diff options
Diffstat (limited to 'drivers/scsi/am53c974.c')
| -rw-r--r-- | drivers/scsi/am53c974.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/scsi/am53c974.c b/drivers/scsi/am53c974.c index 6e88e38bd2a4..25f06196643e 100644 --- a/drivers/scsi/am53c974.c +++ b/drivers/scsi/am53c974.c @@ -18,6 +18,7 @@ #define DRV_MODULE_VERSION "1.00" static bool am53c974_debug; +static bool am53c974_fenab = true; #define esp_dma_log(f, a...) \ do { \ @@ -256,6 +257,8 @@ static void pci_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count, pci_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW); pci_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED); + if (esp->config2 & ESP_CONFIG2_FENAB) + pci_esp_write8(esp, (esp_count >> 16) & 0xff, ESP_TCHI); pci_esp_write32(esp, esp_count, ESP_DMA_STC); pci_esp_write32(esp, addr, ESP_DMA_SPA); @@ -268,6 +271,33 @@ static void pci_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count, pci_esp_write8(esp, ESP_DMA_CMD_START | val, ESP_DMA_CMD); } +static u32 pci_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len) +{ + int dma_limit = 16; + u32 base, end; + + /* + * If CONFIG2_FENAB is set we can + * handle up to 24 bit addresses + */ + if (esp->config2 & ESP_CONFIG2_FENAB) + dma_limit = 24; + + if (dma_len > (1U << dma_limit)) + dma_len = (1U << dma_limit); + + /* + * Prevent crossing a 24-bit address boundary. + */ + base = dma_addr & ((1U << 24) - 1U); + end = base + dma_len; + if (end > (1U << 24)) + end = (1U <<24); + dma_len = end - base; + + return dma_len; +} + static const struct esp_driver_ops pci_esp_ops = { .esp_write8 = pci_esp_write8, .esp_read8 = pci_esp_read8, @@ -281,6 +311,7 @@ static const struct esp_driver_ops pci_esp_ops = { .dma_invalidate = pci_esp_dma_invalidate, .send_dma_cmd = pci_esp_send_dma_cmd, .dma_error = pci_esp_dma_error, + .dma_length_limit = pci_esp_dma_length_limit, }; /* @@ -418,6 +449,12 @@ static int pci_esp_probe_one(struct pci_dev *pdev, * DMA for command submission. */ esp->flags |= ESP_FLAG_USE_FIFO; + /* + * Enable CONFIG2_FENAB to allow for large DMA transfers + */ + if (am53c974_fenab) + esp->config2 |= ESP_CONFIG2_FENAB; + pep->esp = esp; if (pci_request_regions(pdev, DRV_MODULE_NAME)) { @@ -541,5 +578,8 @@ MODULE_VERSION(DRV_MODULE_VERSION); module_param(am53c974_debug, bool, 0644); MODULE_PARM_DESC(am53c974_debug, "Enable debugging"); +module_param(am53c974_fenab, bool, 0444); +MODULE_PARM_DESC(am53c974_fenab, "Enable 24-bit DMA transfer sizes"); + module_init(am53c974_module_init); module_exit(am53c974_module_exit); |