[PATCH] powerpc/cell: add iommu support for larger memory

So far, the iommu code was hardwired to a linear mapping
between 0x20000000 and 0x40000000, so it could only support
512MB of RAM.

This patch still keeps the linear mapping, but looks for
proper ibm,dma-window properties to set up larger windows,
this makes the maximum supported RAM size 2GB.

If there is anything unusual about the dma-window properties,
we fall back to the old behavior.

We also support switching off the iommu completely now
with the regular iommu=off command line option.

Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 176 insertions, 49 deletions

diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index 74f999b4ac9e..46e7cb9c3e64 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -29,6 +29,8 @@
 #include <linux/bootmem.h>
 #include <linux/mm.h>
 #include <linux/dma-mapping.h>
+#include <linux/kernel.h>
+#include <linux/compiler.h>
 
 #include <asm/sections.h>
 #include <asm/iommu.h>
@@ -40,6 +42,7 @@
 #include <asm/abs_addr.h>
 #include <asm/system.h>
 #include <asm/ppc-pci.h>
+#include <asm/udbg.h>
 
 #include "iommu.h"
 
@@ -220,8 +223,6 @@ set_iopt_cache(void __iomem *base, unsigned long index,
 {
         unsigned long __iomem *tags = base + IOC_PT_CACHE_DIR;
         unsigned long __iomem *p = base + IOC_PT_CACHE_REG;
-        pr_debug("iopt %02lx was v%016lx/t%016lx, store v%016lx/t%016lx\n",
-                index, get_iopt_cache(base, index, &oldtag), oldtag, val, tag);
 
         out_be64(p, val);
         out_be64(&tags[index], tag);
@@ -248,67 +249,176 @@ set_iocmd_config(void __iomem *base)
         out_be64(p, conf | IOCMD_CONF_TE);
 }
 
-/* FIXME: get these from the device tree */
-#define ioc_base        0x20000511000ull
-#define ioc_mmio_base   0x20000510000ull
-#define ioid            0x48a
-#define iopt_phys_offset (- 0x20000000) /* We have a 512MB offset from the SB */
-#define io_page_size    0x1000000
-
-static unsigned long map_iopt_entry(unsigned long address)
+static void enable_mapping(void __iomem *base, void __iomem *mmio_base)
 {
-        switch (address >> 20) {
-        case 0x600:
-                address = 0x24020000000ull; /* spider i/o */
-                break;
-        default:
-                address += iopt_phys_offset;
-                break;
-        }
-
-        return get_iopt_entry(address, ioid, IOPT_PROT_RW);
+        set_iocmd_config(base);
+        set_iost_origin(mmio_base);
 }
 
-static void iommu_bus_setup_null(struct pci_bus *b) { }
 static void iommu_dev_setup_null(struct pci_dev *d) { }
+static void iommu_bus_setup_null(struct pci_bus *b) { }
+
+struct cell_iommu {
+        unsigned long base;
+        unsigned long mmio_base;
+        void __iomem *mapped_base;
+        void __iomem *mapped_mmio_base;
+};
+
+static struct cell_iommu cell_iommus[NR_CPUS];
 
 /* initialize the iommu to support a simple linear mapping
  * for each DMA window used by any device. For now, we
  * happen to know that there is only one DMA window in use,
  * starting at iopt_phys_offset. */
-static void cell_map_iommu(void)
+static void cell_do_map_iommu(struct cell_iommu *iommu,
+                              unsigned int ioid,
+                              unsigned long map_start,
+                              unsigned long map_size)
 {
-        unsigned long address;
-        void __iomem *base;
+        unsigned long io_address, real_address;
+        void __iomem *ioc_base, *ioc_mmio_base;
         ioste ioste;
         unsigned long index;
 
-        base = __ioremap(ioc_base, 0x1000, _PAGE_NO_CACHE);
-        pr_debug("%lx mapped to %p\n", ioc_base, base);
-        set_iocmd_config(base);
-        iounmap(base);
+        /* we pretend the io page table was at a very high address */
+        const unsigned long fake_iopt = 0x10000000000ul;
+        const unsigned long io_page_size = 0x1000000; /* use 16M pages */
+        const unsigned long io_segment_size = 0x10000000; /* 256M */
+
+        ioc_base = iommu->mapped_base;
+        ioc_mmio_base = iommu->mapped_mmio_base;
+
+        for (real_address = 0, io_address = 0;
+             io_address <= map_start + map_size;
+             real_address += io_page_size, io_address += io_page_size) {
+                ioste = get_iost_entry(fake_iopt, io_address, io_page_size);
+                if ((real_address % io_segment_size) == 0) /* segment start */
+                        set_iost_cache(ioc_mmio_base,
+                                       io_address >> 28, ioste);
+                index = get_ioc_hash_1way(ioste, io_address);
+                pr_debug("addr %08lx, index %02lx, ioste %016lx\n",
+                                         io_address, index, ioste.val);
+                set_iopt_cache(ioc_mmio_base,
+                        get_ioc_hash_1way(ioste, io_address),
+                        get_ioc_tag(ioste, io_address),
+                        get_iopt_entry(real_address-map_start, ioid, IOPT_PROT_RW));
+        }
+}
 
-        base = __ioremap(ioc_mmio_base, 0x1000, _PAGE_NO_CACHE);
-        pr_debug("%lx mapped to %p\n", ioc_mmio_base, base);
+static void iommu_devnode_setup(struct device_node *d)
+{
+        unsigned int *ioid;
+        unsigned long *dma_window, map_start, map_size, token;
+        struct cell_iommu *iommu;
 
-        set_iost_origin(base);
+        ioid = (unsigned int *)get_property(d, "ioid", NULL);
+        if (!ioid)
+                pr_debug("No ioid entry found !\n");
 
-        for (address = 0; address < 0x100000000ul; address += io_page_size) {
-                ioste = get_iost_entry(0x10000000000ul, address, io_page_size);
-                if ((address & 0xfffffff) == 0) /* segment start */
-                        set_iost_cache(base, address >> 28, ioste);
-                index = get_ioc_hash_1way(ioste, address);
-                pr_debug("addr %08lx, index %02lx, ioste %016lx\n",
-                                         address, index, ioste.val);
-                set_iopt_cache(base,
-                        get_ioc_hash_1way(ioste, address),
-                        get_ioc_tag(ioste, address),
-                        map_iopt_entry(address));
-        }
-        iounmap(base);
+        dma_window = (unsigned long *)get_property(d, "ibm,dma-window", NULL);
+        if (!dma_window)
+                pr_debug("No ibm,dma-window entry found !\n");
+
+        map_start = dma_window[1];
+        map_size = dma_window[2];
+        token = dma_window[0] >> 32;
+
+        iommu = &cell_iommus[token];
+
+        cell_do_map_iommu(iommu, *ioid, map_start, map_size);
+}
+
+static void iommu_bus_setup(struct pci_bus *b)
+{
+        struct device_node *d = (struct device_node *)b->sysdata;
+        iommu_devnode_setup(d);
+}
+
+
+static int cell_map_iommu_hardcoded(int num_nodes)
+{
+        struct cell_iommu *iommu = NULL;
+
+        pr_debug("%s(%d): Using hardcoded defaults\n", __FUNCTION__, __LINE__);
+
+        /* node 0 */
+        iommu = &cell_iommus[0];
+        iommu->mapped_base = __ioremap(0x20000511000, 0x1000, _PAGE_NO_CACHE);
+        iommu->mapped_mmio_base = __ioremap(0x20000510000, 0x1000, _PAGE_NO_CACHE);
+
+        enable_mapping(iommu->mapped_base, iommu->mapped_mmio_base);
+
+        cell_do_map_iommu(iommu, 0x048a,
+                          0x20000000ul,0x20000000ul);
+
+        if (num_nodes < 2)
+                return 0;
+
+        /* node 1 */
+        iommu = &cell_iommus[1];
+        iommu->mapped_base = __ioremap(0x30000511000, 0x1000, _PAGE_NO_CACHE);
+        iommu->mapped_mmio_base = __ioremap(0x30000510000, 0x1000, _PAGE_NO_CACHE);
+
+        enable_mapping(iommu->mapped_base, iommu->mapped_mmio_base);
+
+        cell_do_map_iommu(iommu, 0x048a,
+                          0x20000000,0x20000000ul);
+
+        return 0;
 }
 
 
+static int cell_map_iommu(void)
+{
+        unsigned int num_nodes = 0, *node_id;
+        unsigned long *base, *mmio_base;
+        struct device_node *dn;
+        struct cell_iommu *iommu = NULL;
+
+        /* determine number of nodes (=iommus) */
+        pr_debug("%s(%d): determining number of nodes...", __FUNCTION__, __LINE__);
+        for(dn = of_find_node_by_type(NULL, "cpu");
+            dn;
+            dn = of_find_node_by_type(dn, "cpu")) {
+                node_id = (unsigned int *)get_property(dn, "node-id", NULL);
+
+                if (num_nodes < *node_id)
+                        num_nodes = *node_id;
+                }
+
+        num_nodes++;
+        pr_debug("%i found.\n", num_nodes);
+
+        /* map the iommu registers for each node */
+        pr_debug("%s(%d): Looping through nodes\n", __FUNCTION__, __LINE__);
+        for(dn = of_find_node_by_type(NULL, "cpu");
+            dn;
+            dn = of_find_node_by_type(dn, "cpu")) {
+
+                node_id = (unsigned int *)get_property(dn, "node-id", NULL);
+                base = (unsigned long *)get_property(dn, "ioc-cache", NULL);
+                mmio_base = (unsigned long *)get_property(dn, "ioc-translation", NULL);
+
+                if (!base || !mmio_base || !node_id)
+                        return cell_map_iommu_hardcoded(num_nodes);
+
+                iommu = &cell_iommus[*node_id];
+                iommu->base = *base;
+                iommu->mmio_base = *mmio_base;
+
+                iommu->mapped_base = __ioremap(*base, 0x1000, _PAGE_NO_CACHE);
+                iommu->mapped_mmio_base = __ioremap(*mmio_base, 0x1000, _PAGE_NO_CACHE);
+
+                enable_mapping(iommu->mapped_base,
+                               iommu->mapped_mmio_base);
+
+                /* everything else will be done in iommu_bus_setup */
+        }
+
+        return 1;
+}
+
 static void *cell_alloc_coherent(struct device *hwdev, size_t size,
                            dma_addr_t *dma_handle, gfp_t flag)
 {
@@ -365,11 +475,28 @@ static int cell_dma_supported(struct device *dev, u64 mask)
 
 void cell_init_iommu(void)
 {
-        cell_map_iommu();
-
-        /* Direct I/O, IOMMU off */
-        ppc_md.iommu_dev_setup = iommu_dev_setup_null;
-        ppc_md.iommu_bus_setup = iommu_bus_setup_null;
+        int setup_bus = 0;
+
+        if (of_find_node_by_path("/mambo")) {
+                pr_info("Not using iommu on systemsim\n");
+        } else {
+
+                if (!(of_chosen &&
+                      get_property(of_chosen, "linux,iommu-off", NULL)))
+                        setup_bus = cell_map_iommu();
+
+                if (setup_bus) {
+                        pr_debug("%s: IOMMU mapping activated\n", __FUNCTION__);
+                        ppc_md.iommu_dev_setup = iommu_dev_setup_null;
+                        ppc_md.iommu_bus_setup = iommu_bus_setup;
+                } else {
+                        pr_debug("%s: IOMMU mapping activated, "
+                                 "no device action necessary\n", __FUNCTION__);
+                        /* Direct I/O, IOMMU off */
+                        ppc_md.iommu_dev_setup = iommu_dev_setup_null;
+                        ppc_md.iommu_bus_setup = iommu_bus_setup_null;
+                }
+        }
 
         pci_dma_ops.alloc_coherent = cell_alloc_coherent;
         pci_dma_ops.free_coherent = cell_free_coherent;