[PATCH v12 07/22] riscv: mm: Add p?d_leaf() definitions

[PATCH v12 07/22] riscv: mm: Add p?d_leaf() definitions

[Steven Price]

walk_page_range() is going to be allowed to walk page tables other than
those of user space. For this it needs to know when it has reached a
'leaf' entry in the page tables. This information is provided by the
p?d_leaf() functions/macros.

For riscv a page is a leaf page when it has a read, write or execute bit
set on it.

CC: Palmer Dabbelt <palmer@sifive.com>
CC: Albert Ou <aou@eecs.berkeley.edu>
CC: linux-riscv@lists.infradead.org
Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Acked-by: Paul Walmsley <paul.walmsley@sifive.com> # for arch/riscv
Signed-off-by: Steven Price <steven.price@arm.com>
---
 arch/riscv/include/asm/pgtable-64.h | 7 +++++++
 arch/riscv/include/asm/pgtable.h    | 7 +++++++
 2 files changed, 14 insertions(+)

diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
index 74630989006d..e88a8e8acbdf 100644
--- a/arch/riscv/include/asm/pgtable-64.h
+++ b/arch/riscv/include/asm/pgtable-64.h
@@ -43,6 +43,13 @@ static inline int pud_bad(pud_t pud)
 	return !pud_present(pud);
 }
 
+#define pud_leaf	pud_leaf
+static inline int pud_leaf(pud_t pud)
+{
+	return pud_present(pud)
+		&& (pud_val(pud) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+}
+
 static inline void set_pud(pud_t *pudp, pud_t pud)
 {
 	*pudp = pud;
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 7255f2d8395b..b9a679153265 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -130,6 +130,13 @@ static inline int pmd_bad(pmd_t pmd)
 	return !pmd_present(pmd);
 }
 
+#define pmd_leaf	pmd_leaf
+static inline int pmd_leaf(pmd_t pmd)
+{
+	return pmd_present(pmd)
+		&& (pmd_val(pmd) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
+}
+
 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 {
 	*pmdp = pmd;
-- 
2.20.1


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Re: [PATCH v12 07/22] riscv: mm: Add p?d_leaf() definitions

[Christoph Hellwig]

> +	return pud_present(pud)
> +		&& (pud_val(pud) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
> +}

The operators always need to go before the line break, not after it
per linux coding style.  There are a few more spots like this, so please
audit the whole series for it.

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Re: [PATCH v12 07/22] riscv: mm: Add p?d_leaf() definitions

[Steven Price]

On 18/10/2019 16:57, Christoph Hellwig wrote:
>> +	return pud_present(pud)
>> +		&& (pud_val(pud) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
>> +}
> 
> The operators always need to go before the line break, not after it
> per linux coding style.  There are a few more spots like this, so please
> audit the whole series for it.

Fair enough. In this case I was just copying the example in pte_huge()
that already existed - but you're right this isn't the kernel coding style.

Thanks,

Steve

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