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Diffstat (limited to 'arch/powerpc/mm/hash_utils_64.c')
-rw-r--r--arch/powerpc/mm/hash_utils_64.c87
1 files changed, 54 insertions, 33 deletions
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 1005281be9a6..7635b1c6b5da 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -168,11 +168,11 @@ unsigned long htab_convert_pte_flags(unsigned long pteflags)
 		rflags |= HPTE_R_N;
 	/*
 	 * PP bits:
-	 * Linux use slb key 0 for kernel and 1 for user.
-	 * kernel areas are mapped by PP bits 00
-	 * and and there is no kernel RO (_PAGE_KERNEL_RO).
-	 * User area mapped by 0x2 and read only use by
-	 * 0x3.
+	 * Linux uses slb key 0 for kernel and 1 for user.
+	 * kernel areas are mapped with PP=00
+	 * and there is no kernel RO (_PAGE_KERNEL_RO).
+	 * User area is mapped with PP=0x2 for read/write
+	 * or PP=0x3 for read-only (including writeable but clean pages).
 	 */
 	if (pteflags & _PAGE_USER) {
 		rflags |= 0x2;
@@ -265,28 +265,32 @@ int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
 	return ret < 0 ? ret : 0;
 }
 
-#ifdef CONFIG_MEMORY_HOTPLUG
 int htab_remove_mapping(unsigned long vstart, unsigned long vend,
 		      int psize, int ssize)
 {
 	unsigned long vaddr;
 	unsigned int step, shift;
+	int rc;
+	int ret = 0;
 
 	shift = mmu_psize_defs[psize].shift;
 	step = 1 << shift;
 
-	if (!ppc_md.hpte_removebolted) {
-		printk(KERN_WARNING "Platform doesn't implement "
-				"hpte_removebolted\n");
-		return -EINVAL;
-	}
+	if (!ppc_md.hpte_removebolted)
+		return -ENODEV;
 
-	for (vaddr = vstart; vaddr < vend; vaddr += step)
-		ppc_md.hpte_removebolted(vaddr, psize, ssize);
+	for (vaddr = vstart; vaddr < vend; vaddr += step) {
+		rc = ppc_md.hpte_removebolted(vaddr, psize, ssize);
+		if (rc == -ENOENT) {
+			ret = -ENOENT;
+			continue;
+		}
+		if (rc < 0)
+			return rc;
+	}
 
-	return 0;
+	return ret;
 }
-#endif /* CONFIG_MEMORY_HOTPLUG */
 
 static int __init htab_dt_scan_seg_sizes(unsigned long node,
 					 const char *uname, int depth,
@@ -607,10 +611,28 @@ static int __init htab_dt_scan_pftsize(unsigned long node,
 	return 0;
 }
 
-static unsigned long __init htab_get_table_size(void)
+unsigned htab_shift_for_mem_size(unsigned long mem_size)
 {
-	unsigned long mem_size, rnd_mem_size, pteg_count, psize;
+	unsigned memshift = __ilog2(mem_size);
+	unsigned pshift = mmu_psize_defs[mmu_virtual_psize].shift;
+	unsigned pteg_shift;
+
+	/* round mem_size up to next power of 2 */
+	if ((1UL << memshift) < mem_size)
+		memshift += 1;
+
+	/* aim for 2 pages / pteg */
+	pteg_shift = memshift - (pshift + 1);
 
+	/*
+	 * 2^11 PTEGS of 128 bytes each, ie. 2^18 bytes is the minimum htab
+	 * size permitted by the architecture.
+	 */
+	return max(pteg_shift + 7, 18U);
+}
+
+static unsigned long __init htab_get_table_size(void)
+{
 	/* If hash size isn't already provided by the platform, we try to
 	 * retrieve it from the device-tree. If it's not there neither, we
 	 * calculate it now based on the total RAM size
@@ -620,31 +642,30 @@ static unsigned long __init htab_get_table_size(void)
 	if (ppc64_pft_size)
 		return 1UL << ppc64_pft_size;
 
-	/* round mem_size up to next power of 2 */
-	mem_size = memblock_phys_mem_size();
-	rnd_mem_size = 1UL << __ilog2(mem_size);
-	if (rnd_mem_size < mem_size)
-		rnd_mem_size <<= 1;
-
-	/* # pages / 2 */
-	psize = mmu_psize_defs[mmu_virtual_psize].shift;
-	pteg_count = max(rnd_mem_size >> (psize + 1), 1UL << 11);
-
-	return pteg_count << 7;
+	return 1UL << htab_shift_for_mem_size(memblock_phys_mem_size());
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
 int create_section_mapping(unsigned long start, unsigned long end)
 {
-	return htab_bolt_mapping(start, end, __pa(start),
-				 pgprot_val(PAGE_KERNEL), mmu_linear_psize,
-				 mmu_kernel_ssize);
+	int rc = htab_bolt_mapping(start, end, __pa(start),
+				   pgprot_val(PAGE_KERNEL), mmu_linear_psize,
+				   mmu_kernel_ssize);
+
+	if (rc < 0) {
+		int rc2 = htab_remove_mapping(start, end, mmu_linear_psize,
+					      mmu_kernel_ssize);
+		BUG_ON(rc2 && (rc2 != -ENOENT));
+	}
+	return rc;
 }
 
 int remove_section_mapping(unsigned long start, unsigned long end)
 {
-	return htab_remove_mapping(start, end, mmu_linear_psize,
-			mmu_kernel_ssize);
+	int rc = htab_remove_mapping(start, end, mmu_linear_psize,
+				     mmu_kernel_ssize);
+	WARN_ON(rc < 0);
+	return rc;
 }
 #endif /* CONFIG_MEMORY_HOTPLUG */