cregit-Linux how code gets into the kernel

Release 4.11 drivers/video/fbdev/core/cfbcopyarea.c

/*
 *  Generic function for frame buffer with packed pixels of any depth.
 *
 *      Copyright (C)  1999-2005 James Simmons <jsimmons@www.infradead.org>
 *
 *  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.
 *
 * NOTES:
 *
 *  This is for cfb packed pixels. Iplan and such are incorporated in the
 *  drivers that need them.
 *
 *  FIXME
 *
 *  Also need to add code to deal with cards endians that are different than
 *  the native cpu endians. I also need to deal with MSB position in the word.
 *
 *  The two functions or copying forward and backward could be split up like
 *  the ones for filling, i.e. in aligned and unaligned versions. This would
 *  help moving some redundant computations and branches out of the loop, too.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/fb.h>
#include <asm/types.h>
#include <asm/io.h>
#include "fb_draw.h"

#if BITS_PER_LONG == 32

#  define FB_WRITEL fb_writel

#  define FB_READL  fb_readl
#else

#  define FB_WRITEL fb_writeq

#  define FB_READL  fb_readq
#endif

    /*
     *  Generic bitwise copy algorithm
     */


static void bitcpy(struct fb_info *p, unsigned long __iomem *dst, unsigned dst_idx, const unsigned long __iomem *src, unsigned src_idx, int bits, unsigned n, u32 bswapmask) { unsigned long first, last; int const shift = dst_idx-src_idx; #if 0 /* * If you suspect bug in this function, compare it with this simple * memmove implementation. */ memmove((char *)dst + ((dst_idx & (bits - 1))) / 8, (char *)src + ((src_idx & (bits - 1))) / 8, n / 8); return; #endif first = fb_shifted_pixels_mask_long(p, dst_idx, bswapmask); last = ~fb_shifted_pixels_mask_long(p, (dst_idx+n) % bits, bswapmask); if (!shift) { // Same alignment for source and dest if (dst_idx+n <= bits) { // Single word if (last) first &= last; FB_WRITEL( comp( FB_READL(src), FB_READL(dst), first), dst); } else { // Multiple destination words // Leading bits if (first != ~0UL) { FB_WRITEL( comp( FB_READL(src), FB_READL(dst), first), dst); dst++; src++; n -= bits - dst_idx; } // Main chunk n /= bits; while (n >= 8) { FB_WRITEL(FB_READL(src++), dst++); FB_WRITEL(FB_READL(src++), dst++); FB_WRITEL(FB_READL(src++), dst++); FB_WRITEL(FB_READL(src++), dst++); FB_WRITEL(FB_READL(src++), dst++); FB_WRITEL(FB_READL(src++), dst++); FB_WRITEL(FB_READL(src++), dst++); FB_WRITEL(FB_READL(src++), dst++); n -= 8; } while (n--) FB_WRITEL(FB_READL(src++), dst++); // Trailing bits if (last) FB_WRITEL( comp( FB_READL(src), FB_READL(dst), last), dst); } } else { /* Different alignment for source and dest */ unsigned long d0, d1; int m; int const left = shift & (bits - 1); int const right = -shift & (bits - 1); if (dst_idx+n <= bits) { // Single destination word if (last) first &= last; d0 = FB_READL(src); d0 = fb_rev_pixels_in_long(d0, bswapmask); if (shift > 0) { // Single source word d0 <<= left; } else if (src_idx+n <= bits) { // Single source word d0 >>= right; } else { // 2 source words d1 = FB_READL(src + 1); d1 = fb_rev_pixels_in_long(d1, bswapmask); d0 = d0 >> right | d1 << left; } d0 = fb_rev_pixels_in_long(d0, bswapmask); FB_WRITEL(comp(d0, FB_READL(dst), first), dst); } else { // Multiple destination words /** We must always remember the last value read, because in case SRC and DST overlap bitwise (e.g. when moving just one pixel in 1bpp), we always collect one full long for DST and that might overlap with the current long from SRC. We store this value in 'd0'. */ d0 = FB_READL(src++); d0 = fb_rev_pixels_in_long(d0, bswapmask); // Leading bits if (shift > 0) { // Single source word d1 = d0; d0 <<= left; n -= bits - dst_idx; } else { // 2 source words d1 = FB_READL(src++); d1 = fb_rev_pixels_in_long(d1, bswapmask); d0 = d0 >> right | d1 << left; n -= bits - dst_idx; } d0 = fb_rev_pixels_in_long(d0, bswapmask); FB_WRITEL(comp(d0, FB_READL(dst), first), dst); d0 = d1; dst++; // Main chunk m = n % bits; n /= bits; while ((n >= 4) && !bswapmask) { d1 = FB_READL(src++); FB_WRITEL(d0 >> right | d1 << left, dst++); d0 = d1; d1 = FB_READL(src++); FB_WRITEL(d0 >> right | d1 << left, dst++); d0 = d1; d1 = FB_READL(src++); FB_WRITEL(d0 >> right | d1 << left, dst++); d0 = d1; d1 = FB_READL(src++); FB_WRITEL(d0 >> right | d1 << left, dst++); d0 = d1; n -= 4; } while (n--) { d1 = FB_READL(src++); d1 = fb_rev_pixels_in_long(d1, bswapmask); d0 = d0 >> right | d1 << left; d0 = fb_rev_pixels_in_long(d0, bswapmask); FB_WRITEL(d0, dst++); d0 = d1; } // Trailing bits if (m) { if (m <= bits - right) { // Single source word d0 >>= right; } else { // 2 source words d1 = FB_READL(src); d1 = fb_rev_pixels_in_long(d1, bswapmask); d0 = d0 >> right | d1 << left; } d0 = fb_rev_pixels_in_long(d0, bswapmask); FB_WRITEL(comp(d0, FB_READL(dst), last), dst); } } } }

Contributors

PersonTokensPropCommitsCommitProp
James Simmons54061.50%325.00%
Pavel Pisa15217.31%216.67%
David S. Miller657.40%18.33%
Mikulas Patocka657.40%216.67%
Antonino A. Daplas455.13%216.67%
Anton Vorontsov91.03%18.33%
Linus Torvalds20.23%18.33%
Total878100.00%12100.00%

/* * Generic bitwise copy algorithm, operating backward */
static void bitcpy_rev(struct fb_info *p, unsigned long __iomem *dst, unsigned dst_idx, const unsigned long __iomem *src, unsigned src_idx, int bits, unsigned n, u32 bswapmask) { unsigned long first, last; int shift; #if 0 /* * If you suspect bug in this function, compare it with this simple * memmove implementation. */ memmove((char *)dst + ((dst_idx & (bits - 1))) / 8, (char *)src + ((src_idx & (bits - 1))) / 8, n / 8); return; #endif dst += (dst_idx + n - 1) / bits; src += (src_idx + n - 1) / bits; dst_idx = (dst_idx + n - 1) % bits; src_idx = (src_idx + n - 1) % bits; shift = dst_idx-src_idx; first = ~fb_shifted_pixels_mask_long(p, (dst_idx + 1) % bits, bswapmask); last = fb_shifted_pixels_mask_long(p, (bits + dst_idx + 1 - n) % bits, bswapmask); if (!shift) { // Same alignment for source and dest if ((unsigned long)dst_idx+1 >= n) { // Single word if (first) last &= first; FB_WRITEL( comp( FB_READL(src), FB_READL(dst), last), dst); } else { // Multiple destination words // Leading bits if (first) { FB_WRITEL( comp( FB_READL(src), FB_READL(dst), first), dst); dst--; src--; n -= dst_idx+1; } // Main chunk n /= bits; while (n >= 8) { FB_WRITEL(FB_READL(src--), dst--); FB_WRITEL(FB_READL(src--), dst--); FB_WRITEL(FB_READL(src--), dst--); FB_WRITEL(FB_READL(src--), dst--); FB_WRITEL(FB_READL(src--), dst--); FB_WRITEL(FB_READL(src--), dst--); FB_WRITEL(FB_READL(src--), dst--); FB_WRITEL(FB_READL(src--), dst--); n -= 8; } while (n--) FB_WRITEL(FB_READL(src--), dst--); // Trailing bits if (last != -1UL) FB_WRITEL( comp( FB_READL(src), FB_READL(dst), last), dst); } } else { // Different alignment for source and dest unsigned long d0, d1; int m; int const left = shift & (bits-1); int const right = -shift & (bits-1); if ((unsigned long)dst_idx+1 >= n) { // Single destination word if (first) last &= first; d0 = FB_READL(src); if (shift < 0) { // Single source word d0 >>= right; } else if (1+(unsigned long)src_idx >= n) { // Single source word d0 <<= left; } else { // 2 source words d1 = FB_READL(src - 1); d1 = fb_rev_pixels_in_long(d1, bswapmask); d0 = d0 << left | d1 >> right; } d0 = fb_rev_pixels_in_long(d0, bswapmask); FB_WRITEL(comp(d0, FB_READL(dst), last), dst); } else { // Multiple destination words /** We must always remember the last value read, because in case SRC and DST overlap bitwise (e.g. when moving just one pixel in 1bpp), we always collect one full long for DST and that might overlap with the current long from SRC. We store this value in 'd0'. */ d0 = FB_READL(src--); d0 = fb_rev_pixels_in_long(d0, bswapmask); // Leading bits if (shift < 0) { // Single source word d1 = d0; d0 >>= right; } else { // 2 source words d1 = FB_READL(src--); d1 = fb_rev_pixels_in_long(d1, bswapmask); d0 = d0 << left | d1 >> right; } d0 = fb_rev_pixels_in_long(d0, bswapmask); if (!first) FB_WRITEL(d0, dst); else FB_WRITEL(comp(d0, FB_READL(dst), first), dst); d0 = d1; dst--; n -= dst_idx+1; // Main chunk m = n % bits; n /= bits; while ((n >= 4) && !bswapmask) { d1 = FB_READL(src--); FB_WRITEL(d0 << left | d1 >> right, dst--); d0 = d1; d1 = FB_READL(src--); FB_WRITEL(d0 << left | d1 >> right, dst--); d0 = d1; d1 = FB_READL(src--); FB_WRITEL(d0 << left | d1 >> right, dst--); d0 = d1; d1 = FB_READL(src--); FB_WRITEL(d0 << left | d1 >> right, dst--); d0 = d1; n -= 4; } while (n--) { d1 = FB_READL(src--); d1 = fb_rev_pixels_in_long(d1, bswapmask); d0 = d0 << left | d1 >> right; d0 = fb_rev_pixels_in_long(d0, bswapmask); FB_WRITEL(d0, dst--); d0 = d1; } // Trailing bits if (m) { if (m <= bits - left) { // Single source word d0 <<= left; } else { // 2 source words d1 = FB_READL(src); d1 = fb_rev_pixels_in_long(d1, bswapmask); d0 = d0 << left | d1 >> right; } d0 = fb_rev_pixels_in_long(d0, bswapmask); FB_WRITEL(comp(d0, FB_READL(dst), last), dst); } } } }

Contributors

PersonTokensPropCommitsCommitProp
James Simmons58161.35%430.77%
Pavel Pisa15316.16%215.38%
Mikulas Patocka9810.35%215.38%
David S. Miller636.65%17.69%
Antonino A. Daplas414.33%215.38%
Anton Vorontsov90.95%17.69%
Linus Torvalds20.21%17.69%
Total947100.00%13100.00%


void cfb_copyarea(struct fb_info *p, const struct fb_copyarea *area) { u32 dx = area->dx, dy = area->dy, sx = area->sx, sy = area->sy; u32 height = area->height, width = area->width; unsigned long const bits_per_line = p->fix.line_length*8u; unsigned long __iomem *base = NULL; int bits = BITS_PER_LONG, bytes = bits >> 3; unsigned dst_idx = 0, src_idx = 0, rev_copy = 0; u32 bswapmask = fb_compute_bswapmask(p); if (p->state != FBINFO_STATE_RUNNING) return; /* if the beginning of the target area might overlap with the end of the source area, be have to copy the area reverse. */ if ((dy == sy && dx > sx) || (dy > sy)) { dy += height; sy += height; rev_copy = 1; } // split the base of the framebuffer into a long-aligned address and the // index of the first bit base = (unsigned long __iomem *)((unsigned long)p->screen_base & ~(bytes-1)); dst_idx = src_idx = 8*((unsigned long)p->screen_base & (bytes-1)); // add offset of source and target area dst_idx += dy*bits_per_line + dx*p->var.bits_per_pixel; src_idx += sy*bits_per_line + sx*p->var.bits_per_pixel; if (p->fbops->fb_sync) p->fbops->fb_sync(p); if (rev_copy) { while (height--) { dst_idx -= bits_per_line; src_idx -= bits_per_line; bitcpy_rev(p, base + (dst_idx / bits), dst_idx % bits, base + (src_idx / bits), src_idx % bits, bits, width*p->var.bits_per_pixel, bswapmask); } } else { while (height--) { bitcpy(p, base + (dst_idx / bits), dst_idx % bits, base + (src_idx / bits), src_idx % bits, bits, width*p->var.bits_per_pixel, bswapmask); dst_idx += bits_per_line; src_idx += bits_per_line; } } }

Contributors

PersonTokensPropCommitsCommitProp
James Simmons28878.90%654.55%
Mikulas Patocka3710.14%19.09%
Antonino A. Daplas184.93%19.09%
Pavel Pisa123.29%19.09%
Benjamin Herrenschmidt92.47%19.09%
Linus Torvalds10.27%19.09%
Total365100.00%11100.00%

EXPORT_SYMBOL(cfb_copyarea); MODULE_AUTHOR("James Simmons <jsimmons@users.sf.net>"); MODULE_DESCRIPTION("Generic software accelerated copyarea"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
James Simmons147365.21%1150.00%
Pavel Pisa31714.03%29.09%
Mikulas Patocka2008.85%29.09%
David S. Miller1285.67%14.55%
Antonino A. Daplas1094.83%313.64%
Anton Vorontsov180.80%14.55%
Benjamin Herrenschmidt90.40%14.55%
Linus Torvalds50.22%14.55%
Total2259100.00%22100.00%
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