[PATCH v2 2/2] lib: utils: reset: Add T-HEAD sample platform reset driver
Anup Patel
Anup.Patel at wdc.com
Thu Apr 22 11:04:26 BST 2021
> -----Original Message-----
> From: Anup Patel
> Sent: 21 April 2021 10:00
> To: guoren at kernel.org; Alistair Francis <Alistair.Francis at wdc.com>;
> anup at brainfault.org
> Cc: opensbi at lists.infradead.org; Guo Ren <guoren at linux.alibaba.com>;
> Atish Patra <Atish.Patra at wdc.com>; Xiang W <wxjstz at 126.com>; Bin Meng
> <bmeng.cn at gmail.com>
> Subject: RE: [PATCH v2 2/2] lib: utils: reset: Add T-HEAD sample platform
> reset driver
>
>
>
> > -----Original Message-----
> > From: guoren at kernel.org <guoren at kernel.org>
> > Sent: 17 April 2021 21:56
> > To: guoren at kernel.org; Alistair Francis <Alistair.Francis at wdc.com>;
> > anup at brainfault.org
> > Cc: opensbi at lists.infradead.org; Guo Ren <guoren at linux.alibaba.com>;
> > Anup Patel <Anup.Patel at wdc.com>; Atish Patra <Atish.Patra at wdc.com>;
> > Xiang W <wxjstz at 126.com>; Bin Meng <bmeng.cn at gmail.com>
> > Subject: [PATCH v2 2/2] lib: utils: reset: Add T-HEAD sample platform
> > reset driver
> >
> > From: Guo Ren <guoren at linux.alibaba.com>
> >
> > This driver is for T-HEAD test chip, fpga. It could work with all
> > T-HEAD riscv
> > processors: C9xx series.
> >
> > example1: (Using io-regs for reset)
> > reset: reset-sample {
> > compatible = "thead,reset-sample";
> > plic-delegate = <0xff 0xd81ffffc>;
> > entry-reg = <0xff 0xff019050>;
> > entry-cnt = <4>;
> > control-reg = <0xff 0xff015004>;
> > control-val = <0x1c>;
> > csr-copy = <0x7f3 0x7c0 0x7c1 0x7c2 0x7c3 0x7c5 0x7cc>; };
> >
> > example2: (Using csr-regs for reset)
> > reset: reset-sample {
> > compatible = "thead,reset-sample";
> > plic-delegate = <0xff 0xd81ffffc>;
> > using-csr-reset;
> > csr-copy = <0x7c0 0x7c1 0x7c2 0x7c3 0x7c5 0x7cc
> > 0x3b0 0x3b1 0x3b2 0x3b3
> > 0x3b4 0x3b5 0x3b6 0x3b7
> > 0x3a0>;
> > };
> >
> > example3: (Only delegate plic enable to S-mode)
> > reset: reset-sample {
> > compatible = "thead,reset-sample";
> > plic-delegate = <0xff 0xd81ffffc>;
> > };
> >
> > After this patch, all T-HEAD c9xx would use platform/generic with
> > fw_dynamic as default:
> >
> > CROSS_COMPILE=riscv64-linux-gnu- PLATFORM=generic FW_PIC=y
> > /usr/bin/make
> >
> > dts full example:
> > cpus {
> > #address-cells = <1>;
> > #size-cells = <0>;
> > timebase-frequency = <0x2dc6c0>;
> > cpu at 0 {
> > device_type = "cpu";
> > reg = <0>;
> > status = "okay";
> > compatible = "riscv";
> > riscv,isa = "rv64imafdcsu";
> > mmu-type = "riscv,sv39";
> > cpu0_intc: interrupt-controller {
> > #interrupt-cells = <1>;
> > compatible = "riscv,cpu-intc";
> > interrupt-controller;
> > };
> > };
> > cpu at 1 {
> > device_type = "cpu";
> > reg = <1>;
> > status = "fail";
> > compatible = "riscv";
> > riscv,isa = "rv64imafdcsu";
> > mmu-type = "riscv,sv39";
> > cpu1_intc: interrupt-controller {
> > #interrupt-cells = <1>;
> > compatible = "riscv,cpu-intc";
> > interrupt-controller;
> > };
> > };
> > cpu at 2 {
> > device_type = "cpu";
> > reg = <2>;
> > status = "fail";
> > compatible = "riscv";
> > riscv,isa = "rv64imafdcsu";
> > mmu-type = "riscv,sv39";
> > cpu2_intc: interrupt-controller {
> > #interrupt-cells = <1>;
> > compatible = "riscv,cpu-intc";
> > interrupt-controller;
> > };
> > };
> > cpu at 3 {
> > device_type = "cpu";
> > reg = <3>;
> > status = "fail";
> > compatible = "riscv";
> > riscv,isa = "rv64imafdcsu";
> > mmu-type = "riscv,sv39";
> > cpu3_intc: interrupt-controller {
> > #interrupt-cells = <1>;
> > compatible = "riscv,cpu-intc";
> > interrupt-controller;
> > };
> > };
> > };
> >
> > soc {
> > #address-cells = <2>;
> > #size-cells = <2>;
> > compatible = "simple-bus";
> > ranges;
> >
> > reset: reset-sample {
> > compatible = "thead,reset-sample";
> > plic-delegate = <0xff 0xd81ffffc>;
> > using-csr-reset;
> > csr-copy = <
> > 0x7c0 0x7c1 0x7c2 0x7c3 0x7c5 0x7cc
> > 0x3b0 0x3b1 0x3b2 0x3b3
> > 0x3b4 0x3b5 0x3b6 0x3b7
> > 0x3a0
> > >;
> > };
> >
> > clint0: clint at ffdc000000 {
> > compatible = "riscv,clint0";
> > interrupts-extended = <
> > &cpu0_intc 3 &cpu0_intc 7
> > &cpu1_intc 3 &cpu1_intc 7
> > &cpu2_intc 3 &cpu2_intc 7
> > &cpu3_intc 3 &cpu3_intc 7
> > &cpu4_intc 3 &cpu4_intc 7
> > >;
> > reg = <0xff 0xdc000000 0x0 0x04000000>;
> > clint,has-no-64bit-mmio;
> > };
> >
> > intc: interrupt-controller at ffd8000000 {
> > #interrupt-cells = <1>;
> > compatible = "riscv,plic0";
> > interrupt-controller;
> > interrupts-extended = <
> > &cpu0_intc 0xffffffff &cpu0_intc 9
> > &cpu1_intc 0xffffffff &cpu1_intc 9
> > &cpu2_intc 0xffffffff &cpu2_intc 9
> > &cpu3_intc 0xffffffff &cpu3_intc 9
> > >;
> > reg = <0xff 0xd8000000 0x0 0x04000000>;
> > reg-names = "control";
> > riscv,max-priority = <7>;
> > riscv,ndev = <80>;
> > };
> > }
> >
> > The platform/thead will be deprecated.
> >
> > Change in v2 (by Anup):
> > - Clean up includes in fdt_reset_thead.h and keep the minimum.
> > - Add macro of fence.i & ebreak in riscv_asm&barrier.h.
> > - Fixup system_reset_check() for ebreak and test it on hardware.
> > - Add __FDT_RESET_THEAD_H__ in fdt_reset_thead.h.
> >
> > Signed-off-by: Guo Ren <guoren at linux.alibaba.com>
> > Link:
> > http://lists.infradead.org/pipermail/opensbi/2021-April/000863.html
> > Cc: Anup Patel <anup.patel at wdc.com>
> > Cc: Atish Patra <atish.patra at wdc.com>
> > Cc: Xiang W <wxjstz at 126.com>
> > Cc: Bin Meng <bmeng.cn at gmail.com>
> > ---
>
> The commit description is quite big. I will trim it at time of merging this patch.
>
> Otherwise, Looks good to me.
>
> Reviewed-by: Anup Patel <anup.patel at wdc.com>
I had to fix compile errors for RV32 generic platform at time of
merging this patch. Please test at your end and send patch fix
if required.
Applied this patch to the riscv/opensbi repo
Thanks,
Anup
>
> Regards,
> Anup
>
> > include/sbi/riscv_asm.h | 5 ++
> > include/sbi/riscv_barrier.h | 3 +
> > lib/utils/reset/fdt_reset.c | 2 +
> > lib/utils/reset/fdt_reset_thead.c | 130
> > ++++++++++++++++++++++++++++++++++
> > lib/utils/reset/fdt_reset_thead.h | 23 ++++++
> > lib/utils/reset/fdt_reset_thead_asm.S | 47 ++++++++++++
> > lib/utils/reset/objects.mk | 2 +
> > 7 files changed, 212 insertions(+)
> > create mode 100644 lib/utils/reset/fdt_reset_thead.c create mode
> > 100644 lib/utils/reset/fdt_reset_thead.h create mode 100644
> > lib/utils/reset/fdt_reset_thead_asm.S
> >
> > diff --git a/include/sbi/riscv_asm.h b/include/sbi/riscv_asm.h index
> > 9fa0fe5..1ff36de 100644
> > --- a/include/sbi/riscv_asm.h
> > +++ b/include/sbi/riscv_asm.h
> > @@ -157,6 +157,11 @@ void csr_write_num(int csr_num, unsigned long
> val);
> > __asm__ __volatile__("wfi" ::: "memory"); \
> > } while (0)
> >
> > +#define ebreak() \
> > + do { \
> > + __asm__ __volatile__("ebreak" ::: "memory"); \
> > + } while (0)
> > +
> > /* Get current HART id */
> > #define current_hartid() ((unsigned int)csr_read(CSR_MHARTID))
> >
> > diff --git a/include/sbi/riscv_barrier.h b/include/sbi/riscv_barrier.h
> > index
> > 905ecb4..1fba8b8 100644
> > --- a/include/sbi/riscv_barrier.h
> > +++ b/include/sbi/riscv_barrier.h
> > @@ -18,6 +18,9 @@
> > #define RISCV_FENCE(p, s) \
> > __asm__ __volatile__ ("fence " #p "," #s : : : "memory")
> >
> > +#define RISCV_FENCE_I \
> > + __asm__ __volatile__ ("fence.i" : : : "memory")
> > +
> > /* Read & Write Memory barrier */
> > #define mb() RISCV_FENCE(iorw,iorw)
> >
> > diff --git a/lib/utils/reset/fdt_reset.c b/lib/utils/reset/fdt_reset.c
> > index
> > dead8a3..82532c2 100644
> > --- a/lib/utils/reset/fdt_reset.c
> > +++ b/lib/utils/reset/fdt_reset.c
> > @@ -13,10 +13,12 @@
> >
> > extern struct fdt_reset fdt_reset_sifive; extern struct fdt_reset
> > fdt_reset_htif;
> > +extern struct fdt_reset fdt_reset_thead;
> >
> > static struct fdt_reset *reset_drivers[] = {
> > &fdt_reset_sifive,
> > &fdt_reset_htif,
> > + &fdt_reset_thead,
> > };
> >
> > static struct fdt_reset *current_driver = NULL; diff --git
> > a/lib/utils/reset/fdt_reset_thead.c
> > b/lib/utils/reset/fdt_reset_thead.c
> > new file mode 100644
> > index 0000000..cce0141
> > --- /dev/null
> > +++ b/lib/utils/reset/fdt_reset_thead.c
> > @@ -0,0 +1,130 @@
> > +/*
> > + * SPDX-License-Identifier: BSD-2-Clause */
> > +
> > +#include <libfdt.h>
> > +#include <sbi/riscv_io.h>
> > +#include <sbi/sbi_bitops.h>
> > +#include <sbi/sbi_hart.h>
> > +#include <sbi/sbi_scratch.h>
> > +#include <sbi_utils/fdt/fdt_helper.h> #include
> > +<sbi_utils/reset/fdt_reset.h> #include "fdt_reset_thead.h"
> > +
> > +struct custom_csr custom_csr[MAX_CUSTOM_CSR];
> > +
> > +#define CSR_OPCODE 0x39073
> > +static void clone_csrs(int cnt)
> > +{
> > + unsigned long i;
> > +
> > + for (i = 0; i < cnt; i++) {
> > + /* Write csr BIT[31 - 20] to stub */
> > + __reset_thead_csr_stub[3*i + 1] =
> > + CSR_OPCODE | (custom_csr[i].index << 20);
> > +
> > + /* Mask csr BIT[31 - 20] */
> > + *(u32 *)&__fdt_reset_thead_csrr &= BIT(20) - 1;
> > + smp_mb();
> > +
> > + /* Write csr BIT[31 - 20] to __fdt_reset_thead_csrr */
> > + *(u32 *)&__fdt_reset_thead_csrr |= custom_csr[i].index <<
> > 20;
> > + smp_mb();
> > +
> > + RISCV_FENCE_I;
> > +
> > + custom_csr[i].value = __fdt_reset_thead_csrr();
> > + }
> > +}
> > +
> > +extern void __thead_pre_start_warm(void); static int
> > +thead_reset_init(void *fdt, int nodeoff,
> > + const struct fdt_match *match)
> > +{
> > + void *p;
> > + const fdt64_t *val;
> > + const fdt32_t *val_w;
> > + int len, i, cnt;
> > + u32 tmp = 0;
> > +
> > + /* Prepare clone csrs */
> > + val_w = fdt_getprop(fdt, nodeoff, "csr-copy", &len);
> > + if (len > 0 && val_w) {
> > + cnt = len / sizeof(fdt32_t);
> > +
> > + if (cnt > MAX_CUSTOM_CSR)
> > + sbi_hart_hang();
> > +
> > + for (i = 0; i < cnt; i++) {
> > + custom_csr[i].index = fdt32_to_cpu(val_w[i]);
> > + }
> > + }
> > +
> > + if (cnt)
> > + clone_csrs(cnt);
> > +
> > + /* Delegate plic enable regs for S-mode */
> > + val = fdt_getprop(fdt, nodeoff, "plic-delegate", &len);
> > + if (len > 0 && val) {
> > + p = (void *)fdt64_to_cpu(*val);
> > + writel(BIT(0), p);
> > + }
> > +
> > + /* Old reset method for secondary harts */
> > + if (fdt_getprop(fdt, nodeoff, "using-csr-reset", &len)) {
> > + csr_write(0x7c7, (u64)&__thead_pre_start_warm);
> > + csr_write(0x7c6, -1);
> > + }
> > +
> > + /* Custom reset method for secondary harts */
> > + val = fdt_getprop(fdt, nodeoff, "entry-reg", &len);
> > + if (len > 0 && val) {
> > + p = (void *)fdt64_to_cpu(*val);
> > +
> > + val_w = fdt_getprop(fdt, nodeoff, "entry-cnt", &len);
> > + if (len > 0 && val_w) {
> > + tmp = fdt32_to_cpu(*val_w);
> > +
> > + for (i = 0; i < tmp; i++) {
> > + writel((u64)(&__thead_pre_start_warm), p +
> > 8*i);
> > + writel((u64)(&__thead_pre_start_warm) >>
> > 32, p + 8*i + 4);
> > + }
> > + }
> > +
> > + val = fdt_getprop(fdt, nodeoff, "control-reg", &len);
> > + if (len > 0 && val) {
> > + p = (void *)fdt64_to_cpu(*val);
> > +
> > + val_w = fdt_getprop(fdt, nodeoff, "control-val",
> > &len);
> > + if (len > 0 && val_w) {
> > + tmp = fdt32_to_cpu(*val_w);
> > + tmp |= readl(p);
> > + writel(tmp, p);
> > + }
> > + }
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +int thead_system_reset_check(u32 type, u32 reason) {
> > + return 1;
> > +}
> > +
> > +void thead_system_reset(u32 type, u32 reason) {
> > + ebreak();
> > +}
> > +
> > +static const struct fdt_match thead_reset_match[] = {
> > + { .compatible = "thead,reset-sample" },
> > + { },
> > +};
> > +
> > +struct fdt_reset fdt_reset_thead = {
> > + .match_table = thead_reset_match,
> > + .init = thead_reset_init,
> > + .system_reset_check = thead_system_reset_check,
> > + .system_reset = thead_system_reset
> > +};
> > diff --git a/lib/utils/reset/fdt_reset_thead.h
> > b/lib/utils/reset/fdt_reset_thead.h
> > new file mode 100644
> > index 0000000..d7a686e
> > --- /dev/null
> > +++ b/lib/utils/reset/fdt_reset_thead.h
> > @@ -0,0 +1,23 @@
> > +/*
> > + * SPDX-License-Identifier: BSD-2-Clause */
> > +
> > +#ifndef __FDT_RESET_THEAD_H__
> > +#define __FDT_RESET_THEAD_H__
> > +
> > +#define MAX_CUSTOM_CSR 32
> > +
> > +#ifndef __ASSEMBLER__
> > +struct custom_csr {
> > + unsigned long index;
> > + unsigned long value;
> > +};
> > +
> > +u64 __fdt_reset_thead_csrr(void);
> > +
> > +extern struct custom_csr custom_csr[MAX_CUSTOM_CSR]; extern u32
> > +__reset_thead_csr_stub[];
> > +
> > +#endif /* __ASSEMBLER__ */
> > +
> > +#endif /* __FDT_RESET_THEAD_H__ */
> > diff --git a/lib/utils/reset/fdt_reset_thead_asm.S
> > b/lib/utils/reset/fdt_reset_thead_asm.S
> > new file mode 100644
> > index 0000000..8237951
> > --- /dev/null
> > +++ b/lib/utils/reset/fdt_reset_thead_asm.S
> > @@ -0,0 +1,47 @@
> > +/*
> > + * SPDX-License-Identifier: BSD-2-Clause */
> > +
> > +#include <sbi/riscv_asm.h>
> > +#include "fdt_reset_thead.h"
> > +
> > +/*
> > + * csrrs rd, csr, rs1
> > + * |31 20|19 15|14 12|11 7|6 0|
> > + * csr rs1 010 rd 1110011
> > + */
> > +#define CSR_STUB addi x0, x0, 0
> > +
> > + .option norvc
> > + .align 3
> > + .global __fdt_reset_thead_csrr
> > +__fdt_reset_thead_csrr:
> > + csrrs a0, 0, x0
> > + ret
> > +
> > + .align 3
> > + .global __thead_pre_start_warm
> > +__thead_pre_start_warm:
> > + /*
> > + * Clear L1 cache & BTB & BHT ...
> > + */
> > + li t1, 0x70013
> > + csrw 0x7c2, t1
> > + fence rw,rw
> > +
> > + lla t1, custom_csr
> > +
> > + .global __reset_thead_csr_stub
> > +__reset_thead_csr_stub:
> > +.rept MAX_CUSTOM_CSR
> > + REG_L t2, 8(t1)
> > + CSR_STUB
> > + addi t1, t1, 16
> > +.endr
> > + /*
> > + * Clear L1 cache & BTB & BHT ...
> > + */
> > + li t1, 0x70013
> > + csrw 0x7c2, t1
> > + fence rw,rw
> > + j _start_warm
> > diff --git a/lib/utils/reset/objects.mk b/lib/utils/reset/objects.mk
> > index
> > b447261..b6619f4 100644
> > --- a/lib/utils/reset/objects.mk
> > +++ b/lib/utils/reset/objects.mk
> > @@ -10,3 +10,5 @@
> > libsbiutils-objs-y += reset/fdt_reset.o libsbiutils-objs-y +=
> > reset/fdt_reset_htif.o libsbiutils-objs-y += reset/fdt_reset_sifive.o
> > +libsbiutils-objs-y += reset/fdt_reset_thead.o libsbiutils-objs-y +=
> > +reset/fdt_reset_thead_asm.o
> > --
> > 2.7.4
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