From: Kaustabh Chakraborty kauschluss@disroot.org
[ Upstream commit 57c0902f8bec51add5a1eb908d8b876592725d81 ]
In certain DW MMC implementations (such as in some Exynos7870 controllers), 64-bit read/write is not allowed from a 64-bit FIFO. Add a quirk which facilitates accessing the 64-bit FIFO registers in two 32-bit halves.
Signed-off-by: Kaustabh Chakraborty kauschluss@disroot.org Link: https://lore.kernel.org/r/20250219-exynos7870-mmc-v2-2-b4255a3e39ed@disroot.... Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mmc/host/dw_mmc.c | 94 ++++++++++++++++++++++++++++++++++++++- drivers/mmc/host/dw_mmc.h | 27 +++++++++++ 2 files changed, 119 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index e9f6e4e622901..55158540c28cf 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -2579,6 +2579,91 @@ static void dw_mci_pull_data64(struct dw_mci *host, void *buf, int cnt) } }
+static void dw_mci_push_data64_32(struct dw_mci *host, void *buf, int cnt) +{ + struct mmc_data *data = host->data; + int init_cnt = cnt; + + /* try and push anything in the part_buf */ + if (unlikely(host->part_buf_count)) { + int len = dw_mci_push_part_bytes(host, buf, cnt); + + buf += len; + cnt -= len; + + if (host->part_buf_count == 8) { + mci_fifo_l_writeq(host->fifo_reg, host->part_buf); + host->part_buf_count = 0; + } + } +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + if (unlikely((unsigned long)buf & 0x7)) { + while (cnt >= 8) { + u64 aligned_buf[16]; + int len = min(cnt & -8, (int)sizeof(aligned_buf)); + int items = len >> 3; + int i; + /* memcpy from input buffer into aligned buffer */ + memcpy(aligned_buf, buf, len); + buf += len; + cnt -= len; + /* push data from aligned buffer into fifo */ + for (i = 0; i < items; ++i) + mci_fifo_l_writeq(host->fifo_reg, aligned_buf[i]); + } + } else +#endif + { + u64 *pdata = buf; + + for (; cnt >= 8; cnt -= 8) + mci_fifo_l_writeq(host->fifo_reg, *pdata++); + buf = pdata; + } + /* put anything remaining in the part_buf */ + if (cnt) { + dw_mci_set_part_bytes(host, buf, cnt); + /* Push data if we have reached the expected data length */ + if ((data->bytes_xfered + init_cnt) == + (data->blksz * data->blocks)) + mci_fifo_l_writeq(host->fifo_reg, host->part_buf); + } +} + +static void dw_mci_pull_data64_32(struct dw_mci *host, void *buf, int cnt) +{ +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + if (unlikely((unsigned long)buf & 0x7)) { + while (cnt >= 8) { + /* pull data from fifo into aligned buffer */ + u64 aligned_buf[16]; + int len = min(cnt & -8, (int)sizeof(aligned_buf)); + int items = len >> 3; + int i; + + for (i = 0; i < items; ++i) + aligned_buf[i] = mci_fifo_l_readq(host->fifo_reg); + + /* memcpy from aligned buffer into output buffer */ + memcpy(buf, aligned_buf, len); + buf += len; + cnt -= len; + } + } else +#endif + { + u64 *pdata = buf; + + for (; cnt >= 8; cnt -= 8) + *pdata++ = mci_fifo_l_readq(host->fifo_reg); + buf = pdata; + } + if (cnt) { + host->part_buf = mci_fifo_l_readq(host->fifo_reg); + dw_mci_pull_final_bytes(host, buf, cnt); + } +} + static void dw_mci_pull_data(struct dw_mci *host, void *buf, int cnt) { int len; @@ -3379,8 +3464,13 @@ int dw_mci_probe(struct dw_mci *host) width = 16; host->data_shift = 1; } else if (i == 2) { - host->push_data = dw_mci_push_data64; - host->pull_data = dw_mci_pull_data64; + if ((host->quirks & DW_MMC_QUIRK_FIFO64_32)) { + host->push_data = dw_mci_push_data64_32; + host->pull_data = dw_mci_pull_data64_32; + } else { + host->push_data = dw_mci_push_data64; + host->pull_data = dw_mci_pull_data64; + } width = 64; host->data_shift = 3; } else { diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h index 6447b916990dc..5463392dc8110 100644 --- a/drivers/mmc/host/dw_mmc.h +++ b/drivers/mmc/host/dw_mmc.h @@ -281,6 +281,8 @@ struct dw_mci_board {
/* Support for longer data read timeout */ #define DW_MMC_QUIRK_EXTENDED_TMOUT BIT(0) +/* Force 32-bit access to the FIFO */ +#define DW_MMC_QUIRK_FIFO64_32 BIT(1)
#define DW_MMC_240A 0x240a #define DW_MMC_280A 0x280a @@ -472,6 +474,31 @@ struct dw_mci_board { #define mci_fifo_writel(__value, __reg) __raw_writel(__reg, __value) #define mci_fifo_writeq(__value, __reg) __raw_writeq(__reg, __value)
+/* + * Some dw_mmc devices have 64-bit FIFOs, but expect them to be + * accessed using two 32-bit accesses. If such controller is used + * with a 64-bit kernel, this has to be done explicitly. + */ +static inline u64 mci_fifo_l_readq(void __iomem *addr) +{ + u64 ans; + u32 proxy[2]; + + proxy[0] = mci_fifo_readl(addr); + proxy[1] = mci_fifo_readl(addr + 4); + memcpy(&ans, proxy, 8); + return ans; +} + +static inline void mci_fifo_l_writeq(void __iomem *addr, u64 value) +{ + u32 proxy[2]; + + memcpy(proxy, &value, 8); + mci_fifo_writel(addr, proxy[0]); + mci_fifo_writel(addr + 4, proxy[1]); +} + /* Register access macros */ #define mci_readl(dev, reg) \ readl_relaxed((dev)->regs + SDMMC_##reg)