powerpc/pseries: Add support for dynamic dma windows
If firmware allows us to map all of a partition's memory for DMA on a
particular bridge, create a 1:1 mapping of that memory. Add hooks for
dealing with hotplug events. Dynamic DMA windows can use larger than the
default page size, and we use the largest one possible.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index f4a04c0..b245ce6 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -626,6 +626,10 @@
disable= [IPV6]
See Documentation/networking/ipv6.txt.
+ disable_ddw [PPC/PSERIES]
+ Disable Dynamic DMA Window support. Use this if
+ to workaround buggy firmware.
+
disable_ipv6= [IPV6]
See Documentation/networking/ipv6.txt.
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index edea60b..154c464 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -33,6 +33,7 @@
#include <linux/pci.h>
#include <linux/dma-mapping.h>
#include <linux/crash_dump.h>
+#include <linux/memory.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/rtas.h>
@@ -45,6 +46,7 @@
#include <asm/tce.h>
#include <asm/ppc-pci.h>
#include <asm/udbg.h>
+#include <asm/mmzone.h>
#include "plpar_wrappers.h"
@@ -270,6 +272,152 @@
return tce_ret;
}
+/* this is compatable with cells for the device tree property */
+struct dynamic_dma_window_prop {
+ __be32 liobn; /* tce table number */
+ __be64 dma_base; /* address hi,lo */
+ __be32 tce_shift; /* ilog2(tce_page_size) */
+ __be32 window_shift; /* ilog2(tce_window_size) */
+};
+
+struct direct_window {
+ struct device_node *device;
+ const struct dynamic_dma_window_prop *prop;
+ struct list_head list;
+};
+
+/* Dynamic DMA Window support */
+struct ddw_query_response {
+ u32 windows_available;
+ u32 largest_available_block;
+ u32 page_size;
+ u32 migration_capable;
+};
+
+struct ddw_create_response {
+ u32 liobn;
+ u32 addr_hi;
+ u32 addr_lo;
+};
+
+static LIST_HEAD(direct_window_list);
+/* prevents races between memory on/offline and window creation */
+static DEFINE_SPINLOCK(direct_window_list_lock);
+/* protects initializing window twice for same device */
+static DEFINE_MUTEX(direct_window_init_mutex);
+#define DIRECT64_PROPNAME "linux,direct64-ddr-window-info"
+
+static int tce_clearrange_multi_pSeriesLP(unsigned long start_pfn,
+ unsigned long num_pfn, const void *arg)
+{
+ const struct dynamic_dma_window_prop *maprange = arg;
+ int rc;
+ u64 tce_size, num_tce, dma_offset, next;
+ u32 tce_shift;
+ long limit;
+
+ tce_shift = be32_to_cpu(maprange->tce_shift);
+ tce_size = 1ULL << tce_shift;
+ next = start_pfn << PAGE_SHIFT;
+ num_tce = num_pfn << PAGE_SHIFT;
+
+ /* round back to the beginning of the tce page size */
+ num_tce += next & (tce_size - 1);
+ next &= ~(tce_size - 1);
+
+ /* covert to number of tces */
+ num_tce |= tce_size - 1;
+ num_tce >>= tce_shift;
+
+ do {
+ /*
+ * Set up the page with TCE data, looping through and setting
+ * the values.
+ */
+ limit = min_t(long, num_tce, 512);
+ dma_offset = next + be64_to_cpu(maprange->dma_base);
+
+ rc = plpar_tce_stuff((u64)be32_to_cpu(maprange->liobn),
+ dma_offset,
+ 0, limit);
+ num_tce -= limit;
+ } while (num_tce > 0 && !rc);
+
+ return rc;
+}
+
+static int tce_setrange_multi_pSeriesLP(unsigned long start_pfn,
+ unsigned long num_pfn, const void *arg)
+{
+ const struct dynamic_dma_window_prop *maprange = arg;
+ u64 *tcep, tce_size, num_tce, dma_offset, next, proto_tce, liobn;
+ u32 tce_shift;
+ u64 rc = 0;
+ long l, limit;
+
+ local_irq_disable(); /* to protect tcep and the page behind it */
+ tcep = __get_cpu_var(tce_page);
+
+ if (!tcep) {
+ tcep = (u64 *)__get_free_page(GFP_ATOMIC);
+ if (!tcep) {
+ local_irq_enable();
+ return -ENOMEM;
+ }
+ __get_cpu_var(tce_page) = tcep;
+ }
+
+ proto_tce = TCE_PCI_READ | TCE_PCI_WRITE;
+
+ liobn = (u64)be32_to_cpu(maprange->liobn);
+ tce_shift = be32_to_cpu(maprange->tce_shift);
+ tce_size = 1ULL << tce_shift;
+ next = start_pfn << PAGE_SHIFT;
+ num_tce = num_pfn << PAGE_SHIFT;
+
+ /* round back to the beginning of the tce page size */
+ num_tce += next & (tce_size - 1);
+ next &= ~(tce_size - 1);
+
+ /* covert to number of tces */
+ num_tce |= tce_size - 1;
+ num_tce >>= tce_shift;
+
+ /* We can map max one pageful of TCEs at a time */
+ do {
+ /*
+ * Set up the page with TCE data, looping through and setting
+ * the values.
+ */
+ limit = min_t(long, num_tce, 4096/TCE_ENTRY_SIZE);
+ dma_offset = next + be64_to_cpu(maprange->dma_base);
+
+ for (l = 0; l < limit; l++) {
+ tcep[l] = proto_tce | next;
+ next += tce_size;
+ }
+
+ rc = plpar_tce_put_indirect(liobn,
+ dma_offset,
+ (u64)virt_to_abs(tcep),
+ limit);
+
+ num_tce -= limit;
+ } while (num_tce > 0 && !rc);
+
+ /* error cleanup: caller will clear whole range */
+
+ local_irq_enable();
+ return rc;
+}
+
+static int tce_setrange_multi_pSeriesLP_walk(unsigned long start_pfn,
+ unsigned long num_pfn, void *arg)
+{
+ return tce_setrange_multi_pSeriesLP(start_pfn, num_pfn, arg);
+}
+
+
#ifdef CONFIG_PCI
static void iommu_table_setparms(struct pci_controller *phb,
struct device_node *dn,
@@ -495,6 +643,329 @@
pci_name(dev));
}
+static int __read_mostly disable_ddw;
+
+static int __init disable_ddw_setup(char *str)
+{
+ disable_ddw = 1;
+ printk(KERN_INFO "ppc iommu: disabling ddw.\n");
+
+ return 0;
+}
+
+early_param("disable_ddw", disable_ddw_setup);
+
+static void remove_ddw(struct device_node *np)
+{
+ struct dynamic_dma_window_prop *dwp;
+ struct property *win64;
+ const u32 *ddr_avail;
+ u64 liobn;
+ int len, ret;
+
+ ddr_avail = of_get_property(np, "ibm,ddw-applicable", &len);
+ win64 = of_find_property(np, DIRECT64_PROPNAME, NULL);
+ if (!win64 || !ddr_avail || len < 3 * sizeof(u32))
+ return;
+
+ dwp = win64->value;
+ liobn = (u64)be32_to_cpu(dwp->liobn);
+
+ /* clear the whole window, note the arg is in kernel pages */
+ ret = tce_clearrange_multi_pSeriesLP(0,
+ 1ULL << (be32_to_cpu(dwp->window_shift) - PAGE_SHIFT), dwp);
+ if (ret)
+ pr_warning("%s failed to clear tces in window.\n",
+ np->full_name);
+ else
+ pr_debug("%s successfully cleared tces in window.\n",
+ np->full_name);
+
+ ret = rtas_call(ddr_avail[2], 1, 1, NULL, liobn);
+ if (ret)
+ pr_warning("%s: failed to remove direct window: rtas returned "
+ "%d to ibm,remove-pe-dma-window(%x) %llx\n",
+ np->full_name, ret, ddr_avail[2], liobn);
+ else
+ pr_debug("%s: successfully removed direct window: rtas returned "
+ "%d to ibm,remove-pe-dma-window(%x) %llx\n",
+ np->full_name, ret, ddr_avail[2], liobn);
+}
+
+
+static int dupe_ddw_if_already_created(struct pci_dev *dev, struct device_node *pdn)
+{
+ struct device_node *dn;
+ struct pci_dn *pcidn;
+ struct direct_window *window;
+ const struct dynamic_dma_window_prop *direct64;
+ u64 dma_addr = 0;
+
+ dn = pci_device_to_OF_node(dev);
+ pcidn = PCI_DN(dn);
+ spin_lock(&direct_window_list_lock);
+ /* check if we already created a window and dupe that config if so */
+ list_for_each_entry(window, &direct_window_list, list) {
+ if (window->device == pdn) {
+ direct64 = window->prop;
+ dma_addr = direct64->dma_base;
+ break;
+ }
+ }
+ spin_unlock(&direct_window_list_lock);
+
+ return dma_addr;
+}
+
+static u64 dupe_ddw_if_kexec(struct pci_dev *dev, struct device_node *pdn)
+{
+ struct device_node *dn;
+ struct pci_dn *pcidn;
+ int len;
+ struct direct_window *window;
+ const struct dynamic_dma_window_prop *direct64;
+ u64 dma_addr = 0;
+
+ dn = pci_device_to_OF_node(dev);
+ pcidn = PCI_DN(dn);
+ direct64 = of_get_property(pdn, DIRECT64_PROPNAME, &len);
+ if (direct64) {
+ window = kzalloc(sizeof(*window), GFP_KERNEL);
+ if (!window) {
+ remove_ddw(pdn);
+ } else {
+ window->device = pdn;
+ window->prop = direct64;
+ spin_lock(&direct_window_list_lock);
+ list_add(&window->list, &direct_window_list);
+ spin_unlock(&direct_window_list_lock);
+ dma_addr = direct64->dma_base;
+ }
+ }
+
+ return dma_addr;
+}
+
+static int query_ddw(struct pci_dev *dev, const u32 *ddr_avail,
+ struct ddw_query_response *query)
+{
+ struct device_node *dn;
+ struct pci_dn *pcidn;
+ u32 cfg_addr;
+ u64 buid;
+ int ret;
+
+ /*
+ * Get the config address and phb buid of the PE window.
+ * Rely on eeh to retrieve this for us.
+ * Retrieve them from the pci device, not the node with the
+ * dma-window property
+ */
+ dn = pci_device_to_OF_node(dev);
+ pcidn = PCI_DN(dn);
+ cfg_addr = pcidn->eeh_config_addr;
+ if (pcidn->eeh_pe_config_addr)
+ cfg_addr = pcidn->eeh_pe_config_addr;
+ buid = pcidn->phb->buid;
+ ret = rtas_call(ddr_avail[0], 3, 5, (u32 *)query,
+ cfg_addr, BUID_HI(buid), BUID_LO(buid));
+ dev_info(&dev->dev, "ibm,query-pe-dma-windows(%x) %x %x %x"
+ " returned %d\n", ddr_avail[0], cfg_addr, BUID_HI(buid),
+ BUID_LO(buid), ret);
+ return ret;
+}
+
+static int create_ddw(struct pci_dev *dev, const u32 *ddr_avail,
+ struct ddw_create_response *create, int page_shift,
+ int window_shift)
+{
+ struct device_node *dn;
+ struct pci_dn *pcidn;
+ u32 cfg_addr;
+ u64 buid;
+ int ret;
+
+ /*
+ * Get the config address and phb buid of the PE window.
+ * Rely on eeh to retrieve this for us.
+ * Retrieve them from the pci device, not the node with the
+ * dma-window property
+ */
+ dn = pci_device_to_OF_node(dev);
+ pcidn = PCI_DN(dn);
+ cfg_addr = pcidn->eeh_config_addr;
+ if (pcidn->eeh_pe_config_addr)
+ cfg_addr = pcidn->eeh_pe_config_addr;
+ buid = pcidn->phb->buid;
+
+ do {
+ /* extra outputs are LIOBN and dma-addr (hi, lo) */
+ ret = rtas_call(ddr_avail[1], 5, 4, (u32 *)create, cfg_addr,
+ BUID_HI(buid), BUID_LO(buid), page_shift, window_shift);
+ } while (rtas_busy_delay(ret));
+ dev_info(&dev->dev,
+ "ibm,create-pe-dma-window(%x) %x %x %x %x %x returned %d "
+ "(liobn = 0x%x starting addr = %x %x)\n", ddr_avail[1],
+ cfg_addr, BUID_HI(buid), BUID_LO(buid), page_shift,
+ window_shift, ret, create->liobn, create->addr_hi, create->addr_lo);
+
+ return ret;
+}
+
+/*
+ * If the PE supports dynamic dma windows, and there is space for a table
+ * that can map all pages in a linear offset, then setup such a table,
+ * and record the dma-offset in the struct device.
+ *
+ * dev: the pci device we are checking
+ * pdn: the parent pe node with the ibm,dma_window property
+ * Future: also check if we can remap the base window for our base page size
+ *
+ * returns the dma offset for use by dma_set_mask
+ */
+static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
+{
+ int len, ret;
+ struct ddw_query_response query;
+ struct ddw_create_response create;
+ int page_shift;
+ u64 dma_addr, max_addr;
+ struct device_node *dn;
+ const u32 *uninitialized_var(ddr_avail);
+ struct direct_window *window;
+ struct property *uninitialized_var(win64);
+ struct dynamic_dma_window_prop *ddwprop;
+
+ mutex_lock(&direct_window_init_mutex);
+
+ dma_addr = dupe_ddw_if_already_created(dev, pdn);
+ if (dma_addr != 0)
+ goto out_unlock;
+
+ dma_addr = dupe_ddw_if_kexec(dev, pdn);
+ if (dma_addr != 0)
+ goto out_unlock;
+
+ /*
+ * the ibm,ddw-applicable property holds the tokens for:
+ * ibm,query-pe-dma-window
+ * ibm,create-pe-dma-window
+ * ibm,remove-pe-dma-window
+ * for the given node in that order.
+ * the property is actually in the parent, not the PE
+ */
+ ddr_avail = of_get_property(pdn, "ibm,ddw-applicable", &len);
+ if (!ddr_avail || len < 3 * sizeof(u32))
+ goto out_unlock;
+
+ /*
+ * Query if there is a second window of size to map the
+ * whole partition. Query returns number of windows, largest
+ * block assigned to PE (partition endpoint), and two bitmasks
+ * of page sizes: supported and supported for migrate-dma.
+ */
+ dn = pci_device_to_OF_node(dev);
+ ret = query_ddw(dev, ddr_avail, &query);
+ if (ret != 0)
+ goto out_unlock;
+
+ if (query.windows_available == 0) {
+ /*
+ * no additional windows are available for this device.
+ * We might be able to reallocate the existing window,
+ * trading in for a larger page size.
+ */
+ dev_dbg(&dev->dev, "no free dynamic windows");
+ goto out_unlock;
+ }
+ if (query.page_size & 4) {
+ page_shift = 24; /* 16MB */
+ } else if (query.page_size & 2) {
+ page_shift = 16; /* 64kB */
+ } else if (query.page_size & 1) {
+ page_shift = 12; /* 4kB */
+ } else {
+ dev_dbg(&dev->dev, "no supported direct page size in mask %x",
+ query.page_size);
+ goto out_unlock;
+ }
+ /* verify the window * number of ptes will map the partition */
+ /* check largest block * page size > max memory hotplug addr */
+ max_addr = memory_hotplug_max();
+ if (query.largest_available_block < (max_addr >> page_shift)) {
+ dev_dbg(&dev->dev, "can't map partiton max 0x%llx with %u "
+ "%llu-sized pages\n", max_addr, query.largest_available_block,
+ 1ULL << page_shift);
+ goto out_unlock;
+ }
+ len = order_base_2(max_addr);
+ win64 = kzalloc(sizeof(struct property), GFP_KERNEL);
+ if (!win64) {
+ dev_info(&dev->dev,
+ "couldn't allocate property for 64bit dma window\n");
+ goto out_unlock;
+ }
+ win64->name = kstrdup(DIRECT64_PROPNAME, GFP_KERNEL);
+ win64->value = ddwprop = kmalloc(sizeof(*ddwprop), GFP_KERNEL);
+ if (!win64->name || !win64->value) {
+ dev_info(&dev->dev,
+ "couldn't allocate property name and value\n");
+ goto out_free_prop;
+ }
+
+ ret = create_ddw(dev, ddr_avail, &create, page_shift, len);
+ if (ret != 0)
+ goto out_free_prop;
+
+ ddwprop->liobn = cpu_to_be32(create.liobn);
+ ddwprop->dma_base = cpu_to_be64(of_read_number(&create.addr_hi, 2));
+ ddwprop->tce_shift = cpu_to_be32(page_shift);
+ ddwprop->window_shift = cpu_to_be32(len);
+
+ dev_dbg(&dev->dev, "created tce table LIOBN 0x%x for %s\n",
+ create.liobn, dn->full_name);
+
+ window = kzalloc(sizeof(*window), GFP_KERNEL);
+ if (!window)
+ goto out_clear_window;
+
+ ret = walk_system_ram_range(0, memblock_end_of_DRAM() >> PAGE_SHIFT,
+ win64->value, tce_setrange_multi_pSeriesLP_walk);
+ if (ret) {
+ dev_info(&dev->dev, "failed to map direct window for %s: %d\n",
+ dn->full_name, ret);
+ goto out_clear_window;
+ }
+
+ ret = prom_add_property(pdn, win64);
+ if (ret) {
+ dev_err(&dev->dev, "unable to add dma window property for %s: %d",
+ pdn->full_name, ret);
+ goto out_clear_window;
+ }
+
+ window->device = pdn;
+ window->prop = ddwprop;
+ spin_lock(&direct_window_list_lock);
+ list_add(&window->list, &direct_window_list);
+ spin_unlock(&direct_window_list_lock);
+
+ dma_addr = of_read_number(&create.addr_hi, 2);
+ goto out_unlock;
+
+out_clear_window:
+ remove_ddw(pdn);
+
+out_free_prop:
+ kfree(win64->name);
+ kfree(win64->value);
+ kfree(win64);
+
+out_unlock:
+ mutex_unlock(&direct_window_init_mutex);
+ return dma_addr;
+}
+
static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
{
struct device_node *pdn, *dn;
@@ -541,23 +1012,137 @@
set_iommu_table_base(&dev->dev, pci->iommu_table);
}
+
+static int dma_set_mask_pSeriesLP(struct device *dev, u64 dma_mask)
+{
+ bool ddw_enabled = false;
+ struct device_node *pdn, *dn;
+ struct pci_dev *pdev;
+ const void *dma_window = NULL;
+ u64 dma_offset;
+
+ if (!dev->dma_mask || !dma_supported(dev, dma_mask))
+ return -EIO;
+
+ /* only attempt to use a new window if 64-bit DMA is requested */
+ if (!disable_ddw && dma_mask == DMA_BIT_MASK(64)) {
+ pdev = to_pci_dev(dev);
+
+ dn = pci_device_to_OF_node(pdev);
+ dev_dbg(dev, "node is %s\n", dn->full_name);
+
+ /*
+ * the device tree might contain the dma-window properties
+ * per-device and not neccesarily for the bus. So we need to
+ * search upwards in the tree until we either hit a dma-window
+ * property, OR find a parent with a table already allocated.
+ */
+ for (pdn = dn; pdn && PCI_DN(pdn) && !PCI_DN(pdn)->iommu_table;
+ pdn = pdn->parent) {
+ dma_window = of_get_property(pdn, "ibm,dma-window", NULL);
+ if (dma_window)
+ break;
+ }
+ if (pdn && PCI_DN(pdn)) {
+ dma_offset = enable_ddw(pdev, pdn);
+ if (dma_offset != 0) {
+ dev_info(dev, "Using 64-bit direct DMA at offset %llx\n", dma_offset);
+ set_dma_offset(dev, dma_offset);
+ set_dma_ops(dev, &dma_direct_ops);
+ ddw_enabled = true;
+ }
+ }
+ }
+
+ /* fall-through to iommu ops */
+ if (!ddw_enabled) {
+ dev_info(dev, "Using 32-bit DMA via iommu\n");
+ set_dma_ops(dev, &dma_iommu_ops);
+ }
+
+ *dev->dma_mask = dma_mask;
+ return 0;
+}
+
#else /* CONFIG_PCI */
#define pci_dma_bus_setup_pSeries NULL
#define pci_dma_dev_setup_pSeries NULL
#define pci_dma_bus_setup_pSeriesLP NULL
#define pci_dma_dev_setup_pSeriesLP NULL
+#define dma_set_mask_pSeriesLP NULL
#endif /* !CONFIG_PCI */
+static int iommu_mem_notifier(struct notifier_block *nb, unsigned long action,
+ void *data)
+{
+ struct direct_window *window;
+ struct memory_notify *arg = data;
+ int ret = 0;
+
+ switch (action) {
+ case MEM_GOING_ONLINE:
+ spin_lock(&direct_window_list_lock);
+ list_for_each_entry(window, &direct_window_list, list) {
+ ret |= tce_setrange_multi_pSeriesLP(arg->start_pfn,
+ arg->nr_pages, window->prop);
+ /* XXX log error */
+ }
+ spin_unlock(&direct_window_list_lock);
+ break;
+ case MEM_CANCEL_ONLINE:
+ case MEM_OFFLINE:
+ spin_lock(&direct_window_list_lock);
+ list_for_each_entry(window, &direct_window_list, list) {
+ ret |= tce_clearrange_multi_pSeriesLP(arg->start_pfn,
+ arg->nr_pages, window->prop);
+ /* XXX log error */
+ }
+ spin_unlock(&direct_window_list_lock);
+ break;
+ default:
+ break;
+ }
+ if (ret && action != MEM_CANCEL_ONLINE)
+ return NOTIFY_BAD;
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block iommu_mem_nb = {
+ .notifier_call = iommu_mem_notifier,
+};
+
static int iommu_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node)
{
int err = NOTIFY_OK;
struct device_node *np = node;
struct pci_dn *pci = PCI_DN(np);
+ struct direct_window *window;
switch (action) {
case PSERIES_RECONFIG_REMOVE:
if (pci && pci->iommu_table)
iommu_free_table(pci->iommu_table, np->full_name);
+
+ spin_lock(&direct_window_list_lock);
+ list_for_each_entry(window, &direct_window_list, list) {
+ if (window->device == np) {
+ list_del(&window->list);
+ kfree(window);
+ break;
+ }
+ }
+ spin_unlock(&direct_window_list_lock);
+
+ /*
+ * Because the notifier runs after isolation of the
+ * slot, we are guaranteed any DMA window has already
+ * been revoked and the TCEs have been marked invalid,
+ * so we don't need a call to remove_ddw(np). However,
+ * if an additional notifier action is added before the
+ * isolate call, we should update this code for
+ * completeness with such a call.
+ */
break;
default:
err = NOTIFY_DONE;
@@ -587,6 +1172,7 @@
ppc_md.tce_get = tce_get_pSeriesLP;
ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_pSeriesLP;
ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_pSeriesLP;
+ ppc_md.dma_set_mask = dma_set_mask_pSeriesLP;
} else {
ppc_md.tce_build = tce_build_pSeries;
ppc_md.tce_free = tce_free_pSeries;
@@ -597,6 +1183,7 @@
pSeries_reconfig_notifier_register(&iommu_reconfig_nb);
+ register_memory_notifier(&iommu_mem_nb);
set_pci_dma_ops(&dma_iommu_ops);
}