mmc: Allow host drivers to specify a max block size

Most controllers have an upper limit on the block size. Allow the host
drivers to specify this and make sure we avoid hitting this limit.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

12 files changed, 44 insertions, 12 deletions

diff --git a/drivers/mmc/at91_mci.c b/drivers/mmc/at91_mci.c
index aa152f31851e..e28850dec9ed 100644
--- a/drivers/mmc/at91_mci.c
+++ b/drivers/mmc/at91_mci.c
@@ -823,6 +823,8 @@ static int __init at91_mci_probe(struct platform_device *pdev)
         mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
         mmc->caps = MMC_CAP_BYTEBLOCK;
 
+        mmc->max_blk_size = 4095;
+
         host = mmc_priv(mmc);
         host->mmc = mmc;
         host->buffer = NULL;
diff --git a/drivers/mmc/au1xmmc.c b/drivers/mmc/au1xmmc.c
index 6d6fe6e6d415..74e6ac0c7f71 100644
--- a/drivers/mmc/au1xmmc.c
+++ b/drivers/mmc/au1xmmc.c
@@ -922,6 +922,8 @@ static int __devinit au1xmmc_probe(struct platform_device *pdev)
                 mmc->max_seg_size = AU1XMMC_DESCRIPTOR_SIZE;
                 mmc->max_phys_segs = AU1XMMC_DESCRIPTOR_COUNT;
 
+                mmc->max_blk_size = 2048;
+
                 mmc->ocr_avail = AU1XMMC_OCR;
 
                 host = mmc_priv(mmc);
diff --git a/drivers/mmc/imxmmc.c b/drivers/mmc/imxmmc.c
index bfb9ff693208..2107f8a8605e 100644
--- a/drivers/mmc/imxmmc.c
+++ b/drivers/mmc/imxmmc.c
@@ -960,6 +960,7 @@ static int imxmci_probe(struct platform_device *pdev)
         mmc->max_phys_segs = 64;
         mmc->max_sectors = 64;          /* default 1 << (PAGE_CACHE_SHIFT - 9) */
         mmc->max_seg_size = 64*512;     /* default PAGE_CACHE_SIZE */
+        mmc->max_blk_size = 2048;
 
         host = mmc_priv(mmc);
         host->mmc = mmc;
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index b48c277312de..9bda3fddad17 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -108,6 +108,8 @@ mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
         mrq->cmd->error = 0;
         mrq->cmd->mrq = mrq;
         if (mrq->data) {
+                BUG_ON(mrq->data->blksz > host->max_blk_size);
+
                 mrq->cmd->data = mrq->data;
                 mrq->data->error = 0;
                 mrq->data->mrq = mrq;
@@ -1605,6 +1607,8 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
                 host->max_phys_segs = 1;
                 host->max_sectors = 1 << (PAGE_CACHE_SHIFT - 9);
                 host->max_seg_size = PAGE_CACHE_SIZE;
+
+                host->max_blk_size = 512;
         }
 
         return host;
diff --git a/drivers/mmc/mmci.c b/drivers/mmc/mmci.c
index ccfe6561be24..5d48e0081894 100644
--- a/drivers/mmc/mmci.c
+++ b/drivers/mmc/mmci.c
@@ -534,6 +534,11 @@ static int mmci_probe(struct amba_device *dev, void *id)
          */
         mmc->max_seg_size = mmc->max_sectors << 9;
 
+        /*
+         * Block size can be up to 2048 bytes, but must be a power of two.
+         */
+        mmc->max_blk_size = 2048;
+
         spin_lock_init(&host->lock);
 
         writel(0, host->base + MMCIMASK0);
diff --git a/drivers/mmc/omap.c b/drivers/mmc/omap.c
index d30540b27614..fa69a0dc5969 100644
--- a/drivers/mmc/omap.c
+++ b/drivers/mmc/omap.c
@@ -1099,6 +1099,7 @@ static int __init mmc_omap_probe(struct platform_device *pdev)
          */
         mmc->max_phys_segs = 32;
         mmc->max_hw_segs = 32;
+        mmc->max_blk_size = 2048;       /* BLEN is 11 bits (+1) */
         mmc->max_sectors = 256; /* NBLK max 11-bits, OMAP also limited by DMA */
         mmc->max_seg_size = mmc->max_sectors * 512;
 
diff --git a/drivers/mmc/pxamci.c b/drivers/mmc/pxamci.c
index 6073d998b11f..9fc9aed1a5ef 100644
--- a/drivers/mmc/pxamci.c
+++ b/drivers/mmc/pxamci.c
@@ -450,6 +450,11 @@ static int pxamci_probe(struct platform_device *pdev)
          */
         mmc->max_seg_size = PAGE_SIZE;
 
+        /*
+         * Block length register is 10 bits.
+         */
+        mmc->max_blk_size = 1023;
+
         host = mmc_priv(mmc);
         host->mmc = mmc;
         host->dma = -1;
diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
index 175a9427b9ba..155aafe69bf4 100644
--- a/drivers/mmc/sdhci.c
+++ b/drivers/mmc/sdhci.c
@@ -381,7 +381,7 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
 
         /* Sanity checks */
         BUG_ON(data->blksz * data->blocks > 524288);
-        BUG_ON(data->blksz > host->max_block);
+        BUG_ON(data->blksz > host->mmc->max_blk_size);
         BUG_ON(data->blocks > 65535);
 
         /* timeout in us */
@@ -1290,15 +1290,6 @@ static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot)
         if (caps & SDHCI_TIMEOUT_CLK_UNIT)
                 host->timeout_clk *= 1000;
 
-        host->max_block = (caps & SDHCI_MAX_BLOCK_MASK) >> SDHCI_MAX_BLOCK_SHIFT;
-        if (host->max_block >= 3) {
-                printk(KERN_ERR "%s: Invalid maximum block size.\n",
-                        host->slot_descr);
-                ret = -ENODEV;
-                goto unmap;
-        }
-        host->max_block = 512 << host->max_block;
-
         /*
          * Set host parameters.
          */
@@ -1353,6 +1344,19 @@ static int __devinit sdhci_probe_slot(struct pci_dev *pdev, int slot)
         mmc->max_seg_size = mmc->max_sectors * 512;
 
         /*
+         * Maximum block size. This varies from controller to controller and
+         * is specified in the capabilities register.
+         */
+        mmc->max_blk_size = (caps & SDHCI_MAX_BLOCK_MASK) >> SDHCI_MAX_BLOCK_SHIFT;
+        if (mmc->max_blk_size >= 3) {
+                printk(KERN_ERR "%s: Invalid maximum block size.\n",
+                        host->slot_descr);
+                ret = -ENODEV;
+                goto unmap;
+        }
+        mmc->max_blk_size = 512 << mmc->max_blk_size;
+
+        /*
          * Init tasklets.
          */
         tasklet_init(&host->card_tasklet,
diff --git a/drivers/mmc/sdhci.h b/drivers/mmc/sdhci.h
index f9d1a0a6f03a..bc6bf7e7757d 100644
--- a/drivers/mmc/sdhci.h
+++ b/drivers/mmc/sdhci.h
@@ -174,7 +174,6 @@ struct sdhci_host {
 
         unsigned int            max_clk;        /* Max possible freq (MHz) */
         unsigned int            timeout_clk;    /* Timeout freq (KHz) */
-        unsigned int            max_block;      /* Max block size (bytes) */
 
         unsigned int            clock;          /* Current clock (MHz) */
         unsigned short          power;          /* Current voltage */
diff --git a/drivers/mmc/tifm_sd.c b/drivers/mmc/tifm_sd.c
index ce19b045ca6a..bdfad15371b8 100644
--- a/drivers/mmc/tifm_sd.c
+++ b/drivers/mmc/tifm_sd.c
@@ -886,7 +886,9 @@ static int tifm_sd_probe(struct tifm_dev *sock)
         mmc->max_hw_segs = 1;
         mmc->max_phys_segs = 1;
         mmc->max_sectors = 127;
-        mmc->max_seg_size = mmc->max_sectors << 11; //2k maximum hw block length
+        //2k maximum hw block length
+        mmc->max_seg_size = mmc->max_sectors << 11;
+        mmc->max_blk_size = 2048;
         sock->signal_irq = tifm_sd_signal_irq;
         rc = tifm_sd_initialize_host(host);
 
diff --git a/drivers/mmc/wbsd.c b/drivers/mmc/wbsd.c
index 7a282672f8e9..5711beecb4e8 100644
--- a/drivers/mmc/wbsd.c
+++ b/drivers/mmc/wbsd.c
@@ -1354,6 +1354,12 @@ static int __devinit wbsd_alloc_mmc(struct device *dev)
          */
         mmc->max_seg_size = mmc->max_sectors * 512;
 
+        /*
+         * Maximum block size. We have 12 bits (= 4095) but have to subtract
+         * space for CRC. So the maximum is 4095 - 4*2 = 4087.
+         */
+        mmc->max_blk_size = 4087;
+
         dev_set_drvdata(dev, mmc);
 
         return 0;
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index ae98d6766bdd..2da0c918a8cc 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -94,6 +94,7 @@ struct mmc_host {
         unsigned short          max_phys_segs;  /* see blk_queue_max_phys_segments */
         unsigned short          max_sectors;    /* see blk_queue_max_sectors */
         unsigned short          unused;
+        unsigned int            max_blk_size;   /* maximum size of one mmc block */
 
         /* private data */
         struct mmc_ios          ios;            /* current io bus settings */