[PATCH v5] lib:sbi:platform:generic: Improved mlevel imsic check and init.

Anup Patel anup at brainfault.org
Tue May 7 06:14:13 PDT 2024


On Wed, Apr 10, 2024 at 2:58 PM Cheng Yang <yangcheng.work at foxmail.com> wrote:
>
> The current mlevel imsic check is only for the platform, which
> may cause hart without imsic in the platform to trigger an
> illegal instruction exception when initializing imsic. For
> example, the platform contains a management hart that only
> supports wired interrupts.
>
> This patch will check whether each hart has imsic according
> to fdt and record it in a bitmap, and only allow harts with
> imsic to initialize imsic to avoid triggering illegal instruction
> exceptions.
>
> Signed-off-by: Cheng Yang <yangcheng.work at foxmail.com>

We don't need such a complex solution using bitmap because we
can simply extend imsic_local_irqchip_init() as follows:

diff --git a/lib/utils/irqchip/imsic.c b/lib/utils/irqchip/imsic.c
index f2a35c6..02e3a33 100644
--- a/lib/utils/irqchip/imsic.c
+++ b/lib/utils/irqchip/imsic.c
@@ -12,6 +12,7 @@
 #include <sbi/riscv_io.h>
 #include <sbi/riscv_encoding.h>
 #include <sbi/sbi_console.h>
+#include <sbi/sbi_csr_detect.h>
 #include <sbi/sbi_domain.h>
 #include <sbi/sbi_ipi.h>
 #include <sbi/sbi_irqchip.h>
@@ -222,6 +223,8 @@ static void imsic_local_eix_update(unsigned long base_id,

 void imsic_local_irqchip_init(void)
 {
+    struct sbi_trap_info trap = { 0 };
+
     /*
      * This function is expected to be called from:
      * 1) nascent_init() platform callback which is called
@@ -231,6 +234,11 @@ void imsic_local_irqchip_init(void)
      *    in boot-up path.
      */

+    /* If Smaia not available then do nothing */
+    csr_read_allowed(CSR_MTOPI, (ulong)&trap);
+    if (trap.cause)
+        return;
+
     /* Setup threshold to allow all enabled interrupts */
     imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD);

Regards,
Anup

> Changes V4 -> V5:
>   - Fixed the issue where patch cannot be applied due to the editor automatically removing trailing spaces.
> Changes V3 -> V4:
>   - Rebase to the latest master branch.
> Changes V2 -> V3:
>   - Trailing whitespace.
>   - Replace platform.hart_index2id to generic_hart_index2id.
> Changes V1 -> V2:
>   - Add the processing of plat->hart_index2id be NULL in fdt_check_imsic_mlevel.
> ---
>  include/sbi/sbi_platform.h         |  8 ++++--
>  include/sbi_utils/fdt/fdt_helper.h |  4 ++-
>  lib/sbi/sbi_init.c                 |  2 +-
>  lib/utils/fdt/fdt_helper.c         | 45 ++++++++++++++++++++++++------
>  platform/generic/platform.c        | 26 ++++++++++++-----
>  5 files changed, 64 insertions(+), 21 deletions(-)
>
> diff --git a/include/sbi/sbi_platform.h b/include/sbi/sbi_platform.h
> index 581935a..f62d23d 100644
> --- a/include/sbi/sbi_platform.h
> +++ b/include/sbi/sbi_platform.h
> @@ -75,7 +75,7 @@ struct sbi_platform_operations {
>         bool (*cold_boot_allowed)(u32 hartid);
>
>         /* Platform nascent initialization */
> -       int (*nascent_init)(void);
> +       int (*nascent_init)(u32 hartid);
>
>         /** Platform early initialization */
>         int (*early_init)(bool cold_boot);
> @@ -395,10 +395,12 @@ static inline bool sbi_platform_cold_boot_allowed(
>   *
>   * @return 0 on success and negative error code on failure
>   */
> -static inline int sbi_platform_nascent_init(const struct sbi_platform *plat)
> +static inline int sbi_platform_nascent_init(
> +                                       const struct sbi_platform *plat,
> +                                       u32 hartid)
>  {
>         if (plat && sbi_platform_ops(plat)->nascent_init)
> -               return sbi_platform_ops(plat)->nascent_init();
> +               return sbi_platform_ops(plat)->nascent_init(hartid);
>         return 0;
>  }
>
> diff --git a/include/sbi_utils/fdt/fdt_helper.h b/include/sbi_utils/fdt/fdt_helper.h
> index ab4a80f..1b7fdeb 100644
> --- a/include/sbi_utils/fdt/fdt_helper.h
> +++ b/include/sbi_utils/fdt/fdt_helper.h
> @@ -12,6 +12,7 @@
>
>  #include <sbi/sbi_types.h>
>  #include <sbi/sbi_domain.h>
> +#include <sbi/sbi_platform.h>
>
>  struct fdt_match {
>         const char *compatible;
> @@ -89,7 +90,8 @@ int fdt_parse_aplic_node(void *fdt, int nodeoff, struct aplic_data *aplic);
>
>  struct imsic_data;
>
> -bool fdt_check_imsic_mlevel(void *fdt);
> +int fdt_check_imsic_mlevel(void *fdt, struct sbi_platform *plat,
> +                                                  unsigned long *imsic_bitmap);
>
>  int fdt_parse_imsic_node(void *fdt, int nodeoff, struct imsic_data *imsic);
>
> diff --git a/lib/sbi/sbi_init.c b/lib/sbi/sbi_init.c
> index 389172a..96f71a4 100644
> --- a/lib/sbi/sbi_init.c
> +++ b/lib/sbi/sbi_init.c
> @@ -545,7 +545,7 @@ void __noreturn sbi_init(struct sbi_scratch *scratch)
>          * that platform can initialize platform specific per-HART CSRs
>          * or per-HART devices.
>          */
> -       if (sbi_platform_nascent_init(plat))
> +       if (sbi_platform_nascent_init(plat, hartid))
>                 sbi_hart_hang();
>
>         if (coldboot)
> diff --git a/lib/utils/fdt/fdt_helper.c b/lib/utils/fdt/fdt_helper.c
> index a0e93b9..ae5d9cc 100644
> --- a/lib/utils/fdt/fdt_helper.c
> +++ b/lib/utils/fdt/fdt_helper.c
> @@ -764,27 +764,54 @@ skip_delegate_parse:
>         return 0;
>  }
>
> -bool fdt_check_imsic_mlevel(void *fdt)
> +int fdt_check_imsic_mlevel(void *fdt, struct sbi_platform *plat, unsigned long *imsic_bitmap)
>  {
>         const fdt32_t *val;
> -       int i, len, noff = 0;
> +       int i, h, len, err, cpu_offset, cpu_intc_offset, noff = 0;
> +       u32 phandle, hwirq, hartid;
> +
> +       bitmap_zero(imsic_bitmap, SBI_HARTMASK_MAX_BITS);
>
>         if (!fdt)
> -               return false;
> +               return SBI_ENODEV;
>
>         while ((noff = fdt_node_offset_by_compatible(fdt, noff,
>                                                      "riscv,imsics")) >= 0) {
>                 val = fdt_getprop(fdt, noff, "interrupts-extended", &len);
> -               if (val && len > sizeof(fdt32_t)) {
> -                       len = len / sizeof(fdt32_t);
> -                       for (i = 0; i < len; i += 2) {
> -                               if (fdt32_to_cpu(val[i + 1]) == IRQ_M_EXT)
> -                                       return true;
> +               if (!val || len < sizeof(fdt32_t))
> +                       continue;
> +
> +               len = len / sizeof(fdt32_t);
> +               for (i = 0; i < len; i += 2) {
> +                       phandle = fdt32_to_cpu(val[i]);
> +                       hwirq = fdt32_to_cpu(val[i + 1]);
> +
> +                       if (hwirq != IRQ_M_EXT)
> +                               continue;
> +
> +                       cpu_intc_offset = fdt_node_offset_by_phandle(fdt, phandle);
> +                       if (cpu_intc_offset < 0)
> +                               continue;
> +
> +                       cpu_offset = fdt_parent_offset(fdt, cpu_intc_offset);
> +                       if (cpu_offset < 0)
> +                               continue;
> +
> +                       err = fdt_parse_hart_id(fdt, cpu_offset, &hartid);
> +                       if (err)
> +                               return SBI_EINVAL;
> +
> +                       for (int i = 0; i < plat->hart_count; i++) {
> +                               h = plat->hart_index2id ? plat->hart_index2id[i] : i;
> +                               if (hartid == h) {
> +                                       bitmap_set(imsic_bitmap, i, 1);
> +                                       break;
> +                               }
>                         }
>                 }
>         }
>
> -       return false;
> +       return SBI_OK;
>  }
>
>  int fdt_parse_imsic_node(void *fdt, int nodeoff, struct imsic_data *imsic)
> diff --git a/platform/generic/platform.c b/platform/generic/platform.c
> index 1f46b76..00f8f86 100644
> --- a/platform/generic/platform.c
> +++ b/platform/generic/platform.c
> @@ -70,15 +70,15 @@ static u32 fw_platform_calculate_heap_size(u32 hart_count)
>  }
>
>  extern struct sbi_platform platform;
> -static bool platform_has_mlevel_imsic = false;
>  static u32 generic_hart_index2id[SBI_HARTMASK_MAX_BITS] = { 0 };
>
>  static DECLARE_BITMAP(generic_coldboot_harts, SBI_HARTMASK_MAX_BITS);
> +static DECLARE_BITMAP(generic_hart_has_mlevel_imsic, SBI_HARTMASK_MAX_BITS);
>
>  /*
> - * The fw_platform_coldboot_harts_init() function is called by fw_platform_init()
> + * The fw_platform_coldboot_harts_init() function is called by fw_platform_init()
>   * function to initialize the cold boot harts allowed by the generic platform
> - * according to the DT property "cold-boot-harts" in "/chosen/opensbi-config"
> + * according to the DT property "cold-boot-harts" in "/chosen/opensbi-config"
>   * DT node. If there is no "cold-boot-harts" in DT, all harts will be allowed.
>   */
>  static void fw_platform_coldboot_harts_init(void *fdt)
> @@ -186,7 +186,11 @@ unsigned long fw_platform_init(unsigned long arg0, unsigned long arg1,
>
>         platform.hart_count = hart_count;
>         platform.heap_size = fw_platform_calculate_heap_size(hart_count);
> -       platform_has_mlevel_imsic = fdt_check_imsic_mlevel(fdt);
> +
> +       rc = fdt_check_imsic_mlevel(fdt, &platform,
> +                                                               generic_hart_has_mlevel_imsic);
> +       if (rc)
> +               goto fail;
>
>         fw_platform_coldboot_harts_init(fdt);
>
> @@ -212,10 +216,18 @@ static bool generic_cold_boot_allowed(u32 hartid)
>         return false;
>  }
>
> -static int generic_nascent_init(void)
> +static int generic_nascent_init(u32 hartid)
>  {
> -       if (platform_has_mlevel_imsic)
> -               imsic_local_irqchip_init();
> +       for (int i = 0; i < platform.hart_count; i++) {
> +               if (hartid != generic_hart_index2id[i])
> +                       continue;
> +
> +               if (bitmap_test(generic_hart_has_mlevel_imsic, i)) {
> +                       imsic_local_irqchip_init();
> +                       break;
> +               }
> +       }
> +
>         return 0;
>  }
>
> --
> 2.34.1
>
>
> --
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> opensbi at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/opensbi



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