On Sun, 2 Jul 2023 at 22:37, Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote: > > 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 > --- > 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 55ac73793856..899452038a5b 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -20073,6 +20073,13 @@ 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..863bf0bfef98 > --- /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, unsigned long 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, unsigned long 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, unsigned long 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_cache_ops ax45mp_cmo_ops = { > + .wback = &ax45mp_dma_cache_wback, > + .inv = &ax45mp_dma_cache_inv, > + .wback_inv = &ax45mp_dma_cache_wback_inv, > +}; Hi Prabhakar, If you're respinning this patchset anyway, I think you can mark this struct as __initdata since it's only used by riscv_noncoherent_register_cache_ops which copies the contents. > + > +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 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-riscv
