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> --- 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. --- drivers/Kconfig | 2 + drivers/Makefile | 1 + drivers/cache/Kconfig | 10 ++ drivers/cache/Makefile | 3 + drivers/cache/ax45mp_cache.c | 279 +++++++++++++++++++++++++++++++++++ 5 files changed, 295 insertions(+) create mode 100644 drivers/cache/Kconfig create mode 100644 drivers/cache/Makefile create mode 100644 drivers/cache/ax45mp_cache.c diff --git a/drivers/Kconfig b/drivers/Kconfig index 968bd0a6fd78..44abd2cba3a3 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 bdf1c66141c9..9fc91d2bbe4c 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -6,6 +6,7 @@ # Rewritten to use lists instead of if-statements. # +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..5478adff3d88 --- /dev/null +++ b/drivers/cache/Kconfig @@ -0,0 +1,10 @@ +# SPDX-License-Identifier: GPL-2.0 +menu "Cache Drivers" + +config AX45MP_L2_CACHE + bool "Andes Technology AX45MP L2 Cache controller" + depends on RISCV && RISCV_DMA_NONCOHERENT + 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..556e6875627c --- /dev/null +++ b/drivers/cache/ax45mp_cache.c @@ -0,0 +1,279 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * non-coherent cache functions for Andes AX45MP + * + * Copyright (C) 2022 Renesas Electronics Corp. + */ + +#include <asm/dma-noncoherent.h> +#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/cacheflush.h> +#include <asm/sbi.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 +#define AX45MP_CCTL_L1D_VA_WB 1 + +/* 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 +#define AX45MP_CCTL_L2_PA_WB 0x9 + +#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); +} + +/* + * Software trigger CCTL operation (cache maintenance operations) by writing + * to ucctlcommand and ucctlbeginaddr registers and write-back an L2 cache + * entry. + */ +static void ax45mp_cpu_dcache_wb_range(void *start, void *end, int 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, AX45MP_CCTL_L1D_VA_WB); + + pa = virt_to_phys(start); + writel(pa, base + AX45MP_L2C_REG_CN_ACC_OFFSET(mhartid)); + writel(AX45MP_CCTL_L2_PA_WB, + 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; + } +} + +/* + * Software trigger CCTL operation by writing to ucctlcommand and ucctlbeginaddr + * registers and invalidate the L2 cache entry. + */ +static void ax45mp_cpu_dcache_inval_range(void *start, void *end, int 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, AX45MP_CCTL_L1D_VA_INVAL); + + pa = virt_to_phys(start); + writel(pa, base + AX45MP_L2C_REG_CN_ACC_OFFSET(mhartid)); + writel(AX45MP_CCTL_L2_PA_INVAL, + 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; + } +} + +static void ax45mp_cpu_dma_inval_range(void *vaddr, size_t size) +{ + char cache_buf[2][AX45MP_CACHE_LINE_SIZE]; + unsigned long start = (unsigned long)vaddr; + unsigned long end = start + size; + unsigned long old_start = start; + unsigned long old_end = end; + unsigned long line_size; + unsigned long flags; + + if (unlikely(start == end)) + return; + + line_size = ax45mp_priv->ax45mp_cache_line_size; + + memset(&cache_buf, 0x0, sizeof(cache_buf)); + start = start & (~(line_size - 1)); + end = ((end + line_size - 1) & (~(line_size - 1))); + + local_irq_save(flags); + if (unlikely(start != old_start)) + memcpy(&cache_buf[0][0], (void *)start, line_size); + + if (unlikely(end != old_end)) + memcpy(&cache_buf[1][0], (void *)(old_end & (~(line_size - 1))), line_size); + + ax45mp_cpu_dcache_inval_range(vaddr, (void *)end, line_size); + + if (unlikely(start != old_start)) + memcpy((void *)start, &cache_buf[0][0], (old_start & (line_size - 1))); + + local_irq_restore(flags); +} + +static void ax45mp_cpu_dma_wb_range(void *vaddr, size_t size) +{ + unsigned long start = (unsigned long)vaddr; + unsigned long end = start + size; + unsigned long line_size; + unsigned long flags; + + line_size = ax45mp_priv->ax45mp_cache_line_size; + local_irq_save(flags); + start = start & (~(line_size - 1)); + ax45mp_cpu_dcache_wb_range(vaddr, (void *)end, line_size); + local_irq_restore(flags); +} + +static void ax45mp_no_iocp_cmo(void *vaddr, size_t size, + enum dma_data_direction dir, + enum dma_noncoherent_ops ops) +{ + /* We have nothing to do in case of NON_COHERENT_DMA_PREP */ + if (ops != NON_COHERENT_SYNC_DMA_FOR_DEVICE && + ops != NON_COHERENT_SYNC_DMA_FOR_CPU) + return; + + /* + * In case of DMA_FROM_DEVICE invalidate the L2 cache entries and + * in case of DMA_TO_DEVICE and DMA_BIDIRECTIONAL write-back an L2 + * cache entries. + */ + if (ops == NON_COHERENT_SYNC_DMA_FOR_DEVICE) { + switch (dir) { + case DMA_FROM_DEVICE: + ax45mp_cpu_dma_inval_range(vaddr, size); + break; + case DMA_TO_DEVICE: + case DMA_BIDIRECTIONAL: + ax45mp_cpu_dma_wb_range(vaddr, size); + break; + default: + break; + } + + return; + } + + /* + * ops == NON_COHERENT_SYNC_DMA_FOR_CPU + * + * in case of DMA_BIDIRECTIONAL and DMA_FROM_DEVICE invalidate the L2 + * cache entries. + */ + if (dir == DMA_BIDIRECTIONAL || dir == DMA_FROM_DEVICE) + ax45mp_cpu_dma_inval_range(vaddr, size); +} + +static void ax45mp_get_l2_line_size(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct device *dev = &pdev->dev; + int ret; + + ret = of_property_read_u32(np, "cache-line-size", &ax45mp_priv->ax45mp_cache_line_size); + if (ret) { + dev_err(dev, "Failed to get cache-line-size, defaulting to 64 bytes\n"); + ax45mp_priv->ax45mp_cache_line_size = AX45MP_CACHE_LINE_SIZE; + } + + if (ax45mp_priv->ax45mp_cache_line_size != AX45MP_CACHE_LINE_SIZE) { + dev_err(dev, "Expected cache-line-size to be 64 bytes (found:%u). Defaulting to 64 bytes\n", + ax45mp_priv->ax45mp_cache_line_size); + ax45mp_priv->ax45mp_cache_line_size = AX45MP_CACHE_LINE_SIZE; + } +} + +static int ax45mp_l2c_probe(struct platform_device *pdev) +{ + struct riscv_cache_ops ax45mp_cmo_ops; + + /* + * riscv_cbom_block_size is set very much earlier so we can + * definitely rely on it and only if its being set we continue + * further in the probe path. + */ + if (!riscv_cbom_block_size) + return 0; + + ax45mp_priv = devm_kzalloc(&pdev->dev, sizeof(*ax45mp_priv), GFP_KERNEL); + if (!ax45mp_priv) + return -ENOMEM; + + ax45mp_priv->l2c_base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(ax45mp_priv->l2c_base)) + return PTR_ERR(ax45mp_priv->l2c_base); + + ax45mp_get_l2_line_size(pdev); + + memset(&ax45mp_cmo_ops, 0x0, sizeof(ax45mp_cmo_ops)); + ax45mp_cmo_ops.riscv_dma_noncoherent_cmo_ops = &ax45mp_no_iocp_cmo; + riscv_noncoherent_register_cache_ops(&ax45mp_cmo_ops); + + return 0; +} + +static const struct of_device_id ax45mp_cache_ids[] = { + { .compatible = "andestech,ax45mp-cache" }, + { /* sentinel */ } +}; + +static struct platform_driver ax45mp_l2c_driver = { + .driver = { + .name = "ax45mp-l2c", + .of_match_table = ax45mp_cache_ids, + }, + .probe = ax45mp_l2c_probe, +}; + +static int __init ax45mp_cache_init(void) +{ + return platform_driver_register(&ax45mp_l2c_driver); +} +arch_initcall(ax45mp_cache_init); + +MODULE_AUTHOR("Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>"); +MODULE_DESCRIPTION("Andes AX45MP L2 cache driver"); +MODULE_LICENSE("GPL"); -- 2.25.1
