[U-Boot] [PATCH v4 1/2] armv7m: add instruction & data cache support
Marek Vasut
marex at denx.de
Mon Mar 27 20:34:32 UTC 2017
On 03/27/2017 10:02 PM, Vikas Manocha wrote:
> This patch adds armv7m instruction & data cache support.
>
> Signed-off-by: Vikas Manocha <vikas.manocha at st.com>
> cc: Christophe KERELLO <christophe.kerello at st.com>
> ---
>
> Changed in v4:
> - invalidate_dcache_range() & flush_dcache_range() function added.
> - blank lines added.
> - comments added for registers, functions & barriers.
> - register names changed for better clarity.
> - typecasting moved to macro definitions.
>
> Changed in v3:
> - uint32 replcaed with u32.
> - multiple read of hardware register replaced with single.
> - pointers replaced with macros for base address.
> - register names added as comment for system control block registers.
>
> Changed in v2:
> - changed strucures for memory mapped cache registers to macros
> - added lines better readability.
> - replaced magic numbers with macros.
>
> arch/arm/cpu/armv7m/Makefile | 3 +-
> arch/arm/cpu/armv7m/cache.c | 336 ++++++++++++++++++++++++++++++++++++++++++
> arch/arm/include/asm/armv7m.h | 26 +++-
> arch/arm/lib/Makefile | 2 +
> 4 files changed, 363 insertions(+), 4 deletions(-)
> create mode 100644 arch/arm/cpu/armv7m/cache.c
>
> diff --git a/arch/arm/cpu/armv7m/Makefile b/arch/arm/cpu/armv7m/Makefile
> index e1a6c40..93c9085 100644
> --- a/arch/arm/cpu/armv7m/Makefile
> +++ b/arch/arm/cpu/armv7m/Makefile
> @@ -6,6 +6,5 @@
> #
>
> extra-y := start.o
> -obj-y += cpu.o
> -
> +obj-y += cpu.o cache.o
> obj-$(CONFIG_SYS_ARCH_TIMER) += systick-timer.o
> diff --git a/arch/arm/cpu/armv7m/cache.c b/arch/arm/cpu/armv7m/cache.c
> new file mode 100644
> index 0000000..162cfe3
> --- /dev/null
> +++ b/arch/arm/cpu/armv7m/cache.c
> @@ -0,0 +1,336 @@
> +/*
> + * (C) Copyright 2017
> + * Vikas Manocha, ST Micoelectronics, vikas.manocha at st.com.
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <errno.h>
> +#include <asm/armv7m.h>
> +#include <asm/io.h>
> +
> +/* Cache maintenance operation registers */
> +
> +#define V7M_CACHE_REG_ICIALLU ((u32 *)(V7M_CACHE_MAINT_BASE + 0x00))
^^^^^^^^^^^^^^^^^^^^^
Drop this whole part,
it's a register offset, not address. Just calculate the address
in-place. The cast is also not needed.
> +#define INVAL_ICACHE_POU 0
> +#define V7M_CACHE_REG_ICIMVALU ((u32 *)(V7M_CACHE_MAINT_BASE + 0x08))
> +#define V7M_CACHE_REG_DCIMVAC ((u32 *)(V7M_CACHE_MAINT_BASE + 0x0C))
> +#define V7M_CACHE_REG_DCISW ((u32 *)(V7M_CACHE_MAINT_BASE + 0x10))
> +#define V7M_CACHE_REG_DCCMVAU ((u32 *)(V7M_CACHE_MAINT_BASE + 0x14))
> +#define V7M_CACHE_REG_DCCMVAC ((u32 *)(V7M_CACHE_MAINT_BASE + 0x18))
> +#define V7M_CACHE_REG_DCCSW ((u32 *)(V7M_CACHE_MAINT_BASE + 0x1C))
> +#define V7M_CACHE_REG_DCCIMVAC ((u32 *)(V7M_CACHE_MAINT_BASE + 0x20))
> +#define V7M_CACHE_REG_DCCISW ((u32 *)(V7M_CACHE_MAINT_BASE + 0x24))
> +#define WAYS_SHIFT 30
> +#define SETS_SHIFT 5
> +
> +/* armv7m processor feature registers */
> +
> +#define V7M_PROC_REG_CLIDR ((u32 *)(V7M_PROC_FTR_BASE + 0x00))
> +#define V7M_PROC_REG_CTR ((u32 *)(V7M_PROC_FTR_BASE + 0x04))
> +#define V7M_PROC_REG_CCSIDR ((u32 *)(V7M_PROC_FTR_BASE + 0x08))
> +#define MASK_NUM_WAYS GENMASK(12, 3)
> +#define MASK_NUM_SETS GENMASK(27, 13)
> +#define CLINE_SIZE_MASK GENMASK(2, 0)
> +#define NUM_WAYS_SHIFT 3
> +#define NUM_SETS_SHIFT 13
Well use those macros in MASK_* above ...
> +#define V7M_PROC_REG_CSSELR ((u32 *)(V7M_PROC_FTR_BASE + 0x0C))
> +#define SEL_I_OR_D BIT(0)
> +
> +enum cache_type {
> + DCACHE,
> + ICACHE,
> +};
> +
> +/* PoU : Point of Unification, Poc: Point of Coherency */
> +enum cache_action {
> + INVALIDATE_POU, /* i-cache invalidate by address */
> + INVALIDATE_POC, /* d-cache invalidate by address */
> + INVALIDATE_SET_WAY, /* d-cache invalidate by sets/ways */
> + FLUSH_POU, /* d-cache clean by address to the PoU */
> + FLUSH_POC, /* d-cache clean by address to the PoC */
> + FLUSH_SET_WAY, /* d-cache clean by sets/ways */
> + FLUSH_INVAL_POC, /* d-cache clean & invalidate by addr to PoC */
> + FLUSH_INVAL_SET_WAY, /* d-cache clean & invalidate by set/ways */
> +};
> +
> +#ifndef CONFIG_SYS_DCACHE_OFF
> +struct dcache_config {
> + u32 ways;
> + u32 sets;
> +};
> +
> +static void get_cache_ways_sets(struct dcache_config *cache)
> +{
> + u32 cache_size_id = readl(V7M_PROC_REG_CCSIDR);
> +
> + cache->ways = (cache_size_id & MASK_NUM_WAYS) >> NUM_WAYS_SHIFT;
> + cache->sets = (cache_size_id & MASK_NUM_SETS) >> NUM_SETS_SHIFT;
> +}
> +
> +/*
> + * Return the io register to perform required cache action like clean or clean
> + * & invalidate by sets/ways.
> + */
> +static u32 *get_action_reg_set_ways(enum cache_action action)
> +{
> + switch (action) {
> + case INVALIDATE_SET_WAY:
> + return V7M_CACHE_REG_DCISW;
> + case FLUSH_SET_WAY:
> + return V7M_CACHE_REG_DCCSW;
> + case FLUSH_INVAL_SET_WAY:
> + return V7M_CACHE_REG_DCCISW;
> + default:
> + break;
> + };
> +
> + return NULL;
> +}
> +
> +/*
> + * Return the io register to perform required cache action like clean or clean
> + * & invalidate by adddress or range.
> + */
> +static u32 *get_action_reg_range(enum cache_action action)
> +{
> + switch (action) {
> + case INVALIDATE_POU:
> + return V7M_CACHE_REG_ICIMVALU;
> + case INVALIDATE_POC:
> + return V7M_CACHE_REG_DCIMVAC;
> + case FLUSH_POU:
> + return V7M_CACHE_REG_DCCMVAU;
> + case FLUSH_POC:
> + return V7M_CACHE_REG_DCCMVAC;
> + case FLUSH_INVAL_POC:
> + return V7M_CACHE_REG_DCCIMVAC;
> + default:
> + break;
> + }
> +
> + return NULL;
> +}
> +
> +static u32 get_cline_size(enum cache_type type)
> +{
> + u32 size;
> +
> + if (type == DCACHE)
> + clrbits_le32(V7M_PROC_REG_CSSELR, BIT(SEL_I_OR_D));
> + else if (type == ICACHE)
> + setbits_le32(V7M_PROC_REG_CSSELR, BIT(SEL_I_OR_D));
> + /* Make sure cache selection is effective for next memory access */
> + dsb();
> +
> + size = readl(V7M_PROC_REG_CCSIDR) & CLINE_SIZE_MASK;
> + /* Size enocoded as 2 less than log(no_of_words_in_cache_line) base 2 */
> + size = 1 << (size + 2);
> + debug("cache line size is %d\n", size);
> +
> + return size;
> +}
> +
> +/* Perform the action like invalidate/clean on a range of cache addresses */
> +static int action_cache_range(enum cache_action action, u32 start_addr,
> + int64_t size)
> +{
> + u32 cline_size;
> + u32 *action_reg;
> + enum cache_type type;
Does this ever check whether start_addr and size is unaligned ?
Also, you use u32 all over the place, but size is signed-i64 ? Why?
> + action_reg = get_action_reg_range(action);
> + if (!action_reg)
> + return -EINVAL;
> + if (action == INVALIDATE_POU)
> + type = ICACHE;
> + else
> + type = DCACHE;
> +
> + /* Cache line size is minium size for the cache action */
> + cline_size = get_cline_size(type);
> + /* Align start address to cache line boundary */
> + start_addr &= ~(cline_size - 1);
> + debug("total size for cache action = %llx\n", size);
> + do {
> + writel(start_addr, action_reg);
> + size -= cline_size;
> + start_addr += cline_size;
> + } while (size > cline_size);
> +
> + /* Make sure cache action is effective for next memory access */
> + dsb();
> + isb(); /* Make sure instruction stream sees it */
> + debug("cache action on range done\n");
> +
> + return 0;
> +}
[...]
>
> -#define V7M_SCB_BASE 0xE000ED00
> -#define V7M_MPU_BASE 0xE000ED90
> +/* armv7m fixed base addresses */
> +#define V7M_SCS_BASE 0xE000E000
Is all of this really used in the code ?
> +#define V7M_NVIC_BASE (V7M_SCS_BASE + 0x0100)
> +#define V7M_SCB_BASE (V7M_SCS_BASE + 0x0D00)
> +#define V7M_PROC_FTR_BASE (V7M_SCS_BASE + 0x0D78)
> +#define V7M_MPU_BASE (V7M_SCS_BASE + 0x0D90)
> +#define V7M_FPU_BASE (V7M_SCS_BASE + 0x0F30)
> +#define V7M_CACHE_MAINT_BASE (V7M_SCS_BASE + 0x0F50)
> +#define V7M_ACCESS_CNTL_BASE (V7M_SCS_BASE + 0x0F90)
>
> #define V7M_SCB_VTOR 0x08
>
> @@ -27,6 +34,18 @@ struct v7m_scb {
> uint32_t icsr; /* Interrupt Control and State Register */
> uint32_t vtor; /* Vector Table Offset Register */
> uint32_t aircr; /* App Interrupt and Reset Control Register */
> + uint32_t scr; /* offset 0x10: System Control Register */
> + uint32_t ccr; /* offset 0x14: Config and Control Register */
> + uint32_t shpr1; /* offset 0x18: System Handler Priority Reg 1 */
> + uint32_t shpr2; /* offset 0x1c: System Handler Priority Reg 2 */
> + uint32_t shpr3; /* offset 0x20: System Handler Priority Reg 3 */
> + uint32_t shcrs; /* offset 0x24: System Handler Control State */
> + uint32_t cfsr; /* offset 0x28: Configurable Fault Status Reg */
> + uint32_t hfsr; /* offset 0x2C: HardFault Status Register */
> + uint32_t res; /* offset 0x30: reserved */
> + uint32_t mmar; /* offset 0x34: MemManage Fault Address Reg */
> + uint32_t bfar; /* offset 0x38: BusFault Address Reg */
> + uint32_t afsr; /* offset 0x3C: Auxiliary Fault Status Reg */
> };
> #define V7M_SCB ((struct v7m_scb *)V7M_SCB_BASE)
>
> @@ -39,6 +58,9 @@ struct v7m_scb {
>
> #define V7M_ICSR_VECTACT_MSK 0xFF
>
> +#define V7M_CCR_DCACHE 16
> +#define V7M_CCR_ICACHE 17
> +
> struct v7m_mpu {
> uint32_t type; /* Type Register */
> uint32_t ctrl; /* Control Register */
> diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
> index 166fa9e..52b36b3 100644
> --- a/arch/arm/lib/Makefile
> +++ b/arch/arm/lib/Makefile
> @@ -55,8 +55,10 @@ endif
>
> obj-y += cache.o
> ifndef CONFIG_ARM64
> +ifndef CONFIG_CPU_V7M
> obj-y += cache-cp15.o
> endif
> +endif
>
> obj-y += psci-dt.o
>
>
--
Best regards,
Marek Vasut
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