linux-kernel - [PATCH v6 14/14] x86: kdebugfs do not use __va for getting setup

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Message-Id: <1387186235-15972-15-git-send-email-dyoung@redhat.com>
Date:	Mon, 16 Dec 2013 17:30:35 +0800
From:	Dave Young <dyoung@...hat.com>
To:	linux-kernel@...r.kernel.org
Cc:	linux-efi@...r.kernel.org, x86@...nel.org, mjg59@...f.ucam.org,
	hpa@...or.com, James.Bottomley@...senPartnership.com,
	vgoyal@...hat.com, ebiederm@...ssion.com, horms@...ge.net.au,
	kexec@...ts.infradead.org, bp@...en8.de, greg@...ah.com,
	matt@...sole-pimps.org, toshi.kani@...com,
	akpm@...ux-foundation.org, mingo@...nel.org, msalter@...hat.com,
	leif.lindholm@...aro.org
Subject: [PATCH v6 14/14] x86: kdebugfs do not use __va for getting setup_data virt addr

kdump kernel will use memmap=exactmap kernel cmdline, but __va does not
work in case memmap=exactmap, so let's always use ioremap_cache.

Signed-off-by: Dave Young <dyoung@...hat.com>
---
 arch/x86/kernel/kdebugfs.c | 35 +++++++++++------------------------
 1 file changed, 11 insertions(+), 24 deletions(-)

diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c
index dc1404b..185e1ca 100644
--- a/arch/x86/kernel/kdebugfs.c
+++ b/arch/x86/kernel/kdebugfs.c
@@ -33,7 +33,6 @@ static ssize_t setup_data_read(struct file *file, char __user *user_buf,
 	struct setup_data_node *node = file->private_data;
 	unsigned long remain;
 	loff_t pos = *ppos;
-	struct page *pg;
 	void *p;
 	u64 pa;
 
@@ -47,18 +46,12 @@ static ssize_t setup_data_read(struct file *file, char __user *user_buf,
 		count = node->len - pos;
 
 	pa = node->paddr + sizeof(struct setup_data) + pos;
-	pg = pfn_to_page((pa + count - 1) >> PAGE_SHIFT);
-	if (PageHighMem(pg)) {
-		p = ioremap_cache(pa, count);
-		if (!p)
-			return -ENXIO;
-	} else
-		p = __va(pa);
+	p = ioremap_cache(pa, count);
+	if (!p)
+		return -ENXIO;
 
 	remain = copy_to_user(user_buf, p, count);
-
-	if (PageHighMem(pg))
-		iounmap(p);
+	iounmap(p);
 
 	if (remain)
 		return -EFAULT;
@@ -109,7 +102,6 @@ static int __init create_setup_data_nodes(struct dentry *parent)
 	struct setup_data *data;
 	int error;
 	struct dentry *d;
-	struct page *pg;
 	u64 pa_data;
 	int no = 0;
 
@@ -126,16 +118,12 @@ static int __init create_setup_data_nodes(struct dentry *parent)
 			goto err_dir;
 		}
 
-		pg = pfn_to_page((pa_data+sizeof(*data)-1) >> PAGE_SHIFT);
-		if (PageHighMem(pg)) {
-			data = ioremap_cache(pa_data, sizeof(*data));
-			if (!data) {
-				kfree(node);
-				error = -ENXIO;
-				goto err_dir;
-			}
-		} else
-			data = __va(pa_data);
+		data = ioremap_cache(pa_data, sizeof(*data));
+		if (!data) {
+			kfree(node);
+			error = -ENXIO;
+			goto err_dir;
+		}
 
 		node->paddr = pa_data;
 		node->type = data->type;
@@ -143,8 +131,7 @@ static int __init create_setup_data_nodes(struct dentry *parent)
 		error = create_setup_data_node(d, no, node);
 		pa_data = data->next;
 
-		if (PageHighMem(pg))
-			iounmap(data);
+		iounmap(data);
 		if (error)
 			goto err_dir;
 		no++;
-- 
1.8.3.1

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