eHEA: Introducing support vor DLPAR memory add

This patch adds support for DLPAR memory add to the eHEA driver. To detect
whether memory was added the driver uses its own memory mapping table and
checks for kernel addresses whether they're located in already known memory
sections. If not the function ehea_rereg_mrs() is triggered which performs
a rebuild of the mapping table and a re-registration of the global memory
region.

Signed-off-by: Thomas Klein <tklein@de.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 112 insertions, 44 deletions

diff --git a/drivers/net/ehea/ehea_qmr.c b/drivers/net/ehea/ehea_qmr.c
index 29eaa46948b0..a36fa6c23fdf 100644
--- a/drivers/net/ehea/ehea_qmr.c
+++ b/drivers/net/ehea/ehea_qmr.c
@@ -31,6 +31,13 @@
 #include "ehea_phyp.h"
 #include "ehea_qmr.h"
 
+
+struct ehea_busmap ehea_bmap = { 0, 0, NULL };
+extern u64 ehea_driver_flags;
+extern struct workqueue_struct *ehea_driver_wq;
+extern struct work_struct ehea_rereg_mr_task;
+
+
 static void *hw_qpageit_get_inc(struct hw_queue *queue)
 {
         void *retvalue = hw_qeit_get(queue);
@@ -547,18 +554,84 @@ int ehea_destroy_qp(struct ehea_qp *qp)
         return 0;
 }
 
+int ehea_create_busmap( void )
+{
+        u64 vaddr = EHEA_BUSMAP_START;
+        unsigned long abs_max_pfn = 0;
+        unsigned long sec_max_pfn;
+        int i;
+
+        /*
+         * Sections are not in ascending order -> Loop over all sections and
+         * find the highest PFN to compute the required map size.
+        */
+        ehea_bmap.valid_sections = 0;
+
+        for (i = 0; i < NR_MEM_SECTIONS; i++)
+                if (valid_section_nr(i)) {
+                        sec_max_pfn = section_nr_to_pfn(i);
+                        if (sec_max_pfn > abs_max_pfn)
+                                abs_max_pfn = sec_max_pfn;
+                        ehea_bmap.valid_sections++;
+                }
+
+        ehea_bmap.entries = abs_max_pfn / EHEA_PAGES_PER_SECTION + 1;
+        ehea_bmap.vaddr = vmalloc(ehea_bmap.entries * sizeof(*ehea_bmap.vaddr));
+
+        if (!ehea_bmap.vaddr)
+                return -ENOMEM;
+
+        for (i = 0 ; i < ehea_bmap.entries; i++) {
+                unsigned long pfn = section_nr_to_pfn(i);
+
+                if (pfn_valid(pfn)) {
+                        ehea_bmap.vaddr[i] = vaddr;
+                        vaddr += EHEA_SECTSIZE;
+                } else
+                        ehea_bmap.vaddr[i] = 0;
+        }
+
+        return 0;
+}
+
+void ehea_destroy_busmap( void )
+{
+        vfree(ehea_bmap.vaddr);
+}
+
+u64 ehea_map_vaddr(void *caddr)
+{
+        u64 mapped_addr;
+        unsigned long index = __pa(caddr) >> SECTION_SIZE_BITS;
+
+        if (likely(index < ehea_bmap.entries)) {
+                mapped_addr = ehea_bmap.vaddr[index];
+                if (likely(mapped_addr))
+                        mapped_addr |= (((unsigned long)caddr)
+                                        & (EHEA_SECTSIZE - 1));
+                else
+                        mapped_addr = -1;
+        } else
+                mapped_addr = -1;
+
+        if (unlikely(mapped_addr == -1))
+                if (!test_and_set_bit(__EHEA_STOP_XFER, &ehea_driver_flags))
+                        queue_work(ehea_driver_wq, &ehea_rereg_mr_task);
+
+        return mapped_addr;
+}
+
 int ehea_reg_kernel_mr(struct ehea_adapter *adapter, struct ehea_mr *mr)
 {
-        int i, k, ret;
-        u64 hret, pt_abs, start, end, nr_pages;
-        u32 acc_ctrl = EHEA_MR_ACC_CTRL;
+        int ret;
         u64 *pt;
+        void *pg;
+        u64 hret, pt_abs, i, j, m, mr_len;
+        u32 acc_ctrl = EHEA_MR_ACC_CTRL;
 
-        start = KERNELBASE;
-        end = (u64)high_memory;
-        nr_pages = (end - start) / EHEA_PAGESIZE;
+        mr_len = ehea_bmap.valid_sections * EHEA_SECTSIZE;
 
-        pt =  kzalloc(PAGE_SIZE, GFP_KERNEL);
+        pt =  kzalloc(EHEA_MAX_RPAGE * sizeof(u64), GFP_KERNEL);
         if (!pt) {
                 ehea_error("no mem");
                 ret = -ENOMEM;
@@ -566,7 +639,8 @@ int ehea_reg_kernel_mr(struct ehea_adapter *adapter, struct ehea_mr *mr)
         }
         pt_abs = virt_to_abs(pt);
 
-        hret = ehea_h_alloc_resource_mr(adapter->handle, start, end - start,
+        hret = ehea_h_alloc_resource_mr(adapter->handle,
+                                        EHEA_BUSMAP_START, mr_len,
                                         acc_ctrl, adapter->pd,
                                         &mr->handle, &mr->lkey);
         if (hret != H_SUCCESS) {
@@ -575,49 +649,43 @@ int ehea_reg_kernel_mr(struct ehea_adapter *adapter, struct ehea_mr *mr)
                 goto out;
         }
 
-        mr->vaddr = KERNELBASE;
-        k = 0;
-
-        while (nr_pages > 0) {
-                if (nr_pages > 1) {
-                        u64 num_pages = min(nr_pages, (u64)512);
-                        for (i = 0; i < num_pages; i++)
-                                pt[i] = virt_to_abs((void*)(((u64)start) +
-                                                            ((k++) *
-                                                             EHEA_PAGESIZE)));
-
-                        hret = ehea_h_register_rpage_mr(adapter->handle,
-                                                        mr->handle, 0,
-                                                        0, (u64)pt_abs,
-                                                        num_pages);
-                        nr_pages -= num_pages;
-                } else {
-                        u64 abs_adr = virt_to_abs((void*)(((u64)start) +
-                                                          (k * EHEA_PAGESIZE)));
-
-                        hret = ehea_h_register_rpage_mr(adapter->handle,
-                                                        mr->handle, 0,
-                                                        0, abs_adr,1);
-                        nr_pages--;
-                }
-
-                if ((hret != H_SUCCESS) && (hret != H_PAGE_REGISTERED)) {
-                        ehea_h_free_resource(adapter->handle,
-                                             mr->handle, FORCE_FREE);
-                        ehea_error("register_rpage_mr failed");
-                        ret = -EIO;
-                        goto out;
+        for (i = 0 ; i < ehea_bmap.entries; i++)
+                if (ehea_bmap.vaddr[i]) {
+                        void *sectbase = __va(i << SECTION_SIZE_BITS);
+                        unsigned long k = 0;
+
+                        for (j = 0; j < (PAGES_PER_SECTION / EHEA_MAX_RPAGE);
+                              j++) {
+
+                                for (m = 0; m < EHEA_MAX_RPAGE; m++) {
+                                        pg = sectbase + ((k++) * EHEA_PAGESIZE);
+                                        pt[m] = virt_to_abs(pg);
+                                }
+
+                                hret = ehea_h_register_rpage_mr(adapter->handle,
+                                                                mr->handle,
+                                                                0, 0, pt_abs,
+                                                                EHEA_MAX_RPAGE);
+                                if ((hret != H_SUCCESS)
+                                    && (hret != H_PAGE_REGISTERED)) {
+                                        ehea_h_free_resource(adapter->handle,
+                                                             mr->handle,
+                                                             FORCE_FREE);
+                                        ehea_error("register_rpage_mr failed");
+                                        ret = -EIO;
+                                        goto out;
+                                }
+                        }
                 }
-        }
 
         if (hret != H_SUCCESS) {
-                ehea_h_free_resource(adapter->handle, mr->handle,
-                                     FORCE_FREE);
-                ehea_error("register_rpage failed for last page");
+                ehea_h_free_resource(adapter->handle, mr->handle, FORCE_FREE);
+                ehea_error("registering mr failed");
                 ret = -EIO;
                 goto out;
         }
 
+        mr->vaddr = EHEA_BUSMAP_START;
         mr->adapter = adapter;
         ret = 0;
 out: