diff mbox series

[DO,NOT,REVIEW,v4,4/7] riscv: errata: andes: Fix auipc-jalr addresses in patched alternatives

Message ID 20221124172207.153718-5-prabhakar.mahadev-lad.rj@bp.renesas.com (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show
Series AX45MP: Add support to non-coherent DMA | expand

Commit Message

Lad, Prabhakar Nov. 24, 2022, 5:22 p.m. UTC 
From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

This patch is added just for building purpose, as patch [0] will export
this in its next version.

https://patchwork.kernel.org/project/linux-riscv/patch/20221110164924.529386-6-heiko@sntech.de/

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
Note, as Heiko will be exporting riscv_alternative_fix_auipc_jalr() function
so that it can be used other erratas Ive just included for compilation.
---
 arch/riscv/errata/andes/errata.c | 71 ++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

Comments

Guo Ren Nov. 25, 2022, 1:08 a.m. UTC | #1 
On Fri, Nov 25, 2022 at 1:22 AM Prabhakar <prabhakar.csengg@gmail.com> wrote:
>
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> This patch is added just for building purpose, as patch [0] will export
> this in its next version.
>
> https://patchwork.kernel.org/project/linux-riscv/patch/20221110164924.529386-6-heiko@sntech.de/
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
> Note, as Heiko will be exporting riscv_alternative_fix_auipc_jalr() function
> so that it can be used other erratas Ive just included for compilation.
> ---
>  arch/riscv/errata/andes/errata.c | 71 ++++++++++++++++++++++++++++++++
>  1 file changed, 71 insertions(+)
>
> diff --git a/arch/riscv/errata/andes/errata.c b/arch/riscv/errata/andes/errata.c
> index ec3e052ca8c7..4061ad4983bc 100644
> --- a/arch/riscv/errata/andes/errata.c
> +++ b/arch/riscv/errata/andes/errata.c
> @@ -13,9 +13,80 @@
>  #include <asm/alternative.h>
>  #include <asm/cacheflush.h>
>  #include <asm/errata_list.h>
> +#include <asm/parse_asm.h>
>  #include <asm/patch.h>
> +#include <asm/sbi.h>
>  #include <asm/vendorid_list.h>
>
> +/* Copy of Heiko's code from patch [0]
> + * [0] https://patchwork.kernel.org/project/linux-riscv/patch/20221110164924.529386-6-heiko@sntech.de/
Move it to commit-msg. No link in the code.

> + */
> +DECLARE_INSN(jalr, MATCH_JALR, MASK_JALR)
> +DECLARE_INSN(auipc, MATCH_AUIPC, MASK_AUIPC)
> +
> +static inline bool is_auipc_jalr_pair(long insn1, long insn2)
> +{
> +       return is_auipc_insn(insn1) && is_jalr_insn(insn2);
> +}
> +
> +#define JALR_SIGN_MASK         BIT(I_IMM_SIGN_OPOFF - I_IMM_11_0_OPOFF)
> +#define JALR_OFFSET_MASK       I_IMM_11_0_MASK
> +#define AUIPC_OFFSET_MASK      U_IMM_31_12_MASK
> +#define AUIPC_PAD              (0x00001000)
> +#define JALR_SHIFT             I_IMM_11_0_OPOFF
> +
> +#define to_jalr_imm(offset)                                            \
> +       ((offset & I_IMM_11_0_MASK) << I_IMM_11_0_OPOFF)
> +
> +#define to_auipc_imm(offset)                                           \
> +       ((offset & JALR_SIGN_MASK) ?                                    \
> +       ((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) :                    \
> +       (offset & AUIPC_OFFSET_MASK))
> +
> +static void riscv_alternative_fix_auipc_jalr(unsigned int *alt_ptr,
> +                                            unsigned int len, int patch_offset)
> +{
> +       int num_instr = len / sizeof(u32);
> +       unsigned int call[2];
> +       int i;
> +       int imm1;
> +       u32 rd1;
> +
> +       for (i = 0; i < num_instr; i++) {
> +               /* is there a further instruction? */
> +               if (i + 1 >= num_instr)
> +                       continue;
> +
> +               if (!is_auipc_jalr_pair(*(alt_ptr + i), *(alt_ptr + i + 1)))
> +                       continue;
> +
> +               /* call will use ra register */
> +               rd1 = EXTRACT_RD_REG(*(alt_ptr + i));
> +               if (rd1 != 1)
> +                       continue;
> +
> +               /* get and adjust new target address */
> +               imm1 = EXTRACT_UTYPE_IMM(*(alt_ptr + i));
> +               imm1 += EXTRACT_ITYPE_IMM(*(alt_ptr + i + 1));
> +               imm1 -= patch_offset;
> +
> +               /* pick the original auipc + jalr */
> +               call[0] = *(alt_ptr + i);
> +               call[1] = *(alt_ptr + i + 1);
> +
> +               /* drop the old IMMs */
> +               call[0] &= ~(U_IMM_31_12_MASK);
> +               call[1] &= ~(I_IMM_11_0_MASK << I_IMM_11_0_OPOFF);
> +
> +               /* add the adapted IMMs */
> +               call[0] |= to_auipc_imm(imm1);
> +               call[1] |= to_jalr_imm(imm1);
> +
> +               /* patch the call place again */
> +               patch_text_nosync(alt_ptr + i, call, 8);
> +       }
> +}
> +
>  static bool errata_probe_iocp(unsigned int stage, unsigned long arch_id, unsigned long impid)
>  {
>         if (!IS_ENABLED(CONFIG_ERRATA_ANDES_CMO))
> --
> 2.25.1
>
Lad, Prabhakar Nov. 25, 2022, 10:10 a.m. UTC | #2 
Hi Guo,

On Fri, Nov 25, 2022 at 1:09 AM Guo Ren <guoren@kernel.org> wrote:
>
> On Fri, Nov 25, 2022 at 1:22 AM Prabhakar <prabhakar.csengg@gmail.com> wrote:
> >
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >
> > This patch is added just for building purpose, as patch [0] will export
> > this in its next version.
> >
> > https://patchwork.kernel.org/project/linux-riscv/patch/20221110164924.529386-6-heiko@sntech.de/
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > ---
> > Note, as Heiko will be exporting riscv_alternative_fix_auipc_jalr() function
> > so that it can be used other erratas Ive just included for compilation.
> > ---
> >  arch/riscv/errata/andes/errata.c | 71 ++++++++++++++++++++++++++++++++
> >  1 file changed, 71 insertions(+)
> >
> > diff --git a/arch/riscv/errata/andes/errata.c b/arch/riscv/errata/andes/errata.c
> > index ec3e052ca8c7..4061ad4983bc 100644
> > --- a/arch/riscv/errata/andes/errata.c
> > +++ b/arch/riscv/errata/andes/errata.c
> > @@ -13,9 +13,80 @@
> >  #include <asm/alternative.h>
> >  #include <asm/cacheflush.h>
> >  #include <asm/errata_list.h>
> > +#include <asm/parse_asm.h>
> >  #include <asm/patch.h>
> > +#include <asm/sbi.h>
> >  #include <asm/vendorid_list.h>
> >
> > +/* Copy of Heiko's code from patch [0]
> > + * [0] https://patchwork.kernel.org/project/linux-riscv/patch/20221110164924.529386-6-heiko@sntech.de/
> Move it to commit-msg. No link in the code.
>
This patch is *not* to be merged and is just included for compilation
purposes only.

Cheers,
Prabhakar
diff mbox series

Patch

diff --git a/arch/riscv/errata/andes/errata.c b/arch/riscv/errata/andes/errata.c
index ec3e052ca8c7..4061ad4983bc 100644
--- a/arch/riscv/errata/andes/errata.c
+++ b/arch/riscv/errata/andes/errata.c
@@ -13,9 +13,80 @@ 
 #include <asm/alternative.h>
 #include <asm/cacheflush.h>
 #include <asm/errata_list.h>
+#include <asm/parse_asm.h>
 #include <asm/patch.h>
+#include <asm/sbi.h>
 #include <asm/vendorid_list.h>
 
+/* Copy of Heiko's code from patch [0]
+ * [0] https://patchwork.kernel.org/project/linux-riscv/patch/20221110164924.529386-6-heiko@sntech.de/
+ */
+DECLARE_INSN(jalr, MATCH_JALR, MASK_JALR)
+DECLARE_INSN(auipc, MATCH_AUIPC, MASK_AUIPC)
+
+static inline bool is_auipc_jalr_pair(long insn1, long insn2)
+{
+	return is_auipc_insn(insn1) && is_jalr_insn(insn2);
+}
+
+#define JALR_SIGN_MASK		BIT(I_IMM_SIGN_OPOFF - I_IMM_11_0_OPOFF)
+#define JALR_OFFSET_MASK	I_IMM_11_0_MASK
+#define AUIPC_OFFSET_MASK	U_IMM_31_12_MASK
+#define AUIPC_PAD		(0x00001000)
+#define JALR_SHIFT		I_IMM_11_0_OPOFF
+
+#define to_jalr_imm(offset)						\
+	((offset & I_IMM_11_0_MASK) << I_IMM_11_0_OPOFF)
+
+#define to_auipc_imm(offset)						\
+	((offset & JALR_SIGN_MASK) ?					\
+	((offset & AUIPC_OFFSET_MASK) + AUIPC_PAD) :			\
+	(offset & AUIPC_OFFSET_MASK))
+
+static void riscv_alternative_fix_auipc_jalr(unsigned int *alt_ptr,
+					     unsigned int len, int patch_offset)
+{
+	int num_instr = len / sizeof(u32);
+	unsigned int call[2];
+	int i;
+	int imm1;
+	u32 rd1;
+
+	for (i = 0; i < num_instr; i++) {
+		/* is there a further instruction? */
+		if (i + 1 >= num_instr)
+			continue;
+
+		if (!is_auipc_jalr_pair(*(alt_ptr + i), *(alt_ptr + i + 1)))
+			continue;
+
+		/* call will use ra register */
+		rd1 = EXTRACT_RD_REG(*(alt_ptr + i));
+		if (rd1 != 1)
+			continue;
+
+		/* get and adjust new target address */
+		imm1 = EXTRACT_UTYPE_IMM(*(alt_ptr + i));
+		imm1 += EXTRACT_ITYPE_IMM(*(alt_ptr + i + 1));
+		imm1 -= patch_offset;
+
+		/* pick the original auipc + jalr */
+		call[0] = *(alt_ptr + i);
+		call[1] = *(alt_ptr + i + 1);
+
+		/* drop the old IMMs */
+		call[0] &= ~(U_IMM_31_12_MASK);
+		call[1] &= ~(I_IMM_11_0_MASK << I_IMM_11_0_OPOFF);
+
+		/* add the adapted IMMs */
+		call[0] |= to_auipc_imm(imm1);
+		call[1] |= to_jalr_imm(imm1);
+
+		/* patch the call place again */
+		patch_text_nosync(alt_ptr + i, call, 8);
+	}
+}
+
 static bool errata_probe_iocp(unsigned int stage, unsigned long arch_id, unsigned long impid)
 {
 	if (!IS_ENABLED(CONFIG_ERRATA_ANDES_CMO))