diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/s390/cio/css.c | 133 |
1 files changed, 129 insertions, 4 deletions
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index aea502922646..7b1a440a1f8e 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -20,6 +20,8 @@ #include <linux/reboot.h> #include <linux/suspend.h> #include <linux/proc_fs.h> +#include <linux/genalloc.h> +#include <linux/dma-mapping.h> #include <asm/isc.h> #include <asm/crw.h> @@ -224,6 +226,12 @@ struct subchannel *css_alloc_subchannel(struct subchannel_id schid, INIT_WORK(&sch->todo_work, css_sch_todo); sch->dev.release = &css_subchannel_release; device_initialize(&sch->dev); + /* + * The physical addresses of some the dma structures that can + * belong to a subchannel need to fit 31 bit width (e.g. ccw). + */ + sch->dev.coherent_dma_mask = DMA_BIT_MASK(31); + sch->dev.dma_mask = &sch->dev.coherent_dma_mask; return sch; err: @@ -899,6 +907,13 @@ static int __init setup_css(int nr) dev_set_name(&css->device, "css%x", nr); css->device.groups = cssdev_attr_groups; css->device.release = channel_subsystem_release; + /* + * We currently allocate notifier bits with this (using + * css->device as the device argument with the DMA API) + * and are fine with 64 bit addresses. + */ + css->device.coherent_dma_mask = DMA_BIT_MASK(64); + css->device.dma_mask = &css->device.coherent_dma_mask; mutex_init(&css->mutex); css->cssid = chsc_get_cssid(nr); @@ -1018,6 +1033,111 @@ static struct notifier_block css_power_notifier = { .notifier_call = css_power_event, }; +#define CIO_DMA_GFP (GFP_KERNEL | __GFP_ZERO) +static struct gen_pool *cio_dma_pool; + +/* Currently cio supports only a single css */ +struct device *cio_get_dma_css_dev(void) +{ + return &channel_subsystems[0]->device; +} + +struct gen_pool *cio_gp_dma_create(struct device *dma_dev, int nr_pages) +{ + struct gen_pool *gp_dma; + void *cpu_addr; + dma_addr_t dma_addr; + int i; + + gp_dma = gen_pool_create(3, -1); + if (!gp_dma) + return NULL; + for (i = 0; i < nr_pages; ++i) { + cpu_addr = dma_alloc_coherent(dma_dev, PAGE_SIZE, &dma_addr, + CIO_DMA_GFP); + if (!cpu_addr) + return gp_dma; + gen_pool_add_virt(gp_dma, (unsigned long) cpu_addr, + dma_addr, PAGE_SIZE, -1); + } + return gp_dma; +} + +static void __gp_dma_free_dma(struct gen_pool *pool, + struct gen_pool_chunk *chunk, void *data) +{ + size_t chunk_size = chunk->end_addr - chunk->start_addr + 1; + + dma_free_coherent((struct device *) data, chunk_size, + (void *) chunk->start_addr, + (dma_addr_t) chunk->phys_addr); +} + +void cio_gp_dma_destroy(struct gen_pool *gp_dma, struct device *dma_dev) +{ + if (!gp_dma) + return; + /* this is quite ugly but no better idea */ + gen_pool_for_each_chunk(gp_dma, __gp_dma_free_dma, dma_dev); + gen_pool_destroy(gp_dma); +} + +static int cio_dma_pool_init(void) +{ + /* No need to free up the resources: compiled in */ + cio_dma_pool = cio_gp_dma_create(cio_get_dma_css_dev(), 1); + if (!cio_dma_pool) + return -ENOMEM; + return 0; +} + +void *cio_gp_dma_zalloc(struct gen_pool *gp_dma, struct device *dma_dev, + size_t size) +{ + dma_addr_t dma_addr; + unsigned long addr; + size_t chunk_size; + + if (!gp_dma) + return NULL; + addr = gen_pool_alloc(gp_dma, size); + while (!addr) { + chunk_size = round_up(size, PAGE_SIZE); + addr = (unsigned long) dma_alloc_coherent(dma_dev, + chunk_size, &dma_addr, CIO_DMA_GFP); + if (!addr) + return NULL; + gen_pool_add_virt(gp_dma, addr, dma_addr, chunk_size, -1); + addr = gen_pool_alloc(gp_dma, size); + } + return (void *) addr; +} + +void cio_gp_dma_free(struct gen_pool *gp_dma, void *cpu_addr, size_t size) +{ + if (!cpu_addr) + return; + memset(cpu_addr, 0, size); + gen_pool_free(gp_dma, (unsigned long) cpu_addr, size); +} + +/* + * Allocate dma memory from the css global pool. Intended for memory not + * specific to any single device within the css. The allocated memory + * is not guaranteed to be 31-bit addressable. + * + * Caution: Not suitable for early stuff like console. + */ +void *cio_dma_zalloc(size_t size) +{ + return cio_gp_dma_zalloc(cio_dma_pool, cio_get_dma_css_dev(), size); +} + +void cio_dma_free(void *cpu_addr, size_t size) +{ + cio_gp_dma_free(cio_dma_pool, cpu_addr, size); +} + /* * Now that the driver core is running, we can setup our channel subsystem. * The struct subchannel's are created during probing. @@ -1059,16 +1179,21 @@ static int __init css_bus_init(void) if (ret) goto out_unregister; ret = register_pm_notifier(&css_power_notifier); - if (ret) { - unregister_reboot_notifier(&css_reboot_notifier); - goto out_unregister; - } + if (ret) + goto out_unregister_rn; + ret = cio_dma_pool_init(); + if (ret) + goto out_unregister_pmn; css_init_done = 1; /* Enable default isc for I/O subchannels. */ isc_register(IO_SCH_ISC); return 0; +out_unregister_pmn: + unregister_pm_notifier(&css_power_notifier); +out_unregister_rn: + unregister_reboot_notifier(&css_reboot_notifier); out_unregister: while (i-- > 0) { struct channel_subsystem *css = channel_subsystems[i]; |