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Re: [RFC PATCH 1/2] hw/riscv: sifive_u: Add file-backed OTP. softmmu/vl:
From: |
Bin Meng |
Subject: |
Re: [RFC PATCH 1/2] hw/riscv: sifive_u: Add file-backed OTP. softmmu/vl: add otp-file to boot option |
Date: |
Fri, 24 Jul 2020 22:20:01 +0800 |
Hi Green,
On Fri, Jul 24, 2020 at 5:51 PM Green Wan <green.wan@sifive.com> wrote:
>
> Add a file-backed implementation for OTP of sifive_u machine. Use
> '-boot otp-file=xxx' to enable it. Do file open, mmap and close
> for every OTP read/write in case keep the update-to-date snapshot
> of OTP.
>
> Signed-off-by: Green Wan <green.wan@sifive.com>
> ---
> hw/riscv/sifive_u_otp.c | 88 ++++++++++++++++++++++++++++++++-
> include/hw/riscv/sifive_u_otp.h | 2 +
> qemu-options.hx | 3 +-
> softmmu/vl.c | 6 ++-
> 4 files changed, 96 insertions(+), 3 deletions(-)
>
> diff --git a/hw/riscv/sifive_u_otp.c b/hw/riscv/sifive_u_otp.c
> index f6ecbaa2ca..26e1965821 100644
> --- a/hw/riscv/sifive_u_otp.c
> +++ b/hw/riscv/sifive_u_otp.c
> @@ -24,6 +24,72 @@
> #include "qemu/log.h"
> #include "qemu/module.h"
> #include "hw/riscv/sifive_u_otp.h"
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <unistd.h>
> +#include <fcntl.h>
> +#include <sys/mman.h>
> +#include <string.h>
> +
> +#define TRACE_PREFIX "FU540_OTP: "
> +#define SIFIVE_FU540_OTP_SIZE (SIFIVE_U_OTP_NUM_FUSES * 4)
> +
> +static int otp_backed_fd;
> +static unsigned int *otp_mmap;
> +
> +static void sifive_u_otp_backed_load(const char *filename);
> +static uint64_t sifive_u_otp_backed_read(uint32_t fuseidx);
> +static void sifive_u_otp_backed_write(uint32_t fuseidx,
> + uint32_t paio,
> + uint32_t pdin);
> +static void sifive_u_otp_backed_unload(void);
> +
> +void sifive_u_otp_backed_load(const char *filename)
> +{
> + if (otp_backed_fd < 0) {
> +
> + otp_backed_fd = open(filename, O_RDWR);
> +
> + if (otp_backed_fd < 0)
> + qemu_log_mask(LOG_TRACE,
> + TRACE_PREFIX "Warning: can't open otp file\n");
> + else {
> +
> + otp_mmap = (unsigned int *)mmap(0,
> + SIFIVE_FU540_OTP_SIZE,
> + PROT_READ | PROT_WRITE |
> PROT_EXEC,
> + MAP_FILE | MAP_SHARED,
> + otp_backed_fd,
> + 0);
> +
> + if (otp_mmap == MAP_FAILED)
> + qemu_log_mask(LOG_TRACE,
> + TRACE_PREFIX "Warning: can't mmap otp file\n");
> + }
> + }
> +
> +}
> +
> +uint64_t sifive_u_otp_backed_read(uint32_t fuseidx)
> +{
> + return (uint64_t)(otp_mmap[fuseidx]);
> +}
> +
> +void sifive_u_otp_backed_write(uint32_t fuseidx, uint32_t paio, uint32_t
> pdin)
> +{
> + otp_mmap[fuseidx] &= ~(pdin << paio);
> + otp_mmap[fuseidx] |= (pdin << paio);
> +}
> +
> +
> +void sifive_u_otp_backed_unload(void)
> +{
> + munmap(otp_mmap, SIFIVE_FU540_OTP_SIZE);
> + close(otp_backed_fd);
> + otp_backed_fd = -1;
> +}
>
> static uint64_t sifive_u_otp_read(void *opaque, hwaddr addr, unsigned int
> size)
> {
> @@ -46,7 +112,17 @@ static uint64_t sifive_u_otp_read(void *opaque, hwaddr
> addr, unsigned int size)
> if ((s->pce & SIFIVE_U_OTP_PCE_EN) &&
> (s->pdstb & SIFIVE_U_OTP_PDSTB_EN) &&
> (s->ptrim & SIFIVE_U_OTP_PTRIM_EN)) {
> - return s->fuse[s->pa & SIFIVE_U_OTP_PA_MASK];
> +
> + if (otp_file) {
> + uint64_t val;
> +
> + sifive_u_otp_backed_load(otp_file);
> + val = sifive_u_otp_backed_read(s->pa);
> + sifive_u_otp_backed_unload();
> +
> + return val;
> + } else
> + return s->fuse[s->pa & SIFIVE_U_OTP_PA_MASK];
> } else {
> return 0xff;
> }
> @@ -123,6 +199,12 @@ static void sifive_u_otp_write(void *opaque, hwaddr addr,
> s->ptrim = val32;
> break;
> case SIFIVE_U_OTP_PWE:
> + if (otp_file) {
> + sifive_u_otp_backed_load(otp_file);
> + sifive_u_otp_backed_write(s->pa, s->paio, s->pdin);
> + sifive_u_otp_backed_unload();
> + }
> +
> s->pwe = val32;
> break;
> default:
> @@ -165,6 +247,10 @@ static void sifive_u_otp_reset(DeviceState *dev)
> /* Make a valid content of serial number */
> s->fuse[SIFIVE_U_OTP_SERIAL_ADDR] = s->serial;
> s->fuse[SIFIVE_U_OTP_SERIAL_ADDR + 1] = ~(s->serial);
> +
> + /* Initialize file mmap and descriptor. */
> + otp_mmap = NULL;
> + otp_backed_fd = -1;
> }
>
> static void sifive_u_otp_class_init(ObjectClass *klass, void *data)
> diff --git a/include/hw/riscv/sifive_u_otp.h b/include/hw/riscv/sifive_u_otp.h
> index 639297564a..1342bd7342 100644
> --- a/include/hw/riscv/sifive_u_otp.h
> +++ b/include/hw/riscv/sifive_u_otp.h
> @@ -52,6 +52,8 @@
> #define SIFIVE_U_OTP(obj) \
> OBJECT_CHECK(SiFiveUOTPState, (obj), TYPE_SIFIVE_U_OTP)
>
> +extern const char *otp_file;
> +
> typedef struct SiFiveUOTPState {
> /*< private >*/
> SysBusDevice parent_obj;
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 708583b4ce..eb9a54f4ed 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -415,10 +415,11 @@ ERST
>
> DEF("boot", HAS_ARG, QEMU_OPTION_boot,
> "-boot [order=drives][,once=drives][,menu=on|off]\n"
> - "
> [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n"
> + "
> [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off][,otp-file=otp_file]\n"
> " 'drives': floppy (a), hard disk (c), CD-ROM (d),
> network (n)\n"
> " 'sp_name': the file's name that would be passed to bios
> as logo picture, if menu=on\n"
> " 'sp_time': the period that splash picture last if
> menu=on, unit is ms\n"
> + " 'otp_file': the file name backed OTP\n"
> " 'rb_timeout': the timeout before guest reboot when boot
> failed, unit is ms\n",
Instead of touching generic codes, could we add such property at the
board level?
> QEMU_ARCH_ALL)
> SRST
Regards,
Bin