linux/drivers/clk/mvebu/kirkwood.c
Linus Walleij aaedb9e00e clk: kirkwood: Fix a clocking boot regression
Since a few kernel releases the Pogoplug 4 has crashed like this
during boot:

Unable to handle kernel NULL pointer dereference at virtual address 00000002
(...)
[<c04116ec>] (strlen) from [<c00ead80>] (kstrdup+0x1c/0x4c)
[<c00ead80>] (kstrdup) from [<c04591d8>] (__clk_register+0x44/0x37c)
[<c04591d8>] (__clk_register) from [<c04595ec>] (clk_hw_register+0x20/0x44)
[<c04595ec>] (clk_hw_register) from [<c045bfa8>] (__clk_hw_register_mux+0x198/0x1e4)
[<c045bfa8>] (__clk_hw_register_mux) from [<c045c050>] (clk_register_mux_table+0x5c/0x6c)
[<c045c050>] (clk_register_mux_table) from [<c0acf3e0>] (kirkwood_clk_muxing_setup.constprop.0+0x13c/0x1ac)
[<c0acf3e0>] (kirkwood_clk_muxing_setup.constprop.0) from [<c0aceae0>] (of_clk_init+0x12c/0x214)
[<c0aceae0>] (of_clk_init) from [<c0ab576c>] (time_init+0x20/0x2c)
[<c0ab576c>] (time_init) from [<c0ab3d18>] (start_kernel+0x3dc/0x56c)
[<c0ab3d18>] (start_kernel) from [<00000000>] (0x0)
Code: e3130020 1afffffb e12fff1e c08a1078 (e5d03000)

This is because the "powersave" mux clock 0 was provided in an unterminated
array, which is required by the loop in the driver:

        /* Count, allocate, and register clock muxes */
        for (n = 0; desc[n].name;)
                n++;

Here n will go out of bounds and then call clk_register_mux() on random
memory contents after the mux clock.

Fix this by terminating the array with a blank entry.

Fixes: 105299381d ("cpufreq: kirkwood: use the powersave multiplexer")
Cc: stable@vger.kernel.org
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Chris Packham <chris.packham@alliedtelesis.co.nz>
Cc: Gregory CLEMENT <gregory.clement@bootlin.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210814235514.403426-1-linus.walleij@linaro.org
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2021-08-28 21:11:22 -07:00

360 lines
8.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Marvell Kirkwood SoC clocks
*
* Copyright (C) 2012 Marvell
*
* Gregory CLEMENT <gregory.clement@free-electrons.com>
* Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
* Andrew Lunn <andrew@lunn.ch>
*
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include "common.h"
/*
* Core Clocks
*
* Kirkwood PLL sample-at-reset configuration
* (6180 has different SAR layout than other Kirkwood SoCs)
*
* SAR0[4:3,22,1] : CPU frequency (6281,6292,6282)
* 4 = 600 MHz
* 6 = 800 MHz
* 7 = 1000 MHz
* 9 = 1200 MHz
* 12 = 1500 MHz
* 13 = 1600 MHz
* 14 = 1800 MHz
* 15 = 2000 MHz
* others reserved.
*
* SAR0[19,10:9] : CPU to L2 Clock divider ratio (6281,6292,6282)
* 1 = (1/2) * CPU
* 3 = (1/3) * CPU
* 5 = (1/4) * CPU
* others reserved.
*
* SAR0[8:5] : CPU to DDR DRAM Clock divider ratio (6281,6292,6282)
* 2 = (1/2) * CPU
* 4 = (1/3) * CPU
* 6 = (1/4) * CPU
* 7 = (2/9) * CPU
* 8 = (1/5) * CPU
* 9 = (1/6) * CPU
* others reserved.
*
* SAR0[4:2] : Kirkwood 6180 cpu/l2/ddr clock configuration (6180 only)
* 5 = [CPU = 600 MHz, L2 = (1/2) * CPU, DDR = 200 MHz = (1/3) * CPU]
* 6 = [CPU = 800 MHz, L2 = (1/2) * CPU, DDR = 200 MHz = (1/4) * CPU]
* 7 = [CPU = 1000 MHz, L2 = (1/2) * CPU, DDR = 200 MHz = (1/5) * CPU]
* others reserved.
*
* SAR0[21] : TCLK frequency
* 0 = 200 MHz
* 1 = 166 MHz
* others reserved.
*/
#define SAR_KIRKWOOD_CPU_FREQ(x) \
(((x & (1 << 1)) >> 1) | \
((x & (1 << 22)) >> 21) | \
((x & (3 << 3)) >> 1))
#define SAR_KIRKWOOD_L2_RATIO(x) \
(((x & (3 << 9)) >> 9) | \
(((x & (1 << 19)) >> 17)))
#define SAR_KIRKWOOD_DDR_RATIO 5
#define SAR_KIRKWOOD_DDR_RATIO_MASK 0xf
#define SAR_MV88F6180_CLK 2
#define SAR_MV88F6180_CLK_MASK 0x7
#define SAR_KIRKWOOD_TCLK_FREQ 21
#define SAR_KIRKWOOD_TCLK_FREQ_MASK 0x1
enum { KIRKWOOD_CPU_TO_L2, KIRKWOOD_CPU_TO_DDR };
static const struct coreclk_ratio kirkwood_coreclk_ratios[] __initconst = {
{ .id = KIRKWOOD_CPU_TO_L2, .name = "l2clk", },
{ .id = KIRKWOOD_CPU_TO_DDR, .name = "ddrclk", }
};
static u32 __init kirkwood_get_tclk_freq(void __iomem *sar)
{
u32 opt = (readl(sar) >> SAR_KIRKWOOD_TCLK_FREQ) &
SAR_KIRKWOOD_TCLK_FREQ_MASK;
return (opt) ? 166666667 : 200000000;
}
static const u32 kirkwood_cpu_freqs[] __initconst = {
0, 0, 0, 0,
600000000,
0,
800000000,
1000000000,
0,
1200000000,
0, 0,
1500000000,
1600000000,
1800000000,
2000000000
};
static u32 __init kirkwood_get_cpu_freq(void __iomem *sar)
{
u32 opt = SAR_KIRKWOOD_CPU_FREQ(readl(sar));
return kirkwood_cpu_freqs[opt];
}
static const int kirkwood_cpu_l2_ratios[8][2] __initconst = {
{ 0, 1 }, { 1, 2 }, { 0, 1 }, { 1, 3 },
{ 0, 1 }, { 1, 4 }, { 0, 1 }, { 0, 1 }
};
static const int kirkwood_cpu_ddr_ratios[16][2] __initconst = {
{ 0, 1 }, { 0, 1 }, { 1, 2 }, { 0, 1 },
{ 1, 3 }, { 0, 1 }, { 1, 4 }, { 2, 9 },
{ 1, 5 }, { 1, 6 }, { 0, 1 }, { 0, 1 },
{ 0, 1 }, { 0, 1 }, { 0, 1 }, { 0, 1 }
};
static void __init kirkwood_get_clk_ratio(
void __iomem *sar, int id, int *mult, int *div)
{
switch (id) {
case KIRKWOOD_CPU_TO_L2:
{
u32 opt = SAR_KIRKWOOD_L2_RATIO(readl(sar));
*mult = kirkwood_cpu_l2_ratios[opt][0];
*div = kirkwood_cpu_l2_ratios[opt][1];
break;
}
case KIRKWOOD_CPU_TO_DDR:
{
u32 opt = (readl(sar) >> SAR_KIRKWOOD_DDR_RATIO) &
SAR_KIRKWOOD_DDR_RATIO_MASK;
*mult = kirkwood_cpu_ddr_ratios[opt][0];
*div = kirkwood_cpu_ddr_ratios[opt][1];
break;
}
}
}
static const u32 mv88f6180_cpu_freqs[] __initconst = {
0, 0, 0, 0, 0,
600000000,
800000000,
1000000000
};
static u32 __init mv88f6180_get_cpu_freq(void __iomem *sar)
{
u32 opt = (readl(sar) >> SAR_MV88F6180_CLK) & SAR_MV88F6180_CLK_MASK;
return mv88f6180_cpu_freqs[opt];
}
static const int mv88f6180_cpu_ddr_ratios[8][2] __initconst = {
{ 0, 1 }, { 0, 1 }, { 0, 1 }, { 0, 1 },
{ 0, 1 }, { 1, 3 }, { 1, 4 }, { 1, 5 }
};
static void __init mv88f6180_get_clk_ratio(
void __iomem *sar, int id, int *mult, int *div)
{
switch (id) {
case KIRKWOOD_CPU_TO_L2:
{
/* mv88f6180 has a fixed 1:2 CPU-to-L2 ratio */
*mult = 1;
*div = 2;
break;
}
case KIRKWOOD_CPU_TO_DDR:
{
u32 opt = (readl(sar) >> SAR_MV88F6180_CLK) &
SAR_MV88F6180_CLK_MASK;
*mult = mv88f6180_cpu_ddr_ratios[opt][0];
*div = mv88f6180_cpu_ddr_ratios[opt][1];
break;
}
}
}
static u32 __init mv98dx1135_get_tclk_freq(void __iomem *sar)
{
return 166666667;
}
static const struct coreclk_soc_desc kirkwood_coreclks = {
.get_tclk_freq = kirkwood_get_tclk_freq,
.get_cpu_freq = kirkwood_get_cpu_freq,
.get_clk_ratio = kirkwood_get_clk_ratio,
.ratios = kirkwood_coreclk_ratios,
.num_ratios = ARRAY_SIZE(kirkwood_coreclk_ratios),
};
static const struct coreclk_soc_desc mv88f6180_coreclks = {
.get_tclk_freq = kirkwood_get_tclk_freq,
.get_cpu_freq = mv88f6180_get_cpu_freq,
.get_clk_ratio = mv88f6180_get_clk_ratio,
.ratios = kirkwood_coreclk_ratios,
.num_ratios = ARRAY_SIZE(kirkwood_coreclk_ratios),
};
static const struct coreclk_soc_desc mv98dx1135_coreclks = {
.get_tclk_freq = mv98dx1135_get_tclk_freq,
.get_cpu_freq = kirkwood_get_cpu_freq,
.get_clk_ratio = kirkwood_get_clk_ratio,
.ratios = kirkwood_coreclk_ratios,
.num_ratios = ARRAY_SIZE(kirkwood_coreclk_ratios),
};
/*
* Clock Gating Control
*/
static const struct clk_gating_soc_desc kirkwood_gating_desc[] __initconst = {
{ "ge0", NULL, 0, 0 },
{ "pex0", NULL, 2, 0 },
{ "usb0", NULL, 3, 0 },
{ "sdio", NULL, 4, 0 },
{ "tsu", NULL, 5, 0 },
{ "runit", NULL, 7, 0 },
{ "xor0", NULL, 8, 0 },
{ "audio", NULL, 9, 0 },
{ "sata0", NULL, 14, 0 },
{ "sata1", NULL, 15, 0 },
{ "xor1", NULL, 16, 0 },
{ "crypto", NULL, 17, 0 },
{ "pex1", NULL, 18, 0 },
{ "ge1", NULL, 19, 0 },
{ "tdm", NULL, 20, 0 },
{ }
};
/*
* Clock Muxing Control
*/
struct clk_muxing_soc_desc {
const char *name;
const char **parents;
int num_parents;
int shift;
int width;
unsigned long flags;
};
struct clk_muxing_ctrl {
spinlock_t *lock;
struct clk **muxes;
int num_muxes;
};
static const char *powersave_parents[] = {
"cpuclk",
"ddrclk",
};
static const struct clk_muxing_soc_desc kirkwood_mux_desc[] __initconst = {
{ "powersave", powersave_parents, ARRAY_SIZE(powersave_parents),
11, 1, 0 },
{ }
};
static struct clk *clk_muxing_get_src(
struct of_phandle_args *clkspec, void *data)
{
struct clk_muxing_ctrl *ctrl = (struct clk_muxing_ctrl *)data;
int n;
if (clkspec->args_count < 1)
return ERR_PTR(-EINVAL);
for (n = 0; n < ctrl->num_muxes; n++) {
struct clk_mux *mux =
to_clk_mux(__clk_get_hw(ctrl->muxes[n]));
if (clkspec->args[0] == mux->shift)
return ctrl->muxes[n];
}
return ERR_PTR(-ENODEV);
}
static void __init kirkwood_clk_muxing_setup(struct device_node *np,
const struct clk_muxing_soc_desc *desc)
{
struct clk_muxing_ctrl *ctrl;
void __iomem *base;
int n;
base = of_iomap(np, 0);
if (WARN_ON(!base))
return;
ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
if (WARN_ON(!ctrl))
goto ctrl_out;
/* lock must already be initialized */
ctrl->lock = &ctrl_gating_lock;
/* Count, allocate, and register clock muxes */
for (n = 0; desc[n].name;)
n++;
ctrl->num_muxes = n;
ctrl->muxes = kcalloc(ctrl->num_muxes, sizeof(struct clk *),
GFP_KERNEL);
if (WARN_ON(!ctrl->muxes))
goto muxes_out;
for (n = 0; n < ctrl->num_muxes; n++) {
ctrl->muxes[n] = clk_register_mux(NULL, desc[n].name,
desc[n].parents, desc[n].num_parents,
desc[n].flags, base, desc[n].shift,
desc[n].width, desc[n].flags, ctrl->lock);
WARN_ON(IS_ERR(ctrl->muxes[n]));
}
of_clk_add_provider(np, clk_muxing_get_src, ctrl);
return;
muxes_out:
kfree(ctrl);
ctrl_out:
iounmap(base);
}
static void __init kirkwood_clk_init(struct device_node *np)
{
struct device_node *cgnp =
of_find_compatible_node(NULL, NULL, "marvell,kirkwood-gating-clock");
if (of_device_is_compatible(np, "marvell,mv88f6180-core-clock"))
mvebu_coreclk_setup(np, &mv88f6180_coreclks);
else if (of_device_is_compatible(np, "marvell,mv98dx1135-core-clock"))
mvebu_coreclk_setup(np, &mv98dx1135_coreclks);
else
mvebu_coreclk_setup(np, &kirkwood_coreclks);
if (cgnp) {
mvebu_clk_gating_setup(cgnp, kirkwood_gating_desc);
kirkwood_clk_muxing_setup(cgnp, kirkwood_mux_desc);
of_node_put(cgnp);
}
}
CLK_OF_DECLARE(kirkwood_clk, "marvell,kirkwood-core-clock",
kirkwood_clk_init);
CLK_OF_DECLARE(mv88f6180_clk, "marvell,mv88f6180-core-clock",
kirkwood_clk_init);
CLK_OF_DECLARE(98dx1135_clk, "marvell,mv98dx1135-core-clock",
kirkwood_clk_init);