Re: [PATCH v7 1/7] fbdev/hitfb: Cast I/O offset to address

Helge Deller
2023-05-16T17:44:09Z

On 5/12/23 12:24, Thomas Zimmermann wrote:
> Cast I/O offsets to pointers to use them with I/O functions. The I/O
> functions expect pointers of type 'volatile void __iomem *', but the
> offsets are plain integers. Build warnings are
>
> ../drivers/video/fbdev/hitfb.c: In function 'hitfb_accel_wait':
> ../arch/x86/include/asm/hd64461.h:18:33: warning: passing argument 1 of 'fb_readw' makes pointer from integer without a cast [-Wint-conversion]
> 18 | #define HD64461_IO_OFFSET(x) (HD64461_IOBASE + (x))
> | ^~~~~~~~~~~~~~~~~~~~~~
> | |
> | unsigned int
> ../arch/x86/include/asm/hd64461.h:93:33: note: in expansion of macro 'HD64461_IO_OFFSET'
> 93 | #define HD64461_GRCFGR HD64461_IO_OFFSET(0x1044) /* Accelerator Configuration Register */
> | ^~~~~~~~~~~~~~~~~
> ../drivers/video/fbdev/hitfb.c:47:25: note: in expansion of macro 'HD64461_GRCFGR'
> 47 | while (fb_readw(HD64461_GRCFGR) & HD64461_GRCFGR_ACCSTATUS) ;
> | ^~~~~~~~~~~~~~
> In file included from ../arch/x86/include/asm/fb.h:15,
> from ../include/linux/fb.h:19,
> from ../drivers/video/fbdev/hitfb.c:22:
> ../include/asm-generic/fb.h:52:57: note: expected 'const volatile void *' but argument is of type 'unsigned int'
> 52 | static inline u16 fb_readw(const volatile void __iomem *addr)
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
>
> This patch only fixes the build warnings. It's not clear if the I/O
> offsets can legally be passed to the I/O helpers. It was apparently
> broken in 2007 when custom inw()/outw() helpers got removed by
> commit 34a780a0afeb ("sh: hp6xx pata_platform support."). Fixing the
> driver would require setting the I/O base address.

I think your patch is the best you can do for now... So...

Acked-by: Helge Deller <deller@gmx.de>

Thanks!
Helge

> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202305102136.eMjTSPwH-lkp@intel.com/
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: Artur Rojek <contact@artur-rojek.eu>
> ---
> drivers/video/fbdev/hitfb.c | 122 ++++++++++++++++++++----------------
> 1 file changed, 69 insertions(+), 53 deletions(-)
>
> diff --git a/drivers/video/fbdev/hitfb.c b/drivers/video/fbdev/hitfb.c
> index 3033f5056976..7737923b7a0a 100644
> --- a/drivers/video/fbdev/hitfb.c
> +++ b/drivers/video/fbdev/hitfb.c
> @@ -42,17 +42,33 @@ static struct fb_fix_screeninfo hitfb_fix = {
> .accel = FB_ACCEL_NONE,
> };
>
> +static volatile void __iomem *hitfb_offset_to_addr(unsigned int offset)
> +{
> + return (__force volatile void __iomem *)(uintptr_t)offset;
> +}
> +
> +static u16 hitfb_readw(unsigned int offset)
> +{
> + return fb_readw(hitfb_offset_to_addr(offset));
> +}
> +
> +static void hitfb_writew(u16 value, unsigned int offset)
> +{
> + fb_writew(value, hitfb_offset_to_addr(offset));
> +}
> +
> static inline void hitfb_accel_wait(void)
> {
> - while (fb_readw(HD64461_GRCFGR) & HD64461_GRCFGR_ACCSTATUS) ;
> + while (hitfb_readw(HD64461_GRCFGR) & HD64461_GRCFGR_ACCSTATUS)
> + ;
> }
>
> static inline void hitfb_accel_start(int truecolor)
> {
> if (truecolor) {
> - fb_writew(6, HD64461_GRCFGR);
> + hitfb_writew(6, HD64461_GRCFGR);
> } else {
> - fb_writew(7, HD64461_GRCFGR);
> + hitfb_writew(7, HD64461_GRCFGR);
> }
> }
>
> @@ -63,11 +79,11 @@ static inline void hitfb_accel_set_dest(int truecolor, u16 dx, u16 dy,
> if (truecolor)
> saddr <<= 1;
>
> - fb_writew(width-1, HD64461_BBTDWR);
> - fb_writew(height-1, HD64461_BBTDHR);
> + hitfb_writew(width-1, HD64461_BBTDWR);
> + hitfb_writew(height-1, HD64461_BBTDHR);
>
> - fb_writew(saddr & 0xffff, HD64461_BBTDSARL);
> - fb_writew(saddr >> 16, HD64461_BBTDSARH);
> + hitfb_writew(saddr & 0xffff, HD64461_BBTDSARL);
> + hitfb_writew(saddr >> 16, HD64461_BBTDSARH);
>
> }
>
> @@ -80,7 +96,7 @@ static inline void hitfb_accel_bitblt(int truecolor, u16 sx, u16 sy, u16 dx,
>
> height--;
> width--;
> - fb_writew(rop, HD64461_BBTROPR);
> + hitfb_writew(rop, HD64461_BBTROPR);
> if ((sy < dy) || ((sy == dy) && (sx <= dx))) {
> saddr = WIDTH * (sy + height) + sx + width;
> daddr = WIDTH * (dy + height) + dx + width;
> @@ -91,32 +107,32 @@ static inline void hitfb_accel_bitblt(int truecolor, u16 sx, u16 sy, u16 dx,
> maddr =
> (((width >> 4) + 1) * (height + 1) - 1) * 2;
>
> - fb_writew((1 << 5) | 1, HD64461_BBTMDR);
> + hitfb_writew((1 << 5) | 1, HD64461_BBTMDR);
> } else
> - fb_writew(1, HD64461_BBTMDR);
> + hitfb_writew(1, HD64461_BBTMDR);
> } else {
> saddr = WIDTH * sy + sx;
> daddr = WIDTH * dy + dx;
> if (mask_addr) {
> - fb_writew((1 << 5), HD64461_BBTMDR);
> + hitfb_writew((1 << 5), HD64461_BBTMDR);
> } else {
> - fb_writew(0, HD64461_BBTMDR);
> + hitfb_writew(0, HD64461_BBTMDR);
> }
> }
> if (truecolor) {
> saddr <<= 1;
> daddr <<= 1;
> }
> - fb_writew(width, HD64461_BBTDWR);
> - fb_writew(height, HD64461_BBTDHR);
> - fb_writew(saddr & 0xffff, HD64461_BBTSSARL);
> - fb_writew(saddr >> 16, HD64461_BBTSSARH);
> - fb_writew(daddr & 0xffff, HD64461_BBTDSARL);
> - fb_writew(daddr >> 16, HD64461_BBTDSARH);
> + hitfb_writew(width, HD64461_BBTDWR);
> + hitfb_writew(height, HD64461_BBTDHR);
> + hitfb_writew(saddr & 0xffff, HD64461_BBTSSARL);
> + hitfb_writew(saddr >> 16, HD64461_BBTSSARH);
> + hitfb_writew(daddr & 0xffff, HD64461_BBTDSARL);
> + hitfb_writew(daddr >> 16, HD64461_BBTDSARH);
> if (mask_addr) {
> maddr += mask_addr;
> - fb_writew(maddr & 0xffff, HD64461_BBTMARL);
> - fb_writew(maddr >> 16, HD64461_BBTMARH);
> + hitfb_writew(maddr & 0xffff, HD64461_BBTMARL);
> + hitfb_writew(maddr >> 16, HD64461_BBTMARH);
> }
> hitfb_accel_start(truecolor);
> }
> @@ -127,17 +143,17 @@ static void hitfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
> cfb_fillrect(p, rect);
> else {
> hitfb_accel_wait();
> - fb_writew(0x00f0, HD64461_BBTROPR);
> - fb_writew(16, HD64461_BBTMDR);
> + hitfb_writew(0x00f0, HD64461_BBTROPR);
> + hitfb_writew(16, HD64461_BBTMDR);
>
> if (p->var.bits_per_pixel == 16) {
> - fb_writew(((u32 *) (p->pseudo_palette))[rect->color],
> + hitfb_writew(((u32 *) (p->pseudo_palette))[rect->color],
> HD64461_GRSCR);
> hitfb_accel_set_dest(1, rect->dx, rect->dy, rect->width,
> rect->height);
> hitfb_accel_start(1);
> } else {
> - fb_writew(rect->color, HD64461_GRSCR);
> + hitfb_writew(rect->color, HD64461_GRSCR);
> hitfb_accel_set_dest(0, rect->dx, rect->dy, rect->width,
> rect->height);
> hitfb_accel_start(0);
> @@ -162,7 +178,7 @@ static int hitfb_pan_display(struct fb_var_screeninfo *var,
> if (xoffset != 0)
> return -EINVAL;
>
> - fb_writew((yoffset*info->fix.line_length)>>10, HD64461_LCDCBAR);
> + hitfb_writew((yoffset*info->fix.line_length)>>10, HD64461_LCDCBAR);
>
> return 0;
> }
> @@ -172,33 +188,33 @@ int hitfb_blank(int blank_mode, struct fb_info *info)
> unsigned short v;
>
> if (blank_mode) {
> - v = fb_readw(HD64461_LDR1);
> + v = hitfb_readw(HD64461_LDR1);
> v &= ~HD64461_LDR1_DON;
> - fb_writew(v, HD64461_LDR1);
> + hitfb_writew(v, HD64461_LDR1);
>
> - v = fb_readw(HD64461_LCDCCR);
> + v = hitfb_readw(HD64461_LCDCCR);
> v |= HD64461_LCDCCR_MOFF;
> - fb_writew(v, HD64461_LCDCCR);
> + hitfb_writew(v, HD64461_LCDCCR);
>
> - v = fb_readw(HD64461_STBCR);
> + v = hitfb_readw(HD64461_STBCR);
> v |= HD64461_STBCR_SLCDST;
> - fb_writew(v, HD64461_STBCR);
> + hitfb_writew(v, HD64461_STBCR);
> } else {
> - v = fb_readw(HD64461_STBCR);
> + v = hitfb_readw(HD64461_STBCR);
> v &= ~HD64461_STBCR_SLCDST;
> - fb_writew(v, HD64461_STBCR);
> + hitfb_writew(v, HD64461_STBCR);
>
> - v = fb_readw(HD64461_LCDCCR);
> + v = hitfb_readw(HD64461_LCDCCR);
> v &= ~(HD64461_LCDCCR_MOFF | HD64461_LCDCCR_STREQ);
> - fb_writew(v, HD64461_LCDCCR);
> + hitfb_writew(v, HD64461_LCDCCR);
>
> do {
> - v = fb_readw(HD64461_LCDCCR);
> + v = hitfb_readw(HD64461_LCDCCR);
> } while(v&HD64461_LCDCCR_STBACK);
>
> - v = fb_readw(HD64461_LDR1);
> + v = hitfb_readw(HD64461_LDR1);
> v |= HD64461_LDR1_DON;
> - fb_writew(v, HD64461_LDR1);
> + hitfb_writew(v, HD64461_LDR1);
> }
> return 0;
> }
> @@ -211,10 +227,10 @@ static int hitfb_setcolreg(unsigned regno, unsigned red, unsigned green,
>
> switch (info->var.bits_per_pixel) {
> case 8:
> - fb_writew(regno << 8, HD64461_CPTWAR);
> - fb_writew(red >> 10, HD64461_CPTWDR);
> - fb_writew(green >> 10, HD64461_CPTWDR);
> - fb_writew(blue >> 10, HD64461_CPTWDR);
> + hitfb_writew(regno << 8, HD64461_CPTWAR);
> + hitfb_writew(red >> 10, HD64461_CPTWDR);
> + hitfb_writew(green >> 10, HD64461_CPTWDR);
> + hitfb_writew(blue >> 10, HD64461_CPTWDR);
> break;
> case 16:
> if (regno >= 16)
> @@ -302,11 +318,11 @@ static int hitfb_set_par(struct fb_info *info)
> break;
> }
>
> - fb_writew(info->fix.line_length, HD64461_LCDCLOR);
> - ldr3 = fb_readw(HD64461_LDR3);
> + hitfb_writew(info->fix.line_length, HD64461_LCDCLOR);
> + ldr3 = hitfb_readw(HD64461_LDR3);
> ldr3 &= ~15;
> ldr3 |= (info->var.bits_per_pixel == 8) ? 4 : 8;
> - fb_writew(ldr3, HD64461_LDR3);
> + hitfb_writew(ldr3, HD64461_LDR3);
> return 0;
> }
>
> @@ -337,9 +353,9 @@ static int hitfb_probe(struct platform_device *dev)
> hitfb_fix.smem_start = HD64461_IO_OFFSET(0x02000000);
> hitfb_fix.smem_len = 512 * 1024;
>
> - lcdclor = fb_readw(HD64461_LCDCLOR);
> - ldvndr = fb_readw(HD64461_LDVNDR);
> - ldr3 = fb_readw(HD64461_LDR3);
> + lcdclor = hitfb_readw(HD64461_LCDCLOR);
> + ldvndr = hitfb_readw(HD64461_LDVNDR);
> + ldr3 = hitfb_readw(HD64461_LDR3);
>
> switch (ldr3 & 15) {
> default:
> @@ -429,9 +445,9 @@ static int hitfb_suspend(struct device *dev)
> u16 v;
>
> hitfb_blank(1,0);
> - v = fb_readw(HD64461_STBCR);
> + v = hitfb_readw(HD64461_STBCR);
> v |= HD64461_STBCR_SLCKE_IST;
> - fb_writew(v, HD64461_STBCR);
> + hitfb_writew(v, HD64461_STBCR);
>
> return 0;
> }
> @@ -440,12 +456,12 @@ static int hitfb_resume(struct device *dev)
> {
> u16 v;
>
> - v = fb_readw(HD64461_STBCR);
> + v = hitfb_readw(HD64461_STBCR);
> v &= ~HD64461_STBCR_SLCKE_OST;
> msleep(100);
> - v = fb_readw(HD64461_STBCR);
> + v = hitfb_readw(HD64461_STBCR);
> v &= ~HD64461_STBCR_SLCKE_IST;
> - fb_writew(v, HD64461_STBCR);
> + hitfb_writew(v, HD64461_STBCR);
> hitfb_blank(0,0);
>
> return 0;