[RFC PATCH 2/2] riscv: vendors: andes: Add support for non-cohernet dma
Lad Prabhakar
prabhakar.mahadev-lad.rj at bp.renesas.com
Tue Sep 6 03:21:54 PDT 2022
On the AX45MP core, cache coherency is a specification option so it may
not be supported. In this case DMA will fail. As a workaround, firstly we
allocate a global dma coherent pool from which DMA allocations are taken
and marked as non-cacheable in the PMA region as specified in the device
tree. Synchronization callbacks are implemented to synchronize when doing
DMA transactions.
This feature is based on the work posted [0] by Vincent Chen
<vincentc at andestech.com> for the Andes AndeStart RISC-V CPU.
[0] https://lore.kernel.org/lkml/1540982130-28248-1-git-send-email-vincentc@andestech.com/
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj at bp.renesas.com>
---
arch/riscv/vendors/andes/Makefile | 1 +
arch/riscv/vendors/andes/ax45mp_cache.c | 296 ++++++++++++++++++
arch/riscv/vendors/andes/ax45mp_nocache_dma.c | 65 ++++
arch/riscv/vendors/andes/include/proc.h | 9 +
4 files changed, 371 insertions(+)
create mode 100644 arch/riscv/vendors/andes/ax45mp_cache.c
create mode 100644 arch/riscv/vendors/andes/ax45mp_nocache_dma.c
create mode 100644 arch/riscv/vendors/andes/include/proc.h
diff --git a/arch/riscv/vendors/andes/Makefile b/arch/riscv/vendors/andes/Makefile
index 60fa8226c4a3..f9ec92b92455 100644
--- a/arch/riscv/vendors/andes/Makefile
+++ b/arch/riscv/vendors/andes/Makefile
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_ARCH_R9A07G043) += ax45mp.o
+obj-$(CONFIG_ARCH_R9A07G043) += ax45mp_cache.o ax45mp_nocache_dma.o
diff --git a/arch/riscv/vendors/andes/ax45mp_cache.c b/arch/riscv/vendors/andes/ax45mp_cache.c
new file mode 100644
index 000000000000..6941821e7e4a
--- /dev/null
+++ b/arch/riscv/vendors/andes/ax45mp_cache.c
@@ -0,0 +1,296 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * non-coherent cache functions for AX45MP
+ *
+ * Copyright (C) 2022 Renesas Electronics Corp.
+ *
+ */
+
+#include <linux/cacheinfo.h>
+#include <linux/of_address.h>
+
+#include <asm/sbi.h>
+
+#include "include/sbi.h"
+
+/* D-cache operation */
+#define CCTL_L1D_VA_INVAL 0
+#define CCTL_L1D_VA_WB 1
+
+/* L2 cache */
+#define L2_CACHE_CTL_CEN_MASK 1
+
+/* L2 cache registers */
+#define L2C_REG_CTL_OFFSET 0x8
+#define L2C_REG_C0_CMD_OFFSET 0x40
+#define L2C_REG_C0_ACC_OFFSET 0x48
+#define L2C_REG_STATUS_OFFSET 0x80
+
+/* L2 CCTL status */
+#define CCTL_L2_STATUS_IDLE 0
+
+/* L2 CCTL status cores mask */
+#define CCTL_L2_STATUS_C0_MASK 0xf
+
+/* L2 cache operation */
+#define CCTL_L2_PA_INVAL 0x8
+#define CCTL_L2_PA_WB 0x9
+
+#define L2C_HPM_PER_CORE_OFFSET 0x8
+#define L2C_REG_PER_CORE_OFFSET 0x10
+#define CCTL_L2_STATUS_PER_CORE_OFFSET 4
+
+#define L2C_REG_CN_CMD_OFFSET(n) \
+ (L2C_REG_C0_CMD_OFFSET + ((n) * L2C_REG_PER_CORE_OFFSET))
+#define L2C_REG_CN_ACC_OFFSET(n) \
+ (L2C_REG_C0_ACC_OFFSET + ((n) * L2C_REG_PER_CORE_OFFSET))
+#define CCTL_L2_STATUS_CN_MASK(n) \
+ (CCTL_L2_STATUS_C0_MASK << ((n) * CCTL_L2_STATUS_PER_CORE_OFFSET))
+
+#define MICM_CFG_ISZ_OFFSET 6
+#define MICM_CFG_ISZ_MASK (0x7 << MICM_CFG_ISZ_OFFSET)
+
+#define MDCM_CFG_DSZ_OFFSET 6
+#define MDCM_CFG_DSZ_MASK (0x7 << MDCM_CFG_DSZ_OFFSET)
+
+#define CCTL_REG_UCCTLBEGINADDR_NUM 0x80b
+#define CCTL_REG_UCCTLCOMMAND_NUM 0x80c
+
+#define MCACHE_CTL_CCTL_SUEN_OFFSET 8
+#define MMSC_CFG_CCTLCSR_OFFSET 16
+#define MISA_20_OFFSET 20
+
+#define MCACHE_CTL_CCTL_SUEN_MASK (0x1 << MCACHE_CTL_CCTL_SUEN_OFFSET)
+#define MMSC_CFG_CCTLCSR_MASK (0x1 << MMSC_CFG_CCTLCSR_OFFSET)
+#define MISA_20_MASK (0x1 << MISA_20_OFFSET)
+
+#define MAX_CACHE_LINE_SIZE 256
+
+struct ax45mp_cache_info {
+ bool init_done;
+ int dcache_line_size;
+};
+
+static DEFINE_PER_CPU(struct ax45mp_cache_info, cpu_cache_info) = {
+ .init_done = 0,
+ .dcache_line_size = SZ_64,
+};
+
+static void __iomem *l2c_base;
+
+static uint32_t cpu_get_mcache_ctl_status(void)
+{
+ struct sbiret ret;
+
+ ret = sbi_ecall(SBI_EXT_ANDES, SBI_EXT_ANDES_GET_MCACHE_CTL_STATUS, 0, 0, 0, 0, 0, 0);
+ return ret.value;
+}
+
+static uint32_t cpu_get_micm_cfg_status(void)
+{
+ struct sbiret ret;
+
+ ret = sbi_ecall(SBI_EXT_ANDES, SBI_EXT_ANDES_GET_MICM_CTL_STATUS, 0, 0, 0, 0, 0, 0);
+ return ret.value;
+}
+
+static uint32_t cpu_get_mdcm_cfg_status(void)
+{
+ struct sbiret ret;
+
+ ret = sbi_ecall(SBI_EXT_ANDES, SBI_EXT_ANDES_GET_MDCM_CTL_STATUS, 0, 0, 0, 0, 0, 0);
+ return ret.value;
+}
+
+static uint32_t cpu_get_mmsc_cfg_status(void)
+{
+ struct sbiret ret;
+
+ ret = sbi_ecall(SBI_EXT_ANDES, SBI_EXT_ANDES_GET_MMSC_CTL_STATUS, 0, 0, 0, 0, 0, 0);
+ return ret.value;
+}
+
+static uint32_t cpu_get_misa_cfg_status(void)
+{
+ struct sbiret ret;
+
+ ret = sbi_ecall(SBI_EXT_ANDES, SBI_EXT_ANDES_GET_MISA_CTL_STATUS, 0, 0, 0, 0, 0, 0);
+ return ret.value;
+}
+
+static void fill_cpu_cache_info(struct ax45mp_cache_info *cpu_ci)
+{
+ struct cpu_cacheinfo *this_cpu_ci =
+ get_cpu_cacheinfo(smp_processor_id());
+ struct cacheinfo *this_leaf = this_cpu_ci->info_list;
+ unsigned int i;
+
+ for (i = 0; i < this_cpu_ci->num_leaves ; i++, this_leaf++) {
+ if (this_leaf->type == CACHE_TYPE_DATA)
+ cpu_ci->dcache_line_size = this_leaf->coherency_line_size;
+ }
+
+ cpu_ci->init_done = true;
+}
+
+static inline int get_cache_line_size(void)
+{
+ struct ax45mp_cache_info *cpu_ci =
+ &per_cpu(cpu_cache_info, smp_processor_id());
+
+ if (unlikely(!cpu_ci->init_done))
+ fill_cpu_cache_info(cpu_ci);
+ return cpu_ci->dcache_line_size;
+}
+
+static uint32_t cpu_l2c_get_cctl_status(void)
+{
+ return readl((void *)(l2c_base + L2C_REG_STATUS_OFFSET));
+}
+
+static uint32_t cpu_l2c_ctl_status(void)
+{
+ return readl((void *)(l2c_base + L2C_REG_CTL_OFFSET));
+}
+
+static bool cpu_cache_controlable(void)
+{
+ return (((cpu_get_micm_cfg_status() & MICM_CFG_ISZ_MASK) ||
+ (cpu_get_mdcm_cfg_status() & MDCM_CFG_DSZ_MASK)) &&
+ (cpu_get_misa_cfg_status() & MISA_20_MASK) &&
+ (cpu_get_mmsc_cfg_status() & MMSC_CFG_CCTLCSR_MASK) &&
+ (cpu_get_mcache_ctl_status() & MCACHE_CTL_CCTL_SUEN_MASK));
+}
+
+static void cpu_dcache_wb_range(unsigned long start,
+ unsigned long end,
+ int line_size)
+{
+ bool ucctl_ok = false;
+ unsigned long pa;
+ int mhartid = 0;
+#ifdef CONFIG_SMP
+ mhartid = smp_processor_id();
+#endif
+
+ ucctl_ok = cpu_cache_controlable();
+
+ while (end > start) {
+ if (ucctl_ok) {
+ csr_write(CCTL_REG_UCCTLBEGINADDR_NUM, start);
+ csr_write(CCTL_REG_UCCTLCOMMAND_NUM, CCTL_L1D_VA_WB);
+ }
+
+ if (l2c_base && (cpu_l2c_ctl_status() & L2_CACHE_CTL_CEN_MASK)) {
+ pa = virt_to_phys((void *)start);
+ writel(pa, (void *)(l2c_base + L2C_REG_CN_ACC_OFFSET(mhartid)));
+ writel(CCTL_L2_PA_WB, (void *)(l2c_base + L2C_REG_CN_CMD_OFFSET(mhartid)));
+ while ((cpu_l2c_get_cctl_status() &
+ CCTL_L2_STATUS_CN_MASK(mhartid)) != CCTL_L2_STATUS_IDLE)
+ ;
+ }
+
+ start += line_size;
+ }
+}
+
+static void cpu_dcache_inval_range(unsigned long start,
+ unsigned long end,
+ int line_size)
+{
+ bool ucctl_ok = false;
+ unsigned long pa;
+ int mhartid = 0;
+#ifdef CONFIG_SMP
+ mhartid = smp_processor_id();
+#endif
+
+ ucctl_ok = cpu_cache_controlable();
+
+ while (end > start) {
+ if (ucctl_ok) {
+ csr_write(CCTL_REG_UCCTLBEGINADDR_NUM, start);
+ csr_write(CCTL_REG_UCCTLCOMMAND_NUM, CCTL_L1D_VA_INVAL);
+ }
+
+ if (l2c_base && (cpu_l2c_ctl_status() & L2_CACHE_CTL_CEN_MASK)) {
+ pa = virt_to_phys((void *)start);
+ writel(pa, (void *)(l2c_base + L2C_REG_CN_ACC_OFFSET(mhartid)));
+ writel(CCTL_L2_PA_INVAL,
+ (void *)(l2c_base + L2C_REG_CN_CMD_OFFSET(mhartid)));
+ while ((cpu_l2c_get_cctl_status() &
+ CCTL_L2_STATUS_CN_MASK(mhartid)) != CCTL_L2_STATUS_IDLE)
+ ;
+ }
+
+ start += line_size;
+ }
+}
+
+void cpu_dma_inval_range(unsigned long start, unsigned long end)
+{
+ unsigned long line_size = get_cache_line_size();
+ char cache_buf[2][MAX_CACHE_LINE_SIZE] = { 0 };
+ unsigned long old_start = start;
+ unsigned long old_end = end;
+ unsigned long flags;
+
+ if (unlikely(start == end))
+ return;
+
+ 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);
+
+ cpu_dcache_inval_range(start, end, line_size);
+
+ if (unlikely(start != old_start))
+ memcpy((void *)start, &cache_buf[0][0], (old_start & (line_size - 1)));
+
+ if (unlikely(end != old_end))
+ memcpy((void *)(old_end + 1),
+ &cache_buf[1][(old_end & (line_size - 1)) + 1],
+ end - old_end - 1);
+
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(cpu_dma_inval_range);
+
+void cpu_dma_wb_range(unsigned long start, unsigned long end)
+{
+ unsigned long flags;
+ unsigned long line_size = get_cache_line_size();
+
+ local_irq_save(flags);
+ start = start & (~(line_size - 1));
+ cpu_dcache_wb_range(start, end, line_size);
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL(cpu_dma_wb_range);
+
+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;
+
+ np = of_find_matching_node(NULL, ax45mp_cache_ids);
+ if (!np)
+ return -ENODEV;
+
+ l2c_base = of_iomap(np, 0);
+ if (!l2c_base)
+ return -ENOMEM;
+
+ return 0;
+}
+arch_initcall(ax45mp_cache_init);
diff --git a/arch/riscv/vendors/andes/ax45mp_nocache_dma.c b/arch/riscv/vendors/andes/ax45mp_nocache_dma.c
new file mode 100644
index 000000000000..263012f89d0b
--- /dev/null
+++ b/arch/riscv/vendors/andes/ax45mp_nocache_dma.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMA callbacks implemented for the non-coherent cache
+ * on AX45MP
+ *
+ * Copyright (C) 2022 Renesas Electronics Corp.
+ *
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
+
+#include "include/proc.h"
+
+static inline void cache_op(phys_addr_t paddr, size_t size,
+ void (*fn)(unsigned long start, unsigned long end))
+{
+ unsigned long start;
+
+ start = (unsigned long)phys_to_virt(paddr);
+ fn(start, start + size);
+}
+
+void arch_sync_dma_for_device(phys_addr_t paddr,
+ size_t size, enum dma_data_direction dir)
+{
+ switch (dir) {
+ case DMA_FROM_DEVICE:
+ cache_op(paddr, size, cpu_dma_inval_range);
+ break;
+ case DMA_TO_DEVICE:
+ case DMA_BIDIRECTIONAL:
+ cache_op(paddr, size, cpu_dma_wb_range);
+ break;
+ default:
+ BUG();
+ }
+}
+
+void arch_sync_dma_for_cpu(phys_addr_t paddr,
+ size_t size, enum dma_data_direction dir)
+{
+ switch (dir) {
+ case DMA_TO_DEVICE:
+ break;
+ case DMA_FROM_DEVICE:
+ case DMA_BIDIRECTIONAL:
+ cache_op(paddr, size, cpu_dma_inval_range);
+ break;
+ default:
+ BUG();
+ }
+}
+
+void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
+ gfp_t gfp, unsigned long attrs)
+{
+ return dma_alloc_from_global_coherent(dev, size, handle);
+}
+
+void arch_dma_free(struct device *dev, size_t size, void *vaddr,
+ dma_addr_t handle, unsigned long attrs)
+{
+ dma_release_from_global_coherent(0, vaddr);
+}
diff --git a/arch/riscv/vendors/andes/include/proc.h b/arch/riscv/vendors/andes/include/proc.h
new file mode 100644
index 000000000000..ace9bcfccf6b
--- /dev/null
+++ b/arch/riscv/vendors/andes/include/proc.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef __RISCV_ANDES_PROC_H
+#define __RISCV_ANDES_PROC_H
+
+void cpu_dma_inval_range(unsigned long start, unsigned long end);
+void cpu_dma_wb_range(unsigned long start, unsigned long end);
+
+#endif
--
2.25.1
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