Revision 8f4d38099b3098eae75f7755e1801931f8141350 authored by Ville Syrjälä on 15 December 2016, 17:47:34 UTC, committed by Jani Nikula on 07 June 2017, 13:31:39 UTC
The scanline counter is bonkers on VLV/CHV DSI. The scanline counter
increment is not lined up with the start of vblank like it is on
every other platform and output type. This causes problems for
both the vblank timestamping and atomic update vblank evasion.

On my FFRD8 machine at least, the scanline counter increment
happens about 1/3 of a scanline ahead of the start of vblank (which
is where all register latching happens still). That means we can't
trust the scanline counter to tell us whether we're in vblank or not
while we're on that particular line. In order to keep vblank
timestamping in working condition when called from the vblank irq,
we'll leave scanline_offset at one, which means that the entire
line containing the start of vblank is considered to be inside
the vblank.

For the vblank evasion we'll need to consider that entire line
to be bad, since we can't tell whether the registers already
got latched or not. And we can't actually use the start of vblank
interrupt to get us past that line as the interrupt would fire
too soon, and then we'd up waiting for the next start of vblank
instead. One way around that would using the frame start
interrupt instead since that wouldn't fire until the next
scanline, but that would require some bigger changes in the
interrupt code. So for simplicity we'll just poll until we get
past the bad line.

v2: Adjust the comments a bit

Cc: stable@vger.kernel.org
Cc: Jonas Aaberg <cja@gmx.net>
Tested-by: Jonas Aaberg <cja@gmx.net>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99086
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161215174734.28779-1-ville.syrjala@linux.intel.com
Tested-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
(cherry picked from commit ec1b4ee2834e66884e5b0d3d465f347ff212e372)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
1 parent 5857dbf
Raw File
adfs.h
#include <linux/fs.h>
#include <linux/adfs_fs.h>

/* Internal data structures for ADFS */

#define ADFS_FREE_FRAG		 0
#define ADFS_BAD_FRAG		 1
#define ADFS_ROOT_FRAG		 2

#define ADFS_NDA_OWNER_READ	(1 << 0)
#define ADFS_NDA_OWNER_WRITE	(1 << 1)
#define ADFS_NDA_LOCKED		(1 << 2)
#define ADFS_NDA_DIRECTORY	(1 << 3)
#define ADFS_NDA_EXECUTE	(1 << 4)
#define ADFS_NDA_PUBLIC_READ	(1 << 5)
#define ADFS_NDA_PUBLIC_WRITE	(1 << 6)

#include "dir_f.h"

struct buffer_head;

/*
 * adfs file system inode data in memory
 */
struct adfs_inode_info {
	loff_t		mmu_private;
	unsigned long	parent_id;	/* object id of parent		*/
	__u32		loadaddr;	/* RISC OS load address		*/
	__u32		execaddr;	/* RISC OS exec address		*/
	unsigned int	filetype;	/* RISC OS file type		*/
	unsigned int	attr;		/* RISC OS permissions		*/
	unsigned int	stamped:1;	/* RISC OS file has date/time	*/
	struct inode vfs_inode;
};

/*
 * Forward-declare this
 */
struct adfs_discmap;
struct adfs_dir_ops;

/*
 * ADFS file system superblock data in memory
 */
struct adfs_sb_info {
	union { struct {
		struct adfs_discmap *s_map;	/* bh list containing map */
		const struct adfs_dir_ops *s_dir; /* directory operations */
		};
		struct rcu_head rcu;	/* used only at shutdown time	 */
	};
	kuid_t		s_uid;		/* owner uid */
	kgid_t		s_gid;		/* owner gid */
	umode_t		s_owner_mask;	/* ADFS owner perm -> unix perm */
	umode_t		s_other_mask;	/* ADFS other perm -> unix perm	*/
	int		s_ftsuffix;	/* ,xyz hex filetype suffix option */

	__u32		s_ids_per_zone;	/* max. no ids in one zone */
	__u32		s_idlen;	/* length of ID in map */
	__u32		s_map_size;	/* sector size of a map	*/
	unsigned long	s_size;		/* total size (in blocks) of this fs */
	signed int	s_map2blk;	/* shift left by this for map->sector*/
	unsigned int	s_log2sharesize;/* log2 share size */
	__le32		s_version;	/* disc format version */
	unsigned int	s_namelen;	/* maximum number of characters in name	 */
};

static inline struct adfs_sb_info *ADFS_SB(struct super_block *sb)
{
	return sb->s_fs_info;
}

static inline struct adfs_inode_info *ADFS_I(struct inode *inode)
{
	return container_of(inode, struct adfs_inode_info, vfs_inode);
}

/*
 * Directory handling
 */
struct adfs_dir {
	struct super_block	*sb;

	int			nr_buffers;
	struct buffer_head	*bh[4];

	/* big directories need allocated buffers */
	struct buffer_head	**bh_fplus;

	unsigned int		pos;
	unsigned int		parent_id;

	struct adfs_dirheader	dirhead;
	union  adfs_dirtail	dirtail;
};

/*
 * This is the overall maximum name length
 */
#define ADFS_MAX_NAME_LEN	(256 + 4) /* +4 for ,xyz hex filetype suffix */
struct object_info {
	__u32		parent_id;		/* parent object id	*/
	__u32		file_id;		/* object id		*/
	__u32		loadaddr;		/* load address		*/
	__u32		execaddr;		/* execution address	*/
	__u32		size;			/* size			*/
	__u8		attr;			/* RISC OS attributes	*/
	unsigned int	name_len;		/* name length		*/
	char		name[ADFS_MAX_NAME_LEN];/* file name		*/

	/* RISC OS file type (12-bit: derived from loadaddr) */
	__u16		filetype;
};

/* RISC OS 12-bit filetype converts to ,xyz hex filename suffix */
static inline int append_filetype_suffix(char *buf, __u16 filetype)
{
	if (filetype == 0xffff)	/* no explicit 12-bit file type was set */
		return 0;

	*buf++ = ',';
	*buf++ = hex_asc_lo(filetype >> 8);
	*buf++ = hex_asc_lo(filetype >> 4);
	*buf++ = hex_asc_lo(filetype >> 0);
	return 4;
}

struct adfs_dir_ops {
	int	(*read)(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir);
	int	(*setpos)(struct adfs_dir *dir, unsigned int fpos);
	int	(*getnext)(struct adfs_dir *dir, struct object_info *obj);
	int	(*update)(struct adfs_dir *dir, struct object_info *obj);
	int	(*create)(struct adfs_dir *dir, struct object_info *obj);
	int	(*remove)(struct adfs_dir *dir, struct object_info *obj);
	int	(*sync)(struct adfs_dir *dir);
	void	(*free)(struct adfs_dir *dir);
};

struct adfs_discmap {
	struct buffer_head	*dm_bh;
	__u32			dm_startblk;
	unsigned int		dm_startbit;
	unsigned int		dm_endbit;
};

/* Inode stuff */
struct inode *adfs_iget(struct super_block *sb, struct object_info *obj);
int adfs_write_inode(struct inode *inode, struct writeback_control *wbc);
int adfs_notify_change(struct dentry *dentry, struct iattr *attr);

/* map.c */
extern int adfs_map_lookup(struct super_block *sb, unsigned int frag_id, unsigned int offset);
extern unsigned int adfs_map_free(struct super_block *sb);

/* Misc */
__printf(3, 4)
void __adfs_error(struct super_block *sb, const char *function,
		  const char *fmt, ...);
#define adfs_error(sb, fmt...) __adfs_error(sb, __func__, fmt)

/* super.c */

/*
 * Inodes and file operations
 */

/* dir_*.c */
extern const struct inode_operations adfs_dir_inode_operations;
extern const struct file_operations adfs_dir_operations;
extern const struct dentry_operations adfs_dentry_operations;
extern const struct adfs_dir_ops adfs_f_dir_ops;
extern const struct adfs_dir_ops adfs_fplus_dir_ops;

extern int adfs_dir_update(struct super_block *sb, struct object_info *obj,
			   int wait);

/* file.c */
extern const struct inode_operations adfs_file_inode_operations;
extern const struct file_operations adfs_file_operations;

static inline __u32 signed_asl(__u32 val, signed int shift)
{
	if (shift >= 0)
		val <<= shift;
	else
		val >>= -shift;
	return val;
}

/*
 * Calculate the address of a block in an object given the block offset
 * and the object identity.
 *
 * The root directory ID should always be looked up in the map [3.4]
 */
static inline int
__adfs_block_map(struct super_block *sb, unsigned int object_id,
		 unsigned int block)
{
	if (object_id & 255) {
		unsigned int off;

		off = (object_id & 255) - 1;
		block += off << ADFS_SB(sb)->s_log2sharesize;
	}

	return adfs_map_lookup(sb, object_id >> 8, block);
}
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