summaryrefslogtreecommitdiffstats
path: root/drivers/acpi
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/cppc_acpi.c80
1 files changed, 64 insertions, 16 deletions
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 026cdd4d491a..6970b44d37d5 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -67,6 +67,9 @@ static int pcc_subspace_idx = -1;
static bool pcc_channel_acquired;
static ktime_t deadline;
+/* pcc mapped address + header size + offset within PCC subspace */
+#define GET_PCC_VADDR(offs) (pcc_comm_addr + 0x8 + (offs))
+
/*
* Arbitrary Retries in case the remote processor is slow to respond
* to PCC commands. Keeping it high enough to cover emulators where
@@ -582,29 +585,74 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr)
}
EXPORT_SYMBOL_GPL(acpi_cppc_processor_exit);
-static u64 get_phys_addr(struct cpc_reg *reg)
-{
- /* PCC communication addr space begins at byte offset 0x8. */
- if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM)
- return (u64)comm_base_addr + 0x8 + reg->address;
- else
- return reg->address;
-}
+/*
+ * Since cpc_read and cpc_write are called while holding pcc_lock, it should be
+ * as fast as possible. We have already mapped the PCC subspace during init, so
+ * we can directly write to it.
+ */
-static void cpc_read(struct cpc_reg *reg, u64 *val)
+static int cpc_read(struct cpc_reg *reg, u64 *val)
{
- u64 addr = get_phys_addr(reg);
+ int ret_val = 0;
+
+ *val = 0;
+ if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
+ void __iomem *vaddr = GET_PCC_VADDR(reg->address);
- acpi_os_read_memory((acpi_physical_address)addr,
- val, reg->bit_width);
+ switch (reg->bit_width) {
+ case 8:
+ *val = readb(vaddr);
+ break;
+ case 16:
+ *val = readw(vaddr);
+ break;
+ case 32:
+ *val = readl(vaddr);
+ break;
+ case 64:
+ *val = readq(vaddr);
+ break;
+ default:
+ pr_debug("Error: Cannot read %u bit width from PCC\n",
+ reg->bit_width);
+ ret_val = -EFAULT;
+ }
+ } else
+ ret_val = acpi_os_read_memory((acpi_physical_address)reg->address,
+ val, reg->bit_width);
+ return ret_val;
}
-static void cpc_write(struct cpc_reg *reg, u64 val)
+static int cpc_write(struct cpc_reg *reg, u64 val)
{
- u64 addr = get_phys_addr(reg);
+ int ret_val = 0;
+
+ if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
+ void __iomem *vaddr = GET_PCC_VADDR(reg->address);
- acpi_os_write_memory((acpi_physical_address)addr,
- val, reg->bit_width);
+ switch (reg->bit_width) {
+ case 8:
+ writeb(val, vaddr);
+ break;
+ case 16:
+ writew(val, vaddr);
+ break;
+ case 32:
+ writel(val, vaddr);
+ break;
+ case 64:
+ writeq(val, vaddr);
+ break;
+ default:
+ pr_debug("Error: Cannot write %u bit width to PCC\n",
+ reg->bit_width);
+ ret_val = -EFAULT;
+ break;
+ }
+ } else
+ ret_val = acpi_os_write_memory((acpi_physical_address)reg->address,
+ val, reg->bit_width);
+ return ret_val;
}
/**