powerpc/fsl: Setup PCI inbound window based on actual amount of memory

Previouslly we just always set the inbound window to 2G.  This was
broken for systems with >2G.  If a system has >=4G we will need
SWIOTLB support to handle that case.

We now allocate PCICSRBAR/PEXCSRBAR right below the lowest PCI outbound
address for MMIO or the 4G boundary (if the lowest PCI address is above
4G).

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index b20171d..0de91c6 100644 (file)
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -23,6 +23,8 @@
 #include <linux/string.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
+#include <linux/lmb.h>
+#include <linux/log2.h>
 
 #include <asm/io.h>
 #include <asm/prom.h>
@@ -96,7 +98,13 @@ static void __init setup_pci_atmu(struct pci_controller *hose,
                                  struct resource *rsrc)
 {
        struct ccsr_pci __iomem *pci;
-       int i, j, n;
+       int i, j, n, mem_log, win_idx = 2;
+       u64 mem, sz, paddr_hi = 0;
+       u64 paddr_lo = ULLONG_MAX;
+       u32 pcicsrbar = 0, pcicsrbar_sz;
+       u32 piwar = PIWAR_EN | PIWAR_PF | PIWAR_TGI_LOCAL |
+                       PIWAR_READ_SNOOP | PIWAR_WRITE_SNOOP;
+       char *name = hose->dn->full_name;
 
        pr_debug("PCI memory map start 0x%016llx, size 0x%016llx\n",
                    (u64)rsrc->start, (u64)rsrc->end - (u64)rsrc->start + 1);
@@ -117,6 +125,9 @@ static void __init setup_pci_atmu(struct pci_controller *hose,
                if (!(hose->mem_resources[i].flags & IORESOURCE_MEM))
                        continue;
 
+               paddr_lo = min(paddr_lo, (u64)hose->mem_resources[i].start);
+               paddr_hi = max(paddr_hi, (u64)hose->mem_resources[i].end);
+
                n = setup_one_atmu(pci, j, &hose->mem_resources[i],
                                   hose->pci_mem_offset);
 
@@ -147,14 +158,105 @@ static void __init setup_pci_atmu(struct pci_controller *hose,
                }
        }
 
-       /* Setup 2G inbound Memory Window @ 1 */
-       out_be32(&pci->piw[2].pitar, 0x00000000);
-       out_be32(&pci->piw[2].piwbar,0x00000000);
-       out_be32(&pci->piw[2].piwar, PIWAR_2G);
+       /* convert to pci address space */
+       paddr_hi -= hose->pci_mem_offset;
+       paddr_lo -= hose->pci_mem_offset;
+
+       if (paddr_hi == paddr_lo) {
+               pr_err("%s: No outbound window space\n", name);
+               return ;
+       }
+
+       if (paddr_lo == 0) {
+               pr_err("%s: No space for inbound window\n", name);
+               return ;
+       }
+
+       /* setup PCSRBAR/PEXCSRBAR */
+       early_write_config_dword(hose, 0, 0, PCI_BASE_ADDRESS_0, 0xffffffff);
+       early_read_config_dword(hose, 0, 0, PCI_BASE_ADDRESS_0, &pcicsrbar_sz);
+       pcicsrbar_sz = ~pcicsrbar_sz + 1;
+
+       if (paddr_hi < (0x100000000ull - pcicsrbar_sz) ||
+               (paddr_lo > 0x100000000ull))
+               pcicsrbar = 0x100000000ull - pcicsrbar_sz;
+       else
+               pcicsrbar = (paddr_lo - pcicsrbar_sz) & -pcicsrbar_sz;
+       early_write_config_dword(hose, 0, 0, PCI_BASE_ADDRESS_0, pcicsrbar);
+
+       paddr_lo = min(paddr_lo, (u64)pcicsrbar);
 
-       /* Save the base address and size covered by inbound window mappings */
-       hose->dma_window_base_cur = 0x00000000;
-       hose->dma_window_size = 0x80000000;
+       pr_info("%s: PCICSRBAR @ 0x%x\n", name, pcicsrbar);
+
+       /* Setup inbound mem window */
+       mem = lmb_end_of_DRAM();
+       sz = min(mem, paddr_lo);
+       mem_log = __ilog2_u64(sz);
+
+       /* PCIe can overmap inbound & outbound since RX & TX are separated */
+       if (early_find_capability(hose, 0, 0, PCI_CAP_ID_EXP)) {
+               /* Size window to exact size if power-of-two or one size up */
+               if ((1ull << mem_log) != mem) {
+                       if ((1ull << mem_log) > mem)
+                               pr_info("%s: Setting PCI inbound window "
+                                       "greater than memory size\n", name);
+                       mem_log++;
+               }
+
+               piwar |= (mem_log - 1);
+
+               /* Setup inbound memory window */
+               out_be32(&pci->piw[win_idx].pitar,  0x00000000);
+               out_be32(&pci->piw[win_idx].piwbar, 0x00000000);
+               out_be32(&pci->piw[win_idx].piwar,  piwar);
+               win_idx--;
+
+               hose->dma_window_base_cur = 0x00000000;
+               hose->dma_window_size = (resource_size_t)sz;
+       } else {
+               u64 paddr = 0;
+
+               /* Setup inbound memory window */
+               out_be32(&pci->piw[win_idx].pitar,  paddr >> 12);
+               out_be32(&pci->piw[win_idx].piwbar, paddr >> 12);
+               out_be32(&pci->piw[win_idx].piwar,  (piwar | (mem_log - 1)));
+               win_idx--;
+
+               paddr += 1ull << mem_log;
+               sz -= 1ull << mem_log;
+
+               if (sz) {
+                       mem_log = __ilog2_u64(sz);
+                       piwar |= (mem_log - 1);
+
+                       out_be32(&pci->piw[win_idx].pitar,  paddr >> 12);
+                       out_be32(&pci->piw[win_idx].piwbar, paddr >> 12);
+                       out_be32(&pci->piw[win_idx].piwar,  piwar);
+                       win_idx--;
+
+                       paddr += 1ull << mem_log;
+               }
+
+               hose->dma_window_base_cur = 0x00000000;
+               hose->dma_window_size = (resource_size_t)paddr;
+       }
+
+       if (hose->dma_window_size < mem) {
+#ifndef CONFIG_SWIOTLB
+               pr_err("%s: ERROR: Memory size exceeds PCI ATMU ability to "
+                       "map - enable CONFIG_SWIOTLB to avoid dma errors.\n",
+                        name);
+#endif
+               /* adjusting outbound windows could reclaim space in mem map */
+               if (paddr_hi < 0xffffffffull)
+                       pr_warning("%s: WARNING: Outbound window cfg leaves "
+                               "gaps in memory map. Adjusting the memory map "
+                               "could reduce unnecessary bounce buffering.\n",
+                               name);
+
+               pr_info("%s: DMA window size is 0x%llx\n", name,
+                       (u64)hose->dma_window_size);
+       }
 
        iounmap(pci);
 }
@@ -180,16 +282,6 @@ static void __init setup_pci_cmd(struct pci_controller *hose)
        }
 }
 
-static void __init setup_pci_pcsrbar(struct pci_controller *hose)
-{
-#ifdef CONFIG_PCI_MSI
-       phys_addr_t immr_base;
-
-       immr_base = get_immrbase();
-       early_write_config_dword(hose, 0, 0, PCI_BASE_ADDRESS_0, immr_base);
-#endif
-}
-
 void fsl_pcibios_fixup_bus(struct pci_bus *bus)
 {
        struct pci_controller *hose = (struct pci_controller *) bus->sysdata;
@@ -273,8 +365,6 @@ int __init fsl_add_bridge(struct device_node *dev, int is_primary)
        /* Setup PEX window registers */
        setup_pci_atmu(hose, &rsrc);
 
-       /* Setup PEXCSRBAR */
-       setup_pci_pcsrbar(hose);
        return 0;
 }
 

diff --git a/arch/powerpc/sysdev/fsl_pci.h b/arch/powerpc/sysdev/fsl_pci.h
index 13f30c2..a9d8bbe 100644 (file)
--- a/arch/powerpc/sysdev/fsl_pci.h
+++ b/arch/powerpc/sysdev/fsl_pci.h
@@ -16,7 +16,11 @@
 
 #define PCIE_LTSSM     0x0404          /* PCIE Link Training and Status */
 #define PCIE_LTSSM_L0  0x16            /* L0 state */
-#define PIWAR_2G       0xa0f5501e      /* Enable, Prefetch, Local Mem, Snoop R/W, 2G */
+#define PIWAR_EN               0x80000000      /* Enable */
+#define PIWAR_PF               0x20000000      /* prefetch */
+#define PIWAR_TGI_LOCAL                0x00f00000      /* target - local memory */
+#define PIWAR_READ_SNOOP       0x00050000
+#define PIWAR_WRITE_SNOOP      0x00005000
 
 /* PCI/PCI Express outbound window reg */
 struct pci_outbound_window_regs {