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From:   Laurent Vivier <lvivier@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     linuxppc-dev@lists.ozlabs.org,
        Christophe Leroy <christophe.leroy@c-s.fr>,
        David Gibson <david@gibson.dropbear.id.au>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Laurent Vivier <lvivier@redhat.com>
Subject: [PATCH v3] powerpc/mm: move warning from resize_hpt_for_hotplug()
Date:   Wed, 13 Mar 2019 11:25:28 +0100
Message-Id: <20190313102528.4632-1-lvivier@redhat.com>
MIME-Version: 1.0
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Sender: linux-kernel-owner@vger.kernel.org
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resize_hpt_for_hotplug() reports a warning when it cannot
resize the hash page table ("Unable to resize hash page
table to target order") but in some cases it's not a problem
and can make user thinks something has not worked properly.

This patch moves the warning to arch_remove_memory() to
only report the problem when it is needed.

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---

Notes:
    v3: move "||" to above line and remove parenthesis
    v2: add warning messages for H_PARAMETER and H_RESOURCE

 arch/powerpc/include/asm/sparsemem.h  |  4 ++--
 arch/powerpc/mm/hash_utils_64.c       | 19 +++++++------------
 arch/powerpc/mm/mem.c                 |  3 ++-
 arch/powerpc/platforms/pseries/lpar.c |  3 ++-
 4 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/arch/powerpc/include/asm/sparsemem.h b/arch/powerpc/include/asm/sparsemem.h
index 68da49320592..3192d454a733 100644
--- a/arch/powerpc/include/asm/sparsemem.h
+++ b/arch/powerpc/include/asm/sparsemem.h
@@ -17,9 +17,9 @@ extern int create_section_mapping(unsigned long start, unsigned long end, int ni
 extern int remove_section_mapping(unsigned long start, unsigned long end);
 
 #ifdef CONFIG_PPC_BOOK3S_64
-extern void resize_hpt_for_hotplug(unsigned long new_mem_size);
+extern int resize_hpt_for_hotplug(unsigned long new_mem_size);
 #else
-static inline void resize_hpt_for_hotplug(unsigned long new_mem_size) { }
+static inline int resize_hpt_for_hotplug(unsigned long new_mem_size) { return 0; }
 #endif
 
 #ifdef CONFIG_NUMA
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 0cc7fbc3bd1c..5aa7594ee71b 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -755,12 +755,12 @@ static unsigned long __init htab_get_table_size(void)
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-void resize_hpt_for_hotplug(unsigned long new_mem_size)
+int resize_hpt_for_hotplug(unsigned long new_mem_size)
 {
 	unsigned target_hpt_shift;
 
 	if (!mmu_hash_ops.resize_hpt)
-		return;
+		return 0;
 
 	target_hpt_shift = htab_shift_for_mem_size(new_mem_size);
 
@@ -772,16 +772,11 @@ void resize_hpt_for_hotplug(unsigned long new_mem_size)
 	 * reduce unless the target shift is at least 2 below the
 	 * current shift
 	 */
-	if ((target_hpt_shift > ppc64_pft_size)
-	    || (target_hpt_shift < (ppc64_pft_size - 1))) {
-		int rc;
-
-		rc = mmu_hash_ops.resize_hpt(target_hpt_shift);
-		if (rc && (rc != -ENODEV))
-			printk(KERN_WARNING
-			       "Unable to resize hash page table to target order %d: %d\n",
-			       target_hpt_shift, rc);
-	}
+	if (target_hpt_shift > ppc64_pft_size ||
+	    target_hpt_shift < ppc64_pft_size - 1)
+		return mmu_hash_ops.resize_hpt(target_hpt_shift);
+
+	return 0;
 }
 
 int hash__create_section_mapping(unsigned long start, unsigned long end, int nid)
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 33cc6f676fa6..0d40d970cf4a 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -169,7 +169,8 @@ int __meminit arch_remove_memory(int nid, u64 start, u64 size,
 	 */
 	vm_unmap_aliases();
 
-	resize_hpt_for_hotplug(memblock_phys_mem_size());
+	if (resize_hpt_for_hotplug(memblock_phys_mem_size()) == -ENOSPC)
+		pr_warn("Hash collision while resizing HPT\n");
 
 	return ret;
 }
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index f2a9f0adc2d3..1034ef1fe2b4 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -901,8 +901,10 @@ static int pseries_lpar_resize_hpt(unsigned long shift)
 		break;
 
 	case H_PARAMETER:
+		pr_warn("Invalid argument from H_RESIZE_HPT_PREPARE\n");
 		return -EINVAL;
 	case H_RESOURCE:
+		pr_warn("Operation not permitted from H_RESIZE_HPT_PREPARE\n");
 		return -EPERM;
 	default:
 		pr_warn("Unexpected error %d from H_RESIZE_HPT_PREPARE\n", rc);
@@ -918,7 +920,6 @@ static int pseries_lpar_resize_hpt(unsigned long shift)
 	if (rc != 0) {
 		switch (state.commit_rc) {
 		case H_PTEG_FULL:
-			pr_warn("Hash collision while resizing HPT\n");
 			return -ENOSPC;
 
 		default:
-- 
2.20.1