From b08193bfe3cbd027ceb554e919fcff756ec52103 Mon Sep 17 00:00:00 2001
From: Tao Zeng <tao.zeng@amlogic.com>
Date: Thu, 27 Dec 2018 14:31:29 +0800
Subject: [PATCH] dmc: fix panic problem when show memory in highmem [1/1]

PD#SWPL-2767

Problem:
If DMC violation address is in highmem, then it will panic
when show memory using page_address();

Solution:
map violation address for highmem

Verify:
p212

Change-Id: Ib6213eaab42b129c8c0a381511a0b3376b0d3e66
Signed-off-by: Tao Zeng <tao.zeng@amlogic.com>
---
 drivers/amlogic/ddr_tool/dmc_g12.c | 33 +++++++++++++++++++++---------
 drivers/amlogic/ddr_tool/dmc_gx.c  | 33 +++++++++++++++++++++---------
 2 files changed, 46 insertions(+), 20 deletions(-)

diff --git a/drivers/amlogic/ddr_tool/dmc_g12.c b/drivers/amlogic/ddr_tool/dmc_g12.c
index 9afc61e34d52..8e35e212697e 100644
--- a/drivers/amlogic/ddr_tool/dmc_g12.c
+++ b/drivers/amlogic/ddr_tool/dmc_g12.c
@@ -29,6 +29,7 @@
 #include <linux/irqreturn.h>
 #include <linux/module.h>
 #include <linux/mm.h>
+#include <linux/highmem.h>
 
 #include <linux/cpu.h>
 #include <linux/smp.h>
@@ -76,12 +77,31 @@ static size_t g12_dmc_dump_reg(char *buf)
 	return sz;
 }
 
+static void show_violation_mem(unsigned long addr)
+{
+	struct page *page;
+	unsigned long *p, *q;
+
+	if (!pfn_valid(__phys_to_pfn(addr)))
+		return;
+
+	page = phys_to_page(addr);
+	p = kmap_atomic(page);
+	if (!p)
+		return;
+
+	q = p + ((addr & (PAGE_SIZE - 1)) / sizeof(*p));
+	pr_info(DMC_TAG "[%08lx]:%016lx, f:%8lx, m:%p, a:%ps\n",
+		(unsigned long)q, *q, page->flags & 0xffffffff,
+		page->mapping,
+		(void *)get_page_trace(page));
+	kunmap_atomic(p);
+}
+
 static void check_violation(struct dmc_monitor *mon)
 {
 	int i, port, subport;
 	unsigned long addr, status;
-	struct page *page;
-	unsigned long *p;
 	char id_str[4];
 	char off1 = 21, off2 = 10;
 
@@ -112,14 +132,7 @@ static void check_violation(struct dmc_monitor *mon)
 		pr_info(DMC_TAG", addr:%08lx, s:%08lx, ID:%s, sub:%s, c:%ld\n",
 			addr, status, to_ports(port),
 			to_sub_ports(port, subport, id_str), mon->same_page);
-		if (pfn_valid(__phys_to_pfn(addr))) {
-			page = phys_to_page(addr);
-			p = (page_address(page) + (addr & (PAGE_SIZE - 1)));
-			pr_info(DMC_TAG" [%08lx]:%016lx, f:%8lx, m:%p, a:%pf\n",
-				addr, *p, page->flags & 0xffffffff,
-				page->mapping,
-				(void *)get_page_trace(page));
-		}
+		show_violation_mem(addr);
 		if (!port) /* dump stack for CPU write */
 			dump_stack();
 
diff --git a/drivers/amlogic/ddr_tool/dmc_gx.c b/drivers/amlogic/ddr_tool/dmc_gx.c
index e0b1203974c0..7871970cdd6a 100644
--- a/drivers/amlogic/ddr_tool/dmc_gx.c
+++ b/drivers/amlogic/ddr_tool/dmc_gx.c
@@ -29,6 +29,7 @@
 #include <linux/irqreturn.h>
 #include <linux/module.h>
 #include <linux/mm.h>
+#include <linux/highmem.h>
 
 #include <linux/cpu.h>
 #include <linux/smp.h>
@@ -80,12 +81,31 @@ static size_t gx_dmc_dump_reg(char *buf)
 	return sz;
 }
 
+static void show_violation_mem(unsigned long addr)
+{
+	struct page *page;
+	unsigned long *p, *q;
+
+	if (!pfn_valid(__phys_to_pfn(addr)))
+		return;
+
+	page = phys_to_page(addr);
+	p = kmap_atomic(page);
+	if (!p)
+		return;
+
+	q = p + ((addr & (PAGE_SIZE - 1)) / sizeof(*p));
+	pr_info(DMC_TAG "[%08lx]:%016lx, f:%8lx, m:%p, a:%ps\n",
+		(unsigned long)q, *q, page->flags & 0xffffffff,
+		page->mapping,
+		(void *)get_page_trace(page));
+	kunmap_atomic(p);
+}
+
 static void check_violation(struct dmc_monitor *mon)
 {
 	int i, port, subport;
 	unsigned long addr, status;
-	struct page *page;
-	unsigned long *p;
 	char id_str[4];
 
 	for (i = 1; i < 8; i += 2) {
@@ -109,14 +129,7 @@ static void check_violation(struct dmc_monitor *mon)
 		pr_info(DMC_TAG", addr:%08lx, s:%08lx, ID:%s, sub:%s, c:%ld\n",
 			addr, status, to_ports(port),
 			to_sub_ports(port, subport, id_str), mon->same_page);
-		if (pfn_valid(__phys_to_pfn(addr))) {
-			page = phys_to_page(addr);
-			p = (page_address(page) + (addr & (PAGE_SIZE - 1)));
-			pr_info(DMC_TAG" [%08lx]:%016lx, f:%8lx, m:%p, a:%pf\n",
-				addr, *p, page->flags & 0xffffffff,
-				page->mapping,
-				(void *)get_page_trace(page));
-		}
+		show_violation_mem(addr);
 		if (!port) /* dump stack for CPU write */
 			dump_stack();