[Qemu-devel] [PATCHv2 03/11] libqos: Move BAR assignment to common code

[David Gibson]

The PCI backends in libqos each supply an iomap() and iounmap() function
which is used to set up a specified PCI BAR.  But PCI BAR allocation takes
place entirely within PCI space, so doesn't really need per-backend
versions.  For example, Linux includes generic BAR allocation code used on
platforms where that isn't done by firmware.

This patch merges the BAR allocation from the two existing backends into a
single simplified copy.  The back ends just need to set up some parameters
describing the window of PCI IO and PCI memory addresses which are
available for allocation.  Like both the existing versions the new one uses
a simple bump allocator.

Note that (again like the existing versions) this doesn't really handle
64-bit memory BARs properly.  It is actually used for such a BAR by the
ivshmem test, and apparently the 32-bit MMIO BAR logic is close enough to
work, as long as the BAR isn't too big.  Fixing that to properly handle
64-bit BAR allocation is a problem for another time.

Signed-off-by: David Gibson <address@hidden>
---
 tests/libqos/pci-pc.c    | 87 ++--------------------------------------------
 tests/libqos/pci-spapr.c | 89 ++----------------------------------------------
 tests/libqos/pci.c       | 56 ++++++++++++++++++++++++++++--
 tests/libqos/pci.h       |  7 ++--
 4 files changed, 63 insertions(+), 176 deletions(-)

diff --git a/tests/libqos/pci-pc.c b/tests/libqos/pci-pc.c
index 51dff8a..d0eb84a 100644
--- a/tests/libqos/pci-pc.c
+++ b/tests/libqos/pci-pc.c
@@ -17,7 +17,6 @@
 #include "hw/pci/pci_regs.h"
 
 #include "qemu-common.h"
-#include "qemu/host-utils.h"
 
 
 #define ACPI_PCIHP_ADDR         0xae00
@@ -26,14 +25,6 @@
 typedef struct QPCIBusPC
 {
     QPCIBus bus;
-
-    uint32_t pci_hole_start;
-    uint32_t pci_hole_size;
-    uint32_t pci_hole_alloc;
-
-    uint16_t pci_iohole_start;
-    uint16_t pci_iohole_size;
-    uint16_t pci_iohole_alloc;
 } QPCIBusPC;
 
 static uint8_t qpci_pc_pio_readb(QPCIBus *bus, uint32_t addr)
@@ -132,71 +123,6 @@ static void qpci_pc_config_writel(QPCIBus *bus, int devfn, 
uint8_t offset, uint3
     outl(0xcfc, value);
 }
 
-static void *qpci_pc_iomap(QPCIBus *bus, QPCIDevice *dev, int barno, uint64_t 
*sizeptr)
-{
-    QPCIBusPC *s = container_of(bus, QPCIBusPC, bus);
-    static const int bar_reg_map[] = {
-        PCI_BASE_ADDRESS_0, PCI_BASE_ADDRESS_1, PCI_BASE_ADDRESS_2,
-        PCI_BASE_ADDRESS_3, PCI_BASE_ADDRESS_4, PCI_BASE_ADDRESS_5,
-    };
-    int bar_reg;
-    uint32_t addr;
-    uint64_t size;
-    uint32_t io_type;
-
-    g_assert(barno >= 0 && barno <= 5);
-    bar_reg = bar_reg_map[barno];
-
-    qpci_config_writel(dev, bar_reg, 0xFFFFFFFF);
-    addr = qpci_config_readl(dev, bar_reg);
-
-    io_type = addr & PCI_BASE_ADDRESS_SPACE;
-    if (io_type == PCI_BASE_ADDRESS_SPACE_IO) {
-        addr &= PCI_BASE_ADDRESS_IO_MASK;
-    } else {
-        addr &= PCI_BASE_ADDRESS_MEM_MASK;
-    }
-
-    size = (1ULL << ctzl(addr));
-    if (size == 0) {
-        return NULL;
-    }
-    if (sizeptr) {
-        *sizeptr = size;
-    }
-
-    if (io_type == PCI_BASE_ADDRESS_SPACE_IO) {
-        uint16_t loc;
-
-        g_assert(QEMU_ALIGN_UP(s->pci_iohole_alloc, size) + size
-                 <= s->pci_iohole_size);
-        s->pci_iohole_alloc = QEMU_ALIGN_UP(s->pci_iohole_alloc, size);
-        loc = s->pci_iohole_start + s->pci_iohole_alloc;
-        s->pci_iohole_alloc += size;
-
-        qpci_config_writel(dev, bar_reg, loc | PCI_BASE_ADDRESS_SPACE_IO);
-
-        return (void *)(intptr_t)loc;
-    } else {
-        uint64_t loc;
-
-        g_assert(QEMU_ALIGN_UP(s->pci_hole_alloc, size) + size
-                 <= s->pci_hole_size);
-        s->pci_hole_alloc = QEMU_ALIGN_UP(s->pci_hole_alloc, size);
-        loc = s->pci_hole_start + s->pci_hole_alloc;
-        s->pci_hole_alloc += size;
-
-        qpci_config_writel(dev, bar_reg, loc);
-
-        return (void *)(intptr_t)loc;
-    }
-}
-
-static void qpci_pc_iounmap(QPCIBus *bus, void *data)
-{
-    /* FIXME */
-}
-
 QPCIBus *qpci_init_pc(QGuestAllocator *alloc)
 {
     QPCIBusPC *ret;
@@ -227,16 +153,9 @@ QPCIBus *qpci_init_pc(QGuestAllocator *alloc)
     ret->bus.config_writew = qpci_pc_config_writew;
     ret->bus.config_writel = qpci_pc_config_writel;
 
-    ret->bus.iomap = qpci_pc_iomap;
-    ret->bus.iounmap = qpci_pc_iounmap;
-
-    ret->pci_hole_start = 0xE0000000;
-    ret->pci_hole_size = 0x20000000;
-    ret->pci_hole_alloc = 0;
-
-    ret->pci_iohole_start = 0xc000;
-    ret->pci_iohole_size = 0x4000;
-    ret->pci_iohole_alloc = 0;
+    ret->bus.pio_alloc_ptr = 0xc000;
+    ret->bus.mmio_alloc_ptr = 0xE0000000;
+    ret->bus.mmio_limit = 0x100000000ULL;
 
     return &ret->bus;
 }
diff --git a/tests/libqos/pci-spapr.c b/tests/libqos/pci-spapr.c
index 2d26a94..70a24b5 100644
--- a/tests/libqos/pci-spapr.c
+++ b/tests/libqos/pci-spapr.c
@@ -34,14 +34,6 @@ typedef struct QPCIBusSPAPR {
 
     uint64_t mmio32_cpu_base;
     QPCIWindow mmio32;
-
-    uint64_t pci_hole_start;
-    uint64_t pci_hole_size;
-    uint64_t pci_hole_alloc;
-
-    uint32_t pci_iohole_start;
-    uint32_t pci_iohole_size;
-    uint32_t pci_iohole_alloc;
 } QPCIBusSPAPR;
 
 /*
@@ -167,72 +159,6 @@ static void qpci_spapr_config_writel(QPCIBus *bus, int 
devfn, uint8_t offset,
     qrtas_ibm_write_pci_config(s->alloc, s->buid, config_addr, 4, value);
 }
 
-static void *qpci_spapr_iomap(QPCIBus *bus, QPCIDevice *dev, int barno,
-                              uint64_t *sizeptr)
-{
-    QPCIBusSPAPR *s = container_of(bus, QPCIBusSPAPR, bus);
-    static const int bar_reg_map[] = {
-        PCI_BASE_ADDRESS_0, PCI_BASE_ADDRESS_1, PCI_BASE_ADDRESS_2,
-        PCI_BASE_ADDRESS_3, PCI_BASE_ADDRESS_4, PCI_BASE_ADDRESS_5,
-    };
-    int bar_reg;
-    uint32_t addr;
-    uint64_t size;
-    uint32_t io_type;
-
-    g_assert(barno >= 0 && barno <= 5);
-    bar_reg = bar_reg_map[barno];
-
-    qpci_config_writel(dev, bar_reg, 0xFFFFFFFF);
-    addr = qpci_config_readl(dev, bar_reg);
-
-    io_type = addr & PCI_BASE_ADDRESS_SPACE;
-    if (io_type == PCI_BASE_ADDRESS_SPACE_IO) {
-        addr &= PCI_BASE_ADDRESS_IO_MASK;
-    } else {
-        addr &= PCI_BASE_ADDRESS_MEM_MASK;
-    }
-
-    size = (1ULL << ctzl(addr));
-    if (size == 0) {
-        return NULL;
-    }
-    if (sizeptr) {
-        *sizeptr = size;
-    }
-
-    if (io_type == PCI_BASE_ADDRESS_SPACE_IO) {
-        uint16_t loc;
-
-        g_assert(QEMU_ALIGN_UP(s->pci_iohole_alloc, size) + size
-                 <= s->pci_iohole_size);
-        s->pci_iohole_alloc = QEMU_ALIGN_UP(s->pci_iohole_alloc, size);
-        loc = s->pci_iohole_start + s->pci_iohole_alloc;
-        s->pci_iohole_alloc += size;
-
-        qpci_config_writel(dev, bar_reg, loc | PCI_BASE_ADDRESS_SPACE_IO);
-
-        return (void *)(unsigned long)loc;
-    } else {
-        uint64_t loc;
-
-        g_assert(QEMU_ALIGN_UP(s->pci_hole_alloc, size) + size
-                 <= s->pci_hole_size);
-        s->pci_hole_alloc = QEMU_ALIGN_UP(s->pci_hole_alloc, size);
-        loc = s->pci_hole_start + s->pci_hole_alloc;
-        s->pci_hole_alloc += size;
-
-        qpci_config_writel(dev, bar_reg, loc);
-
-        return (void *)(unsigned long)loc;
-    }
-}
-
-static void qpci_spapr_iounmap(QPCIBus *bus, void *data)
-{
-    /* FIXME */
-}
-
 #define SPAPR_PCI_BASE               (1ULL << 45)
 
 #define SPAPR_PCI_MMIO32_WIN_SIZE    0x80000000 /* 2 GiB */
@@ -270,9 +196,6 @@ QPCIBus *qpci_init_spapr(QGuestAllocator *alloc)
     ret->bus.config_writew = qpci_spapr_config_writew;
     ret->bus.config_writel = qpci_spapr_config_writel;
 
-    ret->bus.iomap = qpci_spapr_iomap;
-    ret->bus.iounmap = qpci_spapr_iounmap;
-
     /* FIXME: We assume the default location of the PHB for now.
      * Ideally we'd parse the device tree deposited in the guest to
      * get the window locations */
@@ -287,15 +210,9 @@ QPCIBus *qpci_init_spapr(QGuestAllocator *alloc)
     ret->mmio32.pci_base = 0x80000000; /* 2 GiB */
     ret->mmio32.size = SPAPR_PCI_MMIO32_WIN_SIZE;
 
-    ret->pci_hole_start = 0xC0000000;
-    ret->pci_hole_size =
-        ret->mmio32.pci_base + ret->mmio32.size - ret->pci_hole_start;
-    ret->pci_hole_alloc = 0;
-
-    ret->pci_iohole_start = 0xc000;
-    ret->pci_iohole_size =
-        ret->pio.pci_base + ret->pio.size - ret->pci_iohole_start;
-    ret->pci_iohole_alloc = 0;
+    ret->bus.pio_alloc_ptr = 0xc000;
+    ret->bus.mmio_alloc_ptr = ret->mmio32.pci_base;
+    ret->bus.mmio_limit = ret->mmio32.pci_base + ret->mmio32.size;
 
     return &ret->bus;
 }
diff --git a/tests/libqos/pci.c b/tests/libqos/pci.c
index 55b01df..bf1c532 100644
--- a/tests/libqos/pci.c
+++ b/tests/libqos/pci.c
@@ -14,6 +14,7 @@
 #include "libqos/pci.h"
 
 #include "hw/pci/pci_regs.h"
+#include "qemu/host-utils.h"
 
 void qpci_device_foreach(QPCIBus *bus, int vendor_id, int device_id,
                          void (*func)(QPCIDevice *dev, int devfn, void *data),
@@ -290,12 +291,63 @@ void qpci_io_writel(QPCIDevice *dev, void *data, uint32_t 
value)
 
 void *qpci_iomap(QPCIDevice *dev, int barno, uint64_t *sizeptr)
 {
-    return dev->bus->iomap(dev->bus, dev, barno, sizeptr);
+    QPCIBus *bus = dev->bus;
+    static const int bar_reg_map[] = {
+        PCI_BASE_ADDRESS_0, PCI_BASE_ADDRESS_1, PCI_BASE_ADDRESS_2,
+        PCI_BASE_ADDRESS_3, PCI_BASE_ADDRESS_4, PCI_BASE_ADDRESS_5,
+    };
+    int bar_reg;
+    uint32_t addr, size;
+    uint32_t io_type;
+    uint64_t loc;
+
+    g_assert(barno >= 0 && barno <= 5);
+    bar_reg = bar_reg_map[barno];
+
+    qpci_config_writel(dev, bar_reg, 0xFFFFFFFF);
+    addr = qpci_config_readl(dev, bar_reg);
+
+    io_type = addr & PCI_BASE_ADDRESS_SPACE;
+    if (io_type == PCI_BASE_ADDRESS_SPACE_IO) {
+        addr &= PCI_BASE_ADDRESS_IO_MASK;
+    } else {
+        addr &= PCI_BASE_ADDRESS_MEM_MASK;
+    }
+
+    g_assert(addr); /* Must have *some* size bits */
+
+    size = 1U << ctz32(addr);
+    if (sizeptr) {
+        *sizeptr = size;
+    }
+
+    if (io_type == PCI_BASE_ADDRESS_SPACE_IO) {
+        loc = QEMU_ALIGN_UP(bus->pio_alloc_ptr, size);
+
+        g_assert(loc >= bus->pio_alloc_ptr);
+        g_assert(loc + size <= QPCI_PIO_LIMIT); /* Keep PIO below 64kiB */
+
+        bus->pio_alloc_ptr = loc + size;
+
+        qpci_config_writel(dev, bar_reg, loc | PCI_BASE_ADDRESS_SPACE_IO);
+    } else {
+        loc = QEMU_ALIGN_UP(bus->mmio_alloc_ptr, size);
+
+        /* Check for space */
+        g_assert(loc >= bus->mmio_alloc_ptr);
+        g_assert(loc + size <= bus->mmio_limit);
+
+        bus->mmio_alloc_ptr = loc + size;
+
+        qpci_config_writel(dev, bar_reg, loc);
+    }
+
+    return (void *)(uintptr_t)loc;
 }
 
 void qpci_iounmap(QPCIDevice *dev, void *data)
 {
-    dev->bus->iounmap(dev->bus, data);
+    /* FIXME */
 }
 
 void qpci_plug_device_test(const char *driver, const char *id,
diff --git a/tests/libqos/pci.h b/tests/libqos/pci.h
index 72a2245..f6f916d 100644
--- a/tests/libqos/pci.h
+++ b/tests/libqos/pci.h
@@ -22,8 +22,7 @@
 typedef struct QPCIDevice QPCIDevice;
 typedef struct QPCIBus QPCIBus;
 
-struct QPCIBus
-{
+struct QPCIBus {
     uint8_t (*pio_readb)(QPCIBus *bus, uint32_t addr);
     uint16_t (*pio_readw)(QPCIBus *bus, uint32_t addr);
     uint32_t (*pio_readl)(QPCIBus *bus, uint32_t addr);
@@ -51,8 +50,8 @@ struct QPCIBus
     void (*config_writel)(QPCIBus *bus, int devfn,
                           uint8_t offset, uint32_t value);
 
-    void *(*iomap)(QPCIBus *bus, QPCIDevice *dev, int barno, uint64_t 
*sizeptr);
-    void (*iounmap)(QPCIBus *bus, void *data);
+    uint16_t pio_alloc_ptr;
+    uint64_t mmio_alloc_ptr, mmio_limit;
 };
 
 struct QPCIDevice
-- 
2.7.4