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alistair23-linux/drivers/clk/clk-stm32f4.c
Daniel Thompson 15ab38273d clk: stm32: Fix out-by-one error path in the index lookup 
If stm32f4_rcc_lookup() is called with primary == 0 and secondary == 192
then it will read beyond the end of the table array due to an out-by-one
error in the range check.

In addition to the fixing the inequality we also modify the r.h.s. to
make it even more explicit that we are comparing against the size of
table in bits.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Fixes: 358bdf892f ("clk: stm32: Add clock driver for STM32F4[23]xxx devices")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-07-02 09:51:26 -07:00

381 lines
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/*
* Author: Daniel Thompson <daniel.thompson@linaro.org>
*
* Inspired by clk-asm9260.c .
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/of.h>
#include <linux/of_address.h>
#define STM32F4_RCC_PLLCFGR 0x04
#define STM32F4_RCC_CFGR 0x08
#define STM32F4_RCC_AHB1ENR 0x30
#define STM32F4_RCC_AHB2ENR 0x34
#define STM32F4_RCC_AHB3ENR 0x38
#define STM32F4_RCC_APB1ENR 0x40
#define STM32F4_RCC_APB2ENR 0x44
struct stm32f4_gate_data {
u8 offset;
u8 bit_idx;
const char *name;
const char *parent_name;
unsigned long flags;
};
static const struct stm32f4_gate_data stm32f4_gates[] __initconst = {
{ STM32F4_RCC_AHB1ENR, 0, "gpioa", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 1, "gpiob", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 2, "gpioc", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 3, "gpiod", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 4, "gpioe", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 5, "gpiof", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 6, "gpiog", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 7, "gpioh", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 8, "gpioi", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 9, "gpioj", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 10, "gpiok", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 12, "crc", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 18, "bkpsra", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 20, "ccmdatam", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 21, "dma1", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 22, "dma2", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 23, "dma2d", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 25, "ethmac", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 26, "ethmactx", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 27, "ethmacrx", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 28, "ethmacptp", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 29, "otghs", "ahb_div" },
{ STM32F4_RCC_AHB1ENR, 30, "otghsulpi", "ahb_div" },
{ STM32F4_RCC_AHB2ENR, 0, "dcmi", "ahb_div" },
{ STM32F4_RCC_AHB2ENR, 4, "cryp", "ahb_div" },
{ STM32F4_RCC_AHB2ENR, 5, "hash", "ahb_div" },
{ STM32F4_RCC_AHB2ENR, 6, "rng", "pll48" },
{ STM32F4_RCC_AHB2ENR, 7, "otgfs", "pll48" },
{ STM32F4_RCC_AHB3ENR, 0, "fmc", "ahb_div",
CLK_IGNORE_UNUSED },
{ STM32F4_RCC_APB1ENR, 0, "tim2", "apb1_mul" },
{ STM32F4_RCC_APB1ENR, 1, "tim3", "apb1_mul" },
{ STM32F4_RCC_APB1ENR, 2, "tim4", "apb1_mul" },
{ STM32F4_RCC_APB1ENR, 3, "tim5", "apb1_mul" },
{ STM32F4_RCC_APB1ENR, 4, "tim6", "apb1_mul" },
{ STM32F4_RCC_APB1ENR, 5, "tim7", "apb1_mul" },
{ STM32F4_RCC_APB1ENR, 6, "tim12", "apb1_mul" },
{ STM32F4_RCC_APB1ENR, 7, "tim13", "apb1_mul" },
{ STM32F4_RCC_APB1ENR, 8, "tim14", "apb1_mul" },
{ STM32F4_RCC_APB1ENR, 11, "wwdg", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 14, "spi2", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 15, "spi3", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 17, "uart2", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 18, "uart3", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 19, "uart4", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 20, "uart5", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 21, "i2c1", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 22, "i2c2", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 23, "i2c3", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 25, "can1", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 26, "can2", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 28, "pwr", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 29, "dac", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 30, "uart7", "apb1_div" },
{ STM32F4_RCC_APB1ENR, 31, "uart8", "apb1_div" },
{ STM32F4_RCC_APB2ENR, 0, "tim1", "apb2_mul" },
{ STM32F4_RCC_APB2ENR, 1, "tim8", "apb2_mul" },
{ STM32F4_RCC_APB2ENR, 4, "usart1", "apb2_div" },
{ STM32F4_RCC_APB2ENR, 5, "usart6", "apb2_div" },
{ STM32F4_RCC_APB2ENR, 8, "adc1", "apb2_div" },
{ STM32F4_RCC_APB2ENR, 9, "adc2", "apb2_div" },
{ STM32F4_RCC_APB2ENR, 10, "adc3", "apb2_div" },
{ STM32F4_RCC_APB2ENR, 11, "sdio", "pll48" },
{ STM32F4_RCC_APB2ENR, 12, "spi1", "apb2_div" },
{ STM32F4_RCC_APB2ENR, 13, "spi4", "apb2_div" },
{ STM32F4_RCC_APB2ENR, 14, "syscfg", "apb2_div" },
{ STM32F4_RCC_APB2ENR, 16, "tim9", "apb2_mul" },
{ STM32F4_RCC_APB2ENR, 17, "tim10", "apb2_mul" },
{ STM32F4_RCC_APB2ENR, 18, "tim11", "apb2_mul" },
{ STM32F4_RCC_APB2ENR, 20, "spi5", "apb2_div" },
{ STM32F4_RCC_APB2ENR, 21, "spi6", "apb2_div" },
{ STM32F4_RCC_APB2ENR, 22, "sai1", "apb2_div" },
{ STM32F4_RCC_APB2ENR, 26, "ltdc", "apb2_div" },
};
/*
* MAX_CLKS is the maximum value in the enumeration below plus the combined
* hweight of stm32f42xx_gate_map (plus one).
*/
#define MAX_CLKS 74
enum { SYSTICK, FCLK };
/*
* This bitmask tells us which bit offsets (0..192) on STM32F4[23]xxx
* have gate bits associated with them. Its combined hweight is 71.
*/
static const u64 stm32f42xx_gate_map[] = { 0x000000f17ef417ffull,
0x0000000000000001ull,
0x04777f33f6fec9ffull };
static struct clk *clks[MAX_CLKS];
static DEFINE_SPINLOCK(stm32f4_clk_lock);
static void __iomem *base;
/*
* "Multiplier" device for APBx clocks.
*
* The APBx dividers are power-of-two dividers and, if *not* running in 1:1
* mode, they also tap out the one of the low order state bits to run the
* timers. ST datasheets represent this feature as a (conditional) clock
* multiplier.
*/
struct clk_apb_mul {
struct clk_hw hw;
u8 bit_idx;
};
#define to_clk_apb_mul(_hw) container_of(_hw, struct clk_apb_mul, hw)
static unsigned long clk_apb_mul_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_apb_mul *am = to_clk_apb_mul(hw);
if (readl(base + STM32F4_RCC_CFGR) & BIT(am->bit_idx))
return parent_rate * 2;
return parent_rate;
}
static long clk_apb_mul_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
struct clk_apb_mul *am = to_clk_apb_mul(hw);
unsigned long mult = 1;
if (readl(base + STM32F4_RCC_CFGR) & BIT(am->bit_idx))
mult = 2;
if (__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT) {
unsigned long best_parent = rate / mult;
*prate =
__clk_round_rate(__clk_get_parent(hw->clk), best_parent);
}
return *prate * mult;
}
static int clk_apb_mul_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
/*
* We must report success but we can do so unconditionally because
* clk_apb_mul_round_rate returns values that ensure this call is a
* nop.
*/
return 0;
}
static const struct clk_ops clk_apb_mul_factor_ops = {
.round_rate = clk_apb_mul_round_rate,
.set_rate = clk_apb_mul_set_rate,
.recalc_rate = clk_apb_mul_recalc_rate,
};
static struct clk *clk_register_apb_mul(struct device *dev, const char *name,
const char *parent_name,
unsigned long flags, u8 bit_idx)
{
struct clk_apb_mul *am;
struct clk_init_data init;
struct clk *clk;
am = kzalloc(sizeof(*am), GFP_KERNEL);
if (!am)
return ERR_PTR(-ENOMEM);
am->bit_idx = bit_idx;
am->hw.init = &init;
init.name = name;
init.ops = &clk_apb_mul_factor_ops;
init.flags = flags;
init.parent_names = &parent_name;
init.num_parents = 1;
clk = clk_register(dev, &am->hw);
if (IS_ERR(clk))
kfree(am);
return clk;
}
/*
* Decode current PLL state and (statically) model the state we inherit from
* the bootloader.
*/
static void stm32f4_rcc_register_pll(const char *hse_clk, const char *hsi_clk)
{
unsigned long pllcfgr = readl(base + STM32F4_RCC_PLLCFGR);
unsigned long pllm = pllcfgr & 0x3f;
unsigned long plln = (pllcfgr >> 6) & 0x1ff;
unsigned long pllp = BIT(((pllcfgr >> 16) & 3) + 1);
const char *pllsrc = pllcfgr & BIT(22) ? hse_clk : hsi_clk;
unsigned long pllq = (pllcfgr >> 24) & 0xf;
clk_register_fixed_factor(NULL, "vco", pllsrc, 0, plln, pllm);
clk_register_fixed_factor(NULL, "pll", "vco", 0, 1, pllp);
clk_register_fixed_factor(NULL, "pll48", "vco", 0, 1, pllq);
}
/*
* Converts the primary and secondary indices (as they appear in DT) to an
* offset into our struct clock array.
*/
static int stm32f4_rcc_lookup_clk_idx(u8 primary, u8 secondary)
{
u64 table[ARRAY_SIZE(stm32f42xx_gate_map)];
if (primary == 1) {
if (WARN_ON(secondary > FCLK))
return -EINVAL;
return secondary;
}
memcpy(table, stm32f42xx_gate_map, sizeof(table));
/* only bits set in table can be used as indices */
if (WARN_ON(secondary >= BITS_PER_BYTE * sizeof(table) ||
0 == (table[BIT_ULL_WORD(secondary)] &
BIT_ULL_MASK(secondary))))
return -EINVAL;
/* mask out bits above our current index */
table[BIT_ULL_WORD(secondary)] &=
GENMASK_ULL(secondary % BITS_PER_LONG_LONG, 0);
return FCLK + hweight64(table[0]) +
(BIT_ULL_WORD(secondary) >= 1 ? hweight64(table[1]) : 0) +
(BIT_ULL_WORD(secondary) >= 2 ? hweight64(table[2]) : 0);
}
static struct clk *
stm32f4_rcc_lookup_clk(struct of_phandle_args *clkspec, void *data)
{
int i = stm32f4_rcc_lookup_clk_idx(clkspec->args[0], clkspec->args[1]);
if (i < 0)
return ERR_PTR(-EINVAL);
return clks[i];
}
static const char *sys_parents[] __initdata = { "hsi", NULL, "pll" };
static const struct clk_div_table ahb_div_table[] = {
{ 0x0, 1 }, { 0x1, 1 }, { 0x2, 1 }, { 0x3, 1 },
{ 0x4, 1 }, { 0x5, 1 }, { 0x6, 1 }, { 0x7, 1 },
{ 0x8, 2 }, { 0x9, 4 }, { 0xa, 8 }, { 0xb, 16 },
{ 0xc, 64 }, { 0xd, 128 }, { 0xe, 256 }, { 0xf, 512 },
{ 0 },
};
static const struct clk_div_table apb_div_table[] = {
{ 0, 1 }, { 0, 1 }, { 0, 1 }, { 0, 1 },
{ 4, 2 }, { 5, 4 }, { 6, 8 }, { 7, 16 },
{ 0 },
};
static void __init stm32f4_rcc_init(struct device_node *np)
{
const char *hse_clk;
int n;
base = of_iomap(np, 0);
if (!base) {
pr_err("%s: unable to map resource", np->name);
return;
}
hse_clk = of_clk_get_parent_name(np, 0);
clk_register_fixed_rate_with_accuracy(NULL, "hsi", NULL, 0,
16000000, 160000);
stm32f4_rcc_register_pll(hse_clk, "hsi");
sys_parents[1] = hse_clk;
clk_register_mux_table(
NULL, "sys", sys_parents, ARRAY_SIZE(sys_parents), 0,
base + STM32F4_RCC_CFGR, 0, 3, 0, NULL, &stm32f4_clk_lock);
clk_register_divider_table(NULL, "ahb_div", "sys",
CLK_SET_RATE_PARENT, base + STM32F4_RCC_CFGR,
4, 4, 0, ahb_div_table, &stm32f4_clk_lock);
clk_register_divider_table(NULL, "apb1_div", "ahb_div",
CLK_SET_RATE_PARENT, base + STM32F4_RCC_CFGR,
10, 3, 0, apb_div_table, &stm32f4_clk_lock);
clk_register_apb_mul(NULL, "apb1_mul", "apb1_div",
CLK_SET_RATE_PARENT, 12);
clk_register_divider_table(NULL, "apb2_div", "ahb_div",
CLK_SET_RATE_PARENT, base + STM32F4_RCC_CFGR,
13, 3, 0, apb_div_table, &stm32f4_clk_lock);
clk_register_apb_mul(NULL, "apb2_mul", "apb2_div",
CLK_SET_RATE_PARENT, 15);
clks[SYSTICK] = clk_register_fixed_factor(NULL, "systick", "ahb_div",
0, 1, 8);
clks[FCLK] = clk_register_fixed_factor(NULL, "fclk", "ahb_div",
0, 1, 1);
for (n = 0; n < ARRAY_SIZE(stm32f4_gates); n++) {
const struct stm32f4_gate_data *gd = &stm32f4_gates[n];
unsigned int secondary =
8 * (gd->offset - STM32F4_RCC_AHB1ENR) + gd->bit_idx;
int idx = stm32f4_rcc_lookup_clk_idx(0, secondary);
if (idx < 0)
goto fail;
clks[idx] = clk_register_gate(
NULL, gd->name, gd->parent_name, gd->flags,
base + gd->offset, gd->bit_idx, 0, &stm32f4_clk_lock);
if (IS_ERR(clks[n])) {
pr_err("%s: Unable to register leaf clock %s\n",
np->full_name, gd->name);
goto fail;
}
}
of_clk_add_provider(np, stm32f4_rcc_lookup_clk, NULL);
return;
fail:
iounmap(base);
}
CLK_OF_DECLARE(stm32f4_rcc, "st,stm32f42xx-rcc", stm32f4_rcc_init);
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