Re: [PATCH v2 10/17] powerpc/mm: Merge vsid calculation in hash_page() and copro_data_segment()

On Wed, 2014-10-01 at 15:25 +0530, Aneesh Kumar K.V wrote:

Michael Neuling [off-list ref] writes:
=20

quoted

From: Ian Munsie <redacted>

The vsid calculation between hash_page() and copro_data_segment() are v=

ery

quoted

similar.  This merges these two different versions.

Signed-off-by: Ian Munsie <redacted>
Signed-off-by: Michael Neuling <redacted>
---
 arch/powerpc/include/asm/mmu-hash64.h |  2 ++
 arch/powerpc/mm/copro_fault.c         | 45 ++++++--------------------
 arch/powerpc/mm/hash_utils_64.c       | 61 ++++++++++++++++++++++-----=

--------

quoted

 3 files changed, 50 insertions(+), 58 deletions(-)

diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/inclu=

de/asm/mmu-hash64.h

quoted

index f84e5a5..bf43fb0 100644

--- a/arch/powerpc/include/asm/mmu-hash64.h
+++ b/arch/powerpc/include/asm/mmu-hash64.h

@@ -322,6 +322,8 @@ extern int __hash_page_64K(unsigned long ea, unsign=

ed long access,

quoted

 			   unsigned int local, int ssize);
 struct mm_struct;
 unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int =

trap);

quoted

+int calculate_vsid(struct mm_struct *mm, u64 ea,
+		   u64 *vsid, int *psize, int *ssize);
 extern int hash_page_mm(struct mm_struct *mm, unsigned long ea, unsign=

ed long access, unsigned long trap);

quoted

 extern int hash_page(unsigned long ea, unsigned long access, unsigned =

long trap);

quoted

 int __hash_page_huge(unsigned long ea, unsigned long access, unsigned =

long vsid,

quoted

diff --git a/arch/powerpc/mm/copro_fault.c b/arch/powerpc/mm/copro_faul=

t.c

quoted

index 939abdf..ba8bf8e 100644

--- a/arch/powerpc/mm/copro_fault.c
+++ b/arch/powerpc/mm/copro_fault.c

@@ -94,45 +94,18 @@ EXPORT_SYMBOL_GPL(copro_handle_mm_fault);

=20
 int copro_data_segment(struct mm_struct *mm, u64 ea, u64 *esid, u64 *v=

sid)

quoted

 {
-	int psize, ssize;
+	int psize, ssize, rc;
=20
 	*esid =3D (ea & ESID_MASK) | SLB_ESID_V;
=20
-	switch (REGION_ID(ea)) {
-	case USER_REGION_ID:
-		pr_devel("copro_data_segment: 0x%llx -- USER_REGION_ID\n", ea);
-#ifdef CONFIG_PPC_MM_SLICES
-		psize =3D get_slice_psize(mm, ea);
-#else
-		psize =3D mm->context.user_psize;
-#endif
-		ssize =3D user_segment_size(ea);
-		*vsid =3D (get_vsid(mm->context.id, ea, ssize)
-			 << slb_vsid_shift(ssize)) | SLB_VSID_USER;
-		break;
-	case VMALLOC_REGION_ID:
-		pr_devel("copro_data_segment: 0x%llx -- VMALLOC_REGION_ID\n", ea);
-		if (ea < VMALLOC_END)
-			psize =3D mmu_vmalloc_psize;
-		else
-			psize =3D mmu_io_psize;
-		ssize =3D mmu_kernel_ssize;
-		*vsid =3D (get_kernel_vsid(ea, mmu_kernel_ssize)
-			 << SLB_VSID_SHIFT) | SLB_VSID_KERNEL;
-		break;
-	case KERNEL_REGION_ID:
-		pr_devel("copro_data_segment: 0x%llx -- KERNEL_REGION_ID\n", ea);
-		psize =3D mmu_linear_psize;
-		ssize =3D mmu_kernel_ssize;
-		*vsid =3D (get_kernel_vsid(ea, mmu_kernel_ssize)
-			 << SLB_VSID_SHIFT) | SLB_VSID_KERNEL;
-		break;
-	default:
-		/* Future: support kernel segments so that drivers can use the
-		 * CoProcessors */
-		pr_debug("invalid region access at %016llx\n", ea);
-		return 1;
-	}
+	rc =3D calculate_vsid(mm, ea, vsid, &psize, &ssize);
+	if (rc)
+		return rc;
+	if (REGION_ID(ea) =3D=3D USER_REGION_ID)
+		*vsid =3D (*vsid << slb_vsid_shift(ssize)) | SLB_VSID_USER;
+	else
+		*vsid =3D (*vsid << SLB_VSID_SHIFT) | SLB_VSID_KERNEL;
+
 	*vsid |=3D mmu_psize_defs[psize].sllp |
 		((ssize =3D=3D MMU_SEGSIZE_1T) ? SLB_VSID_B_1T : 0);
=20

diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_uti=

ls_64.c

quoted

index 0a5c8c0..3fa81ca 100644

--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c

@@ -983,6 +983,38 @@ static void check_paca_psize(unsigned long ea, str=

uct mm_struct *mm,

quoted

 	}
 }
=20
+int calculate_vsid(struct mm_struct *mm, u64 ea,
+		   u64 *vsid, int *psize, int *ssize)
+{
+	switch (REGION_ID(ea)) {
+	case USER_REGION_ID:
+		pr_devel("%s: 0x%llx -- USER_REGION_ID\n", __func__, ea);
+		*psize =3D get_slice_psize(mm, ea);
+		*ssize =3D user_segment_size(ea);
+		*vsid =3D get_vsid(mm->context.id, ea, *ssize);
+		return 0;
+	case VMALLOC_REGION_ID:
+		pr_devel("%s: 0x%llx -- VMALLOC_REGION_ID\n", __func__, ea);
+		if (ea < VMALLOC_END)
+			*psize =3D mmu_vmalloc_psize;
+		else
+			*psize =3D mmu_io_psize;
+		*ssize =3D mmu_kernel_ssize;
+		*vsid =3D get_kernel_vsid(ea, mmu_kernel_ssize);
+		return 0;
+	case KERNEL_REGION_ID:
+		pr_devel("%s: 0x%llx -- KERNEL_REGION_ID\n", __func__, ea);
+		*psize =3D mmu_linear_psize;
+		*ssize =3D mmu_kernel_ssize;
+		*vsid =3D get_kernel_vsid(ea, mmu_kernel_ssize);
+		return 0;
+	default:
+		pr_debug("%s: invalid region access at %016llx\n", __func__, ea);
+		return 1;
+	}
+}
+EXPORT_SYMBOL_GPL(calculate_vsid);
+
 /* Result code is:
  *  0 - handled
  *  1 - normal page fault

@@ -993,7 +1025,7 @@ int hash_page_mm(struct mm_struct *mm, unsigned lo=

ng ea, unsigned long access, u

quoted

 {
 	enum ctx_state prev_state =3D exception_enter();
 	pgd_t *pgdir;
-	unsigned long vsid;
+	u64 vsid;
 	pte_t *ptep;
 	unsigned hugeshift;
 	const struct cpumask *tmp;

@@ -1003,35 +1035,20 @@ int hash_page_mm(struct mm_struct *mm, unsigned=

 long ea, unsigned long access, u

quoted

 	DBG_LOW("%s(ea=3D%016lx, access=3D%lx, trap=3D%lx\n",
 		__func__, ea, access, trap);
=20
-	/* Get region & vsid */
- 	switch (REGION_ID(ea)) {
-	case USER_REGION_ID:
+	/* Get region */
+	if (REGION_ID(ea) =3D=3D USER_REGION_ID) {
 		user_region =3D 1;
 		if (! mm) {
 			DBG_LOW(" user region with no mm !\n");
 			rc =3D 1;
 			goto bail;
 		}
-		psize =3D get_slice_psize(mm, ea);
-		ssize =3D user_segment_size(ea);
-		vsid =3D get_vsid(mm->context.id, ea, ssize);
-		break;
-	case VMALLOC_REGION_ID:
+	} else
 		mm =3D &init_mm;
-		vsid =3D get_kernel_vsid(ea, mmu_kernel_ssize);
-		if (ea < VMALLOC_END)
-			psize =3D mmu_vmalloc_psize;
-		else
-			psize =3D mmu_io_psize;
-		ssize =3D mmu_kernel_ssize;
-		break;
-	default:
-		/* Not a valid range
-		 * Send the problem up to do_page_fault=20
-		 */
-		rc =3D 1;

=20
=20
That part is different now. We now handle kernel_region_id in case of
hash_page. Earlier we used consider it a problem.=20

Yeah, that's going to be the kernel linear mapping.  We should probably
continue to barf as we shouldn't fault on that.  Thanks.

I'll fix.

Mikey

=20

quoted

+	rc =3D calculate_vsid(mm, ea, &vsid, &psize, &ssize);
+	if (rc)
 		goto bail;
-	}
+
 	DBG_LOW(" mm=3D%p, mm->pgdir=3D%p, vsid=3D%016lx\n", mm, mm->pgd, vsi=

d);

quoted

=20
 	/* Bad address. */
--=20
1.9.1

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