Re: [PATCH] platform: Allow platforms to customize TLB operations

On Fri, May 29, 2026 at 05:24:17PM +0800, Xiang W wrote:
> 在 2026-05-29五的 16:56 +0800，Inochi Amaoto写道：
> > On Fri, May 29, 2026 at 03:35:10PM +0800, Xiang W wrote:
> > > Some T-Head based processors, for example the Sophgo SG2044, have a
> > > JTLB errata that requires special handling of certain TLB maintenance
> > > instructions (sfence.vma).
> > > 
> > > Enable the JTLB workaround for affected boards.
> > > 
> > > Signed-off-by: Xiang W <[email protected]>
> > > Signed-off-by: Han Gao <[email protected]>
> > > ---
> > >  include/sbi/sbi_platform.h                   | 162 +++++++++++++++++++
> > >  lib/sbi/sbi_tlb.c                            |  28 ++++
> > >  platform/generic/include/thead/c9xx_errata.h |   1 +
> > >  platform/generic/thead/thead-generic.c       |  26 ++-
> > >  4 files changed, 216 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/include/sbi/sbi_platform.h b/include/sbi/sbi_platform.h
> > > index fe382b56..911b37bf 100644
> > > --- a/include/sbi/sbi_platform.h
> > > +++ b/include/sbi/sbi_platform.h
> > > @@ -56,6 +56,7 @@ struct sbi_domain_memregion;
> > >  struct sbi_ecall_return;
> > >  struct sbi_trap_regs;
> > >  struct sbi_hart_features;
> > > +struct sbi_tlb_info;
> > >  union sbi_ldst_data;
> > >  
> > >  /** Possible feature flags of a platform */
> > > @@ -125,6 +126,27 @@ struct sbi_platform_operations {
> > >  	/** Get tlb fifo num entries*/
> > >  	u32 (*get_tlb_num_entries)(void);
> > >  
> > > +	/** Platform hook for custom fence.i */
> > > +	void (*local_fence_i)(struct sbi_tlb_info *tinfo);
> > > +
> > > +	/** Platform hook for custom supervisor-mode TLB flush */
> > > +	void (*local_sfence_vma)(struct sbi_tlb_info *tinfo);
> > > +
> > > +	/** Platform hook for custom supervisor-mode TLB flush with ASID */
> > > +	void (*local_sfence_vma_asid)(struct sbi_tlb_info *tinfo);
> > > +
> > > +	/** Platform hook for custom G-stage TLB flush for a specific VMID */
> > > +	void (*local_hfence_gvma_vmid)(struct sbi_tlb_info *tinfo);
> > > +
> > > +	/** Platform hook for custom G-stage TLB flush */
> > > +	void (*local_hfence_gvma)(struct sbi_tlb_info *tinfo);
> > > +
> > > +	/** Platform hook for custom VS-stage TLB flush with ASID */
> > > +	void (*local_hfence_vvma_asid)(struct sbi_tlb_info *tinfo);
> > > +
> > > +	/** Platform hook for custom VS-stage TLB flush */
> > > +	void (*local_hfence_vvma)(struct sbi_tlb_info *tinfo);
> > > +
> > >  	/** Initialize platform timer during cold boot */
> > >  	int (*timer_init)(void);
> > >  
> > > @@ -313,6 +335,146 @@ static inline u32 sbi_platform_tlb_fifo_num_entries(const struct sbi_platform *p
> > >  	return sbi_hart_count();
> > >  }
> > >  
> > > +/**
> > > + * Platform hook for custom fence.i
> > > + *
> > > + * @param plat pointer to struct sbi_platform
> > > + * @paeam tinfo pointer to struct sbi_tlb_info
> > > + *
> > > + * @return 0 indicates that the platform supports the operation and the
> > > + * operation was successful; otherwise, a normal operation needs to be performed.
> > > + */
> > > +static inline u32 sbi_platform_local_fence_i(
> > > +					const struct sbi_platform *plat,
> > > +					struct sbi_tlb_info *tinfo)
> > > +{
> > > +	if (plat && sbi_platform_ops(plat)->local_fence_i) {
> > > +		sbi_platform_ops(plat)->local_fence_i(tinfo);
> > > +		return 0;
> > > +	}
> > > +	return SBI_ENOTSUPP;
> > > +}
> > > +
> > > +/**
> > > + * Platform hook for custom supervisor-mode TLB flush
> > > + *
> > > + * @param plat pointer to struct sbi_platform
> > > + * @paeam tinfo pointer to struct sbi_tlb_info
> > > + *
> > > + * @return 0 indicates that the platform supports the operation and the
> > > + * operation was successful; otherwise, a normal operation needs to be performed.
> > > + */
> > > +static inline u32 sbi_platform_local_sfence_vma(
> > > +					const struct sbi_platform *plat,
> > > +					struct sbi_tlb_info *tinfo)
> > > +{
> > > +	if (plat && sbi_platform_ops(plat)->local_sfence_vma) {
> > > +		sbi_platform_ops(plat)->local_sfence_vma(tinfo);
> > > +		return 0;
> > > +	}
> > > +	return SBI_ENOTSUPP;
> > > +}
> > > +
> > > +/**
> > > + * Platform hook for custom supervisor-mode TLB flush with ASID
> > > + *
> > > + * @param plat pointer to struct sbi_platform
> > > + * @paeam tinfo pointer to struct sbi_tlb_info
> > > + *
> > > + * @return 0 indicates that the platform supports the operation and the
> > > + * operation was successful; otherwise, a normal operation needs to be performed.
> > > + */
> > > +static inline u32 sbi_platform_local_sfence_vma_asid(
> > > +					const struct sbi_platform *plat,
> > > +					struct sbi_tlb_info *tinfo)
> > > +{
> > > +	if (plat && sbi_platform_ops(plat)->local_sfence_vma_asid) {
> > > +		sbi_platform_ops(plat)->local_sfence_vma_asid(tinfo);
> > > +		return 0;
> > > +	}
> > > +	return SBI_ENOTSUPP;
> > > +}
> > > +
> > > +/**
> > > + * Platform hook for custom G-stage TLB flush for a specific VMID
> > > + *
> > > + * @param plat pointer to struct sbi_platform
> > > + * @paeam tinfo pointer to struct sbi_tlb_info
> > > + *
> > > + * @return 0 indicates that the platform supports the operation and the
> > > + * operation was successful; otherwise, a normal operation needs to be performed.
> > > + */
> > > +static inline u32 sbi_platform_local_hfence_gvma_vmid(
> > > +					const struct sbi_platform *plat,
> > > +					struct sbi_tlb_info *tinfo)
> > > +{
> > > +	if (plat && sbi_platform_ops(plat)->local_hfence_gvma_vmid) {
> > > +		sbi_platform_ops(plat)->local_hfence_gvma_vmid(tinfo);
> > > +		return 0;
> > > +	}
> > > +	return SBI_ENOTSUPP;
> > > +}
> > > +
> > > +/**
> > > + * Platform hook for custom G-stage TLB flush
> > > + *
> > > + * @param plat pointer to struct sbi_platform
> > > + * @paeam tinfo pointer to struct sbi_tlb_info
> > > + *
> > > + * @return 0 indicates that the platform supports the operation and the
> > > + * operation was successful; otherwise, a normal operation needs to be performed.
> > > + */
> > > +static inline u32 sbi_platform_local_hfence_gvma(
> > > +					const struct sbi_platform *plat,
> > > +					struct sbi_tlb_info *tinfo)
> > > +{
> > > +	if (plat && sbi_platform_ops(plat)->local_hfence_gvma) {
> > > +		sbi_platform_ops(plat)->local_hfence_gvma(tinfo);
> > > +		return 0;
> > > +	}
> > > +	return SBI_ENOTSUPP;
> > > +}
> > > +
> > > +/**
> > > + * Platform hook for custom VS-stage TLB flush with ASID
> > > + *
> > > + * @param plat pointer to struct sbi_platform
> > > + * @paeam tinfo pointer to struct sbi_tlb_info
> > > + *
> > > + * @return 0 indicates that the platform supports the operation and the
> > > + * operation was successful; otherwise, a normal operation needs to be performed.
> > > + */
> > > +static inline u32 sbi_platform_local_hfence_vvma_asid(
> > > +					const struct sbi_platform *plat,
> > > +					struct sbi_tlb_info *tinfo)
> > > +{
> > > +	if (plat && sbi_platform_ops(plat)->local_hfence_vvma_asid) {
> > > +		sbi_platform_ops(plat)->local_hfence_vvma_asid(tinfo);
> > > +		return 0;
> > > +	}
> > > +	return SBI_ENOTSUPP;
> > > +}
> > > +
> > > +/**
> > > + * Platform hook for custom VS-stage TLB flush
> > > + *
> > > + * @param plat pointer to struct sbi_platform
> > > + * @paeam tinfo pointer to struct sbi_tlb_info
> > > + *
> > > + * @return 0 indicates that the platform supports the operation and the
> > > + * operation was successful; otherwise, a normal operation needs to be performed.
> > > + */
> > > +static inline u32 sbi_platform_local_hfence_vvma(
> > > +					const struct sbi_platform *plat,
> > > +					struct sbi_tlb_info *tinfo)
> > > +{
> > > +	if (plat && sbi_platform_ops(plat)->local_hfence_vvma) {
> > > +		sbi_platform_ops(plat)->local_hfence_vvma(tinfo);
> > > +		return 0;
> > > +	}
> > > +	return SBI_ENOTSUPP;
> > > +}
> > > +
> > >  /**
> > >   * Get total number of HARTs supported by the platform
> > >   *
> > > diff --git a/lib/sbi/sbi_tlb.c b/lib/sbi/sbi_tlb.c
> > > index ada60c32..69b8fb48 100644
> > > --- a/lib/sbi/sbi_tlb.c
> > > +++ b/lib/sbi/sbi_tlb.c
> > > @@ -46,6 +46,10 @@ static void sbi_tlb_local_hfence_vvma(struct sbi_tlb_info *tinfo)
> > >  	hgatp = csr_swap(CSR_HGATP,
> > >  			 (vmid << HGATP_VMID_SHIFT) & HGATP_VMID_MASK);
> > >  
> > > +	if (sbi_platform_local_hfence_gvma(
> > > +			sbi_platform_thishart_ptr(), tinfo) == SBI_OK)
> > > +		gito done;
> > > +
> > >  	if ((start == 0 && size == 0) || (size == SBI_TLB_FLUSH_ALL)) {
> > >  		__sbi_hfence_vvma_all();
> > >  		goto done;
> > > @@ -67,6 +71,10 @@ static void sbi_tlb_local_hfence_gvma(struct sbi_tlb_info *tinfo)
> > >  
> > >  	sbi_pmu_ctr_incr_fw(SBI_PMU_FW_HFENCE_GVMA_RCVD);
> > >  
> > > +	if (sbi_platform_local_hfence_gvma(
> > > +			sbi_platform_thishart_ptr(), tinfo) == SBI_OK)
> > > +		return;
> > > +
> > >  	if ((start == 0 && size == 0) || (size == SBI_TLB_FLUSH_ALL)) {
> > >  		__sbi_hfence_gvma_all();
> > >  		return;
> > > @@ -85,6 +93,10 @@ static void sbi_tlb_local_sfence_vma(struct sbi_tlb_info *tinfo)
> > >  
> > >  	sbi_pmu_ctr_incr_fw(SBI_PMU_FW_SFENCE_VMA_RCVD);
> > >  
> > > +	if (sbi_platform_local_sfence_vma(
> > > +			sbi_platform_thishart_ptr(), tinfo) == SBI_OK)
> > > +		return;
> > > +
> > >  	if ((start == 0 && size == 0) || (size == SBI_TLB_FLUSH_ALL)) {
> > >  		__sbi_sfence_vma_all();
> > >  		return;
> > > @@ -111,6 +123,10 @@ static void sbi_tlb_local_hfence_vvma_asid(struct sbi_tlb_info *tinfo)
> > >  	hgatp = csr_swap(CSR_HGATP,
> > >  			 (vmid << HGATP_VMID_SHIFT) & HGATP_VMID_MASK);
> > >  
> > > +	if (sbi_platform_local_hfence_vvma_asid(
> > > +			sbi_platform_thishart_ptr(), tinfo) == SBI_OK)
> > > +		goto done;
> > > +
> > >  	if ((start == 0 && size == 0) || (size == SBI_TLB_FLUSH_ALL)) {
> > >  		__sbi_hfence_vvma_asid(asid);
> > >  		goto done;
> > > @@ -133,6 +149,10 @@ static void sbi_tlb_local_hfence_gvma_vmid(struct sbi_tlb_info *tinfo)
> > >  
> > >  	sbi_pmu_ctr_incr_fw(SBI_PMU_FW_HFENCE_GVMA_VMID_RCVD);
> > >  
> > > +	if (sbi_platform_local_hfence_gvma_vmid(
> > > +			sbi_platform_thishart_ptr(), tinfo) == SBI_OK)
> > > +		return;
> > > +
> > >  	if ((start == 0 && size == 0) || (size == SBI_TLB_FLUSH_ALL)) {
> > >  		__sbi_hfence_gvma_vmid(vmid);
> > >  		return;
> > > @@ -152,6 +172,10 @@ static void sbi_tlb_local_sfence_vma_asid(struct sbi_tlb_info *tinfo)
> > >  
> > >  	sbi_pmu_ctr_incr_fw(SBI_PMU_FW_SFENCE_VMA_ASID_RCVD);
> > >  
> > > +	if (sbi_platform_local_sfence_vma_asid(
> > > +			sbi_platform_thishart_ptr(), tinfo) == SBI_OK)
> > > +		return;
> > > +
> > >  	/* Flush entire MM context for a given ASID */
> > >  	if ((start == 0 && size == 0) || (size == SBI_TLB_FLUSH_ALL)) {
> > >  		__asm__ __volatile__("sfence.vma x0, %0"
> > > @@ -173,6 +197,10 @@ static void sbi_tlb_local_fence_i(struct sbi_tlb_info *tinfo)
> > >  {
> > >  	sbi_pmu_ctr_incr_fw(SBI_PMU_FW_FENCE_I_RECVD);
> > >  
> > > +	if (sbi_platform_local_fence_i(
> > > +			sbi_platform_thishart_ptr(), tinfo) == SBI_OK)
> > > +		return;
> > > +
> > >  	__asm__ __volatile("fence.i");
> > >  }
> > >  
> > 
> > I suggest split the following as a separate patch.
> > 
> > > diff --git a/platform/generic/include/thead/c9xx_errata.h b/platform/generic/include/thead/c9xx_errata.h
> > > index 40c1587b..7a419e41 100644
> > > --- a/platform/generic/include/thead/c9xx_errata.h
> > > +++ b/platform/generic/include/thead/c9xx_errata.h
> > > @@ -8,6 +8,7 @@
> > >   */
> > >  #define THEAD_QUIRK_ERRATA_TLB_FLUSH		BIT(0)
> > >  #define THEAD_QUIRK_ERRATA_THEAD_PMU		BIT(1)
> > > +#define THEAD_QUIRK_ERRATA_JTLB			BIT(2)
> > >  
> > >  void thead_register_tlb_flush_trap_handler(void);
> > >  
> > > diff --git a/platform/generic/thead/thead-generic.c b/platform/generic/thead/thead-generic.c
> > > index ddb4f0bf..86793ab1 100644
> > > --- a/platform/generic/thead/thead-generic.c
> > > +++ b/platform/generic/thead/thead-generic.c
> > > @@ -13,6 +13,7 @@
> > >  #include <sbi/sbi_platform.h>
> > >  #include <sbi/sbi_scratch.h>
> > >  #include <sbi/sbi_string.h>
> > > +#include <sbi/sbi_tlb.h>
> > >  #include <sbi_utils/fdt/fdt_helper.h>
> > >  
> > >  struct thead_generic_quirks {
> > > @@ -39,6 +40,20 @@ static int thead_pmu_extensions_init(struct sbi_hart_features *hfeatures)
> > >  	return 0;
> > >  }
> > >  
> > > +static void thead_jtlb_local_sfence_vma(struct sbi_tlb_info *tinfo)
> > > +{
> > > +	__asm__ __volatile__("sfence.vma");
> > > +}
> > > +
> > > +static void thead_jtlb_local_sfence_vvma_asid(struct sbi_tlb_info *tinfo)
> > > +{
> > > +	/* Flush entire MM context for a given ASID */
> > > +	__asm__ __volatile__("sfence.vma x0, %0"
> > > +			     :
> > > +			     : "r"(tinfo->asid)
> > > +			     : "memory");
> > > +}
> > > +
> > >  static int thead_generic_platform_init(const void *fdt, int nodeoff,
> > >  				       const struct fdt_match *match)
> > >  {
> > > @@ -49,6 +64,11 @@ static int thead_generic_platform_init(const void *fdt, int nodeoff,
> > >  	if (quirks->errata & THEAD_QUIRK_ERRATA_THEAD_PMU)
> > >  		generic_platform_ops.extensions_init = thead_pmu_extensions_init;
> > >  
> > > +	if (quirks->errata &THEAD_QUIRK_ERRATA_JTLB) {
> > > +		generic_platform_ops.local_sfence_vma = thead_jtlb_local_sfence_vma;
> > > +		generic_platform_ops.local_sfence_vma_asid = thead_jtlb_local_sfence_vvma_asid;
> > > +	}
> > > +
> > >  	return 0;
> > >  }
> > >  
> > > @@ -60,13 +80,17 @@ static const struct thead_generic_quirks thead_pmu_quirks = {
> > >  	.errata = THEAD_QUIRK_ERRATA_THEAD_PMU,
> > >  };
> > >  
> > > +static const struct thead_generic_quirks thead_pmu_jtlb_quirks = {
> > > +	.errata = THEAD_QUIRK_ERRATA_THEAD_PMU | THEAD_QUIRK_ERRATA_JTLB,
> > > +};
> > > +
> > 
> > IIRC, it is better to not setting THEAD_QUIRK_ERRATA_THEAD_PMU anymore
> > for sg2044. The T-HEAD specific PMU feature is bad for the cpu version of
> > the sg2044.
> Thanks for the feedback.
> 
> IIRC, you're right that the T-HEAD specific PMU feature may not be suitable 
> for the current SG2044 CPU version.
> 
> However, since this patch is focused on TLB customization for the JTLB errata, 
> I think it's better to keep it independent. Could you please send the PMU quirk 
> change as a separate patch? That would make both changes cleaner and easier to 
> review.
> 
> Best regards,
> Xiang W

It is fine for me to fix it.

I will send the fix patch after this is merged.

Regards,
Inochi


> > 
> > >  static const struct fdt_match thead_generic_match[] = {
> > >  	{ .compatible = "canaan,kendryte-k230", .data = &thead_pmu_quirks },
> > >  	{ .compatible = "sophgo,cv1800b", .data = &thead_pmu_quirks },
> > >  	{ .compatible = "sophgo,cv1812h", .data = &thead_pmu_quirks },
> > >  	{ .compatible = "sophgo,sg2000", .data = &thead_pmu_quirks },
> > >  	{ .compatible = "sophgo,sg2002", .data = &thead_pmu_quirks },
> > > -	{ .compatible = "sophgo,sg2044", .data = &thead_pmu_quirks },
> > > +	{ .compatible = "sophgo,sg2044", .data = &thead_pmu_jtlb_quirks },
> > >  	{ .compatible = "thead,th1520", .data = &thead_th1520_quirks },
> > >  	{ },
> > >  };
> > > -- 
> > > 2.47.3
> > > 
> > > 
> > > -- 
> > > opensbi mailing list
> > > [email protected]
> > > http://lists.infradead.org/mailman/listinfo/opensbi
> 
> 
> -- 
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