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> --- The intent of this patch is similar to the commit "libfdt: Add helpers to read #address-cells and #size-cells" [1]. It is related to "libfdt: add address translation support" [2] but does not attempt to perform address translation and was written from scratch rather than reusing GPL code. If the issues with that patch are resolved, that functionality will complement what is added in this patch. [1] http://www.spinics.net/lists/devicetree-compiler/msg00113.html [2] http://www.spinics.net/lists/devicetree-compiler/msg00093.html libfdt/fdt_addresses.c | 62 ++++++++++++++++++++++++++++++++++++++++++ libfdt/libfdt.h | 29 ++++++++++++++++++++ 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, 180 insertions(+), 1 deletion(-) create mode 100644 tests/addr_size.c diff --git a/libfdt/fdt_addresses.c b/libfdt/fdt_addresses.c index eff4dbc..92cbed9 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 c69e918..1a184a3 100644 --- a/libfdt/libfdt.h +++ b/libfdt/libfdt.h @@ -1085,6 +1085,35 @@ 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). + * + * 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 cff0358..075ffab 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 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..8463efc --- /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 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 -- 1.9.1 -- 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
