tifm_sd: use kmap_atomic instead of kmap for PIO data buffer

Data buffer for PIO transfer used to be mapped in advance with kmap.
Abolish it in favor of on-demand kmap_atomic.

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

diff --git a/drivers/mmc/tifm_sd.c b/drivers/mmc/tifm_sd.c
index f22c3968f2d46e2e7c7f453e4e654caf0d590932..3e762770afcb369ae699f748f2467bc7e7017a44 100644 (file)
--- a/drivers/mmc/tifm_sd.c
+++ b/drivers/mmc/tifm_sd.c
@@ -103,38 +103,51 @@ struct tifm_sd {
        wait_queue_head_t     can_eject;
 
        size_t                written_blocks;
-       char                  *buffer;
        size_t                buffer_size;
        size_t                buffer_pos;
 
 };
 
+static char* tifm_sd_kmap_atomic(struct mmc_data *data)
+{
+       return kmap_atomic(data->sg->page, KM_BIO_SRC_IRQ) + data->sg->offset;
+}
+
+static void tifm_sd_kunmap_atomic(char *buffer, struct mmc_data *data)
+{
+       kunmap_atomic(buffer - data->sg->offset, KM_BIO_SRC_IRQ);
+}
+
 static int tifm_sd_transfer_data(struct tifm_dev *sock, struct tifm_sd *host,
                                        unsigned int host_status)
 {
        struct mmc_command *cmd = host->req->cmd;
        unsigned int t_val = 0, cnt = 0;
+       char *buffer;
 
        if (host_status & TIFM_MMCSD_BRS) {
                /* in non-dma rx mode BRS fires when fifo is still not empty */
-               if (host->buffer && (cmd->data->flags & MMC_DATA_READ)) {
+               if (no_dma && (cmd->data->flags & MMC_DATA_READ)) {
+                       buffer = tifm_sd_kmap_atomic(host->req->data);
                        while (host->buffer_size > host->buffer_pos) {
                                t_val = readl(sock->addr + SOCK_MMCSD_DATA);
-                               host->buffer[host->buffer_pos++] = t_val & 0xff;
-                               host->buffer[host->buffer_pos++] =
+                               buffer[host->buffer_pos++] = t_val & 0xff;
+                               buffer[host->buffer_pos++] =
                                                        (t_val >> 8) & 0xff;
                        }
+                       tifm_sd_kunmap_atomic(buffer, host->req->data);
                }
                return 1;
-       } else if (host->buffer) {
+       } else if (no_dma) {
+               buffer = tifm_sd_kmap_atomic(host->req->data);
                if ((cmd->data->flags & MMC_DATA_READ) &&
                                (host_status & TIFM_MMCSD_AF)) {
                        for (cnt = 0; cnt < TIFM_MMCSD_FIFO_SIZE; cnt++) {
                                t_val = readl(sock->addr + SOCK_MMCSD_DATA);
                                if (host->buffer_size > host->buffer_pos) {
-                                       host->buffer[host->buffer_pos++] =
+                                       buffer[host->buffer_pos++] =
                                                        t_val & 0xff;
-                                       host->buffer[host->buffer_pos++] =
+                                       buffer[host->buffer_pos++] =
                                                        (t_val >> 8) & 0xff;
                                }
                        }
@@ -142,14 +155,16 @@ static int tifm_sd_transfer_data(struct tifm_dev *sock, struct tifm_sd *host,
                           && (host_status & TIFM_MMCSD_AE)) {
                        for (cnt = 0; cnt < TIFM_MMCSD_FIFO_SIZE; cnt++) {
                                if (host->buffer_size > host->buffer_pos) {
-                                       t_val = host->buffer[host->buffer_pos++] & 0x00ff;
-                                       t_val |= ((host->buffer[host->buffer_pos++]) << 8)
-                                                & 0xff00;
+                                       t_val = buffer[host->buffer_pos++]
+                                               & 0x00ff;
+                                       t_val |= ((buffer[host->buffer_pos++])
+                                                 << 8) & 0xff00;
                                        writel(t_val,
                                                sock->addr + SOCK_MMCSD_DATA);
                                }
                        }
                }
+               tifm_sd_kunmap_atomic(buffer, host->req->data);
        }
        return 0;
 }
@@ -561,15 +576,6 @@ static void tifm_sd_request_nodma(struct mmc_host *mmc, struct mmc_request *mrq)
        struct tifm_dev *sock = host->dev;
        unsigned long flags;
        struct mmc_data *r_data = mrq->cmd->data;
-       char *t_buffer = NULL;
-
-       if (r_data) {
-               t_buffer = kmap(r_data->sg->page);
-               if (!t_buffer) {
-                       printk(KERN_ERR DRIVER_NAME ": kmap failed\n");
-                       goto err_out;
-               }
-       }
 
        spin_lock_irqsave(&sock->lock, flags);
        if (host->flags & EJECT) {
@@ -586,7 +592,6 @@ static void tifm_sd_request_nodma(struct mmc_host *mmc, struct mmc_request *mrq)
        if (r_data) {
                tifm_sd_set_data_timeout(host, r_data);
 
-               host->buffer = t_buffer + r_data->sg->offset;
                host->buffer_size = mrq->cmd->data->blocks *
                                        mrq->cmd->data->blksz;
 
@@ -615,9 +620,6 @@ static void tifm_sd_request_nodma(struct mmc_host *mmc, struct mmc_request *mrq)
        return;
 
 err_out:
-       if (t_buffer)
-               kunmap(r_data->sg->page);
-
        mrq->cmd->error = MMC_ERR_TIMEOUT;
        mmc_request_done(mmc, mrq);
 }
@@ -659,7 +661,6 @@ static void tifm_sd_end_cmd_nodma(struct work_struct *work)
                        r_data->bytes_xfered += r_data->blksz -
                                readl(sock->addr + SOCK_MMCSD_BLOCK_LEN) + 1;
                }
-               host->buffer = NULL;
                host->buffer_pos = 0;
                host->buffer_size = 0;
        }
@@ -669,9 +670,6 @@ static void tifm_sd_end_cmd_nodma(struct work_struct *work)
 
        spin_unlock_irqrestore(&sock->lock, flags);
 
-        if (r_data)
-               kunmap(r_data->sg->page);
-
        mmc_request_done(mmc, mrq);
 }