Revision 475049809977bf3975d78f2d2fd992e19ce2d59e authored by Roel Kluin on 10 March 2009, 19:55:45 UTC, committed by Linus Torvalds on 10 March 2009, 22:55:10 UTC
get_nid_for_pfn() returns int Presumably the (nid < 0) case has never happened. We do know that it is happening on one system while creating a symlink for a memory section so it should also happen on the same system if unregister_mem_sect_under_nodes() were called to remove the same symlink. The test was actually added in response to a problem with an earlier version reported by Yasunori Goto where one or more of the leading pages of a memory section on the 2nd node of one of his systems was uninitialized because I believe they coincided with a memory hole. That earlier version did not ignore uninitialized pages and determined the nid by considering only the 1st page of each memory section. This caused the symlink to the 1st memory section on the 2nd node to be incorrectly created in /sys/devices/system/node/node0 instead of /sys/devices/system/node/node1. The problem was fixed by adding the test to skip over uninitialized pages. I suspect we have not seen any reports of the non-removal of a symlink due to the incorrect declaration of the nid variable in unregister_mem_sect_under_nodes() because - systems where a memory section could have an uninitialized range of leading pages are probably rare. - memory remove is probably not done very frequently on the systems that are capable of demonstrating the problem. - lingering symlink(s) that should have been removed may have simply gone unnoticed. [garyhade@us.ibm.com: wrote changelog] Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Cc: Gary Hade <garyhade@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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bt431.h
/*
* linux/drivers/video/bt431.h
*
* Copyright 2003 Thiemo Seufer <seufer@csv.ica.uni-stuttgart.de>
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*/
#include <linux/types.h>
#include <asm/system.h>
/*
* Bt431 cursor generator registers, 32-bit aligned.
* Two twin Bt431 are used on the DECstation's PMAG-AA.
*/
struct bt431_regs {
volatile u16 addr_lo;
u16 pad0;
volatile u16 addr_hi;
u16 pad1;
volatile u16 addr_cmap;
u16 pad2;
volatile u16 addr_reg;
u16 pad3;
};
static inline u16 bt431_set_value(u8 val)
{
return ((val << 8) | (val & 0xff)) & 0xffff;
}
static inline u8 bt431_get_value(u16 val)
{
return val & 0xff;
}
/*
* Additional registers addressed indirectly.
*/
#define BT431_REG_CMD 0x0000
#define BT431_REG_CXLO 0x0001
#define BT431_REG_CXHI 0x0002
#define BT431_REG_CYLO 0x0003
#define BT431_REG_CYHI 0x0004
#define BT431_REG_WXLO 0x0005
#define BT431_REG_WXHI 0x0006
#define BT431_REG_WYLO 0x0007
#define BT431_REG_WYHI 0x0008
#define BT431_REG_WWLO 0x0009
#define BT431_REG_WWHI 0x000a
#define BT431_REG_WHLO 0x000b
#define BT431_REG_WHHI 0x000c
#define BT431_REG_CRAM_BASE 0x0000
#define BT431_REG_CRAM_END 0x01ff
/*
* Command register.
*/
#define BT431_CMD_CURS_ENABLE 0x40
#define BT431_CMD_XHAIR_ENABLE 0x20
#define BT431_CMD_OR_CURSORS 0x10
#define BT431_CMD_AND_CURSORS 0x00
#define BT431_CMD_1_1_MUX 0x00
#define BT431_CMD_4_1_MUX 0x04
#define BT431_CMD_5_1_MUX 0x08
#define BT431_CMD_xxx_MUX 0x0c
#define BT431_CMD_THICK_1 0x00
#define BT431_CMD_THICK_3 0x01
#define BT431_CMD_THICK_5 0x02
#define BT431_CMD_THICK_7 0x03
static inline void bt431_select_reg(struct bt431_regs *regs, int ir)
{
/*
* The compiler splits the write in two bytes without these
* helper variables.
*/
volatile u16 *lo = &(regs->addr_lo);
volatile u16 *hi = &(regs->addr_hi);
mb();
*lo = bt431_set_value(ir & 0xff);
wmb();
*hi = bt431_set_value((ir >> 8) & 0xff);
}
/* Autoincrement read/write. */
static inline u8 bt431_read_reg_inc(struct bt431_regs *regs)
{
/*
* The compiler splits the write in two bytes without the
* helper variable.
*/
volatile u16 *r = &(regs->addr_reg);
mb();
return bt431_get_value(*r);
}
static inline void bt431_write_reg_inc(struct bt431_regs *regs, u8 value)
{
/*
* The compiler splits the write in two bytes without the
* helper variable.
*/
volatile u16 *r = &(regs->addr_reg);
mb();
*r = bt431_set_value(value);
}
static inline u8 bt431_read_reg(struct bt431_regs *regs, int ir)
{
bt431_select_reg(regs, ir);
return bt431_read_reg_inc(regs);
}
static inline void bt431_write_reg(struct bt431_regs *regs, int ir, u8 value)
{
bt431_select_reg(regs, ir);
bt431_write_reg_inc(regs, value);
}
/* Autoincremented read/write for the cursor map. */
static inline u16 bt431_read_cmap_inc(struct bt431_regs *regs)
{
/*
* The compiler splits the write in two bytes without the
* helper variable.
*/
volatile u16 *r = &(regs->addr_cmap);
mb();
return *r;
}
static inline void bt431_write_cmap_inc(struct bt431_regs *regs, u16 value)
{
/*
* The compiler splits the write in two bytes without the
* helper variable.
*/
volatile u16 *r = &(regs->addr_cmap);
mb();
*r = value;
}
static inline u16 bt431_read_cmap(struct bt431_regs *regs, int cr)
{
bt431_select_reg(regs, cr);
return bt431_read_cmap_inc(regs);
}
static inline void bt431_write_cmap(struct bt431_regs *regs, int cr, u16 value)
{
bt431_select_reg(regs, cr);
bt431_write_cmap_inc(regs, value);
}
static inline void bt431_enable_cursor(struct bt431_regs *regs)
{
bt431_write_reg(regs, BT431_REG_CMD,
BT431_CMD_CURS_ENABLE | BT431_CMD_OR_CURSORS
| BT431_CMD_4_1_MUX | BT431_CMD_THICK_1);
}
static inline void bt431_erase_cursor(struct bt431_regs *regs)
{
bt431_write_reg(regs, BT431_REG_CMD, BT431_CMD_4_1_MUX);
}
static inline void bt431_position_cursor(struct bt431_regs *regs, u16 x, u16 y)
{
/*
* Magic from the MACH sources.
*
* Cx = x + D + H - P
* P = 37 if 1:1, 52 if 4:1, 57 if 5:1
* D = pixel skew between outdata and external data
* H = pixels between HSYNCH falling and active video
*
* Cy = y + V - 32
* V = scanlines between HSYNCH falling, two or more
* clocks after VSYNCH falling, and active video
*/
x += 412 - 52;
y += 68 - 32;
/* Use autoincrement. */
bt431_select_reg(regs, BT431_REG_CXLO);
bt431_write_reg_inc(regs, x & 0xff); /* BT431_REG_CXLO */
bt431_write_reg_inc(regs, (x >> 8) & 0x0f); /* BT431_REG_CXHI */
bt431_write_reg_inc(regs, y & 0xff); /* BT431_REG_CYLO */
bt431_write_reg_inc(regs, (y >> 8) & 0x0f); /* BT431_REG_CYHI */
}
static inline void bt431_set_font(struct bt431_regs *regs, u8 fgc,
u16 width, u16 height)
{
int i;
u16 fgp = fgc ? 0xffff : 0x0000;
u16 bgp = fgc ? 0x0000 : 0xffff;
bt431_select_reg(regs, BT431_REG_CRAM_BASE);
for (i = BT431_REG_CRAM_BASE; i <= BT431_REG_CRAM_END; i++) {
u16 value;
if (height << 6 <= i << 3)
value = bgp;
else if (width <= i % 8 << 3)
value = bgp;
else if (((width >> 3) & 0xffff) > i % 8)
value = fgp;
else
value = fgp & ~(bgp << (width % 8 << 1));
bt431_write_cmap_inc(regs, value);
}
}
static inline void bt431_init_cursor(struct bt431_regs *regs)
{
/* no crosshair window */
bt431_select_reg(regs, BT431_REG_WXLO);
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WXLO */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WXHI */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WYLO */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WYHI */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WWLO */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WWHI */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WHLO */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WHHI */
}
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