apply; diff --git a/tests/.gitignore b/tests/.gitignore index 9e209d5cbe6b..acb9335e16c8 100644 --- a/tests/.gitignore +++ b/tests/.gitignore @@ -43,6 +43,7 @@ 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 22581359623c..71a5807baf62 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 000000000000..8463efc416c4 --- /dev/null +++ b/tests/addr_size.c @@ -0,0 +1,74 @@ +/* + * 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(const void *fdt, const char *path, int idx, + uintptr_t addr, size_t size) +{ + int offset, res; + uintptr_t xaddr; + uintptr_t xsize; + + offset = fdt_path_offset(fdt, path); + if (offset < 0) + FAIL("Couldn't find path %s", path); + + res = fdt_simple_addr_size(fdt, offset, idx, &xaddr, &xsize); + if (res < 0) + FAIL("fdt_simple_addr_size gave error: %s", fdt_strerror(res)); + + if (xaddr != addr) + FAIL("Physical address for %s is %p instead of %p\n", + path, (void *) xaddr, (void *) addr); + + if (xsize != size) + FAIL("Size for %s is %zx instead of %zx\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); + PASS(); +} diff --git a/tests/addresses.dts b/tests/addresses.dts index a2faaf59fd7a..32c43795d67d 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 5df148048758..924db6adfb5a 100755 --- a/tests/run_tests.sh +++ b/tests/run_tests.sh @@ -285,6 +285,7 @@ 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 -- 2.13.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree-compiler" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
