From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- drivers/mtd/maps/physmap-versatile.c | 242 +++++++++++++++++++++++++++++++++++ 1 file changed, 242 insertions(+) create mode 100644 drivers/mtd/maps/physmap-versatile.c (limited to 'drivers/mtd/maps/physmap-versatile.c') diff --git a/drivers/mtd/maps/physmap-versatile.c b/drivers/mtd/maps/physmap-versatile.c new file mode 100644 index 000000000..2e779111b --- /dev/null +++ b/drivers/mtd/maps/physmap-versatile.c @@ -0,0 +1,242 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Versatile OF physmap driver add-on + * + * Copyright (c) 2016, Linaro Limited + * Author: Linus Walleij + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "physmap-versatile.h" + +static struct regmap *syscon_regmap; + +enum versatile_flashprot { + INTEGRATOR_AP_FLASHPROT, + INTEGRATOR_CP_FLASHPROT, + VERSATILE_FLASHPROT, + REALVIEW_FLASHPROT, +}; + +static const struct of_device_id syscon_match[] = { + { + .compatible = "arm,integrator-ap-syscon", + .data = (void *)INTEGRATOR_AP_FLASHPROT, + }, + { + .compatible = "arm,integrator-cp-syscon", + .data = (void *)INTEGRATOR_CP_FLASHPROT, + }, + { + .compatible = "arm,core-module-versatile", + .data = (void *)VERSATILE_FLASHPROT, + }, + { + .compatible = "arm,realview-eb-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + { + .compatible = "arm,realview-pb1176-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + { + .compatible = "arm,realview-pb11mp-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + { + .compatible = "arm,realview-pba8-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + { + .compatible = "arm,realview-pbx-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + {}, +}; + +/* + * Flash protection handling for the Integrator/AP + */ +#define INTEGRATOR_SC_CTRLS_OFFSET 0x08 +#define INTEGRATOR_SC_CTRLC_OFFSET 0x0C +#define INTEGRATOR_SC_CTRL_FLVPPEN BIT(1) +#define INTEGRATOR_SC_CTRL_FLWP BIT(2) + +#define INTEGRATOR_EBI_CSR1_OFFSET 0x04 +/* The manual says bit 2, the code says bit 3, trust the code */ +#define INTEGRATOR_EBI_WRITE_ENABLE BIT(3) +#define INTEGRATOR_EBI_LOCK_OFFSET 0x20 +#define INTEGRATOR_EBI_LOCK_VAL 0xA05F + +static const struct of_device_id ebi_match[] = { + { .compatible = "arm,external-bus-interface"}, + { }, +}; + +static int ap_flash_init(struct platform_device *pdev) +{ + struct device_node *ebi; + void __iomem *ebi_base; + u32 val; + int ret; + + /* Look up the EBI */ + ebi = of_find_matching_node(NULL, ebi_match); + if (!ebi) { + return -ENODEV; + } + ebi_base = of_iomap(ebi, 0); + of_node_put(ebi); + if (!ebi_base) + return -ENODEV; + + /* Clear VPP and write protection bits */ + ret = regmap_write(syscon_regmap, + INTEGRATOR_SC_CTRLC_OFFSET, + INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); + if (ret) + dev_err(&pdev->dev, "error clearing Integrator VPP/WP\n"); + + /* Unlock the EBI */ + writel(INTEGRATOR_EBI_LOCK_VAL, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET); + + /* Enable write cycles on the EBI, CSR1 (flash) */ + val = readl(ebi_base + INTEGRATOR_EBI_CSR1_OFFSET); + val |= INTEGRATOR_EBI_WRITE_ENABLE; + writel(val, ebi_base + INTEGRATOR_EBI_CSR1_OFFSET); + + /* Lock the EBI again */ + writel(0, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET); + iounmap(ebi_base); + + return 0; +} + +static void ap_flash_set_vpp(struct map_info *map, int on) +{ + int ret; + + if (on) { + ret = regmap_write(syscon_regmap, + INTEGRATOR_SC_CTRLS_OFFSET, + INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); + if (ret) + pr_err("error enabling AP VPP\n"); + } else { + ret = regmap_write(syscon_regmap, + INTEGRATOR_SC_CTRLC_OFFSET, + INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); + if (ret) + pr_err("error disabling AP VPP\n"); + } +} + +/* + * Flash protection handling for the Integrator/CP + */ + +#define INTCP_FLASHPROG_OFFSET 0x04 +#define CINTEGRATOR_FLVPPEN BIT(0) +#define CINTEGRATOR_FLWREN BIT(1) +#define CINTEGRATOR_FLMASK BIT(0)|BIT(1) + +static void cp_flash_set_vpp(struct map_info *map, int on) +{ + int ret; + + if (on) { + ret = regmap_update_bits(syscon_regmap, + INTCP_FLASHPROG_OFFSET, + CINTEGRATOR_FLMASK, + CINTEGRATOR_FLVPPEN | CINTEGRATOR_FLWREN); + if (ret) + pr_err("error setting CP VPP\n"); + } else { + ret = regmap_update_bits(syscon_regmap, + INTCP_FLASHPROG_OFFSET, + CINTEGRATOR_FLMASK, + 0); + if (ret) + pr_err("error setting CP VPP\n"); + } +} + +/* + * Flash protection handling for the Versatiles and RealViews + */ + +#define VERSATILE_SYS_FLASH_OFFSET 0x4C + +static void versatile_flash_set_vpp(struct map_info *map, int on) +{ + int ret; + + ret = regmap_update_bits(syscon_regmap, VERSATILE_SYS_FLASH_OFFSET, + 0x01, !!on); + if (ret) + pr_err("error setting Versatile VPP\n"); +} + +int of_flash_probe_versatile(struct platform_device *pdev, + struct device_node *np, + struct map_info *map) +{ + struct device_node *sysnp; + const struct of_device_id *devid; + struct regmap *rmap; + static enum versatile_flashprot versatile_flashprot; + int ret; + + /* Not all flash chips use this protection line */ + if (!of_device_is_compatible(np, "arm,versatile-flash")) + return 0; + + /* For first chip probed, look up the syscon regmap */ + if (!syscon_regmap) { + sysnp = of_find_matching_node_and_match(NULL, + syscon_match, + &devid); + if (!sysnp) + return -ENODEV; + + versatile_flashprot = (uintptr_t)devid->data; + rmap = syscon_node_to_regmap(sysnp); + of_node_put(sysnp); + if (IS_ERR(rmap)) + return PTR_ERR(rmap); + + syscon_regmap = rmap; + } + + switch (versatile_flashprot) { + case INTEGRATOR_AP_FLASHPROT: + ret = ap_flash_init(pdev); + if (ret) + return ret; + map->set_vpp = ap_flash_set_vpp; + dev_info(&pdev->dev, "Integrator/AP flash protection\n"); + break; + case INTEGRATOR_CP_FLASHPROT: + map->set_vpp = cp_flash_set_vpp; + dev_info(&pdev->dev, "Integrator/CP flash protection\n"); + break; + case VERSATILE_FLASHPROT: + case REALVIEW_FLASHPROT: + map->set_vpp = versatile_flash_set_vpp; + dev_info(&pdev->dev, "versatile/realview flash protection\n"); + break; + default: + dev_info(&pdev->dev, "device marked as Versatile flash " + "but no system controller was found\n"); + break; + } + + return 0; +} -- cgit v1.3.1