From 2e2ac4a3327479f7e2744cdd88a5c823f2057bad Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Wed, 6 Apr 2022 22:15:20 +0200 Subject: [PATCH] tty: goldfish: Introduce gf_ioread32()/gf_iowrite32() The goldfish TTY device was clearly defined as having little-endian registers, but the switch to __raw_{read,write}l(() broke its driver when running on big-endian kernels (if anyone ever tried this). The m68k qemu implementation got this wrong, and assumed native-endian registers. While this is a bug in qemu, it is probably impossible to fix that since there is no way of knowing which other operating systems have started relying on that bug over the years. Hence revert commit da31de35cd2f ("tty: goldfish: use __raw_writel()/__raw_readl()", and define gf_ioread32()/gf_iowrite32() to be able to use accessors defined by the architecture. Cc: stable@vger.kernel.org # v5.11+ Fixes: da31de35cd2fb78f ("tty: goldfish: use __raw_writel()/__raw_readl()") Signed-off-by: Laurent Vivier Link: https://lore.kernel.org/r/20220406201523.243733-2-laurent@vivier.eu [geert: Add rationale based on Arnd's comments] Signed-off-by: Geert Uytterhoeven --- drivers/tty/goldfish.c | 20 ++++++++++---------- include/linux/goldfish.h | 15 +++++++++++---- 2 files changed, 21 insertions(+), 14 deletions(-) diff --git a/drivers/tty/goldfish.c b/drivers/tty/goldfish.c index ad13532..9e8ccb8 100644 --- a/drivers/tty/goldfish.c +++ b/drivers/tty/goldfish.c @@ -61,13 +61,13 @@ static void do_rw_io(struct goldfish_tty *qtty, spin_lock_irqsave(&qtty->lock, irq_flags); gf_write_ptr((void *)address, base + GOLDFISH_TTY_REG_DATA_PTR, base + GOLDFISH_TTY_REG_DATA_PTR_HIGH); - __raw_writel(count, base + GOLDFISH_TTY_REG_DATA_LEN); + gf_iowrite32(count, base + GOLDFISH_TTY_REG_DATA_LEN); if (is_write) - __raw_writel(GOLDFISH_TTY_CMD_WRITE_BUFFER, + gf_iowrite32(GOLDFISH_TTY_CMD_WRITE_BUFFER, base + GOLDFISH_TTY_REG_CMD); else - __raw_writel(GOLDFISH_TTY_CMD_READ_BUFFER, + gf_iowrite32(GOLDFISH_TTY_CMD_READ_BUFFER, base + GOLDFISH_TTY_REG_CMD); spin_unlock_irqrestore(&qtty->lock, irq_flags); @@ -142,7 +142,7 @@ static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id) unsigned char *buf; u32 count; - count = __raw_readl(base + GOLDFISH_TTY_REG_BYTES_READY); + count = gf_ioread32(base + GOLDFISH_TTY_REG_BYTES_READY); if (count == 0) return IRQ_NONE; @@ -159,7 +159,7 @@ static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty) { struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, port); - __raw_writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD); + gf_iowrite32(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD); return 0; } @@ -167,7 +167,7 @@ static void goldfish_tty_shutdown(struct tty_port *port) { struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, port); - __raw_writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_CMD); + gf_iowrite32(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_CMD); } static int goldfish_tty_open(struct tty_struct *tty, struct file *filp) @@ -202,7 +202,7 @@ static unsigned int goldfish_tty_chars_in_buffer(struct tty_struct *tty) { struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; void __iomem *base = qtty->base; - return __raw_readl(base + GOLDFISH_TTY_REG_BYTES_READY); + return gf_ioread32(base + GOLDFISH_TTY_REG_BYTES_READY); } static void goldfish_tty_console_write(struct console *co, const char *b, @@ -355,7 +355,7 @@ static int goldfish_tty_probe(struct platform_device *pdev) * on Ranchu emulator (qemu2) returns 1 here and * driver will use physical addresses. */ - qtty->version = __raw_readl(base + GOLDFISH_TTY_REG_VERSION); + qtty->version = gf_ioread32(base + GOLDFISH_TTY_REG_VERSION); /* * Goldfish TTY device on Ranchu emulator (qemu2) @@ -374,7 +374,7 @@ static int goldfish_tty_probe(struct platform_device *pdev) } } - __raw_writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD); + gf_iowrite32(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD); ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED, "goldfish_tty", qtty); @@ -436,7 +436,7 @@ static int goldfish_tty_remove(struct platform_device *pdev) #ifdef CONFIG_GOLDFISH_TTY_EARLY_CONSOLE static void gf_early_console_putchar(struct uart_port *port, unsigned char ch) { - __raw_writel(ch, port->membase); + gf_iowrite32(ch, port->membase); } static void gf_early_write(struct console *con, const char *s, unsigned int n) diff --git a/include/linux/goldfish.h b/include/linux/goldfish.h index 12be160..bcc17f9 100644 --- a/include/linux/goldfish.h +++ b/include/linux/goldfish.h @@ -8,14 +8,21 @@ /* Helpers for Goldfish virtual platform */ +#ifndef gf_ioread32 +#define gf_ioread32 ioread32 +#endif +#ifndef gf_iowrite32 +#define gf_iowrite32 iowrite32 +#endif + static inline void gf_write_ptr(const void *ptr, void __iomem *portl, void __iomem *porth) { const unsigned long addr = (unsigned long)ptr; - __raw_writel(lower_32_bits(addr), portl); + gf_iowrite32(lower_32_bits(addr), portl); #ifdef CONFIG_64BIT - __raw_writel(upper_32_bits(addr), porth); + gf_iowrite32(upper_32_bits(addr), porth); #endif } @@ -23,9 +30,9 @@ static inline void gf_write_dma_addr(const dma_addr_t addr, void __iomem *portl, void __iomem *porth) { - __raw_writel(lower_32_bits(addr), portl); + gf_iowrite32(lower_32_bits(addr), portl); #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT - __raw_writel(upper_32_bits(addr), porth); + gf_iowrite32(upper_32_bits(addr), porth); #endif } -- 2.7.4