From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> I/O Coherence Port (IOCP) provides an AXI interface for connecting external non-caching masters, such as DMA controllers. The accesses from IOCP are coherent with D-Caches and L2 Cache. IOCP is a specification option and is disabled on the Renesas RZ/Five SoC due to this reason IP blocks using DMA will fail. The Andes AX45MP core has a Programmable Physical Memory Attributes (PMA) block that allows dynamic adjustment of memory attributes in the runtime. It contains a configurable amount of PMA entries implemented as CSR registers to control the attributes of memory locations in interest. Below are the memory attributes supported: * Device, Non-bufferable * Device, bufferable * Memory, Non-cacheable, Non-bufferable * Memory, Non-cacheable, Bufferable * Memory, Write-back, No-allocate * Memory, Write-back, Read-allocate * Memory, Write-back, Write-allocate * Memory, Write-back, Read and Write-allocate More info about PMA (section 10.3): Link: http://www.andestech.com/wp-content/uploads/AX45MP-1C-Rev.-5.0.0-Datasheet.pdf As a workaround for SoCs with IOCP disabled CMO needs to be handled by software. Firstly OpenSBI configures the memory region as "Memory, Non-cacheable, Bufferable" and passes this region as a global shared dma pool as a DT node. With DMA_GLOBAL_POOL enabled all DMA allocations happen from this region and synchronization callbacks are implemented to synchronize when doing DMA transactions. Example PMA region passes as a DT node from OpenSBI: reserved-memory { #address-cells = <2>; #size-cells = <2>; ranges; pma_resv0@58000000 { compatible = "shared-dma-pool"; reg = <0x0 0x58000000 0x0 0x08000000>; no-map; linux,dma-default; }; }; Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> Tested-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> # tyre-kicking on a d1 --- v11 -> v12 * Used struct riscv_nonstd_cache_ops -> struct riscv_cache_ops v10 -> v11 * Marked ax45mp_cmo_ops as __initdata v9 -> v10 * Dropped preserving the cache lines in ax45mp_dma_cache_inv() callback v8 -> v9 * Updated function pointers v8 -> v9 * Dropped exporting CMO functions as we no more used ALTERNATIVE_X() macro * Now using the riscv_noncoherent_register_cache_ops() for registering CMO ops * Added RB tag from Conor v7 -> v8 * Dropped function pointer usage * Now exporting the functions for clean/inval/flush * Switched to using early_initcall instead of arch_initcall * Dropped entry for "include/cache" from MAINTAINERS * Dropped dependency of RISCV on AX45MP_L2_CACHE * Returning error in case of cache line mismatch * Renamed clean/inval/flush functions v6 -> v7 * Implemented flush callback * Dropped using riscv_dma_noncoherent_cmo_ops v5 -> v6 * Moved driver to cache folder * Switched to new API for CMO v4 -> v5 * Dropped code for configuring L2 cache * Dropped code for configuring PMA * Updated commit message * Added comments * Changed static branch enable/disable order RFC v3 -> v4 * Made use of runtime patching instead of compile time * Now just exposing single function ax45mp_no_iocp_cmo() for CMO handling * Added a check to make sure cache line size is always 64 bytes * Renamed folder rzf -> rzfive * Improved Kconfig description * Dropped L2 cache configuration * Dropped unnecessary casts * Fixed comments pointed by Geert. --- MAINTAINERS | 7 ++ drivers/Kconfig | 2 + drivers/Makefile | 1 + drivers/cache/Kconfig | 11 ++ drivers/cache/Makefile | 3 + drivers/cache/ax45mp_cache.c | 213 +++++++++++++++++++++++++++++++++++ 6 files changed, 237 insertions(+) create mode 100644 drivers/cache/Kconfig create mode 100644 drivers/cache/Makefile create mode 100644 drivers/cache/ax45mp_cache.c diff --git a/MAINTAINERS b/MAINTAINERS index abfc724a2367..f9fa2c66d8e1 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -20250,6 +20250,13 @@ S: Supported T: git git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git F: drivers/staging/ +STANDALONE CACHE CONTROLLER DRIVERS +M: Conor Dooley <conor@xxxxxxxxxx> +L: linux-riscv@xxxxxxxxxxxxxxxxxxx +S: Maintained +T: git https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux.git/ +F: drivers/cache + STARFIRE/DURALAN NETWORK DRIVER M: Ion Badulescu <ionut@xxxxxxxxxx> S: Odd Fixes diff --git a/drivers/Kconfig b/drivers/Kconfig index 514ae6b24cb2..2ae1b6707c2c 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -15,6 +15,8 @@ source "drivers/base/Kconfig" source "drivers/bus/Kconfig" +source "drivers/cache/Kconfig" + source "drivers/connector/Kconfig" source "drivers/firmware/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index 7241d80a7b29..23eb201fe18a 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -11,6 +11,7 @@ ifdef building_out_of_srctree MAKEFLAGS += --include-dir=$(srctree) endif +obj-y += cache/ obj-y += irqchip/ obj-y += bus/ diff --git a/drivers/cache/Kconfig b/drivers/cache/Kconfig new file mode 100644 index 000000000000..a57677f908f3 --- /dev/null +++ b/drivers/cache/Kconfig @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0 +menu "Cache Drivers" + +config AX45MP_L2_CACHE + bool "Andes Technology AX45MP L2 Cache controller" + depends on RISCV_DMA_NONCOHERENT + select RISCV_NONSTANDARD_CACHE_OPS + help + Support for the L2 cache controller on Andes Technology AX45MP platforms. + +endmenu diff --git a/drivers/cache/Makefile b/drivers/cache/Makefile new file mode 100644 index 000000000000..2012e7fb978d --- /dev/null +++ b/drivers/cache/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_AX45MP_L2_CACHE) += ax45mp_cache.o diff --git a/drivers/cache/ax45mp_cache.c b/drivers/cache/ax45mp_cache.c new file mode 100644 index 000000000000..57186c58dc84 --- /dev/null +++ b/drivers/cache/ax45mp_cache.c @@ -0,0 +1,213 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * non-coherent cache functions for Andes AX45MP + * + * Copyright (C) 2023 Renesas Electronics Corp. + */ + +#include <linux/cacheflush.h> +#include <linux/cacheinfo.h> +#include <linux/dma-direction.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> + +#include <asm/dma-noncoherent.h> + +/* L2 cache registers */ +#define AX45MP_L2C_REG_CTL_OFFSET 0x8 + +#define AX45MP_L2C_REG_C0_CMD_OFFSET 0x40 +#define AX45MP_L2C_REG_C0_ACC_OFFSET 0x48 +#define AX45MP_L2C_REG_STATUS_OFFSET 0x80 + +/* D-cache operation */ +#define AX45MP_CCTL_L1D_VA_INVAL 0 /* Invalidate an L1 cache entry */ +#define AX45MP_CCTL_L1D_VA_WB 1 /* Write-back an L1 cache entry */ + +/* L2 CCTL status */ +#define AX45MP_CCTL_L2_STATUS_IDLE 0 + +/* L2 CCTL status cores mask */ +#define AX45MP_CCTL_L2_STATUS_C0_MASK 0xf + +/* L2 cache operation */ +#define AX45MP_CCTL_L2_PA_INVAL 0x8 /* Invalidate an L2 cache entry */ +#define AX45MP_CCTL_L2_PA_WB 0x9 /* Write-back an L2 cache entry */ + +#define AX45MP_L2C_REG_PER_CORE_OFFSET 0x10 +#define AX45MP_CCTL_L2_STATUS_PER_CORE_OFFSET 4 + +#define AX45MP_L2C_REG_CN_CMD_OFFSET(n) \ + (AX45MP_L2C_REG_C0_CMD_OFFSET + ((n) * AX45MP_L2C_REG_PER_CORE_OFFSET)) +#define AX45MP_L2C_REG_CN_ACC_OFFSET(n) \ + (AX45MP_L2C_REG_C0_ACC_OFFSET + ((n) * AX45MP_L2C_REG_PER_CORE_OFFSET)) +#define AX45MP_CCTL_L2_STATUS_CN_MASK(n) \ + (AX45MP_CCTL_L2_STATUS_C0_MASK << ((n) * AX45MP_CCTL_L2_STATUS_PER_CORE_OFFSET)) + +#define AX45MP_CCTL_REG_UCCTLBEGINADDR_NUM 0x80b +#define AX45MP_CCTL_REG_UCCTLCOMMAND_NUM 0x80c + +#define AX45MP_CACHE_LINE_SIZE 64 + +struct ax45mp_priv { + void __iomem *l2c_base; + u32 ax45mp_cache_line_size; +}; + +static struct ax45mp_priv ax45mp_priv; + +/* L2 Cache operations */ +static inline uint32_t ax45mp_cpu_l2c_get_cctl_status(void) +{ + return readl(ax45mp_priv.l2c_base + AX45MP_L2C_REG_STATUS_OFFSET); +} + +static void ax45mp_cpu_cache_operation(unsigned long start, unsigned long end, + unsigned int l1_op, unsigned int l2_op) +{ + unsigned long line_size = ax45mp_priv.ax45mp_cache_line_size; + void __iomem *base = ax45mp_priv.l2c_base; + int mhartid = smp_processor_id(); + unsigned long pa; + + while (end > start) { + csr_write(AX45MP_CCTL_REG_UCCTLBEGINADDR_NUM, start); + csr_write(AX45MP_CCTL_REG_UCCTLCOMMAND_NUM, l1_op); + + pa = virt_to_phys((void *)start); + writel(pa, base + AX45MP_L2C_REG_CN_ACC_OFFSET(mhartid)); + writel(l2_op, base + AX45MP_L2C_REG_CN_CMD_OFFSET(mhartid)); + while ((ax45mp_cpu_l2c_get_cctl_status() & + AX45MP_CCTL_L2_STATUS_CN_MASK(mhartid)) != + AX45MP_CCTL_L2_STATUS_IDLE) + ; + + start += line_size; + } +} + +/* Write-back L1 and L2 cache entry */ +static inline void ax45mp_cpu_dcache_wb_range(unsigned long start, unsigned long end) +{ + ax45mp_cpu_cache_operation(start, end, AX45MP_CCTL_L1D_VA_WB, + AX45MP_CCTL_L2_PA_WB); +} + +/* Invalidate the L1 and L2 cache entry */ +static inline void ax45mp_cpu_dcache_inval_range(unsigned long start, unsigned long end) +{ + ax45mp_cpu_cache_operation(start, end, AX45MP_CCTL_L1D_VA_INVAL, + AX45MP_CCTL_L2_PA_INVAL); +} + +static void ax45mp_dma_cache_inv(phys_addr_t paddr, size_t size) +{ + unsigned long start = (unsigned long)phys_to_virt(paddr); + unsigned long end = start + size; + unsigned long line_size; + unsigned long flags; + + if (unlikely(start == end)) + return; + + line_size = ax45mp_priv.ax45mp_cache_line_size; + + start = start & (~(line_size - 1)); + end = ((end + line_size - 1) & (~(line_size - 1))); + + local_irq_save(flags); + + ax45mp_cpu_dcache_inval_range(start, end); + + local_irq_restore(flags); +} + +static void ax45mp_dma_cache_wback(phys_addr_t paddr, size_t size) +{ + unsigned long start = (unsigned long)phys_to_virt(paddr); + unsigned long end = start + size; + unsigned long line_size; + unsigned long flags; + + line_size = ax45mp_priv.ax45mp_cache_line_size; + start = start & (~(line_size - 1)); + local_irq_save(flags); + ax45mp_cpu_dcache_wb_range(start, end); + local_irq_restore(flags); +} + +static void ax45mp_dma_cache_wback_inv(phys_addr_t paddr, size_t size) +{ + ax45mp_dma_cache_wback(paddr, size); + ax45mp_dma_cache_inv(paddr, size); +} + +static int ax45mp_get_l2_line_size(struct device_node *np) +{ + int ret; + + ret = of_property_read_u32(np, "cache-line-size", &ax45mp_priv.ax45mp_cache_line_size); + if (ret) { + pr_err("Failed to get cache-line-size, defaulting to 64 bytes\n"); + return ret; + } + + if (ax45mp_priv.ax45mp_cache_line_size != AX45MP_CACHE_LINE_SIZE) { + pr_err("Expected cache-line-size to be 64 bytes (found:%u)\n", + ax45mp_priv.ax45mp_cache_line_size); + return -EINVAL; + } + + return 0; +} + +static const struct riscv_nonstd_cache_ops ax45mp_cmo_ops __initdata = { + .wback = &ax45mp_dma_cache_wback, + .inv = &ax45mp_dma_cache_inv, + .wback_inv = &ax45mp_dma_cache_wback_inv, +}; + +static const struct of_device_id ax45mp_cache_ids[] = { + { .compatible = "andestech,ax45mp-cache" }, + { /* sentinel */ } +}; + +static int __init ax45mp_cache_init(void) +{ + struct device_node *np; + struct resource res; + int ret; + + np = of_find_matching_node(NULL, ax45mp_cache_ids); + if (!of_device_is_available(np)) + return -ENODEV; + + ret = of_address_to_resource(np, 0, &res); + if (ret) + return ret; + + /* + * If IOCP is present on the Andes AX45MP core riscv_cbom_block_size + * will be 0 for sure, so we can definitely rely on it. If + * riscv_cbom_block_size = 0 we don't need to handle CMO using SW any + * more so we just return success here and only if its being set we + * continue further in the probe path. + */ + if (!riscv_cbom_block_size) + return 0; + + ax45mp_priv.l2c_base = ioremap(res.start, resource_size(&res)); + if (!ax45mp_priv.l2c_base) + return -ENOMEM; + + ret = ax45mp_get_l2_line_size(np); + if (ret) { + iounmap(ax45mp_priv.l2c_base); + return ret; + } + + riscv_noncoherent_register_cache_ops(&ax45mp_cmo_ops); + + return 0; +} +early_initcall(ax45mp_cache_init); -- 2.34.1
