[PATCH 1/3] riscv: Fixup _PAGE_GLOBAL in _PAGE_KERNEL

[PATCH 1/3] riscv: Fixup _PAGE_GLOBAL in _PAGE_KERNEL

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Kernel virtual address translation should avoid care asid or it'll
cause more TLB-miss and TLB-refill. Because the current asid in satp
belongs to the current process, but the target kernel va TLB entry's
asid still belongs to the previous process.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Anup Patel <anup.patel@wdc.com>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
---
 arch/riscv/include/asm/pgtable.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 78f2323..017da15 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -135,6 +135,7 @@
 				| _PAGE_PRESENT \
 				| _PAGE_ACCESSED \
 				| _PAGE_DIRTY \
+				| _PAGE_GLOBAL \
 				| _PAGE_CACHE)
 
 #define PAGE_KERNEL		__pgprot(_PAGE_KERNEL)
-- 
2.7.4

[PATCH 2/3] riscv: Fixup PAGE_UP in asm/page.h

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Current PAGE_UP implementation is wrong. PAGE_UP(0) should be
0x1000, but current implementation will give out 0.

Although the current PAGE_UP isn't used, it will soon be used in
tlb_flush optimization.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Anup Patel <anup.patel@wdc.com>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
---
 arch/riscv/include/asm/page.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index 6a7761c..c611b20 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -37,7 +37,7 @@
 
 #ifndef __ASSEMBLY__
 
-#define PAGE_UP(addr)	(((addr)+((PAGE_SIZE)-1))&(~((PAGE_SIZE)-1)))
+#define PAGE_UP(addr)	(((addr)+(PAGE_SIZE))&(~((PAGE_SIZE)-1)))
 #define PAGE_DOWN(addr)	((addr)&(~((PAGE_SIZE)-1)))
 
 /* align addr on a size boundary - adjust address up/down if needed */
-- 
2.7.4

[PATCH 3/3] riscv: Use use_asid_allocator flush TLB

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Use static_branch_unlikely(&use_asid_allocator) to keep the origin
tlb flush style, so it's no effect on the existing machine. Here
are the optimized functions:
 - flush_tlb_mm
 - flush_tlb_page
 - flush_tlb_range

All above are based on the below new implement functions:
 - __sbi_tlb_flush_range_asid
 - local_flush_tlb_range_asid

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Anup Patel <anup.patel@wdc.com>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
---
 arch/riscv/include/asm/mmu_context.h |  2 ++
 arch/riscv/include/asm/tlbflush.h    | 22 ++++++++++++++++++++
 arch/riscv/mm/context.c              |  2 +-
 arch/riscv/mm/tlbflush.c             | 40 +++++++++++++++++++++++++++++++++---
 4 files changed, 62 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/include/asm/mmu_context.h b/arch/riscv/include/asm/mmu_context.h
index b065941..7030837 100644
--- a/arch/riscv/include/asm/mmu_context.h
+++ b/arch/riscv/include/asm/mmu_context.h
@@ -33,6 +33,8 @@ static inline int init_new_context(struct task_struct *tsk,
 	return 0;
 }
 
+DECLARE_STATIC_KEY_FALSE(use_asid_allocator);
+
 #include <asm-generic/mmu_context.h>
 
 #endif /* _ASM_RISCV_MMU_CONTEXT_H */
diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h
index c84218a..9390319 100644
--- a/arch/riscv/include/asm/tlbflush.h
+++ b/arch/riscv/include/asm/tlbflush.h
@@ -8,6 +8,7 @@
 #define _ASM_RISCV_TLBFLUSH_H
 
 #include <linux/mm_types.h>
+#include <asm/page.h>
 #include <asm/smp.h>
 #include <asm/errata_list.h>
 
@@ -22,9 +23,30 @@ static inline void local_flush_tlb_page(unsigned long addr)
 {
 	ALT_FLUSH_TLB_PAGE(__asm__ __volatile__ ("sfence.vma %0" : : "r" (addr) : "memory"));
 }
+
+static inline void local_flush_tlb_range_asid(unsigned long start, unsigned long size,
+					      unsigned long asid)
+{
+	unsigned long page_add = PAGE_DOWN(start);
+	unsigned long page_end = PAGE_UP(start + size);
+
+	if (size == -1) {
+		__asm__ __volatile__ ("sfence.vma x0, %0" : : "r" (asid) : "memory");
+		return;
+	}
+
+	while(page_add < page_end) {
+		__asm__ __volatile__ ("sfence.vma %0, %1"
+				:
+				: "r" (page_add), "r" (asid)
+				: "memory");
+		page_add += PAGE_SIZE;
+	}
+}
 #else /* CONFIG_MMU */
 #define local_flush_tlb_all()			do { } while (0)
 #define local_flush_tlb_page(addr)		do { } while (0)
+#define local_flush_tlb_range_asid(addr)	do { } while (0)
 #endif /* CONFIG_MMU */
 
 #if defined(CONFIG_SMP) && defined(CONFIG_MMU)
diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c
index 68aa312..45c1b04 100644
--- a/arch/riscv/mm/context.c
+++ b/arch/riscv/mm/context.c
@@ -18,7 +18,7 @@
 
 #ifdef CONFIG_MMU
 
-static DEFINE_STATIC_KEY_FALSE(use_asid_allocator);
+DEFINE_STATIC_KEY_FALSE(use_asid_allocator);
 
 static unsigned long asid_bits;
 static unsigned long num_asids;
diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c
index 720b443..69588dc 100644
--- a/arch/riscv/mm/tlbflush.c
+++ b/arch/riscv/mm/tlbflush.c
@@ -4,6 +4,7 @@
 #include <linux/smp.h>
 #include <linux/sched.h>
 #include <asm/sbi.h>
+#include <asm/mmu_context.h>
 
 void flush_tlb_all(void)
 {
@@ -39,18 +40,51 @@ static void __sbi_tlb_flush_range(struct cpumask *cmask, unsigned long start,
 	put_cpu();
 }
 
+static void __sbi_tlb_flush_range_asid(struct cpumask *cmask, unsigned long start,
+				       unsigned long size, unsigned long asid)
+{
+	struct cpumask hmask;
+	unsigned int cpuid;
+
+	if (cpumask_empty(cmask))
+		return;
+
+	cpuid = get_cpu();
+
+	if (cpumask_any_but(cmask, cpuid) >= nr_cpu_ids) {
+		local_flush_tlb_range_asid(start, size, asid);
+	} else {
+		riscv_cpuid_to_hartid_mask(cmask, &hmask);
+		sbi_remote_sfence_vma_asid(cpumask_bits(&hmask), start, size, asid);
+	}
+
+	put_cpu();
+}
+
 void flush_tlb_mm(struct mm_struct *mm)
 {
-	__sbi_tlb_flush_range(mm_cpumask(mm), 0, -1);
+	if (static_branch_unlikely(&use_asid_allocator))
+		__sbi_tlb_flush_range_asid(mm_cpumask(mm), 0, -1,
+					   atomic_long_read(&mm->context.id));
+	else
+		__sbi_tlb_flush_range(mm_cpumask(mm), 0, -1);
 }
 
 void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
 {
-	__sbi_tlb_flush_range(mm_cpumask(vma->vm_mm), addr, PAGE_SIZE);
+	if (static_branch_unlikely(&use_asid_allocator))
+		__sbi_tlb_flush_range_asid(mm_cpumask(vma->vm_mm), addr, PAGE_SIZE,
+					   atomic_long_read(&vma->vm_mm->context.id));
+	else
+		__sbi_tlb_flush_range(mm_cpumask(vma->vm_mm), addr, PAGE_SIZE);
 }
 
 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 		     unsigned long end)
 {
-	__sbi_tlb_flush_range(mm_cpumask(vma->vm_mm), start, end - start);
+	if (static_branch_unlikely(&use_asid_allocator))
+		__sbi_tlb_flush_range_asid(mm_cpumask(vma->vm_mm), start, end - start,
+					   atomic_long_read(&vma->vm_mm->context.id));
+	else
+		__sbi_tlb_flush_range(mm_cpumask(vma->vm_mm), start, end - start);
 }
-- 
2.7.4

Re: [PATCH 1/3] riscv: Fixup _PAGE_GLOBAL in _PAGE_KERNEL

[Anup Patel]

On Mon, May 24, 2021 at 12:22 PM <guoren@kernel.org> wrote:
>
> From: Guo Ren <guoren@linux.alibaba.com>
>
> Kernel virtual address translation should avoid care asid or it'll
> cause more TLB-miss and TLB-refill. Because the current asid in satp
> belongs to the current process, but the target kernel va TLB entry's
> asid still belongs to the previous process.
>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Cc: Anup Patel <anup.patel@wdc.com>
> Cc: Palmer Dabbelt <palmerdabbelt@google.com>

First of all thanks for doing this series, I had similar changes in mind
as follow-up to the ASID allocator.

I went through all three patches and at least I don't see any
obvious issue but I think we should try testing it more on a few
existing platforms.

Reviewed-by: Anup Patel <anup@brainfault.org>

Regards,
Anup

> ---
>  arch/riscv/include/asm/pgtable.h | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 78f2323..017da15 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -135,6 +135,7 @@
>                                 | _PAGE_PRESENT \
>                                 | _PAGE_ACCESSED \
>                                 | _PAGE_DIRTY \
> +                               | _PAGE_GLOBAL \
>                                 | _PAGE_CACHE)
>
>  #define PAGE_KERNEL            __pgprot(_PAGE_KERNEL)
> --
> 2.7.4
>

Re: [PATCH 3/3] riscv: Use use_asid_allocator flush TLB

[Anup Patel]

On Mon, May 24, 2021 at 12:22 PM <guoren@kernel.org> wrote:
>
> From: Guo Ren <guoren@linux.alibaba.com>
>
> Use static_branch_unlikely(&use_asid_allocator) to keep the origin
> tlb flush style, so it's no effect on the existing machine. Here
> are the optimized functions:
>  - flush_tlb_mm
>  - flush_tlb_page
>  - flush_tlb_range
>
> All above are based on the below new implement functions:
>  - __sbi_tlb_flush_range_asid
>  - local_flush_tlb_range_asid
>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Cc: Anup Patel <anup.patel@wdc.com>
> Cc: Palmer Dabbelt <palmerdabbelt@google.com>
> ---
>  arch/riscv/include/asm/mmu_context.h |  2 ++
>  arch/riscv/include/asm/tlbflush.h    | 22 ++++++++++++++++++++
>  arch/riscv/mm/context.c              |  2 +-
>  arch/riscv/mm/tlbflush.c             | 40 +++++++++++++++++++++++++++++++++---
>  4 files changed, 62 insertions(+), 4 deletions(-)
>
> diff --git a/arch/riscv/include/asm/mmu_context.h b/arch/riscv/include/asm/mmu_context.h
> index b065941..7030837 100644
> --- a/arch/riscv/include/asm/mmu_context.h
> +++ b/arch/riscv/include/asm/mmu_context.h
> @@ -33,6 +33,8 @@ static inline int init_new_context(struct task_struct *tsk,
>         return 0;
>  }
>
> +DECLARE_STATIC_KEY_FALSE(use_asid_allocator);
> +
>  #include <asm-generic/mmu_context.h>
>
>  #endif /* _ASM_RISCV_MMU_CONTEXT_H */
> diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h
> index c84218a..9390319 100644
> --- a/arch/riscv/include/asm/tlbflush.h
> +++ b/arch/riscv/include/asm/tlbflush.h
> @@ -8,6 +8,7 @@
>  #define _ASM_RISCV_TLBFLUSH_H
>
>  #include <linux/mm_types.h>
> +#include <asm/page.h>
>  #include <asm/smp.h>
>  #include <asm/errata_list.h>
>
> @@ -22,9 +23,30 @@ static inline void local_flush_tlb_page(unsigned long addr)
>  {
>         ALT_FLUSH_TLB_PAGE(__asm__ __volatile__ ("sfence.vma %0" : : "r" (addr) : "memory"));
>  }
> +
> +static inline void local_flush_tlb_range_asid(unsigned long start, unsigned long size,
> +                                             unsigned long asid)
> +{
> +       unsigned long page_add = PAGE_DOWN(start);
> +       unsigned long page_end = PAGE_UP(start + size);

Your PATCH2 is not correct because PAGE_UP(x) should in-fact
return 0 when x == 0.

In fact, if both "start" and "size" are zero then both page_add and
page_end should be zero so that no "sfence.vma" is executed.

If you want at least one TLB entry to be invalidated when size == 0
then you can simply set "size = 1" when size is zero which will force
one TLB invalidation.

Please drop your PATCH2 and the rest of the things look good to me.

Reviewed-by: Anup Patel <anup@brainfault.org>

Regards,
Anup

> +
> +       if (size == -1) {
> +               __asm__ __volatile__ ("sfence.vma x0, %0" : : "r" (asid) : "memory");
> +               return;
> +       }
> +
> +       while(page_add < page_end) {
> +               __asm__ __volatile__ ("sfence.vma %0, %1"
> +                               :
> +                               : "r" (page_add), "r" (asid)
> +                               : "memory");
> +               page_add += PAGE_SIZE;
> +       }
> +}
>  #else /* CONFIG_MMU */
>  #define local_flush_tlb_all()                  do { } while (0)
>  #define local_flush_tlb_page(addr)             do { } while (0)
> +#define local_flush_tlb_range_asid(addr)       do { } while (0)
>  #endif /* CONFIG_MMU */
>
>  #if defined(CONFIG_SMP) && defined(CONFIG_MMU)
> diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c
> index 68aa312..45c1b04 100644
> --- a/arch/riscv/mm/context.c
> +++ b/arch/riscv/mm/context.c
> @@ -18,7 +18,7 @@
>
>  #ifdef CONFIG_MMU
>
> -static DEFINE_STATIC_KEY_FALSE(use_asid_allocator);
> +DEFINE_STATIC_KEY_FALSE(use_asid_allocator);
>
>  static unsigned long asid_bits;
>  static unsigned long num_asids;
> diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c
> index 720b443..69588dc 100644
> --- a/arch/riscv/mm/tlbflush.c
> +++ b/arch/riscv/mm/tlbflush.c
> @@ -4,6 +4,7 @@
>  #include <linux/smp.h>
>  #include <linux/sched.h>
>  #include <asm/sbi.h>
> +#include <asm/mmu_context.h>
>
>  void flush_tlb_all(void)
>  {
> @@ -39,18 +40,51 @@ static void __sbi_tlb_flush_range(struct cpumask *cmask, unsigned long start,
>         put_cpu();
>  }
>
> +static void __sbi_tlb_flush_range_asid(struct cpumask *cmask, unsigned long start,
> +                                      unsigned long size, unsigned long asid)
> +{
> +       struct cpumask hmask;
> +       unsigned int cpuid;
> +
> +       if (cpumask_empty(cmask))
> +               return;
> +
> +       cpuid = get_cpu();
> +
> +       if (cpumask_any_but(cmask, cpuid) >= nr_cpu_ids) {
> +               local_flush_tlb_range_asid(start, size, asid);
> +       } else {
> +               riscv_cpuid_to_hartid_mask(cmask, &hmask);
> +               sbi_remote_sfence_vma_asid(cpumask_bits(&hmask), start, size, asid);
> +       }
> +
> +       put_cpu();
> +}
> +
>  void flush_tlb_mm(struct mm_struct *mm)
>  {
> -       __sbi_tlb_flush_range(mm_cpumask(mm), 0, -1);
> +       if (static_branch_unlikely(&use_asid_allocator))
> +               __sbi_tlb_flush_range_asid(mm_cpumask(mm), 0, -1,
> +                                          atomic_long_read(&mm->context.id));
> +       else
> +               __sbi_tlb_flush_range(mm_cpumask(mm), 0, -1);
>  }
>
>  void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
>  {
> -       __sbi_tlb_flush_range(mm_cpumask(vma->vm_mm), addr, PAGE_SIZE);
> +       if (static_branch_unlikely(&use_asid_allocator))
> +               __sbi_tlb_flush_range_asid(mm_cpumask(vma->vm_mm), addr, PAGE_SIZE,
> +                                          atomic_long_read(&vma->vm_mm->context.id));
> +       else
> +               __sbi_tlb_flush_range(mm_cpumask(vma->vm_mm), addr, PAGE_SIZE);
>  }
>
>  void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
>                      unsigned long end)
>  {
> -       __sbi_tlb_flush_range(mm_cpumask(vma->vm_mm), start, end - start);
> +       if (static_branch_unlikely(&use_asid_allocator))
> +               __sbi_tlb_flush_range_asid(mm_cpumask(vma->vm_mm), start, end - start,
> +                                          atomic_long_read(&vma->vm_mm->context.id));
> +       else
> +               __sbi_tlb_flush_range(mm_cpumask(vma->vm_mm), start, end - start);
>  }
> --
> 2.7.4
>

Re: [PATCH 1/3] riscv: Fixup _PAGE_GLOBAL in _PAGE_KERNEL

[Guo Ren]

Hi Anup,

On Mon, May 24, 2021 at 4:03 PM Anup Patel <anup@brainfault.org> wrote:
>
> On Mon, May 24, 2021 at 12:22 PM <guoren@kernel.org> wrote:
> >
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > Kernel virtual address translation should avoid care asid or it'll
> > cause more TLB-miss and TLB-refill. Because the current asid in satp
> > belongs to the current process, but the target kernel va TLB entry's
> > asid still belongs to the previous process.
> >
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Cc: Anup Patel <anup.patel@wdc.com>
> > Cc: Palmer Dabbelt <palmerdabbelt@google.com>
>
> First of all thanks for doing this series, I had similar changes in mind
> as follow-up to the ASID allocator.
>
> I went through all three patches and at least I don't see any
> obvious issue but I think we should try testing it more on a few
> existing platforms.
We've tested it on Allwinner D1 C906 and C910 SMP*4 for a long time,
just hope it won't affect u540.

(In fact, C910 has used ASID allocator for more than two years with
our own kernel-tree. I remember we've talked about it in 2019
plumber.)

>
> Reviewed-by: Anup Patel <anup@brainfault.org>
>
> Regards,
> Anup
>
> > ---
> >  arch/riscv/include/asm/pgtable.h | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> > index 78f2323..017da15 100644
> > --- a/arch/riscv/include/asm/pgtable.h
> > +++ b/arch/riscv/include/asm/pgtable.h
> > @@ -135,6 +135,7 @@
> >                                 | _PAGE_PRESENT \
> >                                 | _PAGE_ACCESSED \
> >                                 | _PAGE_DIRTY \
> > +                               | _PAGE_GLOBAL \
> >                                 | _PAGE_CACHE)
> >
> >  #define PAGE_KERNEL            __pgprot(_PAGE_KERNEL)
> > --
> > 2.7.4
> >



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

Re: [PATCH 1/3] riscv: Fixup _PAGE_GLOBAL in _PAGE_KERNEL

[Anup Patel]

On Mon, May 24, 2021 at 12:22 PM <guoren@kernel.org> wrote:
>
> From: Guo Ren <guoren@linux.alibaba.com>
>
> Kernel virtual address translation should avoid care asid or it'll
> cause more TLB-miss and TLB-refill. Because the current asid in satp
> belongs to the current process, but the target kernel va TLB entry's
> asid still belongs to the previous process.
>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Cc: Anup Patel <anup.patel@wdc.com>
> Cc: Palmer Dabbelt <palmerdabbelt@google.com>
> ---
>  arch/riscv/include/asm/pgtable.h | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 78f2323..017da15 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -135,6 +135,7 @@
>                                 | _PAGE_PRESENT \
>                                 | _PAGE_ACCESSED \
>                                 | _PAGE_DIRTY \
> +                               | _PAGE_GLOBAL \
>                                 | _PAGE_CACHE)

It seems this patch is not based on the upstream kernel. The
_PAGE_CACHE seems to be from your other patch series.

Please rebase these patches on the latest upstream kernel without
dependency on any other patch series.

Regards,
Anup

>
>  #define PAGE_KERNEL            __pgprot(_PAGE_KERNEL)
> --
> 2.7.4
>

Re: [PATCH 1/3] riscv: Fixup _PAGE_GLOBAL in _PAGE_KERNEL

[Guo Ren]

On Mon, May 24, 2021 at 6:42 PM Anup Patel <anup@brainfault.org> wrote:
>
> On Mon, May 24, 2021 at 12:22 PM <guoren@kernel.org> wrote:
> >
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > Kernel virtual address translation should avoid care asid or it'll
> > cause more TLB-miss and TLB-refill. Because the current asid in satp
> > belongs to the current process, but the target kernel va TLB entry's
> > asid still belongs to the previous process.
> >
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Cc: Anup Patel <anup.patel@wdc.com>
> > Cc: Palmer Dabbelt <palmerdabbelt@google.com>
> > ---
> >  arch/riscv/include/asm/pgtable.h | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> > index 78f2323..017da15 100644
> > --- a/arch/riscv/include/asm/pgtable.h
> > +++ b/arch/riscv/include/asm/pgtable.h
> > @@ -135,6 +135,7 @@
> >                                 | _PAGE_PRESENT \
> >                                 | _PAGE_ACCESSED \
> >                                 | _PAGE_DIRTY \
> > +                               | _PAGE_GLOBAL \
> >                                 | _PAGE_CACHE)
>
> It seems this patch is not based on the upstream kernel. The
> _PAGE_CACHE seems to be from your other patch series.
>
> Please rebase these patches on the latest upstream kernel without
> dependency on any other patch series.
Yes, it based on DMA_COHERENT. I'll rebase in PATCH V2, thx.

>
> Regards,
> Anup
>
> >
> >  #define PAGE_KERNEL            __pgprot(_PAGE_KERNEL)
> > --
> > 2.7.4
> >



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

Re: [PATCH 2/3] riscv: Fixup PAGE_UP in asm/page.h

[Christoph Hellwig]

On Mon, May 24, 2021 at 06:51:07AM +0000, guoren@kernel.org wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
> 
> Current PAGE_UP implementation is wrong. PAGE_UP(0) should be
> 0x1000, but current implementation will give out 0.
> 
> Although the current PAGE_UP isn't used, it will soon be used in
> tlb_flush optimization.

Nak.  Please just remove the PAGE_UP/PAGE_DOWN macros just like they
have been removed from other architectures long ago and use the
generic DIV_ROUND_UP macro for your new code like everyone else.

Re: [PATCH 2/3] riscv: Fixup PAGE_UP in asm/page.h

[Guo Ren]

On Tue, May 25, 2021 at 2:34 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Mon, May 24, 2021 at 06:51:07AM +0000, guoren@kernel.org wrote:
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > Current PAGE_UP implementation is wrong. PAGE_UP(0) should be
> > 0x1000, but current implementation will give out 0.
> >
> > Although the current PAGE_UP isn't used, it will soon be used in
> > tlb_flush optimization.
>
> Nak.  Please just remove the PAGE_UP/PAGE_DOWN macros just like they
> have been removed from other architectures long ago and use the
> generic DIV_ROUND_UP macro for your new code like everyone else.

This patch has been dropped because it's wrong, ref Anup's reply.

Remove PAGE_UP/DOWN is okay for me. How about:
 static inline void local_flush_tlb_range_asid(unsigned long start,
unsigned long size,
                                              unsigned long asid)
 {
-       unsigned long page_add = PAGE_DOWN(start);
-       unsigned long page_end = PAGE_UP(start + size);
+       unsigned long page_add = _ALIGN_DOWN(start, PAGE_SIZE);
+       unsigned long page_end = _ALIGN_UP(start + size, PAGE_SIZE);

_ALIGN_XXX are also defined in arch/riscv/include/asm/page.h.

-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

Re: [PATCH 2/3] riscv: Fixup PAGE_UP in asm/page.h

[Christoph Hellwig]

On Tue, May 25, 2021 at 05:28:21PM +0800, Guo Ren wrote:
> On Tue, May 25, 2021 at 2:34 PM Christoph Hellwig <hch@infradead.org> wrote:
> >
> > On Mon, May 24, 2021 at 06:51:07AM +0000, guoren@kernel.org wrote:
> > > From: Guo Ren <guoren@linux.alibaba.com>
> > >
> > > Current PAGE_UP implementation is wrong. PAGE_UP(0) should be
> > > 0x1000, but current implementation will give out 0.
> > >
> > > Although the current PAGE_UP isn't used, it will soon be used in
> > > tlb_flush optimization.
> >
> > Nak.  Please just remove the PAGE_UP/PAGE_DOWN macros just like they
> > have been removed from other architectures long ago and use the
> > generic DIV_ROUND_UP macro for your new code like everyone else.
> 
> This patch has been dropped because it's wrong, ref Anup's reply.
> 
> Remove PAGE_UP/DOWN is okay for me. How about:
>  static inline void local_flush_tlb_range_asid(unsigned long start,
> unsigned long size,
>                                               unsigned long asid)
>  {
> -       unsigned long page_add = PAGE_DOWN(start);
> -       unsigned long page_end = PAGE_UP(start + size);
> +       unsigned long page_add = _ALIGN_DOWN(start, PAGE_SIZE);
> +       unsigned long page_end = _ALIGN_UP(start + size, PAGE_SIZE);
> 
> _ALIGN_XXX are also defined in arch/riscv/include/asm/page.h.

And these also are leftovers from days gone by and should be removed.

I think this should simply be:

	
	unsigned long page_add = start & PAGE_MASK;
	unsigned long page_end = PAGE_ALIGN(start + size);

(and page_add is a pretty horrible name as well..)