kbuild: rust: keep Rust objects out of Clang LTO with inline helpersgrafted

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 <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

1 files changed, 673 insertions, 0 deletions

diff --git a/arch/mips/ath79/clock.c b/arch/mips/ath79/clock.c
new file mode 100644
index 000000000..050f6553f
--- /dev/null
+++ b/arch/mips/ath79/clock.c
@@ -0,0 +1,673 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Atheros AR71XX/AR724X/AR913X common routines
+ *
+ *  Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
+ *  Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  Parts of this file are based on Atheros' 2.6.15/2.6.31 BSP
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <dt-bindings/clock/ath79-clk.h>
+
+#include <asm/div64.h>
+
+#include <asm/mach-ath79/ath79.h>
+#include <asm/mach-ath79/ar71xx_regs.h>
+#include "common.h"
+
+#define AR71XX_BASE_FREQ	40000000
+#define AR724X_BASE_FREQ	40000000
+
+static struct clk *clks[ATH79_CLK_END];
+static struct clk_onecell_data clk_data = {
+	.clks = clks,
+	.clk_num = ARRAY_SIZE(clks),
+};
+
+static const char * const clk_names[ATH79_CLK_END] = {
+	[ATH79_CLK_CPU] = "cpu",
+	[ATH79_CLK_DDR] = "ddr",
+	[ATH79_CLK_AHB] = "ahb",
+	[ATH79_CLK_REF] = "ref",
+	[ATH79_CLK_MDIO] = "mdio",
+};
+
+static const char * __init ath79_clk_name(int type)
+{
+	BUG_ON(type >= ARRAY_SIZE(clk_names) || !clk_names[type]);
+	return clk_names[type];
+}
+
+static void __init __ath79_set_clk(int type, const char *name, struct clk *clk)
+{
+	if (IS_ERR(clk))
+		panic("failed to allocate %s clock structure", clk_names[type]);
+
+	clks[type] = clk;
+	clk_register_clkdev(clk, name, NULL);
+}
+
+static struct clk * __init ath79_set_clk(int type, unsigned long rate)
+{
+	const char *name = ath79_clk_name(type);
+	struct clk *clk;
+
+	clk = clk_register_fixed_rate(NULL, name, NULL, 0, rate);
+	__ath79_set_clk(type, name, clk);
+	return clk;
+}
+
+static struct clk * __init ath79_set_ff_clk(int type, const char *parent,
+					    unsigned int mult, unsigned int div)
+{
+	const char *name = ath79_clk_name(type);
+	struct clk *clk;
+
+	clk = clk_register_fixed_factor(NULL, name, parent, 0, mult, div);
+	__ath79_set_clk(type, name, clk);
+	return clk;
+}
+
+static unsigned long __init ath79_setup_ref_clk(unsigned long rate)
+{
+	struct clk *clk = clks[ATH79_CLK_REF];
+
+	if (clk)
+		rate = clk_get_rate(clk);
+	else
+		clk = ath79_set_clk(ATH79_CLK_REF, rate);
+
+	return rate;
+}
+
+static void __init ar71xx_clocks_init(void __iomem *pll_base)
+{
+	unsigned long ref_rate;
+	unsigned long cpu_rate;
+	unsigned long ddr_rate;
+	unsigned long ahb_rate;
+	u32 pll;
+	u32 freq;
+	u32 div;
+
+	ref_rate = ath79_setup_ref_clk(AR71XX_BASE_FREQ);
+
+	pll = __raw_readl(pll_base + AR71XX_PLL_REG_CPU_CONFIG);
+
+	div = ((pll >> AR71XX_PLL_FB_SHIFT) & AR71XX_PLL_FB_MASK) + 1;
+	freq = div * ref_rate;
+
+	div = ((pll >> AR71XX_CPU_DIV_SHIFT) & AR71XX_CPU_DIV_MASK) + 1;
+	cpu_rate = freq / div;
+
+	div = ((pll >> AR71XX_DDR_DIV_SHIFT) & AR71XX_DDR_DIV_MASK) + 1;
+	ddr_rate = freq / div;
+
+	div = (((pll >> AR71XX_AHB_DIV_SHIFT) & AR71XX_AHB_DIV_MASK) + 1) * 2;
+	ahb_rate = cpu_rate / div;
+
+	ath79_set_clk(ATH79_CLK_CPU, cpu_rate);
+	ath79_set_clk(ATH79_CLK_DDR, ddr_rate);
+	ath79_set_clk(ATH79_CLK_AHB, ahb_rate);
+}
+
+static void __init ar724x_clocks_init(void __iomem *pll_base)
+{
+	u32 mult, div, ddr_div, ahb_div;
+	u32 pll;
+
+	ath79_setup_ref_clk(AR71XX_BASE_FREQ);
+
+	pll = __raw_readl(pll_base + AR724X_PLL_REG_CPU_CONFIG);
+
+	mult = ((pll >> AR724X_PLL_FB_SHIFT) & AR724X_PLL_FB_MASK);
+	div = ((pll >> AR724X_PLL_REF_DIV_SHIFT) & AR724X_PLL_REF_DIV_MASK) * 2;
+
+	ddr_div = ((pll >> AR724X_DDR_DIV_SHIFT) & AR724X_DDR_DIV_MASK) + 1;
+	ahb_div = (((pll >> AR724X_AHB_DIV_SHIFT) & AR724X_AHB_DIV_MASK) + 1) * 2;
+
+	ath79_set_ff_clk(ATH79_CLK_CPU, "ref", mult, div);
+	ath79_set_ff_clk(ATH79_CLK_DDR, "ref", mult, div * ddr_div);
+	ath79_set_ff_clk(ATH79_CLK_AHB, "ref", mult, div * ahb_div);
+}
+
+static void __init ar933x_clocks_init(void __iomem *pll_base)
+{
+	unsigned long ref_rate;
+	u32 clock_ctrl;
+	u32 ref_div;
+	u32 ninit_mul;
+	u32 out_div;
+
+	u32 cpu_div;
+	u32 ddr_div;
+	u32 ahb_div;
+	u32 t;
+
+	t = ath79_reset_rr(AR933X_RESET_REG_BOOTSTRAP);
+	if (t & AR933X_BOOTSTRAP_REF_CLK_40)
+		ref_rate = (40 * 1000 * 1000);
+	else
+		ref_rate = (25 * 1000 * 1000);
+
+	ath79_setup_ref_clk(ref_rate);
+
+	clock_ctrl = __raw_readl(pll_base + AR933X_PLL_CLOCK_CTRL_REG);
+	if (clock_ctrl & AR933X_PLL_CLOCK_CTRL_BYPASS) {
+		ref_div = 1;
+		ninit_mul = 1;
+		out_div = 1;
+
+		cpu_div = 1;
+		ddr_div = 1;
+		ahb_div = 1;
+	} else {
+		u32 cpu_config;
+		u32 t;
+
+		cpu_config = __raw_readl(pll_base + AR933X_PLL_CPU_CONFIG_REG);
+
+		t = (cpu_config >> AR933X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
+		    AR933X_PLL_CPU_CONFIG_REFDIV_MASK;
+		ref_div = t;
+
+		ninit_mul = (cpu_config >> AR933X_PLL_CPU_CONFIG_NINT_SHIFT) &
+		    AR933X_PLL_CPU_CONFIG_NINT_MASK;
+
+		t = (cpu_config >> AR933X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
+		    AR933X_PLL_CPU_CONFIG_OUTDIV_MASK;
+		if (t == 0)
+			t = 1;
+
+		out_div = (1 << t);
+
+		cpu_div = ((clock_ctrl >> AR933X_PLL_CLOCK_CTRL_CPU_DIV_SHIFT) &
+		     AR933X_PLL_CLOCK_CTRL_CPU_DIV_MASK) + 1;
+
+		ddr_div = ((clock_ctrl >> AR933X_PLL_CLOCK_CTRL_DDR_DIV_SHIFT) &
+		      AR933X_PLL_CLOCK_CTRL_DDR_DIV_MASK) + 1;
+
+		ahb_div = ((clock_ctrl >> AR933X_PLL_CLOCK_CTRL_AHB_DIV_SHIFT) &
+		     AR933X_PLL_CLOCK_CTRL_AHB_DIV_MASK) + 1;
+	}
+
+	ath79_set_ff_clk(ATH79_CLK_CPU, "ref", ninit_mul,
+			 ref_div * out_div * cpu_div);
+	ath79_set_ff_clk(ATH79_CLK_DDR, "ref", ninit_mul,
+			 ref_div * out_div * ddr_div);
+	ath79_set_ff_clk(ATH79_CLK_AHB, "ref", ninit_mul,
+			 ref_div * out_div * ahb_div);
+}
+
+static u32 __init ar934x_get_pll_freq(u32 ref, u32 ref_div, u32 nint, u32 nfrac,
+				      u32 frac, u32 out_div)
+{
+	u64 t;
+	u32 ret;
+
+	t = ref;
+	t *= nint;
+	do_div(t, ref_div);
+	ret = t;
+
+	t = ref;
+	t *= nfrac;
+	do_div(t, ref_div * frac);
+	ret += t;
+
+	ret /= (1 << out_div);
+	return ret;
+}
+
+static void __init ar934x_clocks_init(void __iomem *pll_base)
+{
+	unsigned long ref_rate;
+	unsigned long cpu_rate;
+	unsigned long ddr_rate;
+	unsigned long ahb_rate;
+	u32 pll, out_div, ref_div, nint, nfrac, frac, clk_ctrl, postdiv;
+	u32 cpu_pll, ddr_pll;
+	u32 bootstrap;
+	void __iomem *dpll_base;
+
+	dpll_base = ioremap(AR934X_SRIF_BASE, AR934X_SRIF_SIZE);
+
+	bootstrap = ath79_reset_rr(AR934X_RESET_REG_BOOTSTRAP);
+	if (bootstrap & AR934X_BOOTSTRAP_REF_CLK_40)
+		ref_rate = 40 * 1000 * 1000;
+	else
+		ref_rate = 25 * 1000 * 1000;
+
+	ref_rate = ath79_setup_ref_clk(ref_rate);
+
+	pll = __raw_readl(dpll_base + AR934X_SRIF_CPU_DPLL2_REG);
+	if (pll & AR934X_SRIF_DPLL2_LOCAL_PLL) {
+		out_div = (pll >> AR934X_SRIF_DPLL2_OUTDIV_SHIFT) &
+			  AR934X_SRIF_DPLL2_OUTDIV_MASK;
+		pll = __raw_readl(dpll_base + AR934X_SRIF_CPU_DPLL1_REG);
+		nint = (pll >> AR934X_SRIF_DPLL1_NINT_SHIFT) &
+		       AR934X_SRIF_DPLL1_NINT_MASK;
+		nfrac = pll & AR934X_SRIF_DPLL1_NFRAC_MASK;
+		ref_div = (pll >> AR934X_SRIF_DPLL1_REFDIV_SHIFT) &
+			  AR934X_SRIF_DPLL1_REFDIV_MASK;
+		frac = 1 << 18;
+	} else {
+		pll = __raw_readl(pll_base + AR934X_PLL_CPU_CONFIG_REG);
+		out_div = (pll >> AR934X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
+			AR934X_PLL_CPU_CONFIG_OUTDIV_MASK;
+		ref_div = (pll >> AR934X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
+			  AR934X_PLL_CPU_CONFIG_REFDIV_MASK;
+		nint = (pll >> AR934X_PLL_CPU_CONFIG_NINT_SHIFT) &
+		       AR934X_PLL_CPU_CONFIG_NINT_MASK;
+		nfrac = (pll >> AR934X_PLL_CPU_CONFIG_NFRAC_SHIFT) &
+			AR934X_PLL_CPU_CONFIG_NFRAC_MASK;
+		frac = 1 << 6;
+	}
+
+	cpu_pll = ar934x_get_pll_freq(ref_rate, ref_div, nint,
+				      nfrac, frac, out_div);
+
+	pll = __raw_readl(dpll_base + AR934X_SRIF_DDR_DPLL2_REG);
+	if (pll & AR934X_SRIF_DPLL2_LOCAL_PLL) {
+		out_div = (pll >> AR934X_SRIF_DPLL2_OUTDIV_SHIFT) &
+			  AR934X_SRIF_DPLL2_OUTDIV_MASK;
+		pll = __raw_readl(dpll_base + AR934X_SRIF_DDR_DPLL1_REG);
+		nint = (pll >> AR934X_SRIF_DPLL1_NINT_SHIFT) &
+		       AR934X_SRIF_DPLL1_NINT_MASK;
+		nfrac = pll & AR934X_SRIF_DPLL1_NFRAC_MASK;
+		ref_div = (pll >> AR934X_SRIF_DPLL1_REFDIV_SHIFT) &
+			  AR934X_SRIF_DPLL1_REFDIV_MASK;
+		frac = 1 << 18;
+	} else {
+		pll = __raw_readl(pll_base + AR934X_PLL_DDR_CONFIG_REG);
+		out_div = (pll >> AR934X_PLL_DDR_CONFIG_OUTDIV_SHIFT) &
+			  AR934X_PLL_DDR_CONFIG_OUTDIV_MASK;
+		ref_div = (pll >> AR934X_PLL_DDR_CONFIG_REFDIV_SHIFT) &
+			   AR934X_PLL_DDR_CONFIG_REFDIV_MASK;
+		nint = (pll >> AR934X_PLL_DDR_CONFIG_NINT_SHIFT) &
+		       AR934X_PLL_DDR_CONFIG_NINT_MASK;
+		nfrac = (pll >> AR934X_PLL_DDR_CONFIG_NFRAC_SHIFT) &
+			AR934X_PLL_DDR_CONFIG_NFRAC_MASK;
+		frac = 1 << 10;
+	}
+
+	ddr_pll = ar934x_get_pll_freq(ref_rate, ref_div, nint,
+				      nfrac, frac, out_div);
+
+	clk_ctrl = __raw_readl(pll_base + AR934X_PLL_CPU_DDR_CLK_CTRL_REG);
+
+	postdiv = (clk_ctrl >> AR934X_PLL_CPU_DDR_CLK_CTRL_CPU_POST_DIV_SHIFT) &
+		  AR934X_PLL_CPU_DDR_CLK_CTRL_CPU_POST_DIV_MASK;
+
+	if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_CPU_PLL_BYPASS)
+		cpu_rate = ref_rate;
+	else if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_CPUCLK_FROM_CPUPLL)
+		cpu_rate = cpu_pll / (postdiv + 1);
+	else
+		cpu_rate = ddr_pll / (postdiv + 1);
+
+	postdiv = (clk_ctrl >> AR934X_PLL_CPU_DDR_CLK_CTRL_DDR_POST_DIV_SHIFT) &
+		  AR934X_PLL_CPU_DDR_CLK_CTRL_DDR_POST_DIV_MASK;
+
+	if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_DDR_PLL_BYPASS)
+		ddr_rate = ref_rate;
+	else if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_DDRCLK_FROM_DDRPLL)
+		ddr_rate = ddr_pll / (postdiv + 1);
+	else
+		ddr_rate = cpu_pll / (postdiv + 1);
+
+	postdiv = (clk_ctrl >> AR934X_PLL_CPU_DDR_CLK_CTRL_AHB_POST_DIV_SHIFT) &
+		  AR934X_PLL_CPU_DDR_CLK_CTRL_AHB_POST_DIV_MASK;
+
+	if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_AHB_PLL_BYPASS)
+		ahb_rate = ref_rate;
+	else if (clk_ctrl & AR934X_PLL_CPU_DDR_CLK_CTRL_AHBCLK_FROM_DDRPLL)
+		ahb_rate = ddr_pll / (postdiv + 1);
+	else
+		ahb_rate = cpu_pll / (postdiv + 1);
+
+	ath79_set_clk(ATH79_CLK_CPU, cpu_rate);
+	ath79_set_clk(ATH79_CLK_DDR, ddr_rate);
+	ath79_set_clk(ATH79_CLK_AHB, ahb_rate);
+
+	clk_ctrl = __raw_readl(pll_base + AR934X_PLL_SWITCH_CLOCK_CONTROL_REG);
+	if (clk_ctrl & AR934X_PLL_SWITCH_CLOCK_CONTROL_MDIO_CLK_SEL)
+		ath79_set_clk(ATH79_CLK_MDIO, 100 * 1000 * 1000);
+
+	iounmap(dpll_base);
+}
+
+static void __init qca953x_clocks_init(void __iomem *pll_base)
+{
+	unsigned long ref_rate;
+	unsigned long cpu_rate;
+	unsigned long ddr_rate;
+	unsigned long ahb_rate;
+	u32 pll, out_div, ref_div, nint, frac, clk_ctrl, postdiv;
+	u32 cpu_pll, ddr_pll;
+	u32 bootstrap;
+
+	bootstrap = ath79_reset_rr(QCA953X_RESET_REG_BOOTSTRAP);
+	if (bootstrap &	QCA953X_BOOTSTRAP_REF_CLK_40)
+		ref_rate = 40 * 1000 * 1000;
+	else
+		ref_rate = 25 * 1000 * 1000;
+
+	ref_rate = ath79_setup_ref_clk(ref_rate);
+
+	pll = __raw_readl(pll_base + QCA953X_PLL_CPU_CONFIG_REG);
+	out_div = (pll >> QCA953X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
+		  QCA953X_PLL_CPU_CONFIG_OUTDIV_MASK;
+	ref_div = (pll >> QCA953X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
+		  QCA953X_PLL_CPU_CONFIG_REFDIV_MASK;
+	nint = (pll >> QCA953X_PLL_CPU_CONFIG_NINT_SHIFT) &
+	       QCA953X_PLL_CPU_CONFIG_NINT_MASK;
+	frac = (pll >> QCA953X_PLL_CPU_CONFIG_NFRAC_SHIFT) &
+	       QCA953X_PLL_CPU_CONFIG_NFRAC_MASK;
+
+	cpu_pll = nint * ref_rate / ref_div;
+	cpu_pll += frac * (ref_rate >> 6) / ref_div;
+	cpu_pll /= (1 << out_div);
+
+	pll = __raw_readl(pll_base + QCA953X_PLL_DDR_CONFIG_REG);
+	out_div = (pll >> QCA953X_PLL_DDR_CONFIG_OUTDIV_SHIFT) &
+		  QCA953X_PLL_DDR_CONFIG_OUTDIV_MASK;
+	ref_div = (pll >> QCA953X_PLL_DDR_CONFIG_REFDIV_SHIFT) &
+		  QCA953X_PLL_DDR_CONFIG_REFDIV_MASK;
+	nint = (pll >> QCA953X_PLL_DDR_CONFIG_NINT_SHIFT) &
+	       QCA953X_PLL_DDR_CONFIG_NINT_MASK;
+	frac = (pll >> QCA953X_PLL_DDR_CONFIG_NFRAC_SHIFT) &
+	       QCA953X_PLL_DDR_CONFIG_NFRAC_MASK;
+
+	ddr_pll = nint * ref_rate / ref_div;
+	ddr_pll += frac * (ref_rate >> 6) / (ref_div << 4);
+	ddr_pll /= (1 << out_div);
+
+	clk_ctrl = __raw_readl(pll_base + QCA953X_PLL_CLK_CTRL_REG);
+
+	postdiv = (clk_ctrl >> QCA953X_PLL_CLK_CTRL_CPU_POST_DIV_SHIFT) &
+		  QCA953X_PLL_CLK_CTRL_CPU_POST_DIV_MASK;
+
+	if (clk_ctrl & QCA953X_PLL_CLK_CTRL_CPU_PLL_BYPASS)
+		cpu_rate = ref_rate;
+	else if (clk_ctrl & QCA953X_PLL_CLK_CTRL_CPUCLK_FROM_CPUPLL)
+		cpu_rate = cpu_pll / (postdiv + 1);
+	else
+		cpu_rate = ddr_pll / (postdiv + 1);
+
+	postdiv = (clk_ctrl >> QCA953X_PLL_CLK_CTRL_DDR_POST_DIV_SHIFT) &
+		  QCA953X_PLL_CLK_CTRL_DDR_POST_DIV_MASK;
+
+	if (clk_ctrl & QCA953X_PLL_CLK_CTRL_DDR_PLL_BYPASS)
+		ddr_rate = ref_rate;
+	else if (clk_ctrl & QCA953X_PLL_CLK_CTRL_DDRCLK_FROM_DDRPLL)
+		ddr_rate = ddr_pll / (postdiv + 1);
+	else
+		ddr_rate = cpu_pll / (postdiv + 1);
+
+	postdiv = (clk_ctrl >> QCA953X_PLL_CLK_CTRL_AHB_POST_DIV_SHIFT) &
+		  QCA953X_PLL_CLK_CTRL_AHB_POST_DIV_MASK;
+
+	if (clk_ctrl & QCA953X_PLL_CLK_CTRL_AHB_PLL_BYPASS)
+		ahb_rate = ref_rate;
+	else if (clk_ctrl & QCA953X_PLL_CLK_CTRL_AHBCLK_FROM_DDRPLL)
+		ahb_rate = ddr_pll / (postdiv + 1);
+	else
+		ahb_rate = cpu_pll / (postdiv + 1);
+
+	ath79_set_clk(ATH79_CLK_CPU, cpu_rate);
+	ath79_set_clk(ATH79_CLK_DDR, ddr_rate);
+	ath79_set_clk(ATH79_CLK_AHB, ahb_rate);
+}
+
+static void __init qca955x_clocks_init(void __iomem *pll_base)
+{
+	unsigned long ref_rate;
+	unsigned long cpu_rate;
+	unsigned long ddr_rate;
+	unsigned long ahb_rate;
+	u32 pll, out_div, ref_div, nint, frac, clk_ctrl, postdiv;
+	u32 cpu_pll, ddr_pll;
+	u32 bootstrap;
+
+	bootstrap = ath79_reset_rr(QCA955X_RESET_REG_BOOTSTRAP);
+	if (bootstrap &	QCA955X_BOOTSTRAP_REF_CLK_40)
+		ref_rate = 40 * 1000 * 1000;
+	else
+		ref_rate = 25 * 1000 * 1000;
+
+	ref_rate = ath79_setup_ref_clk(ref_rate);
+
+	pll = __raw_readl(pll_base + QCA955X_PLL_CPU_CONFIG_REG);
+	out_div = (pll >> QCA955X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
+		  QCA955X_PLL_CPU_CONFIG_OUTDIV_MASK;
+	ref_div = (pll >> QCA955X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
+		  QCA955X_PLL_CPU_CONFIG_REFDIV_MASK;
+	nint = (pll >> QCA955X_PLL_CPU_CONFIG_NINT_SHIFT) &
+	       QCA955X_PLL_CPU_CONFIG_NINT_MASK;
+	frac = (pll >> QCA955X_PLL_CPU_CONFIG_NFRAC_SHIFT) &
+	       QCA955X_PLL_CPU_CONFIG_NFRAC_MASK;
+
+	cpu_pll = nint * ref_rate / ref_div;
+	cpu_pll += frac * ref_rate / (ref_div * (1 << 6));
+	cpu_pll /= (1 << out_div);
+
+	pll = __raw_readl(pll_base + QCA955X_PLL_DDR_CONFIG_REG);
+	out_div = (pll >> QCA955X_PLL_DDR_CONFIG_OUTDIV_SHIFT) &
+		  QCA955X_PLL_DDR_CONFIG_OUTDIV_MASK;
+	ref_div = (pll >> QCA955X_PLL_DDR_CONFIG_REFDIV_SHIFT) &
+		  QCA955X_PLL_DDR_CONFIG_REFDIV_MASK;
+	nint = (pll >> QCA955X_PLL_DDR_CONFIG_NINT_SHIFT) &
+	       QCA955X_PLL_DDR_CONFIG_NINT_MASK;
+	frac = (pll >> QCA955X_PLL_DDR_CONFIG_NFRAC_SHIFT) &
+	       QCA955X_PLL_DDR_CONFIG_NFRAC_MASK;
+
+	ddr_pll = nint * ref_rate / ref_div;
+	ddr_pll += frac * ref_rate / (ref_div * (1 << 10));
+	ddr_pll /= (1 << out_div);
+
+	clk_ctrl = __raw_readl(pll_base + QCA955X_PLL_CLK_CTRL_REG);
+
+	postdiv = (clk_ctrl >> QCA955X_PLL_CLK_CTRL_CPU_POST_DIV_SHIFT) &
+		  QCA955X_PLL_CLK_CTRL_CPU_POST_DIV_MASK;
+
+	if (clk_ctrl & QCA955X_PLL_CLK_CTRL_CPU_PLL_BYPASS)
+		cpu_rate = ref_rate;
+	else if (clk_ctrl & QCA955X_PLL_CLK_CTRL_CPUCLK_FROM_CPUPLL)
+		cpu_rate = ddr_pll / (postdiv + 1);
+	else
+		cpu_rate = cpu_pll / (postdiv + 1);
+
+	postdiv = (clk_ctrl >> QCA955X_PLL_CLK_CTRL_DDR_POST_DIV_SHIFT) &
+		  QCA955X_PLL_CLK_CTRL_DDR_POST_DIV_MASK;
+
+	if (clk_ctrl & QCA955X_PLL_CLK_CTRL_DDR_PLL_BYPASS)
+		ddr_rate = ref_rate;
+	else if (clk_ctrl & QCA955X_PLL_CLK_CTRL_DDRCLK_FROM_DDRPLL)
+		ddr_rate = cpu_pll / (postdiv + 1);
+	else
+		ddr_rate = ddr_pll / (postdiv + 1);
+
+	postdiv = (clk_ctrl >> QCA955X_PLL_CLK_CTRL_AHB_POST_DIV_SHIFT) &
+		  QCA955X_PLL_CLK_CTRL_AHB_POST_DIV_MASK;
+
+	if (clk_ctrl & QCA955X_PLL_CLK_CTRL_AHB_PLL_BYPASS)
+		ahb_rate = ref_rate;
+	else if (clk_ctrl & QCA955X_PLL_CLK_CTRL_AHBCLK_FROM_DDRPLL)
+		ahb_rate = ddr_pll / (postdiv + 1);
+	else
+		ahb_rate = cpu_pll / (postdiv + 1);
+
+	ath79_set_clk(ATH79_CLK_CPU, cpu_rate);
+	ath79_set_clk(ATH79_CLK_DDR, ddr_rate);
+	ath79_set_clk(ATH79_CLK_AHB, ahb_rate);
+}
+
+static void __init qca956x_clocks_init(void __iomem *pll_base)
+{
+	unsigned long ref_rate;
+	unsigned long cpu_rate;
+	unsigned long ddr_rate;
+	unsigned long ahb_rate;
+	u32 pll, out_div, ref_div, nint, hfrac, lfrac, clk_ctrl, postdiv;
+	u32 cpu_pll, ddr_pll;
+	u32 bootstrap;
+
+	/*
+	 * QCA956x timer init workaround has to be applied right before setting
+	 * up the clock. Else, there will be no jiffies
+	 */
+	u32 misc;
+
+	misc = ath79_reset_rr(AR71XX_RESET_REG_MISC_INT_ENABLE);
+	misc |= MISC_INT_MIPS_SI_TIMERINT_MASK;
+	ath79_reset_wr(AR71XX_RESET_REG_MISC_INT_ENABLE, misc);
+
+	bootstrap = ath79_reset_rr(QCA956X_RESET_REG_BOOTSTRAP);
+	if (bootstrap &	QCA956X_BOOTSTRAP_REF_CLK_40)
+		ref_rate = 40 * 1000 * 1000;
+	else
+		ref_rate = 25 * 1000 * 1000;
+
+	ref_rate = ath79_setup_ref_clk(ref_rate);
+
+	pll = __raw_readl(pll_base + QCA956X_PLL_CPU_CONFIG_REG);
+	out_div = (pll >> QCA956X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
+		  QCA956X_PLL_CPU_CONFIG_OUTDIV_MASK;
+	ref_div = (pll >> QCA956X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
+		  QCA956X_PLL_CPU_CONFIG_REFDIV_MASK;
+
+	pll = __raw_readl(pll_base + QCA956X_PLL_CPU_CONFIG1_REG);
+	nint = (pll >> QCA956X_PLL_CPU_CONFIG1_NINT_SHIFT) &
+	       QCA956X_PLL_CPU_CONFIG1_NINT_MASK;
+	hfrac = (pll >> QCA956X_PLL_CPU_CONFIG1_NFRAC_H_SHIFT) &
+	       QCA956X_PLL_CPU_CONFIG1_NFRAC_H_MASK;
+	lfrac = (pll >> QCA956X_PLL_CPU_CONFIG1_NFRAC_L_SHIFT) &
+	       QCA956X_PLL_CPU_CONFIG1_NFRAC_L_MASK;
+
+	cpu_pll = nint * ref_rate / ref_div;
+	cpu_pll += (lfrac * ref_rate) / ((ref_div * 25) << 13);
+	cpu_pll += (hfrac >> 13) * ref_rate / ref_div;
+	cpu_pll /= (1 << out_div);
+
+	pll = __raw_readl(pll_base + QCA956X_PLL_DDR_CONFIG_REG);
+	out_div = (pll >> QCA956X_PLL_DDR_CONFIG_OUTDIV_SHIFT) &
+		  QCA956X_PLL_DDR_CONFIG_OUTDIV_MASK;
+	ref_div = (pll >> QCA956X_PLL_DDR_CONFIG_REFDIV_SHIFT) &
+		  QCA956X_PLL_DDR_CONFIG_REFDIV_MASK;
+	pll = __raw_readl(pll_base + QCA956X_PLL_DDR_CONFIG1_REG);
+	nint = (pll >> QCA956X_PLL_DDR_CONFIG1_NINT_SHIFT) &
+	       QCA956X_PLL_DDR_CONFIG1_NINT_MASK;
+	hfrac = (pll >> QCA956X_PLL_DDR_CONFIG1_NFRAC_H_SHIFT) &
+	       QCA956X_PLL_DDR_CONFIG1_NFRAC_H_MASK;
+	lfrac = (pll >> QCA956X_PLL_DDR_CONFIG1_NFRAC_L_SHIFT) &
+	       QCA956X_PLL_DDR_CONFIG1_NFRAC_L_MASK;
+
+	ddr_pll = nint * ref_rate / ref_div;
+	ddr_pll += (lfrac * ref_rate) / ((ref_div * 25) << 13);
+	ddr_pll += (hfrac >> 13) * ref_rate / ref_div;
+	ddr_pll /= (1 << out_div);
+
+	clk_ctrl = __raw_readl(pll_base + QCA956X_PLL_CLK_CTRL_REG);
+
+	postdiv = (clk_ctrl >> QCA956X_PLL_CLK_CTRL_CPU_POST_DIV_SHIFT) &
+		  QCA956X_PLL_CLK_CTRL_CPU_POST_DIV_MASK;
+
+	if (clk_ctrl & QCA956X_PLL_CLK_CTRL_CPU_PLL_BYPASS)
+		cpu_rate = ref_rate;
+	else if (clk_ctrl & QCA956X_PLL_CLK_CTRL_CPU_DDRCLK_FROM_CPUPLL)
+		cpu_rate = ddr_pll / (postdiv + 1);
+	else
+		cpu_rate = cpu_pll / (postdiv + 1);
+
+	postdiv = (clk_ctrl >> QCA956X_PLL_CLK_CTRL_DDR_POST_DIV_SHIFT) &
+		  QCA956X_PLL_CLK_CTRL_DDR_POST_DIV_MASK;
+
+	if (clk_ctrl & QCA956X_PLL_CLK_CTRL_DDR_PLL_BYPASS)
+		ddr_rate = ref_rate;
+	else if (clk_ctrl & QCA956X_PLL_CLK_CTRL_CPU_DDRCLK_FROM_DDRPLL)
+		ddr_rate = cpu_pll / (postdiv + 1);
+	else
+		ddr_rate = ddr_pll / (postdiv + 1);
+
+	postdiv = (clk_ctrl >> QCA956X_PLL_CLK_CTRL_AHB_POST_DIV_SHIFT) &
+		  QCA956X_PLL_CLK_CTRL_AHB_POST_DIV_MASK;
+
+	if (clk_ctrl & QCA956X_PLL_CLK_CTRL_AHB_PLL_BYPASS)
+		ahb_rate = ref_rate;
+	else if (clk_ctrl & QCA956X_PLL_CLK_CTRL_AHBCLK_FROM_DDRPLL)
+		ahb_rate = ddr_pll / (postdiv + 1);
+	else
+		ahb_rate = cpu_pll / (postdiv + 1);
+
+	ath79_set_clk(ATH79_CLK_CPU, cpu_rate);
+	ath79_set_clk(ATH79_CLK_DDR, ddr_rate);
+	ath79_set_clk(ATH79_CLK_AHB, ahb_rate);
+}
+
+static void __init ath79_clocks_init_dt(struct device_node *np)
+{
+	struct clk *ref_clk;
+	void __iomem *pll_base;
+
+	ref_clk = of_clk_get(np, 0);
+	if (!IS_ERR(ref_clk))
+		clks[ATH79_CLK_REF] = ref_clk;
+
+	pll_base = of_iomap(np, 0);
+	if (!pll_base) {
+		pr_err("%pOF: can't map pll registers\n", np);
+		goto err_clk;
+	}
+
+	if (of_device_is_compatible(np, "qca,ar7100-pll"))
+		ar71xx_clocks_init(pll_base);
+	else if (of_device_is_compatible(np, "qca,ar7240-pll") ||
+		 of_device_is_compatible(np, "qca,ar9130-pll"))
+		ar724x_clocks_init(pll_base);
+	else if (of_device_is_compatible(np, "qca,ar9330-pll"))
+		ar933x_clocks_init(pll_base);
+	else if (of_device_is_compatible(np, "qca,ar9340-pll"))
+		ar934x_clocks_init(pll_base);
+	else if (of_device_is_compatible(np, "qca,qca9530-pll"))
+		qca953x_clocks_init(pll_base);
+	else if (of_device_is_compatible(np, "qca,qca9550-pll"))
+		qca955x_clocks_init(pll_base);
+	else if (of_device_is_compatible(np, "qca,qca9560-pll"))
+		qca956x_clocks_init(pll_base);
+
+	if (!clks[ATH79_CLK_MDIO])
+		clks[ATH79_CLK_MDIO] = clks[ATH79_CLK_REF];
+
+	if (of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data)) {
+		pr_err("%pOF: could not register clk provider\n", np);
+		goto err_iounmap;
+	}
+
+	return;
+
+err_iounmap:
+	iounmap(pll_base);
+
+err_clk:
+	clk_put(ref_clk);
+}
+
+CLK_OF_DECLARE(ar7100_clk, "qca,ar7100-pll", ath79_clocks_init_dt);
+CLK_OF_DECLARE(ar7240_clk, "qca,ar7240-pll", ath79_clocks_init_dt);
+CLK_OF_DECLARE(ar9130_clk, "qca,ar9130-pll", ath79_clocks_init_dt);
+CLK_OF_DECLARE(ar9330_clk, "qca,ar9330-pll", ath79_clocks_init_dt);
+CLK_OF_DECLARE(ar9340_clk, "qca,ar9340-pll", ath79_clocks_init_dt);
+CLK_OF_DECLARE(ar9530_clk, "qca,qca9530-pll", ath79_clocks_init_dt);
+CLK_OF_DECLARE(ar9550_clk, "qca,qca9550-pll", ath79_clocks_init_dt);
+CLK_OF_DECLARE(ar9560_clk, "qca,qca9560-pll", ath79_clocks_init_dt);