[PATCH v2 2/2] lib: utils/sys: Extend HTIF library to allow custom base address

Anup Patel anup at brainfault.org
Tue Jan 11 04:49:10 PST 2022


On Tue, Jan 11, 2022 at 4:01 AM Atish Patra <atishp at atishpatra.org> wrote:
>
> On Sun, Jan 9, 2022 at 7:20 AM Anup Patel <apatel at ventanamicro.com> wrote:
> >
> > Some of RISC-V emulators provide HTIF at fixed base address so for
> > such emulators users have to hard-code HTIF base address in the
> > linker script.
> >
> > To address this problem, we let users optionally provide fixed HTIF
> > base address via platform support (or device tree).
> >
> > Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> > Reviewed-by: Dong Du <Dd_nirvana at sjtu.edu.cn>
> > ---
> >  include/sbi_utils/sys/htif.h       |  8 ++-
> >  lib/utils/reset/fdt_reset_htif.c   | 12 ++++-
> >  lib/utils/serial/fdt_serial_htif.c | 12 ++++-
> >  lib/utils/sys/htif.c               | 85 ++++++++++++++++++++++++++----
> >  4 files changed, 103 insertions(+), 14 deletions(-)
> >
> > diff --git a/include/sbi_utils/sys/htif.h b/include/sbi_utils/sys/htif.h
> > index 9cc9634..78784cf 100644
> > --- a/include/sbi_utils/sys/htif.h
> > +++ b/include/sbi_utils/sys/htif.h
> > @@ -10,8 +10,12 @@
> >
> >  #include <sbi/sbi_types.h>
> >
> > -int htif_serial_init(void);
> > +int htif_serial_init(bool custom_addr,
> > +                    unsigned long custom_fromhost_addr,
> > +                    unsigned long custom_tohost_addr);
> >
> > -int htif_system_reset_init(void);
> > +int htif_system_reset_init(bool custom_addr,
> > +                          unsigned long custom_fromhost_addr,
> > +                          unsigned long custom_tohost_addr);
> >
> >  #endif
> > diff --git a/lib/utils/reset/fdt_reset_htif.c b/lib/utils/reset/fdt_reset_htif.c
> > index dd08660..2cc52dd 100644
> > --- a/lib/utils/reset/fdt_reset_htif.c
> > +++ b/lib/utils/reset/fdt_reset_htif.c
> > @@ -14,7 +14,17 @@
> >  static int htif_reset_init(void *fdt, int nodeoff,
> >                            const struct fdt_match *match)
> >  {
> > -       return htif_system_reset_init();
> > +       bool custom = false;
> > +       uint64_t fromhost_addr = 0, tohost_addr = 0;
> > +
> > +       if (!fdt_get_node_addr_size(fdt, nodeoff, 0, &fromhost_addr, NULL)) {
> > +               custom = true;
> > +               tohost_addr = fromhost_addr + sizeof(uint64_t);
> > +       }
> > +
> > +       fdt_get_node_addr_size(fdt, nodeoff, 1, &tohost_addr, NULL);
> > +
> > +       return htif_system_reset_init(custom, fromhost_addr, tohost_addr);
> >  }
> >
> >  static const struct fdt_match htif_reset_match[] = {
> > diff --git a/lib/utils/serial/fdt_serial_htif.c b/lib/utils/serial/fdt_serial_htif.c
> > index fae55b8..61f66d6 100644
> > --- a/lib/utils/serial/fdt_serial_htif.c
> > +++ b/lib/utils/serial/fdt_serial_htif.c
> > @@ -19,7 +19,17 @@ static const struct fdt_match serial_htif_match[] = {
> >  static int serial_htif_init(void *fdt, int nodeoff,
> >                             const struct fdt_match *match)
> >  {
> > -       return htif_serial_init();
> > +       bool custom = false;
> > +       uint64_t fromhost_addr = 0, tohost_addr = 0;
> > +
> > +       if (!fdt_get_node_addr_size(fdt, nodeoff, 0, &fromhost_addr, NULL)) {
> > +               custom = true;
> > +               tohost_addr = fromhost_addr + sizeof(uint64_t);
> > +       }
> > +
> > +       fdt_get_node_addr_size(fdt, nodeoff, 1, &tohost_addr, NULL);
> > +
> > +       return htif_serial_init(custom, fromhost_addr, tohost_addr);
> >  }
> >
> >  struct fdt_serial fdt_serial_htif = {
> > diff --git a/lib/utils/sys/htif.c b/lib/utils/sys/htif.c
> > index 7c69c7f..d7cbeaf 100644
> > --- a/lib/utils/sys/htif.c
> > +++ b/lib/utils/sys/htif.c
> > @@ -7,6 +7,7 @@
> >
> >  #include <sbi/riscv_locks.h>
> >  #include <sbi/sbi_console.h>
> > +#include <sbi/sbi_error.h>
> >  #include <sbi/sbi_system.h>
> >  #include <sbi_utils/sys/htif.h>
> >
> > @@ -47,15 +48,46 @@
> >
> >  volatile uint64_t tohost __attribute__((section(".htif")));
> >  volatile uint64_t fromhost __attribute__((section(".htif")));
> > +
> > +static uint64_t *htif_fromhost = NULL;
> > +static uint64_t *htif_tohost = NULL;
> > +static bool htif_custom = false;
> > +
> >  static int htif_console_buf;
> >  static spinlock_t htif_lock = SPIN_LOCK_INITIALIZER;
> >
> > +static inline uint64_t __read_tohost(void)
> > +{
> > +       return (htif_custom) ? *htif_tohost : tohost;
> > +}
> > +
> > +static inline void __write_tohost(uint64_t val)
> > +{
> > +       if (htif_custom)
> > +               *htif_tohost = val;
> > +       else
> > +               tohost = val;
> > +}
> > +
> > +static inline uint64_t __read_fromhost(void)
> > +{
> > +       return (htif_custom) ? *htif_fromhost : fromhost;
> > +}
> > +
> > +static inline void __write_fromhost(uint64_t val)
> > +{
> > +       if (htif_custom)
> > +               *htif_fromhost = val;
> > +       else
> > +               fromhost = val;
> > +}
> > +
> >  static void __check_fromhost()
> >  {
> > -       uint64_t fh = fromhost;
> > +       uint64_t fh = __read_fromhost();
> >         if (!fh)
> >                 return;
> > -       fromhost = 0;
> > +       __write_fromhost(0);
> >
> >         /* this should be from the console */
> >         if (FROMHOST_DEV(fh) != HTIF_DEV_CONSOLE)
> > @@ -73,9 +105,26 @@ static void __check_fromhost()
> >
> >  static void __set_tohost(uint64_t dev, uint64_t cmd, uint64_t data)
> >  {
> > -       while (tohost)
> > +       while (__read_tohost())
> >                 __check_fromhost();
> > -       tohost = TOHOST_CMD(dev, cmd, data);
> > +       __write_tohost(TOHOST_CMD(dev, cmd, data));
> > +}
> > +
> > +static int set_custom_addr(bool custom_addr,
> > +                          unsigned long custom_fromhost_addr,
> > +                          unsigned long custom_tohost_addr)
> > +{
> > +       if (custom_addr) {
> > +               if (htif_custom &&
> > +                   ((custom_fromhost_addr != (unsigned long)htif_fromhost) ||
> > +                    (custom_tohost_addr != (unsigned long)htif_tohost)))
> > +                       return SBI_EINVAL;
> > +               htif_fromhost = (uint64_t *)custom_fromhost_addr;
> > +               htif_tohost = (uint64_t *)custom_tohost_addr;
> > +               htif_custom = true;
> > +       }
> > +
> > +       return 0;
> >  }
> >
> >  #if __riscv_xlen == 32
> > @@ -148,10 +197,18 @@ static struct sbi_console_device htif_console = {
> >         .console_getc = htif_getc
> >  };
> >
> > -int htif_serial_init(void)
> > +int htif_serial_init(bool custom_addr,
> > +                    unsigned long custom_fromhost_addr,
> > +                    unsigned long custom_tohost_addr)
> >  {
> > -       sbi_console_set_device(&htif_console);
> > +       int rc;
> > +
> > +       rc = set_custom_addr(custom_addr, custom_fromhost_addr,
> > +                            custom_tohost_addr);
> > +       if (rc)
> > +               return rc;
> >
> > +       sbi_console_set_device(&htif_console);
> >         return 0;
> >  }
> >
> > @@ -163,8 +220,8 @@ static int htif_system_reset_check(u32 type, u32 reason)
> >  static void htif_system_reset(u32 type, u32 reason)
> >  {
> >         while (1) {
> > -               fromhost = 0;
> > -               tohost = 1;
> > +               __write_fromhost(0);
> > +               __write_tohost(1);
> >         }
> >  }
> >
> > @@ -174,9 +231,17 @@ static struct sbi_system_reset_device htif_reset = {
> >         .system_reset = htif_system_reset
> >  };
> >
> > -int htif_system_reset_init(void)
> > +int htif_system_reset_init(bool custom_addr,
> > +                          unsigned long custom_fromhost_addr,
> > +                          unsigned long custom_tohost_addr)
> >  {
> > -       sbi_system_reset_add_device(&htif_reset);
> > +       int rc;
> > +
> > +       rc = set_custom_addr(custom_addr, custom_fromhost_addr,
> > +                            custom_tohost_addr);
> > +       if (rc)
> > +               return rc;
> >
> > +       sbi_system_reset_add_device(&htif_reset);
> >         return 0;
> >  }
> > --
> > 2.25.1
> >
>
> Reviewed-by: Atish Patra <atishp at rivosinc.com>

Applied this patch to the riscv/opensbi repo.

Thanks,
Anup

>
>
> --
> Regards,
> Atish



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