From f9c2a0dc42a6938ff2a80e55ca2bbd1d5581c72e Mon Sep 17 00:00:00 2001 From: Seungwon Jeon Date: Thu, 9 Feb 2012 14:32:43 +0900 Subject: [PATCH] mmc: dw_mmc: Fix PIO mode with support of highmem Current PIO mode makes a kernel crash with CONFIG_HIGHMEM. Highmem pages have a NULL from sg_virt(sg). This patch fixes the following problem. Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 Internal error: Oops: 817 [#1] PREEMPT SMP Modules linked in: CPU: 0 Not tainted (3.0.15-01423-gdbf465f #589) PC is at dw_mci_pull_data32+0x4c/0x9c LR is at dw_mci_read_data_pio+0x54/0x1f0 pc : [] lr : [] psr: 20000193 sp : c0619d48 ip : c0619d70 fp : c0619d6c r10: 00000000 r9 : 00000002 r8 : 00001000 r7 : 00000200 r6 : 00000000 r5 : e1dd3100 r4 : 00000000 r3 : 65622023 r2 : 0000007f r1 : eeb96000 r0 : e1dd3100 Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment xkernel Control: 10c5387d Table: 61e2004a DAC: 00000015 Process swapper (pid: 0, stack limit = 0xc06182f0) Stack: (0xc0619d48 to 0xc061a000) 9d40: e1dd3100 e1a4f000 00000000 e1dd3100 e1a4f000 00000200 9d60: c0619da4 c0619d70 c035988c c03587e4 c0619d9c e18158f4 e1dd3100 e1dd3100 9d80: 00000020 00000000 00000000 00000020 c06e8a84 00000000 c0619e04 c0619da8 9da0: c0359b24 c0359844 e18158f4 e1dd3164 e1dd3168 e1dd3150 3d02fc79 e1dd3154 9dc0: e1dd3178 00000000 00000020 00000000 e1dd3150 00000000 c10dd7e8 e1a84900 9de0: c061e7cc 00000000 00000000 0000008d c06e8a84 c061e780 c0619e4c c0619e08 9e00: c00c4738 c0359a34 3d02fc79 00000000 c0619e4c c05a1698 c05a1670 c05a165c 9e20: c04de8b0 c061e780 c061e7cc e1a84900 ffffed68 0000008d c0618000 00000000 9e40: c0619e6c c0619e50 c00c48b4 c00c46c8 c061e780 c00423ac c061e7cc ffffed68 9e60: c0619e8c c0619e70 c00c7358 c00c487c 0000008d ffffee38 c0618000 ffffed68 9e80: c0619ea4 c0619e90 c00c4258 c00c72b0 c00423ac ffffee38 c0619ecc c0619ea8 9ea0: c004241c c00c4234 ffffffff f8810000 0000006d 00000002 00000001 7fffffff 9ec0: c0619f44 c0619ed0 c0048bc0 c00423c4 220ae7a9 00000000 386f0d30 0005d3a4 9ee0: c00423ac c10dd0b8 c06f2cd8 c0618000 c0594778 c003a674 7fffffff c0619f44 9f00: 386f0d30 c0619f18 c00a6f94 c005be3c 80000013 ffffffff 386f0d30 0005d3a4 9f20: 386f0d30 0005d2d1 c10dd0a8 c10dd0b8 c06f2cd8 c0618000 c0619f74 c0619f48 9f40: c0345858 c005be00 c00a2440 c0618000 c0618000 c00410d8 c06c1944 c00410fc 9f60: c0594778 c003a674 c0619f9c c0619f78 c004a7e8 c03457b4 c0618000 c06c18f8 9f80: 00000000 c0039c70 c06c18d4 c003a674 c0619fb4 c0619fa0 c04ceafc c004a714 9fa0: c06287b4 c06c18f8 c0619ff4 c0619fb8 c0008b68 c04cea68 c0008578 00000000 9fc0: 00000000 c003a674 00000000 10c5387d c0628658 c003aa78 c062f1c4 4000406a 9fe0: 413fc090 00000000 00000000 c0619ff8 40008044 c0008858 00000000 00000000 Backtrace: [] (dw_mci_pull_data32+0x0/0x9c) from [] (dw_mci_read_data_pio+0x54/0x1f0) r6:00000200 r5:e1a4f000 r4:e1dd3100 [] (dw_mci_read_data_pio+0x0/0x1f0) from [] (dw_mci_interrupt+0xfc/0x4a4) [] (dw_mci_interrupt+0x0/0x4a4) from [] (handle_irq_event_percpu+0x7c/0x1b4) [] (handle_irq_event_percpu+0x0/0x1b4) from [] (handle_irq_event+0x44/0x64) [] (handle_irq_event+0x0/0x64) from [] (handle_fasteoi_irq+0xb4/0x124) r7:ffffed68 r6:c061e7cc r5:c00423ac r4:c061e780 [] (handle_fasteoi_irq+0x0/0x124) from [] (generic_handle_irq+0x30/0x38) r7:ffffed68 r6:c0618000 r5:ffffee38 r4:0000008d [] (generic_handle_irq+0x0/0x38) from [] (asm_do_IRQ+0x64/0xe0) r5:ffffee38 r4:c00423ac [] (asm_do_IRQ+0x0/0xe0) from [] (__irq_svc+0x80/0x14c) Exception stack(0xc0619ed0 to 0xc0619f18) Signed-off-by: Seungwon Jeon Acked-by: Will Newton Cc: stable Signed-off-by: Chris Ball --- drivers/mmc/host/dw_mmc.c | 144 +++++++++++++++++++------------------ include/linux/mmc/dw_mmc.h | 6 +- 2 files changed, 79 insertions(+), 71 deletions(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 0e342793ff14..8bec1c36b159 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -22,7 +22,6 @@ #include #include #include -#include #include #include #include @@ -502,8 +501,14 @@ static void dw_mci_submit_data(struct dw_mci *host, struct mmc_data *data) host->dir_status = DW_MCI_SEND_STATUS; if (dw_mci_submit_data_dma(host, data)) { + int flags = SG_MITER_ATOMIC; + if (host->data->flags & MMC_DATA_READ) + flags |= SG_MITER_TO_SG; + else + flags |= SG_MITER_FROM_SG; + + sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags); host->sg = data->sg; - host->pio_offset = 0; host->part_buf_start = 0; host->part_buf_count = 0; @@ -972,6 +977,7 @@ static void dw_mci_tasklet_func(unsigned long priv) * generates a block interrupt, hence setting * the scatter-gather pointer to NULL. */ + sg_miter_stop(&host->sg_miter); host->sg = NULL; ctrl = mci_readl(host, CTRL); ctrl |= SDMMC_CTRL_FIFO_RESET; @@ -1311,54 +1317,44 @@ static void dw_mci_pull_data(struct dw_mci *host, void *buf, int cnt) static void dw_mci_read_data_pio(struct dw_mci *host) { - struct scatterlist *sg = host->sg; - void *buf = sg_virt(sg); - unsigned int offset = host->pio_offset; + struct sg_mapping_iter *sg_miter = &host->sg_miter; + void *buf; + unsigned int offset; struct mmc_data *data = host->data; int shift = host->data_shift; u32 status; unsigned int nbytes = 0, len; + unsigned int remain, fcnt; do { - len = host->part_buf_count + - (SDMMC_GET_FCNT(mci_readl(host, STATUS)) << shift); - if (offset + len <= sg->length) { - dw_mci_pull_data(host, (void *)(buf + offset), len); + if (!sg_miter_next(sg_miter)) + goto done; + host->sg = sg_miter->__sg; + buf = sg_miter->addr; + remain = sg_miter->length; + offset = 0; + + do { + fcnt = (SDMMC_GET_FCNT(mci_readl(host, STATUS)) + << shift) + host->part_buf_count; + len = min(remain, fcnt); + if (!len) + break; + dw_mci_pull_data(host, (void *)(buf + offset), len); offset += len; nbytes += len; - - if (offset == sg->length) { - flush_dcache_page(sg_page(sg)); - host->sg = sg = sg_next(sg); - if (!sg) - goto done; - - offset = 0; - buf = sg_virt(sg); - } - } else { - unsigned int remaining = sg->length - offset; - dw_mci_pull_data(host, (void *)(buf + offset), - remaining); - nbytes += remaining; - - flush_dcache_page(sg_page(sg)); - host->sg = sg = sg_next(sg); - if (!sg) - goto done; - - offset = len - remaining; - buf = sg_virt(sg); - dw_mci_pull_data(host, buf, offset); - nbytes += offset; - } + remain -= len; + } while (remain); + sg_miter->consumed = offset; status = mci_readl(host, MINTSTS); mci_writel(host, RINTSTS, SDMMC_INT_RXDR); if (status & DW_MCI_DATA_ERROR_FLAGS) { host->data_status = status; data->bytes_xfered += nbytes; + sg_miter_stop(sg_miter); + host->sg = NULL; smp_wmb(); set_bit(EVENT_DATA_ERROR, &host->pending_events); @@ -1367,65 +1363,66 @@ static void dw_mci_read_data_pio(struct dw_mci *host) return; } } while (status & SDMMC_INT_RXDR); /*if the RXDR is ready read again*/ - host->pio_offset = offset; data->bytes_xfered += nbytes; + + if (!remain) { + if (!sg_miter_next(sg_miter)) + goto done; + sg_miter->consumed = 0; + } + sg_miter_stop(sg_miter); return; done: data->bytes_xfered += nbytes; + sg_miter_stop(sg_miter); + host->sg = NULL; smp_wmb(); set_bit(EVENT_XFER_COMPLETE, &host->pending_events); } static void dw_mci_write_data_pio(struct dw_mci *host) { - struct scatterlist *sg = host->sg; - void *buf = sg_virt(sg); - unsigned int offset = host->pio_offset; + struct sg_mapping_iter *sg_miter = &host->sg_miter; + void *buf; + unsigned int offset; struct mmc_data *data = host->data; int shift = host->data_shift; u32 status; unsigned int nbytes = 0, len; + unsigned int fifo_depth = host->fifo_depth; + unsigned int remain, fcnt; do { - len = ((host->fifo_depth - - SDMMC_GET_FCNT(mci_readl(host, STATUS))) << shift) - - host->part_buf_count; - if (offset + len <= sg->length) { - host->push_data(host, (void *)(buf + offset), len); + if (!sg_miter_next(sg_miter)) + goto done; + host->sg = sg_miter->__sg; + buf = sg_miter->addr; + remain = sg_miter->length; + offset = 0; + + do { + fcnt = ((fifo_depth - + SDMMC_GET_FCNT(mci_readl(host, STATUS))) + << shift) - host->part_buf_count; + len = min(remain, fcnt); + if (!len) + break; + host->push_data(host, (void *)(buf + offset), len); offset += len; nbytes += len; - if (offset == sg->length) { - host->sg = sg = sg_next(sg); - if (!sg) - goto done; - - offset = 0; - buf = sg_virt(sg); - } - } else { - unsigned int remaining = sg->length - offset; - - host->push_data(host, (void *)(buf + offset), - remaining); - nbytes += remaining; - - host->sg = sg = sg_next(sg); - if (!sg) - goto done; - - offset = len - remaining; - buf = sg_virt(sg); - host->push_data(host, (void *)buf, offset); - nbytes += offset; - } + remain -= len; + } while (remain); + sg_miter->consumed = offset; status = mci_readl(host, MINTSTS); mci_writel(host, RINTSTS, SDMMC_INT_TXDR); if (status & DW_MCI_DATA_ERROR_FLAGS) { host->data_status = status; data->bytes_xfered += nbytes; + sg_miter_stop(sg_miter); + host->sg = NULL; smp_wmb(); @@ -1435,12 +1432,20 @@ static void dw_mci_write_data_pio(struct dw_mci *host) return; } } while (status & SDMMC_INT_TXDR); /* if TXDR write again */ - host->pio_offset = offset; data->bytes_xfered += nbytes; + + if (!remain) { + if (!sg_miter_next(sg_miter)) + goto done; + sg_miter->consumed = 0; + } + sg_miter_stop(sg_miter); return; done: data->bytes_xfered += nbytes; + sg_miter_stop(sg_miter); + host->sg = NULL; smp_wmb(); set_bit(EVENT_XFER_COMPLETE, &host->pending_events); } @@ -1643,6 +1648,7 @@ static void dw_mci_work_routine_card(struct work_struct *work) * block interrupt, hence setting the * scatter-gather pointer to NULL. */ + sg_miter_stop(&host->sg_miter); host->sg = NULL; ctrl = mci_readl(host, CTRL); diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h index e8779c6d1759..aae5d1f1bb39 100644 --- a/include/linux/mmc/dw_mmc.h +++ b/include/linux/mmc/dw_mmc.h @@ -14,6 +14,8 @@ #ifndef LINUX_MMC_DW_MMC_H #define LINUX_MMC_DW_MMC_H +#include + #define MAX_MCI_SLOTS 2 enum dw_mci_state { @@ -40,7 +42,7 @@ struct mmc_data; * @lock: Spinlock protecting the queue and associated data. * @regs: Pointer to MMIO registers. * @sg: Scatterlist entry currently being processed by PIO code, if any. - * @pio_offset: Offset into the current scatterlist entry. + * @sg_miter: PIO mapping scatterlist iterator. * @cur_slot: The slot which is currently using the controller. * @mrq: The request currently being processed on @cur_slot, * or NULL if the controller is idle. @@ -115,7 +117,7 @@ struct dw_mci { void __iomem *regs; struct scatterlist *sg; - unsigned int pio_offset; + struct sg_mapping_iter sg_miter; struct dw_mci_slot *cur_slot; struct mmc_request *mrq;