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ipq40xx: qcom_scm: Fix cold boot address command

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See my upstream questions:
https://lore.kernel.org/linux-arm-msm/20200913201608.GA3162100@bDebian/

This effectively reverts upstream Linux commit 13e77747800e ("firmware:
qcom: scm: Use atomic SCM for cold boot"), because Google WiFi boot
firmwares don't support the atomic variant.

This fixes SMP support for Google WiFi.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
This commit is contained in:
Brian Norris 2020-09-12 15:41:23 -07:00 committed by Christian Lamparter
parent a93ec36630
commit 26af098e0e
1 changed files with 121 additions and 0 deletions
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121
target/linux/ipq40xx/patches-5.10/421-firmware-qcom-scm-cold-boot-address.patch Normal file
View File

@ -0,0 +1,121 @@
--- a/drivers/firmware/qcom_scm-legacy.c
+++ b/drivers/firmware/qcom_scm-legacy.c
@@ -13,6 +13,9 @@
#include <linux/arm-smccc.h>
#include <linux/dma-mapping.h>
+#include <asm/cacheflush.h>
+#include <asm/outercache.h>
+
#include "qcom_scm.h"
static DEFINE_MUTEX(qcom_scm_lock);
@@ -117,6 +120,25 @@ static void __scm_legacy_do(const struct
} while (res->a0 == QCOM_SCM_INTERRUPTED);
}
+static void qcom_scm_inv_range(unsigned long start, unsigned long end)
+{
+ u32 cacheline_size, ctr;
+
+ asm volatile("mrc p15, 0, %0, c0, c0, 1" : "=r" (ctr));
+ cacheline_size = 4 << ((ctr >> 16) & 0xf);
+
+ start = round_down(start, cacheline_size);
+ end = round_up(end, cacheline_size);
+ outer_inv_range(start, end);
+ while (start < end) {
+ asm ("mcr p15, 0, %0, c7, c6, 1" : : "r" (start)
+ : "memory");
+ start += cacheline_size;
+ }
+ dsb();
+ isb();
+}
+
/**
* qcom_scm_call() - Sends a command to the SCM and waits for the command to
* finish processing.
@@ -160,10 +182,16 @@ int scm_legacy_call(struct device *dev,
rsp = scm_legacy_command_to_response(cmd);
- cmd_phys = dma_map_single(dev, cmd, alloc_len, DMA_TO_DEVICE);
- if (dma_mapping_error(dev, cmd_phys)) {
- kfree(cmd);
- return -ENOMEM;
+ if (dev) {
+ cmd_phys = dma_map_single(dev, cmd, alloc_len, DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, cmd_phys)) {
+ kfree(cmd);
+ return -ENOMEM;
+ }
+ } else {
+ cmd_phys = virt_to_phys(cmd);
+ __cpuc_flush_dcache_area(cmd, alloc_len);
+ outer_flush_range(cmd_phys, cmd_phys + alloc_len);
}
smc.args[0] = 1;
@@ -179,13 +207,26 @@ int scm_legacy_call(struct device *dev,
goto out;
do {
- dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len,
- sizeof(*rsp), DMA_FROM_DEVICE);
+ if (dev) {
+ dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) +
+ cmd_len, sizeof(*rsp),
+ DMA_FROM_DEVICE);
+ } else {
+ unsigned long start = (uintptr_t)cmd + sizeof(*cmd) +
+ cmd_len;
+ qcom_scm_inv_range(start, start + sizeof(*rsp));
+ }
} while (!rsp->is_complete);
- dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len +
- le32_to_cpu(rsp->buf_offset),
- resp_len, DMA_FROM_DEVICE);
+ if (dev) {
+ dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len +
+ le32_to_cpu(rsp->buf_offset),
+ resp_len, DMA_FROM_DEVICE);
+ } else {
+ unsigned long start = (uintptr_t)cmd + sizeof(*cmd) + cmd_len +
+ le32_to_cpu(rsp->buf_offset);
+ qcom_scm_inv_range(start, start + resp_len);
+ }
if (res) {
res_buf = scm_legacy_get_response_buffer(rsp);
@@ -193,7 +234,8 @@ int scm_legacy_call(struct device *dev,
res->result[i] = le32_to_cpu(res_buf[i]);
}
out:
- dma_unmap_single(dev, cmd_phys, alloc_len, DMA_TO_DEVICE);
+ if (dev)
+ dma_unmap_single(dev, cmd_phys, alloc_len, DMA_TO_DEVICE);
kfree(cmd);
return ret;
}
--- a/drivers/firmware/qcom_scm.c
+++ b/drivers/firmware/qcom_scm.c
@@ -344,6 +344,17 @@ int qcom_scm_set_cold_boot_addr(void *en
desc.args[0] = flags;
desc.args[1] = virt_to_phys(entry);
+ /*
+ * Factory firmware doesn't support the atomic variant. Non-atomic SCMs
+ * require ugly DMA invalidation support that was dropped upstream a
+ * while ago. For more info, see:
+ *
+ * [RFC] qcom_scm: IPQ4019 firmware does not support atomic API?
+ * https://lore.kernel.org/linux-arm-msm/20200913201608.GA3162100@bDebian/
+ */
+ if (of_machine_is_compatible("google,wifi"))
+ return qcom_scm_call(__scm ? __scm->dev : NULL, &desc, NULL);
+
return qcom_scm_call_atomic(__scm ? __scm->dev : NULL, &desc, NULL);
}
EXPORT_SYMBOL(qcom_scm_set_cold_boot_addr);