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hw/mips/gt64xxx_pci: Endian-swap using PCI_HOST_BRIDGE MemoryRegionOps

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GT64120's PCI endianness swapping works on little-endian hosts,
but doesn't on big-endian ones. Instead of complicating how
CFGADDR/CFGDATA registers deal with endianness, use the existing
MemoryRegionOps from hw/pci/pci_host.c. Doing so also reduce the
access to internal PCI_HOST_BRIDGE fields.

Map the PCI_HOST_BRIDGE MemoryRegionOps into the corresponding
CFGADDR/CFGDATA regions in the ISD MMIO and remove the unused
code in the current ISD read/write handlers.

Update the mapping when PCI0_CMD register is accessed (in case
the endianness is changed).

This allows using the GT64120 on a big-endian host (and boot
the MIPS Malta machine in little-endian).

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230104133935.4639-6-philmd@linaro.org>
This commit is contained in:
Philippe Mathieu-Daudé 2023-01-04 10:03:14 +01:00
parent 65423e6efe
commit 145e2198d7
1 changed files with 50 additions and 20 deletions
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70
hw/mips/gt64xxx_pci.c
View file

@ -298,6 +298,50 @@ static void gt64120_isd_mapping(GT64120State *s)
memory_region_transaction_commit();
}
static void gt64120_update_pci_cfgdata_mapping(GT64120State *s)
{
/* Indexed on MByteSwap bit, see Table 158: PCI_0 Command, Offset: 0xc00 */
static const MemoryRegionOps *pci_host_conf_ops[] = {
&pci_host_conf_be_ops, &pci_host_conf_le_ops
};
static const MemoryRegionOps *pci_host_data_ops[] = {
&pci_host_data_be_ops, &pci_host_data_le_ops
};
PCIHostState *phb = PCI_HOST_BRIDGE(s);
memory_region_transaction_begin();
/*
* The setting of the MByteSwap bit and MWordSwap bit in the PCI Internal
* Command Register determines how data transactions from the CPU to/from
* PCI are handled along with the setting of the Endianess bit in the CPU
* Configuration Register. See:
* - Table 16: 32-bit PCI Transaction Endianess
* - Table 158: PCI_0 Command, Offset: 0xc00
*/
if (memory_region_is_mapped(&phb->conf_mem)) {
memory_region_del_subregion(&s->ISD_mem, &phb->conf_mem);
object_unparent(OBJECT(&phb->conf_mem));
}
memory_region_init_io(&phb->conf_mem, OBJECT(phb),
pci_host_conf_ops[s->regs[GT_PCI0_CMD] & 1],
s, "pci-conf-idx", 4);
memory_region_add_subregion_overlap(&s->ISD_mem, GT_PCI0_CFGADDR << 2,
&phb->conf_mem, 1);
if (memory_region_is_mapped(&phb->data_mem)) {
memory_region_del_subregion(&s->ISD_mem, &phb->data_mem);
object_unparent(OBJECT(&phb->data_mem));
}
memory_region_init_io(&phb->data_mem, OBJECT(phb),
pci_host_data_ops[s->regs[GT_PCI0_CMD] & 1],
s, "pci-conf-data", 4);
memory_region_add_subregion_overlap(&s->ISD_mem, GT_PCI0_CFGDATA << 2,
&phb->data_mem, 1);
memory_region_transaction_commit();
}
static void gt64120_pci_mapping(GT64120State *s)
{
memory_region_transaction_begin();
@ -389,7 +433,6 @@ static void gt64120_writel(void *opaque, hwaddr addr,
uint64_t val, unsigned size)
{
GT64120State *s = opaque;
PCIHostState *phb = PCI_HOST_BRIDGE(s);
uint32_t saddr = addr >> 2;
trace_gt64120_write(addr, val);
@ -592,6 +635,7 @@ static void gt64120_writel(void *opaque, hwaddr addr,
case GT_PCI0_CMD:
case GT_PCI1_CMD:
s->regs[saddr] = val & 0x0401fc0f;
gt64120_update_pci_cfgdata_mapping(s);
break;
case GT_PCI0_TOR:
case GT_PCI0_BS_SCS10:
@ -632,15 +676,9 @@ static void gt64120_writel(void *opaque, hwaddr addr,
saddr << 2, size, size << 1, val);
break;
case GT_PCI0_CFGADDR:
phb->config_reg = val & 0x80fffffc;
break;
case GT_PCI0_CFGDATA:
if (!(s->regs[GT_PCI0_CMD] & 1) && (phb->config_reg & 0x00fff800)) {
val = bswap32(val);
}
if (phb->config_reg & (1u << 31)) {
pci_data_write(phb->bus, phb->config_reg, val, 4);
}
/* Mapped via in gt64120_pci_mapping() */
g_assert_not_reached();
break;
/* Interrupts */
@ -698,7 +736,6 @@ static uint64_t gt64120_readl(void *opaque,
hwaddr addr, unsigned size)
{
GT64120State *s = opaque;
PCIHostState *phb = PCI_HOST_BRIDGE(s);
uint32_t val;
uint32_t saddr = addr >> 2;
@ -883,17 +920,9 @@ static uint64_t gt64120_readl(void *opaque,
/* PCI Internal */
case GT_PCI0_CFGADDR:
val = phb->config_reg;
break;
case GT_PCI0_CFGDATA:
if (!(phb->config_reg & (1 << 31))) {
val = 0xffffffff;
} else {
val = pci_data_read(phb->bus, phb->config_reg, 4);
}
if (!(s->regs[GT_PCI0_CMD] & 1) && (phb->config_reg & 0x00fff800)) {
val = bswap32(val);
}
/* Mapped via in gt64120_pci_mapping() */
g_assert_not_reached();
break;
case GT_PCI0_CMD:
@ -1153,6 +1182,7 @@ static void gt64120_reset(DeviceState *dev)
gt64120_isd_mapping(s);
gt64120_pci_mapping(s);
gt64120_update_pci_cfgdata_mapping(s);
}
static void gt64120_realize(DeviceState *dev, Error **errp)