sfc: Eliminate struct efx_mtd

Currently we use struct efx_mtd to represent a physical NVRAM device
and struct efx_mtd_partition to represent a partition on that device.
But this only really makes sense for Falcon, as we don't know or care
whether MC-managed NVRAM partitions are on one or more physical
devices.  It complicates iteration and provides little benefit.
Therefore:

- Replace the pointer to efx_mtd in mtd_info::priv with a pointer to efx_nic
- Move the falcon_spi_device pointer into the union in struct efx_mtd_partition
- Move the device name to efx_mtd_partition::dev_type_name
- Move the efx_mtd_ops pointer to efx_nic::mtd_ops
- Make efx_nic::mtd_list a list of partitions

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

2 files changed, 120 insertions, 160 deletions

diff --git a/drivers/net/ethernet/sfc/mtd.c b/drivers/net/ethernet/sfc/mtd.c
index e4b35c61e90b..ba6c87a73d86 100644
--- a/drivers/net/ethernet/sfc/mtd.c
+++ b/drivers/net/ethernet/sfc/mtd.c
@@ -25,6 +25,7 @@
 #define FALCON_SPI_VERIFY_BUF_LEN 16
 
 struct efx_mtd_partition {
+        struct list_head node;
         struct mtd_info mtd;
         union {
                 struct {
@@ -32,8 +33,12 @@ struct efx_mtd_partition {
                         u8 nvram_type;
                         u16 fw_subtype;
                 } mcdi;
-                size_t offset;
+                struct {
+                        const struct falcon_spi_device *spi;
+                        size_t offset;
+                } falcon;
         };
+        const char *dev_type_name;
         const char *type_name;
         char name[IFNAMSIZ + 20];
 };
@@ -47,21 +52,6 @@ struct efx_mtd_ops {
         int (*sync)(struct mtd_info *mtd);
 };
 
-struct efx_mtd {
-        struct list_head node;
-        struct efx_nic *efx;
-        const struct falcon_spi_device *spi;
-        const char *name;
-        const struct efx_mtd_ops *ops;
-        size_t n_parts;
-        struct efx_mtd_partition part[0];
-};
-
-#define efx_for_each_partition(part, efx_mtd)                   \
-        for ((part) = &(efx_mtd)->part[0];                      \
-             (part) != &(efx_mtd)->part[(efx_mtd)->n_parts];    \
-             (part)++)
-
 #define to_efx_mtd_partition(mtd)                               \
         container_of(mtd, struct efx_mtd_partition, mtd)
 
@@ -73,9 +63,8 @@ static int siena_mtd_probe(struct efx_nic *efx);
 static int
 falcon_spi_slow_wait(struct efx_mtd_partition *part, bool uninterruptible)
 {
-        struct efx_mtd *efx_mtd = part->mtd.priv;
-        const struct falcon_spi_device *spi = efx_mtd->spi;
-        struct efx_nic *efx = efx_mtd->efx;
+        const struct falcon_spi_device *spi = part->falcon.spi;
+        struct efx_nic *efx = part->mtd.priv;
         u8 status;
         int rc, i;
 
@@ -93,7 +82,8 @@ falcon_spi_slow_wait(struct efx_mtd_partition *part, bool uninterruptible)
                 if (signal_pending(current))
                         return -EINTR;
         }
-        pr_err("%s: timed out waiting for %s\n", part->name, efx_mtd->name);
+        pr_err("%s: timed out waiting for %s\n",
+               part->name, part->dev_type_name);
         return -ETIMEDOUT;
 }
 
@@ -135,9 +125,8 @@ falcon_spi_unlock(struct efx_nic *efx, const struct falcon_spi_device *spi)
 static int
 falcon_spi_erase(struct efx_mtd_partition *part, loff_t start, size_t len)
 {
-        struct efx_mtd *efx_mtd = part->mtd.priv;
-        const struct falcon_spi_device *spi = efx_mtd->spi;
-        struct efx_nic *efx = efx_mtd->efx;
+        const struct falcon_spi_device *spi = part->falcon.spi;
+        struct efx_nic *efx = part->mtd.priv;
         unsigned pos, block_len;
         u8 empty[FALCON_SPI_VERIFY_BUF_LEN];
         u8 buffer[FALCON_SPI_VERIFY_BUF_LEN];
@@ -185,10 +174,10 @@ falcon_spi_erase(struct efx_mtd_partition *part, loff_t start, size_t len)
 
 static int efx_mtd_erase(struct mtd_info *mtd, struct erase_info *erase)
 {
-        struct efx_mtd *efx_mtd = mtd->priv;
+        struct efx_nic *efx = mtd->priv;
         int rc;
 
-        rc = efx_mtd->ops->erase(mtd, erase->addr, erase->len);
+        rc = efx->mtd_ops->erase(mtd, erase->addr, erase->len);
         if (rc == 0) {
                 erase->state = MTD_ERASE_DONE;
         } else {
@@ -202,13 +191,13 @@ static int efx_mtd_erase(struct mtd_info *mtd, struct erase_info *erase)
 static void efx_mtd_sync(struct mtd_info *mtd)
 {
         struct efx_mtd_partition *part = to_efx_mtd_partition(mtd);
-        struct efx_mtd *efx_mtd = mtd->priv;
+        struct efx_nic *efx = mtd->priv;
         int rc;
 
-        rc = efx_mtd->ops->sync(mtd);
+        rc = efx->mtd_ops->sync(mtd);
         if (rc)
                 pr_err("%s: %s sync failed (%d)\n",
-                       part->name, efx_mtd->name, rc);
+                       part->name, part->dev_type_name, rc);
 }
 
 static void efx_mtd_remove_partition(struct efx_mtd_partition *part)
@@ -222,86 +211,84 @@ static void efx_mtd_remove_partition(struct efx_mtd_partition *part)
                 ssleep(1);
         }
         WARN_ON(rc);
+        list_del(&part->node);
 }
 
-static void efx_mtd_remove_device(struct efx_mtd *efx_mtd)
-{
-        struct efx_mtd_partition *part;
-
-        efx_for_each_partition(part, efx_mtd)
-                efx_mtd_remove_partition(part);
-        list_del(&efx_mtd->node);
-        kfree(efx_mtd);
-}
-
-static void efx_mtd_rename_device(struct efx_mtd *efx_mtd)
+static void efx_mtd_rename_partition(struct efx_mtd_partition *part)
 {
-        struct efx_mtd_partition *part;
+        struct efx_nic *efx = part->mtd.priv;
 
-        efx_for_each_partition(part, efx_mtd)
-                if (efx_nic_rev(efx_mtd->efx) >= EFX_REV_SIENA_A0)
-                        snprintf(part->name, sizeof(part->name),
-                                 "%s %s:%02x", efx_mtd->efx->name,
-                                 part->type_name, part->mcdi.fw_subtype);
-                else
-                        snprintf(part->name, sizeof(part->name),
-                                 "%s %s", efx_mtd->efx->name,
-                                 part->type_name);
+        if (efx_nic_rev(efx) >= EFX_REV_SIENA_A0)
+                snprintf(part->name, sizeof(part->name), "%s %s:%02x",
+                         efx->name, part->type_name, part->mcdi.fw_subtype);
+        else
+                snprintf(part->name, sizeof(part->name), "%s %s",
+                         efx->name, part->type_name);
 }
 
-static int efx_mtd_probe_device(struct efx_nic *efx, struct efx_mtd *efx_mtd)
+static int efx_mtd_add(struct efx_nic *efx,
+                       struct efx_mtd_partition *parts, size_t n_parts)
 {
         struct efx_mtd_partition *part;
+        size_t i;
 
-        efx_mtd->efx = efx;
+        for (i = 0; i < n_parts; i++) {
+                part = &parts[i];
 
-        efx_mtd_rename_device(efx_mtd);
-
-        efx_for_each_partition(part, efx_mtd) {
                 part->mtd.writesize = 1;
 
                 part->mtd.owner = THIS_MODULE;
-                part->mtd.priv = efx_mtd;
+                part->mtd.priv = efx;
                 part->mtd.name = part->name;
                 part->mtd._erase = efx_mtd_erase;
-                part->mtd._read = efx_mtd->ops->read;
-                part->mtd._write = efx_mtd->ops->write;
+                part->mtd._read = efx->mtd_ops->read;
+                part->mtd._write = efx->mtd_ops->write;
                 part->mtd._sync = efx_mtd_sync;
 
+                efx_mtd_rename_partition(part);
+
                 if (mtd_device_register(&part->mtd, NULL, 0))
                         goto fail;
+
+                /* Add to list in order - efx_mtd_remove() depends on this */
+                list_add_tail(&part->node, &efx->mtd_list);
         }
 
-        list_add(&efx_mtd->node, &efx->mtd_list);
         return 0;
 
 fail:
-        while (part != &efx_mtd->part[0]) {
-                --part;
-                efx_mtd_remove_partition(part);
-        }
+        while (i--)
+                efx_mtd_remove_partition(&parts[i]);
         /* Failure is unlikely here, but probably means we're out of memory */
         return -ENOMEM;
 }
 
 void efx_mtd_remove(struct efx_nic *efx)
 {
-        struct efx_mtd *efx_mtd, *next;
+        struct efx_mtd_partition *parts, *part, *next;
 
         WARN_ON(efx_dev_registered(efx));
 
-        list_for_each_entry_safe(efx_mtd, next, &efx->mtd_list, node)
-                efx_mtd_remove_device(efx_mtd);
+        if (list_empty(&efx->mtd_list))
+                return;
+
+        parts = list_first_entry(&efx->mtd_list, struct efx_mtd_partition,
+                                 node);
+
+        list_for_each_entry_safe(part, next, &efx->mtd_list, node)
+                efx_mtd_remove_partition(part);
+
+        kfree(parts);
 }
 
 void efx_mtd_rename(struct efx_nic *efx)
 {
-        struct efx_mtd *efx_mtd;
+        struct efx_mtd_partition *part;
 
         ASSERT_RTNL();
 
-        list_for_each_entry(efx_mtd, &efx->mtd_list, node)
-                efx_mtd_rename_device(efx_mtd);
+        list_for_each_entry(part, &efx->mtd_list, node)
+                efx_mtd_rename_partition(part);
 }
 
 int efx_mtd_probe(struct efx_nic *efx)
@@ -318,17 +305,15 @@ static int falcon_mtd_read(struct mtd_info *mtd, loff_t start,
                            size_t len, size_t *retlen, u8 *buffer)
 {
         struct efx_mtd_partition *part = to_efx_mtd_partition(mtd);
-        struct efx_mtd *efx_mtd = mtd->priv;
-        const struct falcon_spi_device *spi = efx_mtd->spi;
-        struct efx_nic *efx = efx_mtd->efx;
+        struct efx_nic *efx = mtd->priv;
         struct falcon_nic_data *nic_data = efx->nic_data;
         int rc;
 
         rc = mutex_lock_interruptible(&nic_data->spi_lock);
         if (rc)
                 return rc;
-        rc = falcon_spi_read(efx, spi, part->offset + start, len,
-                             retlen, buffer);
+        rc = falcon_spi_read(efx, part->falcon.spi, part->falcon.offset + start,
+                             len, retlen, buffer);
         mutex_unlock(&nic_data->spi_lock);
         return rc;
 }
@@ -336,15 +321,14 @@ static int falcon_mtd_read(struct mtd_info *mtd, loff_t start,
 static int falcon_mtd_erase(struct mtd_info *mtd, loff_t start, size_t len)
 {
         struct efx_mtd_partition *part = to_efx_mtd_partition(mtd);
-        struct efx_mtd *efx_mtd = mtd->priv;
-        struct efx_nic *efx = efx_mtd->efx;
+        struct efx_nic *efx = mtd->priv;
         struct falcon_nic_data *nic_data = efx->nic_data;
         int rc;
 
         rc = mutex_lock_interruptible(&nic_data->spi_lock);
         if (rc)
                 return rc;
-        rc = falcon_spi_erase(part, part->offset + start, len);
+        rc = falcon_spi_erase(part, part->falcon.offset + start, len);
         mutex_unlock(&nic_data->spi_lock);
         return rc;
 }
@@ -353,17 +337,15 @@ static int falcon_mtd_write(struct mtd_info *mtd, loff_t start,
                             size_t len, size_t *retlen, const u8 *buffer)
 {
         struct efx_mtd_partition *part = to_efx_mtd_partition(mtd);
-        struct efx_mtd *efx_mtd = mtd->priv;
-        const struct falcon_spi_device *spi = efx_mtd->spi;
-        struct efx_nic *efx = efx_mtd->efx;
+        struct efx_nic *efx = mtd->priv;
         struct falcon_nic_data *nic_data = efx->nic_data;
         int rc;
 
         rc = mutex_lock_interruptible(&nic_data->spi_lock);
         if (rc)
                 return rc;
-        rc = falcon_spi_write(efx, spi, part->offset + start, len,
-                              retlen, buffer);
+        rc = falcon_spi_write(efx, part->falcon.spi,
+                              part->falcon.offset + start, len, retlen, buffer);
         mutex_unlock(&nic_data->spi_lock);
         return rc;
 }
@@ -371,8 +353,7 @@ static int falcon_mtd_write(struct mtd_info *mtd, loff_t start,
 static int falcon_mtd_sync(struct mtd_info *mtd)
 {
         struct efx_mtd_partition *part = to_efx_mtd_partition(mtd);
-        struct efx_mtd *efx_mtd = mtd->priv;
-        struct efx_nic *efx = efx_mtd->efx;
+        struct efx_nic *efx = mtd->priv;
         struct falcon_nic_data *nic_data = efx->nic_data;
         int rc;
 
@@ -392,66 +373,50 @@ static const struct efx_mtd_ops falcon_mtd_ops = {
 static int falcon_mtd_probe(struct efx_nic *efx)
 {
         struct falcon_nic_data *nic_data = efx->nic_data;
+        struct efx_mtd_partition *parts;
         struct falcon_spi_device *spi;
-        struct efx_mtd *efx_mtd;
+        size_t n_parts;
         int rc = -ENODEV;
 
         ASSERT_RTNL();
 
+        efx->mtd_ops = &falcon_mtd_ops;
+
+        /* Allocate space for maximum number of partitions */
+        parts = kcalloc(2, sizeof(*parts), GFP_KERNEL);
+        n_parts = 0;
+
         spi = &nic_data->spi_flash;
         if (falcon_spi_present(spi) && spi->size > FALCON_FLASH_BOOTCODE_START) {
-                efx_mtd = kzalloc(sizeof(*efx_mtd) + sizeof(efx_mtd->part[0]),
-                                  GFP_KERNEL);
-                if (!efx_mtd)
-                        return -ENOMEM;
-
-                efx_mtd->spi = spi;
-                efx_mtd->name = "flash";
-                efx_mtd->ops = &falcon_mtd_ops;
-
-                efx_mtd->n_parts = 1;
-                efx_mtd->part[0].mtd.type = MTD_NORFLASH;
-                efx_mtd->part[0].mtd.flags = MTD_CAP_NORFLASH;
-                efx_mtd->part[0].mtd.size = spi->size - FALCON_FLASH_BOOTCODE_START;
-                efx_mtd->part[0].mtd.erasesize = spi->erase_size;
-                efx_mtd->part[0].offset = FALCON_FLASH_BOOTCODE_START;
-                efx_mtd->part[0].type_name = "sfc_flash_bootrom";
-
-                rc = efx_mtd_probe_device(efx, efx_mtd);
-                if (rc) {
-                        kfree(efx_mtd);
-                        return rc;
-                }
+                parts[n_parts].falcon.spi = spi;
+                parts[n_parts].falcon.offset = FALCON_FLASH_BOOTCODE_START;
+                parts[n_parts].dev_type_name = "flash";
+                parts[n_parts].type_name = "sfc_flash_bootrom";
+                parts[n_parts].mtd.type = MTD_NORFLASH;
+                parts[n_parts].mtd.flags = MTD_CAP_NORFLASH;
+                parts[n_parts].mtd.size = spi->size - FALCON_FLASH_BOOTCODE_START;
+                parts[n_parts].mtd.erasesize = spi->erase_size;
+                n_parts++;
         }
 
         spi = &nic_data->spi_eeprom;
         if (falcon_spi_present(spi) && spi->size > FALCON_EEPROM_BOOTCONFIG_START) {
-                efx_mtd = kzalloc(sizeof(*efx_mtd) + sizeof(efx_mtd->part[0]),
-                                  GFP_KERNEL);
-                if (!efx_mtd)
-                        return -ENOMEM;
-
-                efx_mtd->spi = spi;
-                efx_mtd->name = "EEPROM";
-                efx_mtd->ops = &falcon_mtd_ops;
-
-                efx_mtd->n_parts = 1;
-                efx_mtd->part[0].mtd.type = MTD_RAM;
-                efx_mtd->part[0].mtd.flags = MTD_CAP_RAM;
-                efx_mtd->part[0].mtd.size =
+                parts[n_parts].falcon.spi = spi;
+                parts[n_parts].falcon.offset = FALCON_EEPROM_BOOTCONFIG_START;
+                parts[n_parts].dev_type_name = "EEPROM";
+                parts[n_parts].type_name = "sfc_bootconfig";
+                parts[n_parts].mtd.type = MTD_RAM;
+                parts[n_parts].mtd.flags = MTD_CAP_RAM;
+                parts[n_parts].mtd.size =
                         min(spi->size, FALCON_EEPROM_BOOTCONFIG_END) -
                         FALCON_EEPROM_BOOTCONFIG_START;
-                efx_mtd->part[0].mtd.erasesize = spi->erase_size;
-                efx_mtd->part[0].offset = FALCON_EEPROM_BOOTCONFIG_START;
-                efx_mtd->part[0].type_name = "sfc_bootconfig";
-
-                rc = efx_mtd_probe_device(efx, efx_mtd);
-                if (rc) {
-                        kfree(efx_mtd);
-                        return rc;
-                }
+                parts[n_parts].mtd.erasesize = spi->erase_size;
+                n_parts++;
         }
 
+        rc = efx_mtd_add(efx, parts, n_parts);
+        if (rc)
+                kfree(parts);
         return rc;
 }
 
@@ -461,8 +426,7 @@ static int siena_mtd_read(struct mtd_info *mtd, loff_t start,
                           size_t len, size_t *retlen, u8 *buffer)
 {
         struct efx_mtd_partition *part = to_efx_mtd_partition(mtd);
-        struct efx_mtd *efx_mtd = mtd->priv;
-        struct efx_nic *efx = efx_mtd->efx;
+        struct efx_nic *efx = mtd->priv;
         loff_t offset = start;
         loff_t end = min_t(loff_t, start + len, mtd->size);
         size_t chunk;
@@ -485,8 +449,7 @@ out:
 static int siena_mtd_erase(struct mtd_info *mtd, loff_t start, size_t len)
 {
         struct efx_mtd_partition *part = to_efx_mtd_partition(mtd);
-        struct efx_mtd *efx_mtd = mtd->priv;
-        struct efx_nic *efx = efx_mtd->efx;
+        struct efx_nic *efx = mtd->priv;
         loff_t offset = start & ~((loff_t)(mtd->erasesize - 1));
         loff_t end = min_t(loff_t, start + len, mtd->size);
         size_t chunk = part->mtd.erasesize;
@@ -517,8 +480,7 @@ static int siena_mtd_write(struct mtd_info *mtd, loff_t start,
                            size_t len, size_t *retlen, const u8 *buffer)
 {
         struct efx_mtd_partition *part = to_efx_mtd_partition(mtd);
-        struct efx_mtd *efx_mtd = mtd->priv;
-        struct efx_nic *efx = efx_mtd->efx;
+        struct efx_nic *efx = mtd->priv;
         loff_t offset = start;
         loff_t end = min_t(loff_t, start + len, mtd->size);
         size_t chunk;
@@ -548,8 +510,7 @@ out:
 static int siena_mtd_sync(struct mtd_info *mtd)
 {
         struct efx_mtd_partition *part = to_efx_mtd_partition(mtd);
-        struct efx_mtd *efx_mtd = mtd->priv;
-        struct efx_nic *efx = efx_mtd->efx;
+        struct efx_nic *efx = mtd->priv;
         int rc = 0;
 
         if (part->mcdi.updating) {
@@ -589,11 +550,9 @@ static const struct siena_nvram_type_info siena_nvram_types[] = {
 };
 
 static int siena_mtd_probe_partition(struct efx_nic *efx,
-                                     struct efx_mtd *efx_mtd,
-                                     unsigned int part_id,
+                                     struct efx_mtd_partition *part,
                                      unsigned int type)
 {
-        struct efx_mtd_partition *part = &efx_mtd->part[part_id];
         const struct siena_nvram_type_info *info;
         size_t size, erase_size;
         bool protected;
@@ -615,6 +574,7 @@ static int siena_mtd_probe_partition(struct efx_nic *efx,
                 return -ENODEV; /* hide it */
 
         part->mcdi.nvram_type = type;
+        part->dev_type_name = "Siena NVRAM manager";
         part->type_name = info->name;
 
         part->mtd.type = MTD_NORFLASH;
@@ -626,55 +586,54 @@ static int siena_mtd_probe_partition(struct efx_nic *efx,
 }
 
 static int siena_mtd_get_fw_subtypes(struct efx_nic *efx,
-                                     struct efx_mtd *efx_mtd)
+                                     struct efx_mtd_partition *parts,
+                                     size_t n_parts)
 {
-        struct efx_mtd_partition *part;
         uint16_t fw_subtype_list[
                 MC_CMD_GET_BOARD_CFG_OUT_FW_SUBTYPE_LIST_MAXNUM];
+        size_t i;
         int rc;
 
         rc = efx_mcdi_get_board_cfg(efx, NULL, fw_subtype_list, NULL);
         if (rc)
                 return rc;
 
-        efx_for_each_partition(part, efx_mtd)
-                part->mcdi.fw_subtype = fw_subtype_list[part->mcdi.nvram_type];
+        for (i = 0; i < n_parts; i++)
+                parts[i].mcdi.fw_subtype =
+                        fw_subtype_list[parts[i].mcdi.nvram_type];
 
         return 0;
 }
 
 static int siena_mtd_probe(struct efx_nic *efx)
 {
-        struct efx_mtd *efx_mtd;
-        int rc = -ENODEV;
+        struct efx_mtd_partition *parts;
         u32 nvram_types;
         unsigned int type;
+        size_t n_parts;
+        int rc;
 
         ASSERT_RTNL();
 
+        efx->mtd_ops = &siena_mtd_ops;
+
         rc = efx_mcdi_nvram_types(efx, &nvram_types);
         if (rc)
                 return rc;
 
-        efx_mtd = kzalloc(sizeof(*efx_mtd) +
-                          hweight32(nvram_types) * sizeof(efx_mtd->part[0]),
-                          GFP_KERNEL);
-        if (!efx_mtd)
+        parts = kcalloc(hweight32(nvram_types), sizeof(*parts), GFP_KERNEL);
+        if (!parts)
                 return -ENOMEM;
 
-        efx_mtd->name = "Siena NVRAM manager";
-
-        efx_mtd->ops = &siena_mtd_ops;
-
         type = 0;
-        efx_mtd->n_parts = 0;
+        n_parts = 0;
 
         while (nvram_types != 0) {
                 if (nvram_types & 1) {
-                        rc = siena_mtd_probe_partition(efx, efx_mtd,
-                                                       efx_mtd->n_parts, type);
+                        rc = siena_mtd_probe_partition(efx, &parts[n_parts],
+                                                       type);
                         if (rc == 0)
-                                efx_mtd->n_parts++;
+                                n_parts++;
                         else if (rc != -ENODEV)
                                 goto fail;
                 }
@@ -682,14 +641,14 @@ static int siena_mtd_probe(struct efx_nic *efx)
                 nvram_types >>= 1;
         }
 
-        rc = siena_mtd_get_fw_subtypes(efx, efx_mtd);
+        rc = siena_mtd_get_fw_subtypes(efx, parts, n_parts);
         if (rc)
                 goto fail;
 
-        rc = efx_mtd_probe_device(efx, efx_mtd);
+        rc = efx_mtd_add(efx, parts, n_parts);
 fail:
         if (rc)
-                kfree(efx_mtd);
+                kfree(parts);
         return rc;
 }
 
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 555dd013bda7..958ede16077a 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -868,6 +868,7 @@ struct efx_nic {
         struct delayed_work selftest_work;
 
 #ifdef CONFIG_SFC_MTD
+        const struct efx_mtd_ops *mtd_ops;
         struct list_head mtd_list;
 #endif